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Nanoparticles: advances in synthesis, characterization, theoretical modelling and applications

Recent advances in the synthesis of nanoparticles, and in atomic-scale characterization, coupled with insights from theoretical modelling, have opened exciting possibilities to tailor nanoparticles for many applications, such as catalysis, plasmonics, sensors, magnetism, and biomedical applications.

Scope:

Nanoparticles are attracting much interest for both fundamental scientific reasons as well as for practical applications. In studying their fundamental properties, chemist, physicists, and materials scientists meet. Their properties are strikingly different from those of the corresponding macrocrystalline materials, and based on that applications can be found in fields as diverse as biomedical applications, environmental sciences, optics, electronics and catalysis. Important recent progress is due to advances in controlled assembly of nanoparticles, both by wet-chemical as well as by physical preparation techniques, impressive progress in the resolution of characerisation techniques, offering more and more the possibility to study the formation and functionality of these nanoparticles in situ, coupled to important developments in the field of computatonal chemistry and physiscs, allowing to increasingly understand the fundamental basis of their properties.

This symposium builds on last years success and will bring together again leading experts on advanced techniques for nanoparticle synthesis, in order to promote cross fertilization and to inspire progresses in the control of nanoparticle size, shape, composition and functionalization as well as in the fabrication of nanopartucles with controlled morpmplex morphologies and composition. Characterization techniques with high spatial resolution, spectroscopic capability and chemical sensitivity are an essential tool not only to investigate the output of the synthesis procedures but also to elucidate the structure-property relationships of these particles. This interdisciplinary forum will be completed by the participation of renowned experts in theoretical modelling and simulation of NPs structure and properties, which is of paramount importance both for understanding atomic and electronic structure and to predict non- trivial unexpected behaviour and new phenomena. The symposium will include also a few selected experts on functionality and practical applications of these nanomaterials. Given the “hot topic” nature of the symposium and the unique interdisciplinary discussion opportunities it will provide, we expect a numerous and high quality attendance.

Hot topics to be covered by the symposium:

1. Recent development in nanoparticle synthesis techniques

  • Wet-chemical : colloidal preparation, emulsions, impregnation  
  • Gas phase preparation : ALD, spark discharge, size-selected nanoclusters
  • Lithography

2. Structural / chemical analysis of nanoparticles

  • Electron microscopy : high resolution/in-situ/acquisition and detection methodology
  • Advanced spectroscopy
  • Advanced difrraction and scattering techniques

3. Theoretical modelling of nanoparticles

  • Atomic ordering and electronic structure
  • Dynamical processes, excitations, reactions

4. Applications of nanoparticles

  • Structure-property relationships
  • Theoretical predictions vs experiment
  • Optical, catalytic, electronic, magnetic, sensing, biomedical

Invited speakers:

  • Stig Helveg (Haldor Topsoe, Denmark): “Electron microscopy advances in catalysis”
  • Andrea Baldi (DIFFER Institute for Energy Research, the Netherlands): “Plasmonics for Chemistry: sensing and driving chemical reactions using noble metal nanoparticles”
  • Zineb Saghi (CEA, France): “Advanced methods for 3D characterization of nanostructures”
  • Paola Luches (National Research Council, Italy): "Interaction between plasmonic nanoparticles and reducible oxides"
  • Sarah Haigh (Manchester University, United Kingdom)
  • Maria-Magdalena Titirici (Imperial College London, United Kingdom): “Biomass-derived carbon dots: Synthesis, Characterisation and Applications”
  • Hyunjeong Kim (National Institute of Advance Industrial Science & Technology, Japan): ”Structure of nanoconfined particles using atomic pair distribution function analysis”
  • Laura Prati (University of Milan, Italy): “Bimetallic particles prepared via colloidal routes: synthesis and application”
  • Paola Ceroni (University of Bologna, Italy): “Luminescent silicon nanocrystals for energy conversion and imaging”
  • Thomas Reisinger (Karlsruhe Inst. of Technol., Germany): “'Magnetic properties of nanocomposite thin films prepared with size-selective cluster-ion beam deposition”
  • Tanja Kallio (Aalto University, Finland): “”Platinum electrocatalysts with ultra-low metal loadings: effect of morphology”
  • Matthieu Bugnet (Lyon University, France): “Advancing the understanding of gas-surface interactions of ceria nanoparticles with environmental TEM”
  • Engelbert Redel (Karlsruhe Institute of Technology, Germany): “Growing nanoparticles in Surface Anchored Metal Organic Frameworks: Methods, Synthesis and Applications”
  • Deanna D’Alessandro (The University of Sydney, Australia, tbc)
  • Claudia Zlotea (CNRS, France) : ”Hydrogen interaction with noble metal nanoparticles : size and composition effects”

Scientific Advisory Commitee:

  • Bjorn C. Hauback (NO)
  • Hannes Jonsson (IS)
  • Horst Hahn (DE)
  • Tejs Vegge (DK)
  • Asunción Fernández (ES)
  • Renu Sharma (USA)
  • Rik Brydson (UK)
  • Damien Alloyeau (FR)
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Synthesis I - Physical Methods : Luca Pasquini
09:00
Authors : T. Reisinger, C. Benel, G. Iankevich, N. Gack, R. Witte, D. Wang, L. Estrada, R. Kruk, H. Hahn
Affiliations : Karlsruhe Institute of Technology, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology

Resume : The functional properties of nanocomposites promise to meet many of the demanding material requirements faced by the modern high-tech industry. However, precise control over features such as chemistry, morphology and microstructure, as well as their preparation under well-defined conditions remain challenging. Here we show that the combination of size-selective cluster-ion-beam deposition and physical vapor deposition under ultra-high-vacuum conditions provides an excellent platform to address such difficulties. The deposition system in our lab provides single-step synthesis of nanocomposite thin films with well-defined features such as and most importantly cluster size and cluster concentration. In particular, we have used the method to prepare nanocomposite thin films composed of magnetic nanoparticles (Fe) with a spread in the size distribution of less than 10% and embedded in various matrices (Ag, Cr, Ge) at well-defined concentrations. The influence of these parameters on blocking temperature and saturation magnetization at low temperatures have been characterized using SQUID magnetometry. In addition, electric transport properties of the Ge based films have been investigated. Finally, characterization of the chemistry, morphology and microstructure of the films has been performed using transmission electron microscopy, X-ray photo-electron spectroscopy and energy-dispersive X-ray spectroscopy.

Q.1.1
09:30
Authors : V. Scardaci, M. Condorelli, M. Pulvirenti, G. Compagnini
Affiliations : Università degli Studi di Catania, Dipartimento di Scienze Chimiche, V.le A. Doria 6, 95125 Catania (Italy)

Resume : One important property of metal nanoparticles is plasmonic excitation under an electromagnetic field, dependent on a number of factors, such as composition, surrounding medium, spatial arrangement, and geometrical factors like size and shape. Here, we describe the synthesis of Ag nanoplates and their application in plasmonic sensing and Surface Enhanced Raman Scattering (SERS). Initially, spherical Ag nanoparticles are produced by pulsed laser ablation in water solution in presence of citrate. Spherical nanoparticles are transformed into flat nanoplates by irradiation under white or monochromatic light and hydrogen peroxide addition. Nanoplates are triangular, 100-200 nm wide depending on the irradiation conditions and 15-20 nm thick, as characterized by TEM, SEM and AFM. Such materials exhibit a plasmon sensitivity of nearly 500 nm/RIU and a SERS enhancement factor of the order of 10^4

Q.1.2
09:45
Authors : Leslie Schlag, Nishchay A. Isaac, Helene Nahrstedt, Johannes Reiprich, Jörg Pezoldt, Heiko O. Jacobs
Affiliations : Fachgebiet Nanotechnologie Institut für Mikro- und Nanotechnologien Gustav-Kirchhoff-Str. 7 98693 Ilmenau Germany

Resume : This talk addresses next to production of metallic nanoparticles in the gas phase also special application examples that have resulted from recent research. Nanoparticles can be produced in many ways. One requirement of a process is always the exact adjustment of the particle size. Experiments in the gas phase, especially in a spark discharge, have shown in recent years that both the plasma power and the transport gas flow have the greatest influence on the particle size distribution, so that the size can be finely adjusted. On a TEM grid, this initially looks understandable and predictions can be made so that deposition experiments with the particles appear predictable at first glance. However, reality shows that every new application always brings new insights into the process that had not previously occurred in this way. In this talk we present our current research on 1D, 2D and 3D deposits produced from metallic nanoparticles. One focus of our group is the localized deposition of any metal in pure form or as oxide, so that rods, layers or 3D nano bridges can be captured by an electric field-based process. The field-based effect is mainly driven by the charged transport gas ions, To gain knowlegde about the gas ions influence on the process, we have performed an in-situ charge to mass ratio determination. The presentation will thus discuss the various properties of the plasma jet and show how changes in spark power, transport gas flow and substrate voltage affect both layers and locally growing structures. The localized growing nanostructures are suitable for contacting domains laterally and metallization layers vertically, as well as gas sensors. The talk presents recent research that will be published within the 2nd half of 2019.

Q.1.3
10:00
Authors : A. Morone *°, L. Allocca°, U. Gambardella§, G. Gentile^, E. Sieni#, and M. Forzan
Affiliations : *Consiglio Nazionale delle Ricerche ? Istituto di Struttura della Materia U.O. di Tito Scalo, Zona Industriale di Tito Scalo, I85050, Italia °Istituto Motori, Viale Marconi 8, Napoli, I80125 Italia §Istituto Nazionale di Fisica Nucleare, Sez. di Napoli, Via Cinthia, Napoli I80125 Italia^Consiglio Nazionale delle Ricerche-Istituto per i Polimeri Compositi e Biomateriali, Via Campi Flegrei 34, I80078 Pozzuoli (Na) Italia #Università dell?INSUBRIA, Dip. Scienze Teoriche e Applicate, via J.H. Dunant 3 ? Varese I21100 ItaliaUniversità degli Studi di Padova ? Dipartimento Ingegneria Industriale, Via G. Gradenigo 6A, Padova, I35131 Italia

Resume : SmCo is a permanent magnetic material having peculiar characteristics.The SmCo Nanoparticles can be used in different application fields like sensors and biosensors for environmental and biological measurements. SmCo nanoparticles could be applied for temperature treatments of the cancer in medicine. Hyperthermia is the physic procedure that permits increasing the local temperature in human body using radio frequency magnetic fields. When a cancer culture cell is exposed to temperature in range 40- 43°C, a cell apoptosis occurs. The number of cancer cells is reduced and using also chemotherapy treatment the cancer disruption could be obtained (1,2,3). In this paper, we present preliminary experimental results and we discuss both Transmission Electron Microscopy and the SmCo NPs thermal data to hyperthermia applications. Bibliography 1) Stauffer, P.R., Cetas, T.C., Fletcher, A.M., Deyoung, D.W., Dewhirst, M.W., Oleson, J.R., Roemer, R.B. (1984) Observations on the use of ferromagnetic implants for inducing hyperthermia. IEEE Trans Biomed Eng. 31(1):76?90 2) Gordon, R.T., Hines, J.R., Gordon, D. (1979) Intracellular hyperthermia: a biophysical approach to cancer treatment via intracellular temperature and biophysical alterations. Med Hypotheses 5(1):83?102 3) Rosensweig, R.E. (2002) Heating magnetic fluid with alternating magnetic field. J Magnetism Magn. Mater 252(1?3):370?374

Q.1.4
10:15
Authors : Maulida Zakia, Seong Il Yoo
Affiliations : Department of Polymer Engineering, Pukyong National University, Busan, South Korea

Resume : Noble metal nanoparticles (NPs) have attracted immense interest due to their localized surface plasmon resonance (LSPR) properties, which are coherent oscillation of the metal electrons in resonance with light of certain frequency. In addition, plasmon coupling effect between the NPs was observed when multiple metal NPs is present in nanoscale proximity. Therefore, the assembly of distinct metal NPs into superstructures can arise new properties beyond single NPs owing to the interparticle plasmonic coupling phenomena. Among various methods for the preparation of a well-defined superstructure, diblock copolymer micelles have received considerable attention due to its ability to self-assemble into various nanostructures. In this work, we synthesize two different NPs, i.e. Au and Ag NPs, in polystyrene-block-poly(acrylic acid), PS?PAA micelles, to selectively organize distinct metal NPs in different domain inside micellar structure. To this end, the surface of Au NPs were modified by Raman active ligand and encapsulated inside PS core using the method reported previously. Subsequently, we synthesized Ag NPs in PAA corona by adding AgNO3 and hydroquinone. The resulting heterogeneous micellar NPs assembly exhibit significantly higher SERS activity than single Au NPs inside PS-PAA micellar structure. Interestingly, the resulting micellar NP assemblies show the inhibition of plasmonic coupling between Au and Ag NPs in PS-PAA micelles. However, we found strong plasmonic coupling between satellite Ag NPs, which can induce light scattering and creating multiple scattering. This phenomena, in turn, can increase the path length of the incident photons for Raman absorption that is responsible for a significant SERS enhancement by orders of magnitude. Considering the multiple scattering mechanism provides an exciting opportunity to enhance SERS activity, we additionally evaluated the Raman spectra from mixture of a single Au NPs inside PS-PAA micelles by simple addition of Ag NPs into the micellar solution, which resulted in the enhancement of SERS intensities.

Q.1.5
10:30 Coffee break    
 
Synthesis II - Chemical Methods : Laura Prati
11:00
Authors : Laura Prati
Affiliations : Università degli Studi di Milano - Chemistry Department

Resume : Scientists consider colloids as quasi-homogeneous systems, but because of their intrinsic thermodynamic instability, they need different capping agents providing sufficient stability. The strength and the nature of the interaction between the protective (or functionalizing) molecule and the NP surface is of utmost importance. Here the advantages in using this technique will be describe to produce high metal dispersion on a large variety of supports with the possibility of tuning to a large extent the size and (even partially) the shape and the structure of bimetallic nanoparticles. Specifically, we highlight how, depending on its nature, the protective agent not only mediates the activity of NPs in several process but also actively participates in the anchoring process and to the stability of NPs depending on the support surface. The modification of the metal surface operated by the capping agent can be fruitfully used to prepare bimetallic species and influence the surface potential, which modifies the intrinsic activity of the NP. Examples of bimetallic species made with Au, Pd, Cu, Ag will be used as representative of different strategies of synthesis.

Q.2.1
11:30
Authors : Miquel Torras, Anna Roig
Affiliations : Institut de Ciència de Materials de Barcelona, CSIC, Carrer dels Til·lers s/n, 08193 Bellaterra, Spain ; Institut de Ciència de Materials de Barcelona, CSIC, Carrer dels Til·lers s/n, 08193 Bellaterra, Spain

Resume : The fabrication of different size silver nanoparticles (Ag NPs) by a very fast and simple microwave-assisted synthesis is presented. The Ag NPs are synthesized using polyvinylpyrrolidone (PVP) as reducing, capping and stabilizing agent through a polyol approach. The effects of reaction time, reaction temperature and silver nitrate concentration were studied. Control experiments to study the agitation, the PVP concentration and silver nitrate solvent influences were also prepared. It was found that at short reaction times, at low temperatures and at low silver nitrate concentrations particles are polydisperse and their size is around several hundreds of nm. However, when these parameters increase their values in a certain range, particles experiment a size refinement, decreasing the size up to 10 nm and becoming spherical. Above this range, particles first increase their size and then lose the refinement in different ways depending on the reaction parameter. Mechanistic insights to understand the Ag NPs synthetic route here presented are provided based on the characterization of reaction snapshots by transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy (UV-Vis). Comprising all these effects allows to control particle size and tune Ag NPs on demand using cross experiments. Moreover, the detailed conclusions extract from this study can be applied to the synthesis of other noble metal nanoparticles or more complex nanoscopic systems. Copper nanoparticles and silver nanofoams cases are presented.

Q.2.2
11:45
Authors : Seyed Naveed Hosseini, Arnout Imhof, Patrick Baesjou, Alfons van Blaaderen
Affiliations : Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, The Netherlands.

Resume : Titanium dioxide (TiO2) nanorods have attracted significant attention due to an interesting combination of properties in many fields such as photovoltaics, photocatalysis and optoelectronics. Embedding these anisotropic nanocrystals in suitable solvents creates exceptional inorganic liquid crystals offering enhanced collective and orientation-dependent properties which are ideal for fabricating functional materials. Here, we report the synthesis and characterization of highly monodisperse titanium dioxide nanorods. The nanorods are highly crystalline and mainly composed of the brookite phase with tunable lengths from 20 to almost 100 nm. Moreover, we show self-assembled structures of TiO2 nanorods mainly formed by an entropy-driven assembly process into smectic liquid crystalline phases, as well as vertically aligned nanorods with hexagonal and tetragonal symmetries obtained by a liquid-air interface technique. Upon increasing the nanorods concentration in the dispersion, the liquid crystalline phases were formed in bulk, as well. Birefringent domains and Schlieren textures were investigated by polarized optical microscope and could simply be manipulated by shear forces or an external electric field. These unique self-assembled structures and tunable anisotropic properties are promising for a wide range of photonic applications.

Q.2.3
12:00
Authors : Jonathan G. C. Veinot, Md Asjad Hossain
Affiliations : Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G2G2

Resume : Germanium quantum dots (GeQDs) have been touted as active materials suitable for application far reaching applications including, solar cells, lithium-ion batteries, field-effect transistors, data storage devices, and photodetectors. This attention arises partly because the small band gap (0.67 eV) and large Bohr radius (~24 nm) of Ge could see quantum confinement effects arise in comparatively large particles that would be more readily processed into device structures. Surprisingly, reports of GeQD optical properties, which often serve as a first indication of quantum confinement effects, are inconclusive and even contradictory; particles that are seemingly identical (e.g., size, composition, etc.) can often show photoluminescence spanning from the blue to NIR spectral regions and many are not luminescent at all. These observations are reminiscent of past reports related to SiQDs for which many factors (e.g., particle size, composition, surface chemistry, etc.) play important roles in optical properties. In light of past studies involving SiQDs, and the attractive properties of GeQDs, establishing reliable methods for preparing well-defined materials and predictably tailoring their surface chemistry is essential if they are to realize their full practical potential. This presentation will outline new protocols developed in our laboratory for preparing GeQDs, investigations into surface functionalization via homo and heteronuclear dehydrocoupling reactions, as well as the role of surface species on material optical response.

Q.2.4
12:15
Authors : Jong-Min Lim
Affiliations : Department of Chemical Engineering, Soonchunhyang University

Resume : Microfluidic platforms are adopted for the synthesis of various nanoparticles due to controllability and reproducibility in their physicochemical properties. However, there are several intrinsic limitations in conventional polydimethylsiloxane (PDMS) microfluidic systems for the synthesis of nanoparticles. In this presentation, I will discuss a coaxial turbulent jet mixer capable of synthesizing various types of polymeric nanoparticles with high-throughput manner, while maintaining the controllability and reproducibility of PDMS microfluidic systems. In the coaxial turbulent jet mixer, the inner flow stream containing raw materials is mixed with outer stream of non-solvent by turbulent flow for self-assembly of nanoparticles by rapid solvent exchange method called nanoprecipitation. Nanoparticles obtained using the coaxial turbulent jet mixer at high Reynolds number were more homogeneous and smaller than those synthesized by bulk mixing. Since the coaxial turbulent jet mixer is compatible with various organic solvents, it is versatile system where various types of nanoparticles. Various functional agents including anticancer drug, insulin, and fluorescent dye could be loaded in the nanoparticles for diagnostic and therapeutic applications during the nanoprecipitation. The coaxial turbulent jet mixer can be used to make functional nanoparticles with high-throughput and reproducible manner suitable for clinical studies and mass production.

Q.2.5
12:30
Authors : Matteo Parente, Andrea Baldi
Affiliations : DIFFER - Dutch Institute for Fundamental Energy Research

Resume : Networks of silver nanowires (AgNWs) combine high conductivities with low optical absorption in the visible part of the spectrum. These unique properties make them an attractive, cheap, and flexible alternative to doped metal oxides as transparent conductive layers in a variety of applications, from solar cells, to displays and touch panels. Typically, AgNWs are produced in large quantities by the so-called ?polyol? synthesis, which however results in the formation of a large amount of randomly shaped nanoparticles as by-products. These nanoparticles degrade the optical transparency of silver nanowire electrodes and must therefore be removed through several cycles of purification, increasing the nanowire production time and cost. Here, we report a strategy to synthesize silver nanowires (AgNWs) with very high densities and almost no by-products. Our simple and fast synthetic strategy, which relies on the use of optimized nucleation sites and on the control of the gas pressure in the reaction vessel, can drastically decrease the time and cost of AgNWs production.

Q.2.6
12:45 Lunch break    
 
Carbon and Hybrid Nanomaterials : Claudia Zlotea
14:00
Authors : MAGDALENA TITIRICI
Affiliations : IMPERIAL COLLEGE LONDON

Resume : One of the grand challenges facing humanity today is access to sustainable materials and chemicals which are at the heart of sustainable technologies. The production of materials, chemicals and fuels from abundant and renewable resources will eliminate our dependence on petroleum/critical metal-based supplies and will provide access to a new economy based on available reserves. We have demonstrated that it is possible to mimicking the natural process of carbon formation and prepare carbon nanomaterials from biomass using mild hydrothermal processes. Along with amorphous carbon materials (denoted HTC), this procedure also enables biomass transformation into useful chemicals such as 5-hydroxymethylfurfural (5-HMF) or levulinic acid (LA). Recently, we have discovered a third product of Hydrothermal Carbonisation - a crystalline form of carbon - arising at the interface between the amorphous HTC microspheres and the aqueous phase containing the biomass-derived chemicals. In this talk I will present some of the fundamentals governing the production of carbon nanomaterials. We will also discuss the application of HTC materials in electrocatalytic reactions such as Oxygen Reduction Reaction and Oxygen Evolution Reaction. Finally, some of the photo-physics governing the optoelectronic properties of the new family of fluorescent hydrothermal carbon nanocrystals and their applications as sensitizers in solar cells will be presented.

Q.3.1
14:30
Authors : Stephanie Seré*, Stefaan Van Gool, Jin Won Seo, Sandra Jacobs, Ilse Lenaerts, Jean-Pierre Locquet
Affiliations : Functional Nanosystems, Department of Physics and Astronomy, KU Leuven, Leuven Belgium; Immunologisch Onkologisches Zentrum, Köln, Germany; Surface and Interface Engineered Materials, Department of Materials Engineering, KU Leuven, Leuven, Belgium; Department of Oncology, Pediatric oncology, UZ Leuven, Leuven, Belgium; Functional Nanosystems, Department of Physics and Astronomy, KU Leuven, Leuven Belgium; Functional Nanosystems, Department of Physics and Astronomy, KU Leuven, Leuven Belgium

Resume : This work provides proof of concept for mesoporous silica nanoparticle (MSNP) based vaccines as cost-effective alternatives for dendritic cell (DC) immunotherapy. Synthesis and surface chemistry of the NPs are optimized for protein conjugation and NPs are characterized for their physicochemical properties and biodegradation. Ovalbumin (OVA) is used as a model protein to load NPs to produce a nanovaccine. The vaccine is tested in vitro on DC cultures to verify NP and vaccine uptake, toxicity, maturation effects and explicitly OVA cross-presentation on MHC class I molecules. The optimized synthesis protocol renders reproducible MSNPs which are resistant against agglomeration, within the required size range and have carboxylic surface functionalization necessary for protein conjugation. They are biodegradable over a time span of one week. This period is adjustable by changing synthesis parameters. UV sterilization of MSNPs does not induce quality loss of the NPs, nor does it have toxic effects on DCs. Treatment with MSNPs increases expression of MHC and costimulatory molecules of DCs, indicating an adjuvant effect of NPs on the adaptive immune system. Nanovaccine uptake and cross-presentation of OVA are observed and the latter is increased when delivered by MSNPs as compared to control conditions. This confirms the large potential of MSNP based vaccines to replace DC-based active specific immunotherapy, offering a more standardized production process and higher efficacy.

Q.3.2
14:45
Authors : A. Gala Morena, Ivaylo Stefanov, Kristina Ivanova, Sílvia Pérez-Rafael, Tzanko Tzanov
Affiliations : Grup de Biotecnologia Molecular i Industrial (GBMI), Department of Chemical Engineering, Universitat Politècnica de Catalunya, Rambla Sant Nebridi, 22, Terrassa, Barcelona, Spain.

Resume : Chronic wounds are a major healthcare problem, especially among the elderly and patients with diabetes mellitus, and involve huge economic costs in the healthcare systems. Many factors are implicated in chronic wound development, such as deregulation of enzyme activities, increasing of reactive oxygen species (ROS) and bacterial colonization. Antibacterial polyurethane foams have been prepared for the treatment of cutaneous infections by using different strategies, such as the incorporation of quaternary ammonium, imidazolium or pyrrolidinium cationic groups and physisorption of silver-based nanoparticles. However, the polyurethane foams with incorporated cationic groups can act on contact-killing principle, while the foams prepared by silver nanoparticles physisorption are characterized by loss of antimicrobial properties due to their leaching over time. Therefore, polyurethane foams with covalently grafted nanoparticles for sustained release over time are expected to possess superior properties over the physically linked counterparts. In this work, we synthesized lignin-capped silver nanoparticles through a green-method and immobilized them in situ into polyurethane foam. Lignin, which was previously enzymatically modified with natural phenolic compounds, was used as a reducing agent of silver and as an additive to polyurethane formulations due to its high polyphenol content, reactive towards the isocyanates. The nanoparticles were dispersed into a pre-foam solution prior to the polyurethane foam synthesis. The prepared polyurethane foams with incorporated nanoparticles shown to possess broad antibacterial activity against gram-positive and gram-negative bacterial strains. They revealed sustained silver release behavior over time, which is prerequisite for effective eradication of a broad spectrum of bacterial strains in the bacteria-divergent chronic wound microflora. Moreover, the wound dressings presented excellent swelling capacities, necessary to remove the excess of exudates, and antioxidant properties, which allows the ROS scavenging in the wound. Their physico-mechanical and antibacterial properties, together with their biocompatibility, make these multifunctional dressings an excellent biomaterial for chronic wound treatment.

Q.3.3
15:00
Authors : Jae-Kap Lee
Affiliations : Opto-Electronic Materials and Devices Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea

Resume : Single-wall carbon nanotubes (SWNTs) have raised considerable interests globally since their first reports in 1993 [1], due to their superior physical properties and unique nanostructure. The prominent performances of CNTs bombarded with numerous papers was enough to expect that they would be novel essential materials in diverse fields including electronics, energy as well as composite materials. However, their applications are still limited although there have been numerous studies for last decades. In this talk, I will reinterpret the structure of SWNTs to be a graphene helix, based on based on my 10 years of study including high-resolution transmission electron microscope (HRTEM) observation, energy calculation [2], simulations of Raman and electronic properties as well as Raman measurements [3]. I will explain some misinterpreted features of SWNTs, their underestimated diameters of 0.8~1.5 nm (which is ~2 nm by HRTEM observation) and semiconducting property reported (SWNTs are intrinsically metallic), which may explain the reasons of the delay or failure of their applications. Finally, I will also discuss the structure of multi-wall CNTs which is of AA? graphite helix [4,5], as well as ways of utilizing the one dimensional materials and their potential applications. References 1. Iijima, S., Helical microtubules of graphitic carbon, Nature 354, 56 (1991). 2. J.-K. Lee et al., Structure of single-wall carbon nanotubes: A graphene helix, Small 10, 3283 (2014). 3. Park et al., Reinterpretation of single-wall carbon nanotubes by Raman spectroscopy, J. Phys. Chem. C. DOI: 10.1021/acs.jpcc.9b02174 (2019). 4. J.-K. Lee et al., Structure of multi-wall carbon nanotubes: AA? graphene helices, Appl. Phys. Lett. 102, 161911 (2013). 5. J.-K. Lee et al., The nature of metastable AA? graphite: Low dimensional nano- and single-crystalline Forms. Sci. Rep. 6, 39624 (2017).

Q.3.4
15:15
Authors : Inbal Weisbord [1], Neta Shomrat [1], Hen Moshe [2], Alejandro Sosnik [2], Tamar Segal-Peretz [1]
Affiliations : [1] Department of Chemical Engineering, Technion ? Israel Institute of Technology; [2] Department of Materials Science and Engineering, Technion ? Israel Institute of Technology;

Resume : Block copolymers (BCP) are known to self-assemble into highly ordered and periodic nanoscale structures with periodicities of 5-50 nm. When BCP self-assembly is confined in macro and nano spheres, a variety of morphologies including onion and pupa-like can be achieved, making them attractive materials for various applications ranging from drug delivery to catalysis. BCP nanoparticles (NP) morphologies can be controlled by tailoring BCP chemical composition, solvents, and process parameters. Until now, BCP NP were mainly fabricated through emulsion-based methods. However, there is a need to develop novel methods for BCP NP fabrication which will enable new NP morphologies as well as have scalability potential. In this research, we develop a new route for BCP NP fabrication through confinement of BCP within sprayed nano-droplets using Nano Spray drying (NSD). Poly(styrene-block-methyl methacrylate) (PS-b-PMMA) and poly(styrene-block-vinyl-pyridine) (PS-b-PVP) were spray dried from toluene and chloroform. Scanning and transmission electron microscopy (SEM and TEM, respectively) were used to study the relationship between BCP NP morphologies and BCP chemistry, solvent, and NSD process parameters. Following the NSD, PS-b-P4VP or PS-b-PMMA NP were suspended in non-solvents, with or without surfactant, and solvent annealed with chloroform to tune the internal NP morphology. Finally, hybrid organic-inorganic particles were created through Sequential Infiltration Synthesis (SIS), a method that enables growth of metal-oxides within polymers. Using SIS, alumina and zinc-oxide were selectively grown in the BCP polar domains, transforming the BCP NP into hybrid NP, or BCP-templated inorganic NP.

Q.3.5
15:30 Coffee break    
 
Structure-Size-Property Relationships : Tanja Kallio
16:00
Authors : Hyunjeong Kim
Affiliations : National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8569, JAPAN

Resume : Great efforts have been made to prepare various nanoscale materials since nanosizing often leads to interesting properties that are not usually seen in their bulk counterparts. One of widely used methods for preparing nanoscale materials is nanoconfinement. Namely, materials of interest are embedded in the matrix or pores of host materials. Owing to their unique structures, the discreteness of the nanosized materials can be effectively kept during their operation. Structures of such nanoconfined materials are often difficult to characterize using the conventional crystallographic technique alone since their diffraction peaks are not well defined and signals from host materials are large. The atomic pair distribution function (PDF) technique is a powerful local structural probing technique that gives information about the interatomic distance distribution of materials [1]. This technique has been successfully applied to unraveling nanoscale structural features of various materials, which are difficult to detect by conventional diffraction methods. We have been applied the PDF technique to investigating the structures of various nanoconfined materials. In this talk, we will introduce our structural studies on nano- and subnano-sized metal nanoparticles confined in pores of metal-organic frameworks (MOFs) and nanosized phases formed in the thin films of immiscible elements. [1] Egami, T.; Billinge, S. J. L. Underneath the Bragg Peaks: Structural Analysis of Complex Materials: Pergamon Press Elsevier: Oxford, England, 2003.

Q.4.1
16:30
Authors : Aleksandra Bokuniaeva, Andrey Vorokh
Affiliations : Institute of Solid State Chemistry of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, 620990, Russia; Institute of Natural Sciences and Mathematics, Ural Federal University, Ekaterinburg, 620002, Russia

Resume : Particle size remains one of the most important parameters of substance. The Debye equation and the Scherrer formula are two the most widespread methods to this parameter. Both methods have their own limitations: the application of the Debye equation may be time-consuming, and values calculated through the Scherrer formula have a bounded accuracy. In this paper, a new method for particle size estimation is proposed. It represents a combination of two methods listed earlier. This method has been applied to estimate particle size of TiO2 powder consisting of anatase/brookite mixture. The sample was synthesized by sol-gel method and investigated by the X-ray diffraction (XRD). The following steps were performed for particle size estimation: (i) by the Scherrer formula, experimental XRD pattern was described. The particle diameters were defined: 2.1 nm for anatase and 1.8 nm for brookite. (ii) by the Debye equation, XRD pattern was simulated for anatase/brookite particles defined at the previous step, and then compared with the experimental XRD pattern by the R-factor. A few iterations of simulation were made by the varying of particle sizes, and anatase particle diameter was refined, 3.5 nm, and brookite particle diameter remained the same, 1.8 nm. (iii) The phase content of powder was found by the R-factor minimization: 73% of anatase and 27 % brookite. The study was supported by the Russian Science Foundation (Project 17-79-20165) and performed at ISSC UB RAS.

Q.4.2
16:45
Authors : Bruno P. Falcão1*, Joaquim P. Leitão1, Maria R. Soares2, Joana Rodrigues1, Lídia Ricardo3, Rodrigo Martins3, Hugo Águas3, Rui N. Pereira1,4
Affiliations : 1 Departamento de Física & I3N, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal 2 Laboratório Central de Análises, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal 3 CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, CEMOP-UNINOVA, 2829-516 Caparica, Portugal 4 Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany * Corresponding author: bfalcao@ua.pt

Resume : Due to their large surface-to-volume ratio, nanoparticles (NPs) are extremely sensitive to surface-related phenomena with impact on NPs-based nanotechnologies. Optical spectroscopy techniques are unrivalled tools to investigate technological properties of nanomaterials; recent examples being the study of energy dissipation under illumination [1], morphology/structure [2], and strain [3]. In the present work, we applied Raman and photoluminescence spectroscopies to unveiling the influence of the surface on physical properties of crystalline Si NPs. Si NPs are made of environmentally inert, biocompatible, and highly abundant elements and are potentially compatible with well-established CMOS microelectronics. Here, we show that H-terminated Si NPs are virtually unstrained and their luminescence is mainly due to recombination amongst band tail states, whereas in surface-oxidized NPs compressive strain appears in the Si core of the NPs. Moreover, the luminescence of surface-oxidized NPs exhibits two components from recombination in both the Si core and at oxide states, with their relative contribution depending on NPs size. For Si NPs below ~3 nm, the luminescence is fully dominated by the oxide-related emission. Recombination of photoexcited carriers is independent of the NPs surface, being dominated by electron-hole bimolecular (monomolecular) channels at high (low) excitation power. [1] B. Falcão et al., Phys. Rev. B 95, 115439 (2017) [2] B. Falcão et al., Phys. Rev. B 98, 195406 (2018) [3] B. Falcão et al., Phys. Rev. Appl. 11, 024054 (2019)

Q.4.3
17:00
Authors : Stefan T. Bromley
Affiliations : 1. Institut de Química Teòrica i Computacional de la Universitat de Barcelona (IQTC-UB) & Departament de Ciència de Materials i Química Física de la Universitat de Barcelon, 08028 Barcelona, Spain 2. Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain

Resume : We present an overview of our computer modelling work investigating when non-bulk-like oxide nanoparticles start to display properties (e.g. structure, band gap) more characteristic of the corresponding macroscopic material with increasing size. We approach this problem using oxide nanoparticle structures derived from both bottom-up global optimization and top-down cuts from bulk oxide crystals and using both classical atomistic and quantum mechanical electronic modelling methods. In this way we attempt to discern the nanoscale-to-bulk crossover size range for these important materials with respect to their structure and physical/chemical properties. We show examples from a range of systems to show the differences and similarities between the size dependent behaviour of various nanoscale oxide systems. We highlight recent results on both binary oxides such as titania (TiO2) [1-3], zinc oxide (ZnO) [4] and ternary oxides such as titanosilicates [5]. Implications of our results for nano-oxide based (photo)catalytic technologies will be briefly discussed [2,3]. 1. Predicting Size-dependent Emergence of Crystallinity in Nanomaterials: Titania Nanoclusters versus Nanocrystals, O. Lamiel-Garcia, A. Cuko, M. Calatayud, F. Illas, S. T. Bromley, Nanoscale (2017) 9, 1049. 2. Size-Dependent Level Alignment between Rutile and Anatase TiO2 Nanoparticles: Implications for Photocatalysis,K. C. Ko, S. T. Bromley, J. Y. Lee, F. Illas, Journal of Physical Chemistry Letters (2017) 8, 5593 3. Understanding the interplay between size, morphology and energy gap in photoactive TiO2 nanoparticles, Á. Morales-García, A. Macià Escatllar, F. Illas, and S. T. Bromley, Nanoscale (2019) 11, 9032. 4. Size dependent structural and polymorphic transitions in ZnO: from nanocluster to bulk, F. Viñes, O. Lamiel-Garcia, F. Illas, S. T. Bromley, Nanoscale (2017) 9, 10067. 5. Stability of Mixed-oxide Titanosilicates: Dependency on Size and Composition from Nanocluster to Bulk, A. Cuko, M. Calatayud, S. T. Bromley, Nanoscale (2018) 10, 832.

Q.4.4
17:15
Authors : Joanna Kwiczak-Yigitbasi, Recep Erdem Ahan, Bilge Baytekin
Affiliations : Joanna Kwiczak-Yi?itba??, Chemistry Department, Bilkent University, 06800, Ankara, TURKEY; Recep Erdem Ahan, UNAM, Bilkent University, 06800, Ankara, TURKEY; Bilge Baytekin, Chemistry Department, Bilkent University, 06800, Ankara, TURKEY, UNAM, Bilkent University, 06800, Ankara, TURKEY

Resume : During the past few decades, noble metal polymer nanocomposites have attracted considerable attention due to their possible applications in medicine, biology or industry. However, both the materials of choice and the preparation of nanocomposites suffer from several disadvantages, e.g., their synthesis is multistep or include toxic reagents. In this study, we use cellulose - a sustainable material - for a fully green mechanochemical preparation of cellulose-based nanocomposites. Our method involves, generation of cellulose mechanoradicals during ball-milling, and the usage of these radicals for in-situ reduction of various metal ions to the corresponding metal NPs (Au, Ag, Pt, Pd, Co, and Cu) in the cellulose matrix. The single-step method bypasses utilization of toxic reagent and stabilizing agents that are commonly used by conventional multistep methods. Cellulose metal nanocomposites exhibit a wide range of properties, i.e., cellulose-Au, -Ag, -Pd, -Pt nanocomposites are used in the catalytic transformation of 4-nitrophenol into 4-aminophenol, and cellulose-Ag NPs display antimicrobial activity of against E. Coli and B. Subtilis. Finally, the ball milling method is also used in the preparation of cellulose-synthetic polymer-gold NPs blends, in which the physical properties are tuned by the blend composition. In the prepared nanocomposites, cellulose acts as an excellent supporting matrix and gives a good access to ?naked? metal NPs.

Q.4.5
 
Poster Session I: Synthesis and Theory : Luca Pasquini and Petra Szilagyi
17:30
Authors : Swayam Prakash Sahoo, Gunther Richter
Affiliations : Swayam Prakash Sahoo, Gunther Richter: Thin films laboratory, Central Scientific facility, Max Plank Institute for Intelligent systems, Stuttgart

Resume : High surface to volume ratio in nanomaterials has opened up new perspectives in structure-property relationship to design advanced materials and exploit various applications. Scientists have reported Nanoporous Gold (NPG) as a highly active catalyst for low-temperature oxidation of CO, actuators, and antennae for SERS. We report the fabrication of NPG nanowhiskers (NWs) from physical vapor co-deposited Au-Ag alloy nanowhiskers on Molybdenum substrate. Various compositions of single crystalline alloy NWs are grown under the combination of flux rates for gold (0.2-0.6 Å/s) and silver (1.4-1.8 Å/s) and substrate temperatures. During a deposition, NWs grow at different diameters. We found the composition of wire as a function of diameter. EDS reveals non-homogeneous solid solution of gold and silver in each wire. Silver in the whiskers is selectively leached using 14M nitric acid to produce NPG NWs. The NPG NWs are compared to and with each other in terms of morphology, composition, and crystallinity by means of HAADF, Energy-dispersive X-ray Spectroscopy (EDS) and High-resolution transmission electron microscopy (HRTEM). The NPG NWs are found to be single crystals. The percolation limit and parting limit of these wires are also discussed.

Q.PI.1
17:30
Authors : Sung-Ho Shin1, Junghyo Nah1, Min Hyung Lee2
Affiliations : 1. Chungnam National University, Daejeon 34134, Korea 2. Kyung Hee University, Yongin 17104, Korea

Resume : Multifunctional flexible strain sensors have been of great interest in robotic, medical, and healthcare applications.1,2 These sensors mainly employs resistive sensing principles, where they have been developed3on a single flexible substrate using conductive nanowires and conductive polymer4 in order to perceive mechanical and thermal stimuli from target objects. These approaches have been regarded as one of the durable ways for flexible motion sensor. However, the recovery time of resistive sensing element is not sufficient to sense instantaneous movements5,6. Besides, limited efforts have been made to integrate multifunctionalities on a single flexible device. In this work, we report a facile route to enhance the performance of flexible motion sensor with integrated multifunctionalities, providing additional sensing information for precise determination of motions. The sensor device is fabricated as follows. A Si wafer was first treated with anti-adhesive trichloro(1H,1H,2H,2H-perfluorooctyl) silane (FOTS), followed by Ag NWs and PEDOT:PSS spray-coating and transferring processes using polydimethylsiloxane (PDMS). Subsequently, ferroelectric Li-doped ZnO NWs were embedded in the PDMS layer, sandwiched between Ag NWs electrode layers. Both strain and temperature sensitivities of the developed sensor were comparable and superior to the ones reported previously and the nanowires-polymer based device ensures mechanical durability as well. Above all, thanks to integrated piezoelectric element, the sensor can offer more precise motion information under different mechanical stimuli such as strain, stretching, and pressure applied normal to the device plane. The approach introduced here is a simple, effective, and suitable platform to realize the high performance flexible multifunctional artificial electronics.

Q.PI.2
17:30
Authors : Kahina Lounis, El Hocine Megchiche, Hand Zenia
Affiliations : Laboratoire de Physique et Chimie Quantique (LPCQ), Université Mouloud Mammeri, BP 17, 15000 Tizi-Ouzou, Algérie

Resume : The present work is concerned with the study the interactions of multiple oxygen atoms with vacancy clusters Vm of size m (m=1 à 3) in bulk nickel employing a classical molecular statics approach, implemented in the LAMMPS code. using a reactive potential developed recently for the NiO system containing vacancies. Firstly, we present the stability of the vacancy clusters V m (m=1 à 3). Each vacancy cluster of size m can have many different conformations. In order to compare their relative stability, we computed the formation energy and the binding energy per vacancy for each conformation. The results show that most stable conformations are those with the largest first nearest neighbor (1nn) bonds between the monovacancies forming the cluster. Secondly we studied the stability of vacancy-oxygen complexes (VmO1 m=1-3) in bulk nickel using two methods of calculation : (a) semi-empirical with the reactive potential ReaxFF, and (b) ab initio using the VASP code. The results indicate that atomic oxygen inside the vacancy clusters is more stable than at the conventional interstitial sites of the perfect Ni system. The stability of atomic oxygen inside a cavity increases with the cavity?s size. This suggests that presence of solute oxygen inside the host nickel, would assist the vacancy segregation process. The study of the stability of the complexes V1 On et V2 On show that the clusters V1 and V2 can trap up to 14 and 22 oxygen atoms, respectively. The qualitative agreement between the two calculation methods used is very good. However, we pointed also to some quantitative discrepancies between the two approaches. In conclusion, we find that there are strong attractive interactions between oxygen atoms and vacancy clusters in Ni. This behavior was equally well established using both approaches: atomistic and first principles calculations. We think that these interactions will lead to a dramatic increase in the oxygen solubility in nickel and its alloys, in presence of vacancies. We argue that while the reactive potential does not yield results in exact quantitative agreement with the first principles method, it can nevertheess be used for large scale simulations when only qualitative trends are sought.

Q.PI.3
17:30
Authors : Liwu Jiang, Chuanhui Zhang, Peng Shi
Affiliations : National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 10083, China

Resume : Rapid quenching of Ni from crystal to metallic glass (MG) at different external pressures was simulated by molecular dynamics. The pair distribution functions (PDFs), mean-square displacement, glass transition temperature (Tg) and elastic property were calculated and compared with each other. Then the split of the second PDF peak mean the liquid's transition to glass state starts as previously reported for other MGs. And the Ri=R1 ratio rule was found to hold very well in Ni MG and reveals the SPO structural feature in the configurations. Moreover, with high external pressure, Tg values were more approximated by density-temperature and enthalpy-temperature curves. At last, the elastic modulus and mechanics modulus of quenching models produced a monotonous effect with increasing external pressure and temperature.

Q.PI.4
17:30
Authors : N.V. Roik, L.A. Belyakova, M.O. Dziazko
Affiliations : Chuiko Institute of Surface Chemistry of NAS of Ukraine

Resume : Hydrothermal sol-gel synthesis of MCM-41-type aminopropyl silicas was realized in the presence of cetyltrimethylammonium and decyltrimethylammonium bromide as pore generating agents. The effect of azo dyes, alizarin yellow and methyl red, as cosurfactants and their alkoxysilane derivatives as structure-forming silanes on mesostructure and morphology of resulting materials was studied. As it was found from the results of low-temperature adsorption-desorption of nitrogen, the introduction of azo dyes in sol-gel synthesis leads to the substantial increase of specific surface area, total pore volume and decrease of pore diameter of organosilicas. In accordance with the x-ray diffraction analysis, the formation of more distinct long-range ordering of porous structure takes place. Visualization of mesoporous structure of synthesized materials by transmission electron spectroscopy demonstrates hexagonally arranged cylindrical pores, entrances to which are oriented outside of particles that provide accessibility of functional groups. Presence of azo dye compounds in sol-gel reaction mixture does not influence the morphology of resulting organosilica nanoparticles in noticeable extent, but causes formation of highly ordered arrays of cylindrical mesopores. The obtained results are important for understanding the influence of organic additives, including azo dyes, on morphology of nanoparticles and mesoporous structure of organosilicas prepared by template-assisted sol-gel synthesis.

Q.PI.5
17:30
Authors : Junrong Li, Guannan Zhang, Jing Wang, Yadveer S. Grewal, Jiming Hu, Aiguo Shen,* Yuling Wang,* Matt Trau*
Affiliations : J. Li; J. Wang; Y. Grewal; M. Trau; Centre for Personalized Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland 4072, Australia G. Zhang; J.Hu; A. Shen; Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, P. R. China Y. Wang; Department of Molecular Sciences, Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Faculty of Science and Engineering, Macquarie University, Sydney, New South Wales 2109, Australia

Resume : Highly active plasmonic nanostructures that enable strong Raman signal enhancement can facilitate ultrasensitive surface-enhanced Raman scattering (SERS) bioanalysis. Anisotropic nanoparticles are believed to be ideal candidates for SERS plasmonic nanostructures due to the enhanced electromagnetic field on specific regions. To this end, we prepared highly active anisotropic gold-silver alloy nanoboxes as SERS plasmonic nanostructures.1 Our developed strategy follows a straightforward and environmentally friendly synthetic workflow and doesn?t require surfactants, high temperature or an organic phase. Our prepared nanoboxes exhibited about 10 times stronger Raman signal enhancement capability than the commonly used spherical gold nanoparticles under the same particle concentration. Significantly, the nanoboxes showed the superior single-particle SERS activity as illustrated by the Raman mapping and SEM image. By capitalizing on the nanoboxes as high-performance SERS plasmonic nanostructures, we sensitively detected a panel of soluble cancer protein biomarkers,2 including soluble programmed death 1 (sPD-1), soluble programmed death-ligand 1 (sPD-L1) and soluble epithermal growth factor receptor (sEGFR), which are related to disease progression and treatment efficacy. We successfully detected sPD-1, sPD-L1, and sEGFR with a limit of detection (LOD) of 6.17 pg/mL, 0.68 pg/mL, and 69.86 pg/mL, respectively. We further tested the detection of these three soluble cancer protein biomarkers in human serum and achieved recovery rates between 82.99%-101.67%. References: (1) J. Li et.al., ?ACS Appl. Mater. Interfaces 2018, 10, 32526-32535. (2) J. Li et.al.,. Anal. Chem. 2018, 90, 10377-10384.

Q.PI.6
17:30
Authors : Roberto González, William López-Pérez, Álvaro González-García, María G. Moreno-Armenta, Rafael González-Hernández
Affiliations : Roberto González; William López-Pérez; Álvaro González-García; Rafael González-Hernández Grupo de Investigación en Física Aplicada. Departament of Physics, Universidad del Norte, Barranquilla, Colombia María G. Moreno-Armenta; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autonoma de Mexico, Ensenada B.C. Mexico

Resume : Similar to graphene, III-V semiconductors offer extraordinary properties on a diversity of morphologies. Theoretical results based on density functional theory (DFT) calculations have predicted a stable 2D phase for GaN, known as g-GaN (honeycomb type). We studied their structural and electronic properties, in which vacancy charged defects have been introduced, by using first-principle calculations within the framework of DFT. These Ga and N vacancies with different states of charge introduce defect levels that modify the material, giving it exceptional properties. The Ga-Ga (or N-N) bond lengths around the vacancy increased for the Ga-vacancies and decreased for the N- vacancies, with respect to the bond distance without vacancy. Vacancy-induced defect levels are responsible for the total magnetic moment in g-GaN, generating a magnetic moment located at the N atoms for Ga-vacancies or delocalized one in the lattice for N-vacancies, making it a potential candidate for future spintronics applications. Thermodynamic transition levels close to the conduction band minimum are identified for both. N-vacancy has formation energy lower than the Ga-vacancy. N-vacancy is the dominant defect in g-GaN and could be responsible for the n-type behavior of GaN observed experimentally. Similarly, the w-GaN, gallium vacancies have a higher formation energy than those of nitrogen. However, gallium vacancies could be successfully grown in order to design a two-dimensional p-type semiconductor.

Q.PI.8
17:30
Authors : Parth VASHISHTHA?; Gautam?; Yanan Fang?; Xin Yu CHIN; Alasdair Angus Macintyre Brown; Annalisa BRUNO; Nripan MATHEWS; Subodh G. MHAISALKAR; Timothy J. WHITE
Affiliations : ?School of Materials Science and Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, Singapore 639798, Republic of Singapore §Energy Research Institute @ NTU (ERI@N), Research Techno Plaza, X-Frontier Block, Level 5, 50 Nanyang Drive, Singapore, 637553, Republic of Singapore

Resume : Inorganic halide perovskites are one of the most promising candidates for light-emitting applications due to their high photoluminescence (PL) quantum yield, color tunability, and thermal stability. However, perovskites with blue emission still lag behind the PL quantum yield. More importantly, the best performing perovskite contains toxic lead. In order to overcome this issue, lead-free perovskites have gained significant attention in past few years, where researchers have invented several perovskite materials by replacing Pb with Ag, In, Bi, and Sn as a cation. Still, most lead-free perovskites exhibit very low PL quantum yield and thermal stability. Very recently, Cs3Cu2I5 microcrystalline film with zero-dimensional electronic structure was proposed to have high PL quantum yield of 60% at ~440 nm. However, LEDs of this material still show low external quantum efficiency (EQE). Nanocrystals of this material can combine the advantage of perovskite structure as well as the confinement effect, which allows the precise control of crystal formation and offers superior optical properties. Here, we demonstrate the solution process synthesis of Cs3Cu2I5 nanocrystals with superior optical properties and higher stability. A controlled over the structural composition of these nanocrystals is also conducted, which shows the high quality green emitting lead free perovskite nanocrystals. These nanocrystals can be used as an active material for light-emitting applications and produce high efficiency LEDs.

Q.PI.9
17:30
Authors : R.I. Eglitis, J. Purans and J. Gabrusenoks
Affiliations : Institute of Solid State Physics, University of Latvia, 8 Kengaraga str., Riga LV1063, Latvia

Resume : By means of the hybrid exchange-correlation functionals, ab initio calculations for ReO3 as well as main ABO3 perovskite surfaces, namely SrTiO3, BaTiO3, PbTiO3, CaTiO3, SrZrO3, BaZrO3, PbZrO3 and CaZrO3, were performed [1-5]. For ABO3 perovskite (001) surfaces, with a few exceptions, all atoms of the upper surface layer relax inwards, all atoms of the second surface layer relax outwards, and all third layer atoms, again, inwards. The relaxation of (001) surface metal atoms for ABO3 perovskite upper two surface layers for both AO and BO2-terminations, in most cases, are considerably larger than that of oxygen atoms, what leads to a considerable rumpling of the outermost plane. The ABO3 perovskite (001) surface energies always are smaller than the (011) and especially (111) surface energies. The ABO3 perovskite AO and BO2-terminated (001) surface band gaps always are reduced with respect to the bulk values. The B-O chemical bond population in ABO3 perovskite bulk always are smaller than near the (001) and especially (011) surfaces. Electronic and atomic structure of BaTiO3/SrTiO3 and SrZrO3/PbZrO3 (001) interfaces are analyzed [6,7]. Systematic trends of F-center calculations in ABO3 perovskite bulk and on their (001) surfaces are analyzed. References: 1. R.I. Eglitis and A.I. Popov, J. Saudi Chem. Soc. 22, 459-468 (2018) 2. R.I. Eglitis and D. Vanderbilt, Phys. Rev. B 76, 155439 (2007) 3. R.I. Eglitis and D. Vanderbilt, Phys. Rev. B 77, 195408 (2008) 4. R.I. Eglitis and D. Vanderbilt, Phys. Rev. B 78, 155420 (2008) 5. R.I. Eglitis, Applied Surface Science 358, 556-562 (2015) 6. S. Piskukov and R.I. Eglitis, Nucl. Inst. & Methods B 374, 20-23 (2016) 7. S. Piskunov and R.I. Eglitis, Solid State Ionics 274, 29-33 (2015)

Q.PI.10
17:30
Authors : Helene Nahrstedt, Leslie Schlag, Nishchay A. Isaac, Jörg Pezoldt, Heiko O. Jacobs
Affiliations : Fachgebiet Nanotechnologie Institut für Mikro- und Nanotechnologien Gustav- Kirchhoff-Str. 1 98693 Ilmenau

Resume : This poster will present recent results of metallic nickel and ruthenium nanoparticles produced in the gas phase at atmospheric pressure. The synthesis of the nanoparticles occurs in an electric spark discharge. The particles are then transported in a forming gas flow (5% hydrogen in nitrogen) and deposited locally in layers or as nanostructures. The sorting mechanism involves the different force directions of a negative substrate voltage combined with the drag force of the gas flow. This method is referred to as ?gas phase electrodeposition?. The focus of this poster is the derivation of a structural zone model for layers and local structures, which were produced with this method out of metallic nanoparticles. The morphology is affected by influencing parameters. The influencing parameters of transport gas flow, spark power, substrate voltage and thermal energy input by a flash lamp are considered. It turns out, spark power and transport gas flow have the greatest influence on the morphology of deposited layers and nanostructures.

Q.PI.11
17:30
Authors : Seon-Min Hwang(1, 2), Jei-Pil Wang(2), Dong-Won Lee (1, *) * Correspondence : ldw1623@kims.re.kr
Affiliations : 1 Titanium Department, Korea Institute of Materials Science (KIMS), Changwon, Gyeongnam 641-010, Korea; 2 Department of Metallurgical Engineering, Pukyoung National University, Busan 48513, Korea

Resume : Tantalum has been widely used as an alloying element into a super-alloy applied in the military parts such as jet engine, missile and so on due to the good elasticity, corrosion resistance and high melting point. The pure metals are normally extracted by reduction of their oxide phase with a reductant media such as hydrogen or carbon. The tantalum pentoxide (Ta2O5) can be regarded as an initial material to prepare metallic tantalum however its reduction is nearly impossible practically and theoretically by hydrogen gas, vacuum or carbon due to its high thermodynamic stability. In this study, the metallic nano-sized tantalum powder was successfully synthesized by reduction of tantalum pentoxide (Ta2O5) with magnesium gas at 1073~1223 K for 10 hrs inside the chamber held under an argon atmosphere. The powder obtained after reduction shows the Ta?MgO mixed structure and the MgO component was dissolved and removed fully with stirring in a water-based HCl solution. The particle size in the tantalum powder obtained after acid leaching was shown to be in a range of 50~300 nm and the mean internal crystallite sizes measured by the Scherrer equation varied from 11.5 to 24.7 nm according to the increase in reduction temperatures. The temperature to give the maximal reduction effect was found to be 1173 K because the oxygen content was minimized to about 1.3 wt. %.

Q.PI.12
17:30
Authors : 1 Dong-Won Lee
Affiliations : 1Titanium Department, Korea Institute of Materials Science (KIMS), Changwon, Gyeongnam 641-010, Korea

Resume : Tantalum carbide (TaC) has been actively added into hard metals in order to increase the abrasion resistance and machinability. Conventionally, TaC powder has been manufactured by carbothermal reduction by reaction of Ta2O5 and graphite, which has required very high reaction temperature and resulted in free carbon. In general, for the carburization to avoid the formation of free carbon, to use not solid carbon but gas phase as carbon source has been advantageous. In this study, firstly metallic nano-sized tantalum powder was prepared by reducing tantalum pentoxide (Ta2O5) with magnesium gas and with this powder it was tried the gas-carburization using the carbon gas evaporated from activated carbon at 1100 ~ 1400°C for 5~20 hours. In the carburized powders, the carbon, oxygen and nitrogen were analyzed, the phases and microstructures were also evaluated by X-ray diffractometer and scanning electron microscope and the activation energy of carburization reaction and lattice parameter of products were also studied.

Q.PI.13
17:30
Authors : D. Kotsikau, V. Pankov
Affiliations : Belarusian State University, Minsk, Belarus

Resume : Colloidal magnetic nanocomposites based on spinel-type oxides and silica have attracted a considerable attention due to a wide range of their applications, including water purification from heavy metals and dyes, separation and purification of biomolecules, biosensing etc. These materials are characterized by a combination of a suitable colloidal stability in aqueous dispersions, a high magnetic response and a functionalized surface. The long-term stability of the phase composition and completeness of the solid phase separation under magnetic field are the key features of the magnetic sorbents. Liquid-phase preparation of the magnetic nanoparticles is preferable for further functionalization and formation of water suspensions of the sorbents. Two high-temperature approaches for the preparation of gamma-Fe2O3 nanoparticles have been compared here. The first rout supposes a hydrolysis of iron (III) salts in ethylene glycol at 190 degree in the presence of reducing agents. The second way applies a combined hydrolysis of iron (III) and iron (II) salts at 80 degree. Both approaches allow preparing well-crystalline and maghemite particles with a size ranging from 50 to 200 nm. The materials were found to have high thermal stability, high magnetization (~50-70 emu/g) and hydrophilic surface, which is important for their functionalization and further use as sorbents. Magnetic core-silica nanocomposites prepared using the synthesized materials have shown sedimentation stability and sorption characteristics suitable for their environmental and biomedical applications.

Q.PI.14
17:30
Authors : Grzegorz Matyszczak, S?awomir Podsiad?o, Aleksandra Fidler
Affiliations : Warsaw University of Technology, Faculty of Chemistry

Resume : A large interest in nanomaterials is observed due to wide range of their applications. Copper sulfide is interesting due to its potential applications in photovoltaics, biomedical engineering and catalysis. This study presents ultrasound assisted synthesis of copper sulfide micro- and nanopowders from solutions of copper chloride and thioacetamide in ethanol and dimethyl sulfoxide. Composition of the obtained materials have been determined with powder X-ray diffraction and energy-dispersive X-ray spectroscopy. Size of particles have been determined from scanning electron microscopy images and using the Scherrer equation. Band gaps of the obtained materials have been estimated with Tauc method.

Q.PI.15
17:30
Authors : Adrien Chauvin,1 Abdel-Aziz El Mel,2 Stephanos Konstantinidis,3 Cinthia Antunes Corrêa,1 Anna Fucikova,1 Elen Duverger-Nédellec,1 Lukas Horak,1 Pierre-Yves Tessier,2 and Milan Dopita1
Affiliations : 1 Charles University, Ke Karlovu 3, 121 16 Praha 2, Czech Republic; 2 Institut des Matériaux Jean Rouxel, Université de Nantes, CNRS, 2 rue de la Houssinière B.P. 32229, 44322 Nantes cedex 3, France; 3 Chimie des Interactions Plasma-Surface (ChIPS), CIRMAP, Research Institute for Materials Science and Engineering, University of Mons, 23 Place du Parc, B-7000 Mons, Belgium

Resume : Both nanoporous metals and metallic nanoparticles have attracted considerable interest for applications such as biosensors or catalysis. The easiest way to create a nanoporous structure is to use the dealloying process. It consists of removing the less noble metal of an alloy. Most of the studies of the nanoporous nanoparticles deal with the creation of alloy precursor by dewetting. A major drawback of this approach is the restriction of the substrate used for the synthesis due to the high temperature needed for the dewetting. The aim of this study is to create nanoporous particles in a solution which can be deposited on any substrate. In order to create alloy nanoparticles in solution, the synthesis of nanoparticles by a physical way through sputtering onto a liquid substrate. This approach was chosen due to the high purity of nanoparticles and without using toxic reagent compared to the chemical way. In this contribution, we show the creation of gold-copper alloy nanoparticles by co-sputtering of a pure gold and a pure copper targets over pentaerythritol ethoxylate, an organic oil, as a substrate. By tuning the power on the gold target, we demonstrate the creation of different solution containing AuCu alloy nanoparticles. These nanoparticles can be then dealloyed in order to create nanoporous gold nanoparticles. Such particles with a diameter of few nanometers can be considered as potential candidates for the development of highly sensitive optics sensors.

Q.PI.16
17:30
Authors : Lyubov I. Karbivska, Volodymyr L. Karbivskii, Anastas A. Romansky
Affiliations : G.V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine

Resume : The mechanism of the Cu, Ag, Au, and In nanorelief formation on the Si (111) and (110) single crystal surface was studied during multistep thermal deposition. By changing the technological parameters of the deposition and, as a consequence, controlling the flow of the evaporated substance, one can obtain various patterns of self-organizing nanostructures with very clear and regular geometric shapes. The symmetry of the interface surface of the single crystal silicon plane Si (111) 7x7 is determinant in the growth mechanism of hexagonal-pyramidal structures of copper and gold. The height of hexagonal-pyramidal structures of copper and gold is determined by the linear dimensions of the hexagon of the pyramid base and the characteristic offset distance of the beginning of the next pyramid growth (~ 3.0 nm), which ultimately leads to an average height of the pyramid of ~ 2.0 - 3.0 nm. During thermal deposition of In on the Si (111) and (110) surface, the formation of clusters of regular cubic shape is observed. The transformation of the In density of electronic states from a separate cluster (~ 10 nm in size) on the Si (111) surface to the bunch of clusters coating of the single crystal surface with a coating thickness of no more than 30?40 nm has been established.

Q.PI.18
17:30
Authors : Haoyang Yu,? Tobias Helbich,? Lavinia M. Scherf,¶ Jian Chen,§ Kai Cui,§ Thomas F. Fässler,¶ Bernhard Rieger,? and Jonathan G.C. Veinot?,?
Affiliations : ?Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta Canada T6G 2G2; ?Catalysis Research Center Wacker-Lehrstuhl für Makromolekulare Chemie, Department of Chemistry, Technische Uni-versität Muünchen, Lichtenbergstraße 4, 85748 Garching, Germany; ¶Lehrstuhl für Anorganische Chemie mit Schwerpunkt Neue Materialien, Department of Chemistry, Technische Univer-sität Muünchen, Lichtenbergstraße. 4, 85748 Garching, Germany; §National Institute for Nanotechnology, National Research Council Canada, 11421 Saskatchewan Drive, Edmonton, AB T6G 2M9, Canada

Resume : A wide variety of 2D materials including, graphene, molybdenum disulfide, black phosphorous, and boron nitride have been reported. Heavier Group 14 elements (i.e., silicon and germanium) 2D structures are now of considerable interest because of their vast potential in optoelectronics, energy storage, and the semiconductor industry. The synthesis of germanium nanosheets (Ge-NSs) with well-defined surface chemistry will provide a convenient approach by which Ge-NSs electronic structure and properties may be controlled. This presentation will focus on our straightforward route to modify the surfaces of freestanding hydride-terminated Ge-NSs. Furthermore, we demonstrate that following functionalization, the crystal structure of the Ge-NSs remains intact and the introduction of organic moieties to the Ge-NSs surfaces imparts improved thermal stability and solvent compatibility.

Q.PI.19
17:30
Authors : D. Beketova, M. Motola, H. Sopha, V. ?i?mancova, F. Dvo?ak, L. Hromadko, M. Stoica, J. M. Macak
Affiliations : D. Beketova1; M. Motola1; H. Sopha1,2; V. ?i?mancova1; F. Dvo?ak1; L. Hromadko1,2; M. Stoica3; J. M. Macak1,2 1. Center of Materials and Nanotechnologies, Faculty of Chemical Technology, University of Pardubice, Nam. Cs. Legii 565, 530 02, Pardubice, Czech Republic 2. Central European Institute of Technology, Brno University of Technology, Purkynova 123, 612 00 Brno, Czech Republic 3. Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland

Resume : Magnetic micro/nanoparticles are widely exploited in many biotechnological or biomedical applications [1,2]. There are also complex inorganic and magnetically guidable materials, such as combinations of TiO2, Al2O3, SiO2 oxides of different morphologies with superparamagnetic nanoparticles, that are utilized e.g. for purification of biomolecules, such as proteins or peptides [3-5]. However, in many of these works, the superparamagnetic particles are deposited onto the inorganic oxide matrix from commercially available colloidal suspensions yielding only limited adhesion of the particles to the matrix. Unwanted detachment from the matrix and contamination of the surrounding environment may occur. It is necessary to develop synthetic routes, that will establish strong chemical bonds and sufficiently good binding of the particles to the matrix. In this work, we propose facile, one-pot solvothermal approach based on the synthesis of iron oleate complex and its subsequent decomposition to decorate 1D anodic TiO2 nanotubes with magnetite nanoparticles. The resulted composite materials were decorated with the 14-28 nm semi-spherical nanoparticles in inner and outer shell of the nanotubes. In contrast to various techniques, the approach ensures a stability of the as-prepared material under any subsequent treatment. Influence of oleic acid and iron precursor concentration, duration of synthesis was investigated, and optimal synthesis conditions were found. The as-prepared materials represent promising magnetically guidable photocatalysts in biomedicine for drug delivery [6]. [1] Gijs M. et al. Chem. Rev. 2010, 110, 1518?1563. [2] Schladt T. D. et al. Dalton Trans. 2011, 40, 6315?6343 [3] Ma W.-F. et al. ACS Nano. 2012, 6, 3179?3188 [4] Ni, Q. et al. Chromatogr. 2016, 30, 566?573. [5] Kupcik R. et al ACS Appl. Mater. Interfaces 2017, 9, 28233?28242 [6] D. Beketova et al., Ms in preparation.

Q.PI.20
17:30
Authors : S Sadhujan [a], P Natarajan [a], A Shalabny[a], T Heckenthaler [a],Sherina Harilal[a], M Y Bashouti [a],[b],*
Affiliations : [a] Department of Solar Energy and Environmental Physics, Swiss Institute for Dryland Environmental and Energy Research, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshset Ben-Gurion 8499000, Israel. [b] The IlSe-Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beersheva, 8410501, Israel.

Resume : Silicon nanowires (Si NWs) with controllable doping concentrations has significant interest in the field of nanoelectronics, thermoelectronics and battery electrodes. In this work a systematic study of the effect of dopant type (B, P dopants) and doping concentration on MACE of silicon was studied. Key factors involved in determining the surface morphology, pore size, and length of Si NWs was the doping concentration of the silicon wafer and ?=HF/(HF+H2O2) ratio. Heavily doped silicon nanowires were obtained only from ? = 0.90-0.96. Moreover, mesoporous Si NWs was obtained when highly doped silicon was used as substrate for MACE. The electron transfer process among Si, Ag+, Ag nanoparticles and H2O2 was investigated to explain the formation of porosity, and Si NW formation. A mechanism is proposed from the electrochemistry at silicon/metal(Ag) interface based on localized etching at semiconductor/ metal interface. The highly doped mesoporous Si NWs open new door to develop wide applications derived from high surface area and quantum confinement effects.

Q.PI.21
17:30
Authors : Hong-Gu Jeon, Bora Kang, Song-Ho Byeon
Affiliations : Department of Applied Chemistry, Kyung Hee University, Korea

Resume : Layered rare earth hydroxides (LRHs) represented by the general formula RE2(OH)5(Am?)1/m·nH2O (RE = rare earths, X = interlayer anions) are composed of alternately stacked [RE2(OH)5?nH2O]+ rare earth hydroxocation layers and (Am?)1/m anion layers. This emerging class of layered materials show wide potential applications such as luminescent films and colloids, bioimaging and bioprobing, environmental adsorbents, antimicrobial composite materials, and drug-delivery systems. In the present work, we successfully designed and assembled white light-emitting hybrid colloids and composite films based on efficient energy-transfer between Tb3+/Eu3+ and organic sensitizer in the gallery of LRHs. In view of the lowest triplet state (23,300 cm-1) close to the resonance energy level of Tb3+ (5D4: 20,500 cm-1), salicylate (sal) was selected as an organic sensitizer to harvest UV-light through S0 ? S1 (?, ?*) transition followed by an efficient energy-transfer. Eu3+-doped layered terbium hydroxide (LTbH:Eu), Tb3+-doped layered yttrium hydroxide (LYH:Tb), and layered yttrium hydroxide (LYH) were selected as host matrices for red, green, and blue light emitting hybrid materials, respectively. Considering that flexible luminescent materials have attracted an extensive interest due to their applicability in optoelectronic devices, novel transparent white-emitting nano-composite films have been fabricated by using biocompatible polyvinyl alcohol (PVA). White light emission with (0.317, 0.342) CIE coordinate was readily achieved by simple mixing of resulting sal-LTbH:Eu, sal-LYH:Tb, and sal-LYH colloids with appropriate ratios. Highly increased photostability of salicylate in the interlayer space of LRH provides both colloids and composite films high performance durable for long period under simulated sun light.

Q.PI.22
17:30
Authors : Alma Dauletbekova1*, Zein Baimukhanov1, Artem Kozlovskii2, Lyudmila Vlasukova3, Sholpan Giniyatova1, Abai Usseinov1, Aiman Akylbekova1, Zhakyp Karipbayev1 and MaximZdorovets2,4
Affiliations : 1)L.N. Gumilyov Eurasian National University, Nur-Sultan 01008, Kazakhstan 2)Institute of Nuclear Physics, Nur-Sultan 010008, Kazakhstan 3) Scientific Research Laboratory of Materials and Device Structures, Belarus State University, Minsk 220064, Belarus 4)Ural Federal University, Yekaterinburg 620002, Russia

Resume : This research presents the results on the synthesis of ZnSe2O5 nanocrystals in ?-SiO2/Si-n track template. For electrochemical deposition (ECD), the following electrolyte composition was used: Zn - 7.2 g/l, SeO2 - 0.2 g/l. Also, the standard electrolytic cell was used, with zinc electrodes, the voltage across the electrodes was 1.25 V and deposition time was 15 minutes. XRD patterns were obtained using the X-ray diffractometer D8 ADVANCE ECO. As result, we shown that ZnSe2O5 nanocrystals is created after ECD and they have an orthorhombic crystal structure. Thus, ZnSe2O5 nanocrystals were first obtained by synthesis into a-SiO2/Si-n track templates. To confirm the experimental data and the basic properties of ZnSe2O5 nanostructures, we also performed ab-initio calculations. The calculations are performed in the program CRYSTAL [. The calculated lattice parameters, material density, and band structure well consistent with experimental data obtained from our experiments and literature. It was shown that ZnSe2O5 have a direct bandgap at ?-point; the calculated effective charges indicate considerable covalency of chemical bonds.

Q.PI.23
17:30
Authors : Dzimitry Ivashenka, Elena Petrova, Vladimir Pankov
Affiliations : Belarusian state university, Faculty of Chemistry

Resume : Spinel ferrites nanoparticles are potentially suitable for several applications including electronics, sensors, catalytic degradation of organic/inorganic pollutants. Recently, they have also attracted considerable attention for biomedical applications, such as hyperthermia treatment of cancer, contrast agents for magnetic resonance imaging, drug delivery systems. In this work, zinc-substituted magnesium ferrite nanoparticles (Mg,Zn)Fe2O4 were prepared by ultrasonic spray pyrolysis technique with subsequent calcination. The novelty of the method used lies in the choice of substrate for spray pyrolysis stage. Initially, suspension of ferrite was prepared by coprecipitation from water solution of corresponding nitrates. Only then spray pyrolysis were carried out using derived suspension with addition of NaCl. The powders obtained were annealed at 300-900 °? to increase specific magnetization of nanoferrites. The isolating matrix of NaCl formed between the particles during spray pyrolysis prevented them from aggregation during annealing. After the annealing, NaCl matrix was removed by washing with deionised water. All the particles exhibit superparamagnetic behavior with no coercivity at room temperature, and their average size does not exceed 100 nm even after annealing at 900 °?. This proves the method to be effective for producing non-agglomerated ferrites nanoparticles with increased magnetization and crystallinity.

Q.PI.24
17:30
Authors : Martyna Trukawka*, Krzysztof Cendrowski*, Magda Peru?y?ska^, Wojciech Konicki#, Marek Dro?dzik^, Ewa Mijowska*
Affiliations : *Nanomaterials Physicochemistry Department, Institute of Chemical and Environment Engineering, West Pomeranian University of Technology, al. Piastów 45, 70-322 Szczecin, Poland ^Department of Experimental & Clinical Pharmacology, Pomeranian Medical University, Powstancow Wlkp. 72, 70-111 Szczecin, Poland #Department of Integrated Transport Technology and Environmental Protection, Maritime University of Szczecin, H. Poboznego St. 11, 70-507 Szczecin, Poland

Resume : Mesoporous silica materials, due to their high specific surface area, the ability to multiple functionalities and biocompatibility are very popular in biomedical applications. The vast majority of records reports on core/shell nanosphere or completely porous structures. They are particularly attractive due to the possibility of both chemical modification of the surface and adsorption of the anticancer drug in the pores of the material. The advanced level of research on the adsorption and desorption of anticancer drugs from mesoporous silica materials allows to focus on the methods of targeting nanostructures to cancer cells. In the presented research, mesoporous silica nanoflakes with potential application in targeted anti-cancer therapy were used. The aim of the presented research was to obtain mesoporous silica flakes produced on a graphene oxide template, their functionalization with folic acid and the adsorption of an anticancer drug in their pores. As well as confirmation the stability of the connection between the folic acid and the silica structure and also drug releasing. The structure and elemental composition of materials were determined by transmission electron microscopy and EDX as its mode. The morphology of the flakes was checked using a scanning electron microscope. The effectiveness of the functionalization was determined using FT-IR spectroscopy. Thermogravimetric analysis was also carried out to determine the content of folic acid and drug in the obtained flakes. This research was funded by National Science Centre (Poland) within the project No. 2016/21/N/ST8/02397 (PRELUDIUM 11).

Q.PI.25
17:30
Authors : Marjeta Ma?ek Kr?manc*, Hana Ur?i?#, Nina Daneu*, ?pela Kunej*, Matja? Spreitzer*, Ioana Dorina Vlaicu+, Daniela Ghica+?
Affiliations : *Advanced Materials Department, Jo?ef Stefan Institute, Jamova 39, Ljubljana 1000, Slovenia; #Electronic Ceramics Department, Jo?ef Stefan Institute, Jamova 39, Ljubljana 1000, Slovenia; +National Institute of Materials Physics, Atomistilor Str. 405A, Magurele, 077125, Romania

Resume : Topochemical conversion (TC) is commonly used for synthesis of MTiO3 (M=Ba, Sr) perovskite (nano)plates. TC offers the possibility to prepare perovskite plates with mixed composition, which enables the straightforward control of their functional and structural characteristics. In this research, the TC of Bi4Ti3O12 to (Ba,Ca)TiO3 plate-like particles was studied. We found that the incorporation of Ca in the (Ba,Ca)TiO3 plates is limited and that the elimination of Bi is lower (2 at. %) than in the case of the TC to BaTiO3 plates (1 at. %). X-ray diffraction (XRD) analyses revealed the characteristic (001)/(100) tetragonal splitting in the plates with a Ca:Ba ratio of up to 0.05:0.95, indicating the presence of ferroelectric a- and c-domains. The presence of large, 500-nm-sized domains was confirmed using a piezo-response-force microscope (PFM). The local piezoelectric d33 values (50?180 pm/V), determined with the PFM, were comparable to the d33 reported for polycrystalline (Ba,Ca)TiO3-based ceramics. We found that the thickness and the composition of the plates are important, but not the only, factors that determine the d33 values. In addition, the influence of the Ca and Bi distributions and the presence of extended defects were considered, and studies using scanning transmission electron microscopy (STEM) were performed. Our study elucidates the possibilities for tailoring the characteristics of (Ba,Ca)TiO3-based ferroelectric plates prepared by TC.

Q.PI.26
17:30
Authors : Klaudia Maslana. Ewa Mijowska
Affiliations : West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Piastow Ave. 42, 71-065 Szczecin, Poland

Resume : Carbon-based materials (CBM) are considered to be one of the key components in nanotechnology. Especially graphene is considered as the most promising form in future technologies. But disadvantages as high price and difficulty in obtaining single layer thick sheet, which shows excellent results, limits its commercial application. One of CBM is graphitic carbon nitride (g-C3N4) with his layered structure is very similar to graphite. That material consist atoms of carbon, nitrogen and hydrogen. It is environmental friendly material and low price results in high potential for practical applications. It presents unique physicochemical properties which is the reason why it is widely use in fields such as: photocatalysis, sensing or electrochemistry. The presented results will concern the preparation method and physicochemical characterization of novel form of graphitic carbon nitride-tubular form. The obtained material was examined using various research techniques, such as X-ray photoelectron spectroscopy, X-ray diffraction spectroscopy, scanning and transmission electron microscopy, Raman spectroscopy and others. The potential applications of these materials will be investigated, e.g.: lithium-ion batteries, HER/OER reactions, photocatalytic hydrogen evolution and others. The most promising results will be presented.

Q.PI.27
17:30
Authors : Nazrin Abdullayeva, Berkay Bayraktar, Esra Demet Karaca, Muratcan Hamarat, Oyku Demirel, Mehmet Sankir, Nurdan Demirci Sankir
Affiliations : TOBB University of Economics and Technology, Materials Science and Nanotechnology Engineering

Resume : One of the recent rising trends in zinc oxide (ZnO) based optoelectronic devices is the ability to maintain their selective growth on the patterned substrates. It is specifically anticipated that aligned and patterned growth of ZnO nanostructures improves the device properties by increasing their sensitivity towards various stimulants (light, amount of gas, etc.). Lithographic methods that have been proposed for selective deposition of ZnO to date possess common disadvantages like high manufacturing cost, the requirement for special equipment and time sink. In this regard, for the very first time in the literature, a rapid, easy, and affordable method for selective ZnO deposition is being proposed in this work. Our process is based on the patterned deposition of ZnO through the formation of bilayer thin film coating that provides two different nucleation rates in Chemical Bath Deposition (CBD) of ZnO. One of these thin films (ZnO) provides a favorable environment for easy and fast ZnO nanorod nucleation, while the other (titanium) plays the role of ZnO nucleation retardant agent. The selectivity is achieved through the ablation of upper titanium (Ti) thin film via nanosecond fiber laser under proper fluence energy. The best ablation has been obtained at 7W, 150 kHz, 4500 mm/s which corresponds to 3.7 J/cm2 fluence energy/spot. Ablations performed at higher fluence energies (? 5 J/cm2) resulted in Na+ diffusion from the glass substrate affecting the resulting nanostructure of CBD grown ZnO, which has shown an alteration from nanorod to nanoflake structure. At last but not least, the photoluminance characteristics of the ZnO patterns has been investigated for further optoelectronic applications.

Q.PI.28
17:30
Authors : Cezary Czosnek, Honorata Osip, Mariusz Dryga?, Jerzy F. Janik
Affiliations : AGH University of Science and Technology, Faculty of Energy and Fuels, Al. Mickiewicza 30, 30-059 Krakow, Poland

Resume : Our previous studies confirmed the great potential of the spray pyrolysis method to prepare C/SiC nanocomposites of spheroidal particle morphology from oxygen-containing organosilicon precursors. In the first stage, the short residence time of the precursor mist in the high-temperature zone of aerosol reactor and competitive side reactions usually resulted in raw products still containing some oxygen. The latter could be removed in an additional pyrolysis stage at higher temperatures. Herein, presented are results of a study on the preparation of silicon nitride (or oxynitride) nanopowders by the two-stage spray pyrolysis method from readily available organosilicon precursors. First, white raw powders were produced in an aerosol reactor from the mist of precursors reacting in flowing ammonia at 1000 °C and 1200 °C (or 1400 °C). Second, the raw powders were pyrolyzed at 1400 °C under ammonia to complete the ammonothermal reduction of Si?O groups and assist the formation of Si-N bonds. The final creamy powders were characterized at this stage with powder XRD, SEM, and FT-IR spectroscopy. Acknowledgments. The study was supported by AGH University of Science and Technology Grant No. 16.16.210.476

Q.PI.29
17:30
Authors : Joanna Kwiczak-Yigitbasi, Mine Demir, Fatma Demir, Bilge Baytekin
Affiliations : Joanna Kwiczak-Yigitbasi, Chemistry Department, Bilkent University, 06800, Ankara, TURKEY; Mine Demir, Chemistry Department, Bilkent University, 06800, Ankara, TURKEY; Fatma Demir, Chemistry Department, Bilkent University, 06800, Ankara, TURKEY; Bilge Baytekin, Chemistry Department, Bilkent University, 06800, Ankara, TURKEY, UNAM, Bilkent University, 06800, Ankara, TURKEY

Resume : Cellulose, the most common polymer in nature, has gained increasing attention in the preparation of sustainable materials mostly because it is natural, low-cost, nonabrasive and biodegradable. In order to prepare such eco-friendly and multifunctional materials, mechanochemistry emerged as a green alternative in comparison to conventional multistep methods, which often include the usage of toxic reagents. With mechanical input on cellulose, chemical bonds are broken and mechanoradicals are formed. In the course of this work, for the production of such radicals, ultrasonication was used. Formed radicals were quantified using radical scavenger 2,2-diphenyl-1-picrylhydrazyl and structural and morphological changes of cotton occurred upon ultrasonication were studied by FTIR-ATR, XRD, and SEM. Later on, cellulose mechanoradicals were used to reduce Au3 ions during the sonication process, resulting in the formation of gold nanoparticles (NPs) in the cellulose matrix. The nature of NPs was monitored by SEM, XRD, and XPS, which showed Au NPs retained stable in the cotton matrix. Our results show that ultrasonication method in preparation of Au NP-cellulose composites successfully avoids hazardous solvents and reagents, and provides a straightforward access to catalytically active, useful nanocomposites.

Q.PI.30
17:30
Authors : Tomasz Necio, Magdalena Birowska
Affiliations : University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland

Resume : Two-dimensional (2D) materials are widely studied since the discovery of the graphene layer in 2004. The vertical stacking of the 2D materials opens a way for the new class of materials known as the van der Waals structures [1], in which the properties originating from the individual layers can be significantly improved. In addition, stacking the 2D magnetic crystals with different orientations might result in a different magnetic order as well as of the new physical phenomena. In this communication, we study the impact of the graphene substrate on the properties of the antiferromagnetic NiPS3 material, in the framework of the density functional theory (DFT) within the DFT+U approach, and inclusion of the weak van der Waals forces. The NiPS3 layered crystal is one important example from the family of transition metal phosphorus trisulfide compounds [2] (MPX3 where M=Mn, Fe, Ni; X=S, Se). In the present work, various properties of the freestanding NiPS3 monolayer, and the monolayer of the NiPS3 vertically stacked on the graphene will be discussed and compared. The results of the different mutual orientations of the NiPS3 monolayer, and graphene layer will be presented from the point of view of the differences in electronic structure and optical spectrum. The work is funded by the National Science Center grant no. UMO-2016/23/D/ST3/03446. [1] A. K. Geim, I. V. Grigorieva, Nat. Vol.499, 419 (2013) [2] M. Evain, R. Brec, M.-H. Whangbo, J. Solid State Chem. vol.71, p.244 (1987).

Q.PI.31
17:30
Authors : Farid Behboodi Sadabad, Joerg Lahann
Affiliations : Dr. Farid Behboodi Sadabad, Institute of Functional Interfaces, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.; Prof. Dr. Joerg Lahann, Institute of Functional Interfaces, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany. Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA.

Resume : Different polymerization methods have been reported to prepare MOF-templated materials. However, each polymerization method has limitations such as the requirement to a specific catalyst or initiator, solvent, high temperature, and long reaction time that narrow its applicability. A key limitation of MOF-templated polymerization is the diffusion of the monomer (usually in liquid phase) in the MOF nanopores. Furthermore, insertion of high molecular weight polymers is extremely difficult, because of their low diffusivities, limiting the approach to oligomers and short polymers. Here, we used chemical vapor deposition (CVD) polymerization to template poly(p-xylylenes) in (HKUST-1 and ZIF-8) MOF particles. This strategy enabled to establish a general but simple protocol for the preparation of polymer-MOF composites and MOF-templated polymers. CVD polymerization of gas phase [2.2]paracyclophane monomers in the presence of MOF particles was carried out at room temperature for 15 min to yield PPX-MOF composite. Templated poly(p-xylylene) (PPX) was achieved after washing the MOF away by immersion of the composites in a ethylenediaminetetraacetic acid (EDTA) solution for 30 min at room temperature. PPX-MOF composite formation was confirmed with infrared spectroscopy (IR) and X-Ray diffraction (XRD) analysis. Scanning electron microscopy (SEM) of the polymer-MOF particles before and after polymerization indicated that the templated PPX retained the shape and morphology of the MOF particles. Therefore, chemical vapor polymerization (CVD) can provide a facile strategy to prepare polymer-MOF composites and MOF-templated polymers with unique features in terms of synthesis, physical properties, and biomedical applications.

Q.PI.32
17:30
Authors : Gye Seok An, Ah Hyun Oh, Ji Hyun Cha, Sung-Churl Choi
Affiliations : Hanyang University

Resume : Fe3O4@SiO2 core/shell structured nanoparticles are promising materials in bio-field such as drug delivery system and nucleic acid purification based on superparamagnetic properties of Fe3O4 core and bonding capacity with other molecules of hydroxyl groups of silica shell. In this core/shell structure, the bonding capacity of silica coating layer is increased by enhancing surface area, and it knows as well that the method for improving the surface area is to form a hollow or mesoporous structure. To fabricate inorganic hollow materials, the soft-templating method has been used generally, but the degeneration of a primary particle could be occurred in the template removal process due to thermal processing or use of strong acid or base. In this study, therefore, the cetyl trimethyl ammonium bromide (CTAB) which is a water-washable hydrophilic surfactant was used as a template, and synthesis of magnetic nanoparticle that has hollow interlayer and mesoporous silica coating layer was performed. Additionally, the separate purification of Plasmid DNA was carried out with the manufactured particles. As a result of the addition of CTAB, the surfactant layer was formed due to electrostatic attraction with Fe3O4 nanoparticle and CTAB. And it was confirmed that the morphology of the silica coating layer formed over the CTAB layer varies as the concentration of the surfactant. Consequently, as the surface area of the silica layer increases, the adsorption site of plasmid DNA was advanced, so the purification concentration of plasmid DNA was considerably increased.

Q.PI.33
17:30
Authors : Saad Abdeslam
Affiliations : IOMP, Ferhat Abbas University of Setif 1

Resume : By using molecular dynamics methodology, we have simulate the mechanical behavior of iron?chromium binary nanomaterials alloys under tensile test and nanoindentation. In this study, we investigate the influence of Cr concentration, strain rate, indentation velocity and temperature on the mechanical parameters and on the microstructure evolution. Obtained results showed that the elastic limit of the nanomaterial decreases as the Cr concentration increases and this means that the Cr contribuates to weakening the material. Finaly, our simulated results agree well with previous work.

Q.PI.34
17:30
Authors : Rama Kotni and Prof. Alfons van Blaaderen
Affiliations : Debye Institute for Nanomaterials Science, SOFT Condensed Matter group, Utrecht University, The Netherlands.

Resume : Anisotropic colloidal particles promise a great diversity in fabricating functional materials and opens the door for many applications in different fields of science. However, fabricating highly ordered superlattices with anisotropic particles has remained a challenge. In this work, we report an approach to synthesize and self-assemble highly monodisperse matchstick type silica rods. We discuss the effect of seed particles on obtaining monodisperse matchstick colloids also inhibit the spike formation on seed particles. We have developed a procedure to obtain the matchstick silica rods with tunable orientation of the hematite cores in the heads of the matchstick silica rods using partially hydrolyzed TEOS. Thus, obtaining matchstick silica rods which possess single crystalline hematite ellipsoids in the heads, and exhibit magnetic interactions, making them a more interesting system for self-assembly studies. At a liquid-air interface, these matchstick silica rods self-assemble in liquid crystal phases such as smectic domains, with the hematite heads pointing in one direction, such observations are potential for the development of new materials based on matchstick particles. We also studied their activity towards decomposition of hydrogen peroxide in the presence of blue light.

Q.PI.36
17:30
Authors : Richard Krumpolec, Dominik Ba?a, David C. Cameron, Jana Jurmanová, Ond?ej Caha, Josef Humli?ek
Affiliations : Richard Krumpolec; Dominik Ba?a; David C. Cameron; Jana Jurmanová R & D Center for Low-Cost Plasma and Nanotechnology Surface Modifications (CEPLANT), Department of Physical Electronics, Faculty of Science, Masaryk University, Kotláská 267/2, 611 37 Brno, Czech Republic Ond?ej Caha; Josef Humli?ek Department of Condensed Matter Physics, Masaryk University, Kotlá?ská 267/2, 611 37 Brno, Czech Republic

Resume : Zinc blende-structured copper (I) halides are wide-band, direct gap semiconductors with high exciton binding energies which have been investigated for some time for their application to optoelectronic devices. The possibility of stable, room temperature, UV emission, together with high biexciton binding energies, enables optoelectronic effects such as bistability and four-wave mixing with the potential for new short wavelength devices. For optoelectronic devices it is important to be able to control the deposition either in thin film form or as arrays of nanocrystallites. Atomic Layer Deposition (ALD) is capable of enabling uniform and well controlled deposition of thin films and nanocrystallites. This technique has previously been applied to copper chloride CuCl [1,2]. Deposition using an ALD-like process has also been reported using different precursors [3]. This paper reports on the deposition of copper bromide CuBr using [Bis(trimethylsilyl)acetylene]-(hexafluoroacetylacetonato)copper(I) and pyridine-HBr as precursors. The crystal structural, chemical composition and optoelectronic properties of the CuBr films are reported and the deposition is compared to that of CuCl. Acknowledgement: This work was financially supported by the Czech Science Foundation (No.17-02328S). [1] G. Natarajan, et al., Appl. Phys. Letts. 97 (2010) 241905 [2] P. S. Maydannik, G. Natarajan, D. C. Cameron, J Mater Sci: Mater Electron. 28 (2017) 11695?11701 [3] R. Krumpolec, et al., Coatings 8 (2018) 369

Q.PI.37
17:30
Authors : Mario Urso1, Giovanna Pellegrino1, Vincenzina Strano2, Elena Bruno1,2, Francesco Priolo1,2, Salvo Mirabella1,2
Affiliations : 1 MATIS IMM-CNR and Dipartimento di Fisica e Astronomia "Ettore Majorana", Università di Catania, via S. Sofia 64, 95123 Catania, Italy; 2 BRIT (Bio-nanotech Research Innovation Tower), Università di Catania, via S. Sofia 89, 95123 Catania, Italy.

Resume : Ni based nanostructures are attractive catalytic materials for many electrochemical applications among which non-enzymatic sensing, energy storage, water splitting. In this work, we clarify the synthesis kinetics of 3D nanoporous Ni film formed chains-like clusters of Ni nanoparticles (20 nm in size) grown by chemical bath deposition (CBD) and thermal annealing in reducing atmosphere [1]. By using scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and Rutherford backscattering spectrometry (RBS) we found that during CBD the growth occurs through two regimes: first, a quick random growth leading to disordered sheets of Ni oxy-hydroxide, followed by a slower growth of well-aligned sheets of Ni hydroxide. The growth temperature of 50°C, leading mainly to well-aligned sheets, offers superior electrochemical properties in terms of charge storage, charge carrier transport and catalytic action, as confirmed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses. Finally the optimized structure was applied to non-enzymatic glucose sensing, reaching the utmost sensitivity of 31 mA/(cm2mM) in the detection range of 0.02-0.4 mM for the detection of glucose in human saliva and tears. [1] M Urso et al 2018 Nanotechnology 29 165601

Q.PI.38
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Methods for Nanoscale Dynamic Processes : Patricia Abellan
09:00
Authors : Matthieu Bugnet
Affiliations : Univ Lyon, INSA Lyon, UCBL Lyon1, MATEIS, CNRS UMR 5510, F-69621 Villeurbanne, France

Resume : Ceria (CeO2) is a fundamentally interesting and industrially relevant catalyst. However, it remains a very challenging material for TEM observations, as it reduces strongly and spontaneously under the electron beam in high vacuum. In this presentation, I will highlight how controlling the nature of the atmosphere within an aberration-corrected environmental TEM (ETEM) is an efficient and powerful way to control the redox state of ceria, while providing numerous opportunities to study a wide range of physical and chemical phenomena at the atomic scale. For instance, the atomic mobility at {100} surfaces is strongly affected by the nature of the surrounding gas, and could be used to indirectly indicate the adsorption/desorption of gaseous species. This work also demonstrates the direct visualization of adsorbed oxygen or CO2 molecules at {100} surfaces. The nature of the contrasts is evaluated from high resolution TEM (HRTEM) simulations, which reproduce semi-quantitatively the experimental images. Directly visualizing the projected atomic structure of the top surface of ceria through HRTEM imaging is a great opportunity to investigate the current capabilities of the ETEM to validate atomistic models of adsorbed molecules at surfaces. This work highlights the potential of the ETEM at high spatial resolution to directly image adsorbed molecules, and thereby better understand the surface coverage and the nature of adsorption sites predicted by atomistic calculations.

Q.5.1
09:30
Authors : Bence Gajdics [1,2], János J. Tomán [1], Helena Zapolsky [2], Zoltán Erdélyi [1], Gilles Demange [2]
Affiliations : [1] Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary ; [2] GPM, UMR CNRS 6643, University of Rouen, 76575 Saint Étienne du Rouvray, France

Resume : We report a new multi-scale procedure based on the recently developed Stochastic Kinetic Mean Field (SKMF) approach, combined with the Phase Field model (PFM) and CALPHAD database, to study the nucleation-growth-coarsening process in the Ag-Cu alloy. The SKMF approach reproduces the nucleation and early growth of copper precipitates in the silver matrix, and the PFM then simulates the coarsening of the microstructure. To ensure the consistency of the procedure, the length and time scales of SKMF and PFM are connected by matching the interface profiles and growth velocity of an isolated growing precipitate as simulated by both methods. Moreover, the free energy used in the PFM is derived from the interaction energies used in SKMF. Two different implementations of the procedure are proposed. First, the post-nucleation microstructure as provided by SKMF is used as the initial condition for subsequent PFM simulations. Second, only the particle size distribution and particle density are transferred to PFM, thereby giving access to bigger systems.

Q.5.3
09:45
Authors : János J. Tomán(1), Bence D. Gajdics(1,2), Fanni Misják(3), György Radnóczi(3), Zoltán Erdélyi(1)
Affiliations : (1) Department of Solid State Physics, University of Debrecen, H-4002, Debrecen, PO Box 400, Hungary (2) GPM, UMR 6634, University of Normandy, Saint-Etienne du Rouvray, France (3) Research Centre for Energy Research, Hungarian Academy of Sciences, H-1525, Budapest, PO Box 49, Hungary

Resume : For revealing internal atomic processes in bimetallic nanoparticles, individual hemispherical Ag-Cu alloy particles were grown by direct current (DC) magnetron sputtering. Phase separation of particles was found to be size- and composition-dependent. Particles smaller than 5 nm in diameter remained as a solid solution of the components for all tested compositions (15-80 at.% Ag). At 15 and 30 at.% Ag compositions phase separation was observed only for particles above 5 nm in diameter. The solubility curve is asymmetric in Ag-Cu, which means that the excess free energy function cannot be described by a second order polynomial of the composition (non-regular solution), that is the interaction energy is composition dependent. In this work we apply the Cahn-Hilliard theory and a 3D atomistic kinetic model, the Stochastic Kinetic Mean Field (SKMF), what we further developed purposefully so it can use the Redlich-Kister polinomials from CALPHAD calculations. We demonstrated that the gradient energy coefficient - composition function can be calculated from the interaction energy. We also showed that when the interaction energy is composition dependent this necessarily means that the gradient energy coefficient is also composition dependent.

Q.5.4
10:00
Authors : Mathias O. Mosig
Affiliations : Protochips, Inc., Germany

Resume : New innovations are transforming the Transmission Electron Microscope (TEM) from a simple high-resolution image acquisition tool into a nanoscale materials research and development laboratory. Researchers can now better understand material behavior by analyzing samples in real-world gas or liquid environments, at high temperature and with ultra-low noise electrochemical and electrical biasing techniques. With the new in situ tools from Protochips, materials research occurs in highly controlled environments at high resolution without sacrificing the analytical capabilities of the TEM such as EDS. Applications for these tools include heterogeneous catalyst reactions, imaging of living cells, nanostructure nucleation and growth, battery and fuel cell materials, high temperature nanoparticle behavior, soft materials, and semiconductor devices. In this presentation we show the most recent results using the Protochips Atmosphere™ gas cell, the Protochips Poseidon™ Select flowing liquid and electrochemistry cell, and the Protochips Fusion™ heating and electrical biasing system. Sample preparation methods using Focused Ion Beam techniques were developed to address the different challenges emerging from in situ heating and biasing experiments. A full Clarity software suite allows for the control of experiments, data recording and analysis as well the as the seamless integration of in-situ data into TEM camera software.

Q..0
10:20 Coffee break    
 
3D Characterization and Multidimensional Data : Matthieu Bugnet
11:00
Authors : Sarah J. Haigh, Yichi Wang, Matthew Lindley, Daniel Kelly, Thomas Slater,
Affiliations : University of Manchester, Manchester, M13 9PL, United Kingdom; Electron Physical Sciences Imaging Centre, Diamond Light Source Ltd., Oxfordshire OX11 0DE, United Kingdom

Resume : The properties of nanoparticles are known to critically depend on their local chemistry but characterizing three-dimensional (3D) elemental segregation at the nanometer scale is highly challenging. Scanning transmission electron microscope (STEM) tomographic imaging is one of the few techniques able to measure local chemistry for inorganic nanoparticles but conventional methodologies often fail due to the high electron dose imparted. Here, we demonstrate realization of a new spectroscopic single particle reconstruction approach built on the ?single particle? method developed by structural biologists [1]. We apply this technique to the imaging of PtNi nanocatalysts and find new evidence of a complex inhomogeneous alloying with a Pt-rich core, a Ni-rich hollow octahedral intermediate shell and a Pt-rich rhombic dodecahedral skeleton framework with less Pt at ?100? vertices. The ability to gain evidence of local surface enrichment that varies with the crystallographic orientation of facets and vertices is expected to provide significant insight toward the development of nanoparticles for sensing, medical imaging, and catalysis. We also discuss recent advances in elemental characterisation of nanoparticles in liquids and gases using engineered graphene liquid cells [2] and in situ holders optimised for X-ray spectroscopy in situ. [1] Wang et al, Nano Lett., 2019, 19 (2), pp 732?738 DOI: 10.1021/acs.nanolett.8b03768 [2] Nano Lett., 2018, 18 (2), pp 1168?1174 DOI: 10.1021/acs.nanolett.7b04713

Q.6.1
11:30
Authors : R. Demoulin (1), M. Roussel (1) , S. Duguay (1), P. Pareige (1), E. Talbot (1), D. Muller (2), D. Mathiot (2), H. Rinnert (3)
Affiliations : (1) Groupe de Physique des Matériaux, Normandie Univ, UNIROUEN, INSA Rouen, CNRS, 76000 Rouen, France ; (2) ICube Laboratory, Université de Strasbourg, CNRS, B.P. 20, 67037 Strasbourg cedex, France ; (3) Institut Jean Lamour, Université de Lorraine, CNRS, 54011 Nancy cedex, France

Resume : Compared to bulk silicon, silicon nanocrystals (Si-ncs) show strong optical and electrical properties due to quantum confinement, making them suitable for a plenty of applications in optoelectronic. As in bulk silicon, a fine control of impurity doping allow to tune Si-ncs based devices for a specific use. Si-ncs can be synthesized from the decomposition of silicon supersaturated SiO2 film. In such host material, the properties of doped Si-ncs are determined by the effective location of impurities (in the core of Si-ncs, at the Si/SiO2 interface or in the surrounding matrix). If some studies have been carried out on theoretical structural description, only a few relate experimental results. In this work, a deep structural analysis of n (P, As) and p (B) doping of Si-ncs embedded in SiO2 elaborated using different elaboration process has been performed using Atom Probe Tomography. It allowed us to perform 3D mapping of these materials at the atomic scale to investigate the location of impurities and the Si clustering characteristics (size distribution, composition ?). We showed that n-type impurities are, in each cases, efficiently introduced in the core of every single Si-ncs allowing a high doping of Si-ncs. However, the comparison between As and P doping revealed a strong influence of the dopant nature on the Si-ncs growth. P-type doping seems much more complicated. In fact, B remain in majority in the matrix, but some Si-ncs still contain a low level of impurities.

Q.6.2
11:45
Authors : Zineb SAGHI(1), Martin JACOB(1), Julien SOREL(1,2), Thierry EPICIER(2), Pascale BAYLE-GUILLEMAUD(3)
Affiliations : (1) Univ. Grenoble Alpes, CEA-LETI, F-38000 Grenoble, France. (2) Univ. Lyon, INSA-Lyon, Université C. Bernard Lyon 1, MATEIS, UMR CNRS 5510, 69621 Villeurbanne Cedex, France. (3) Univ. Grenoble Alpes, CEA-INAC, MEM, F-38000 Grenoble, France.

Resume : Electron tomography is a 3D characterization technique that has greatly contributed to the understanding of materials at the nanometer level. Recently, the technique has been extended to spectroscopic signals such as electron energy loss spectroscopy (EELS) and X-ray energy dispersive spectroscopy (EDX), bringing valuable 3D information about the structure and chemistry of the nanomaterials. Using conventional spectral processing and reconstruction algorithms, these modes require: 1) long acquisition times, and hence electron doses, to acquire high signal-to-noise ratio spectra; and 2) a large number of spectrum images to faithfully reconstruct the structure in 3D. To avoid damaging the sample during the tomographic acquisition, it is necessary to explore advanced machine learning methods and reconstruction algorithms. Several decomposition methods have been successfully applied to EELS and EDX analysis, either for denoising or for dimensionality reduction. In parallel, recent advances in reconstruction algorithms, in particular the development of compressed sensing approaches, have allowed reliable 3D information to be extracted from heavily sub-sampled datasets. In this talk, we will present recent advances in both fields, and apply them to EELS and EDX tomography of various nanostructures.

Q.6.3
12:15 Lunch break    
 
Interaction between Nanoparticles and Molecules : Petra de Jongh
14:00
Authors : Claudia Zlotea, Abdelmalek Malouche, Wang Liu, Anna Celeste
Affiliations : Institut de Chimie et des Matériaux de Paris Est, CNRS-UPEC

Resume : It is well known that nanosizing significantly affects the physical properties of the matter. This is mainly explained by the fact that at the nanoscale the ratio between surface and bulk atoms is very high leading to a large atomic population at the surface with modified properties. Thus, the surface energy in the thermodynamic description cannot be longer ignored. For metal-hydride systems, the hydrogen solubility, the kinetics and the enthalpy of hydride formation can be modified by decreasing the particle size. Moreover, the surface reaction kinetics are enhanced and the reaction paths involving atomic diffusion within the particles are reduced, which allow very fast reaction rates. Accordingly, nanosizing gives the possibility to tailor both thermodynamic and kinetics properties. In this work, the interaction of hydrogen with Pd, Rh nanoparticles and Pd-Rh nanoalloys stabilized on different supports will be addressed as function of nanoparticle size from tens down to 1 nm. In contrast with bulk metal, Pd nanoparticles with 1 nm average size form solid solutions with hydrogen at standard conditions. The case of Rh is also interesting since bulk metal does not form a hydride phase at standard conditions, whereas Rh nanoparticles with sizes below 2 nm absorb hydrogen forming a hydride phase. Finally, the interaction of Pd and Rh nanoparticles with hydrogen has important consequences on the catalytic performances in several reactions involving hydrogen.

Q.7.1
14:30
Authors : Petra H. Keijzer, Lee J. Durndell, Baira Donoeva, Jovana Ze?evi?, Krijn P. de Jong, Petra E. de Jongh
Affiliations : Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands

Resume : Silver catalysts are industrially used amongst others to produce formaldehyde from methanol, and for the epoxidation of ethylene to ethylene oxide [1]. Moreover, silver has promising catalytic properties for the selective hydrogenation of ?,?-unsaturated aldehydes [2]. Supported silver catalysts are generally synthesized using precipitation or impregnation routes. In this work, we explore melt infiltration as an alternative technique: we heat a physical mixture of silver nitrate and a porous support above the melting point of silver nitrate, which then enters the pores as a result of capillary forces. This strategy allows high metal loadings and eliminates the need for a solvent [3], but challenges arise regarding control over the silver particle size and distribution. The narrow pore size distribution of the chosen ordered mesoporous silica support, SBA-15, allowed us to follow the infiltration process of the silver nitrate in situ, and study its subsequent decomposition to form metallic silver. By varying the decomposition conditions (temperature and atmosphere), we attained either silver nanowires or small spherical silver particles inside the mesopores of the SBA-15. We show the synthesis of either supported silver nanowires or spherical particles, and their application in the hydrogenation of cinnamaldehyde. 1. M. O. Ozbek, I. Onal, R. A. van Santen, J. Catal., 284, 230?235 (2011) 2. P. Claus, H. Hofmeister, J. Phys. Chem. B, 103, 2766-2775 (1999) 3. P. E. de Jongh, T. M. Eggenhuisen, Adv. Mater., 25, 6672?6690 (2013)

Q.7.2
15:00
Authors : Elodie Disa (a), Léa Doubtsof (a), Katia Guérin (a), Christine Taviot-Guého (a), David Bourgogne (a), Antoine Moreau (b), Angélique Bousquet (a), Guillaume Rogez (c) and Pierre Bonnet (a)
Affiliations : (a): Institut de Chimie de Clermont-Ferrand, Université Clermont Auvergne / CNRS / Sigma Clermont - France (b): Institut Pascal, Université Clermont Auvergne / CNRS / Sigma Clermont - France (c) : Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg / CNRS - France

Resume : In this study, we present the conversion of metallic Ni nanoparticles into NiF2 through fluorination under pure molecular fluorine F2. For such purpose, Ni nanoparticles of median diameter of 50 nm were purchased and fluorinated at temperatures ranged in between room temperature and 450°C. It was then possible to get different proportions of NiF2 shell onto Ni core. The structure of Ni-doped NiF2 was investigated by X-ray diffraction (XRD) and Pair Distribution Function (PDF) and the texture by transmission electron microscopy (MET) and magnetic force microscopy (MFM). The proportion of NiF2 and Ni phases and the fluorination mechanisms change depending the fluorination temperature, then it appears possible to tune the stoichiometry of the material by the control of this parameter. Structural data obtained by XRD and PDF, but also TEM pictures, show first the progressive formation of a thin and continuous NiF2 shell until 250°C, the initial spherical shape is preserved but only a third of Ni can be converted into NiF2. Increasing the fluorination temperature leads to damages into the shell and affects the spherical shape. Finally, at the highest temperature, the total conversion of Ni into NiF2 can then be obtained and agglomerated NiF2 nanoparticles are obtained. The properties of such materials depend strongly of the Ni/NiF2 composition but also of its nanostructuration and the interfaces. So, in this presentation, we will present how the electronic, optical and magnetic properties can be adjusted by a judicious choice of the synthesis parameter set (among them the fluorination temperature) and we will underline the advantages of syntheses by gas-solid fluorination. Some applications as lithium batteries, magnetism will be discussed.

Q.7.3
15:15
Authors : Kai Sellschopp (1), Johannes Gäding (1), Wolfgang Heckel (1), Clemens Schröter (2), Andreas Hensel (2), Tobias Vossmeyer (2), Horst Weller (2), Stefan Müller (1), Gregor B. V. Feldbauer (1)
Affiliations : (1) Institute of Advanced Ceramics, Hamburg University of Technology; (2) Institute of Physical Chemistry, University of Hamburg

Resume : Titania (TiO2) nanoparticles can be applied as photo-catalyst, as a protection from UV irradiation in sunscreen, or as the hard component in hybrid materials. The reactivity of titania nanoparticles and the mechanical properties of hybrid materials is influenced by the particle shape to a large extend. During aqueous and non-aqueous synthesis the shape can be controlled adjusting the concentration of the different components in the solution, namely hydrohalic acids, carboxylic acids, and amines. Fluoric acid, for example, is known to stabilize platelet shaped particles, whereas amines stabilize a rod-like shape. From the theoretical point of view the stabilization mechanism of fluoride is well understood. The influence of amines, halides other than fluoride, and carboxylic acids on the particle shape, however, is less studied and not understood so far. Here, results from DFT calculations on the adsorption of these components at the dominant titania surfaces are presented. The space of possible adsorption configurations is sampled exhaustively to find the most stable structures. The nanoparticle shape at different thermodynamic conditions is predicted using the Wulff construction. For the hydrohalic and carboxylic acids theoretical and experimental particle shapes agree very well, but except for fluoride only bi-pyramidal particles are observed. On the other hand, the results for the amines show that the explanation of rod shaped particles is not that simple.

Q.7.4
15:30 Coffee break    
 
(photo)electrochemical applications : Andrea Baldi
16:00
Authors : Taneli Rajala, Rasmus Kronberg, Kari Laasonen, Tanja Kallio
Affiliations : Department of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, P.O. Box 16100, FI-00076 Aalto, Finland

Resume : Solar and wind based energy supply will increase by more than one decade by the year 2040, which lays foundation for the hydrogen economy concept where hydrogen serves as an energy carrier. Hydrogen utilization requires, however, introduction of efficient, durable and economically feasible electrochemical conversion of electrical energy into hydrogen bond energy. Electrochemical water splitting can meet these expectations if its key components, electrocatalysts, can be improved. Today scarce platinum group metals (PGMs) are utilized to electrocatalyze the hydrogen evolution reaction. In addition to PGM availability and cost issues, these electrocatalysts suffer from inadequate durability because of the altering operation conditions. Single-walled carbon nanotubes (SWNTs) have several beneficial properties needed for electrochemical applications: high conductivity, good chemical and electrochemical durability and appropriate properties for fabricating 3D electrodes. Here, the unique morphology of SWNTs contributes to achieve material with ultra-low loadings Pt nanowires (PtNW). The high activity and excellent durability is attributed to favorable PtNW interaction with the SWNTs as well as exposed PtNW edge-sites which adsorb hydrogen optimally and help to alleviate repulsive interactions on the nanowire surface. In addition, the metallic nature of Pt, morphological effects and enhanced surface wetting contribute positively to the performance.

Q.8.1
16:30
Authors : M. Monte[1,#], A. López Cámara[1], C.L. Bolívar-Díaz[1], D. Costa[2], J.C. Conesa[1], P. Pérez-Bailac[1], V. Cortés-Corberán[1], A. Martínez-Arias[1]
Affiliations : [1] Inst.de Catálisis y Petroleoquímica, CSIC, Madrid (Spain); [2] Inst. de Recherches Chimie-Paris, ENSCP, Paris (France); [#] Present address: ESRF, Grenoble (France)

Resume : CuOx/CeO2 catalysts are active in the preferential CO oxidation (CO-PROX) and water gas shift (WGS) reactions. For the first we found that their selectivity to get CO2, not H2O, improves if CuOx lies on CeO2 nanocubes (NCs) exposing (001) faces, instead of lying on ceria nanospheres (NSs). DFT calculations show a stronger CuOx-CeO2 interaction on (001) faces, stabilizing Cu cations against reduction. This explains the better selectivity as Cu(0) is known to be the phase activating H2. Operando DRIFTS shows that if Cu lies on NCs Cu+ carbonyls remain to higher temperature than on NSs or nanorods (NRs), correlating with the high selectivity. Synchrotron XPS data show that heating in dry O2 spreads CuO on NCs (a wetting effect) but not on NSs. XAFS data in same conditions show, for samples with same Cu surface load, more distinct next-nearest neighbours around Cu on the NC sample, agreeing also with the stronger interaction predicted by DFT. Finally, NEXAFS data show that under CO the NC-supported sample resists reduction better than the NS-supported sample, agreeing with the DFT predictions. XPS data in these experiments show also for CuOx on NSs Cu(2p) peaks at unusual positions; DFT models suggest this may be due to Cu+ with higher O coordination at the CuOx-CeO2 interface. We started also studies on CeO2 shape effects in Ni/CeO2 catalysts used in ethanol steam reforming, observing again differences in selectivity towards several products depending on the nanoceria particle shape.

Q.8.2
16:45
Authors : Fatemeh S. M. Hashemi 1, Fabio Grillo 1, Vikram R. Ravikumar 1, Dominik Benz 1, Ankit Shekhar 1, Matthew B. E. Griffiths 2, Sea?n T. Barry 2 and J. Ruud van Ommen 1.
Affiliations : 1 Department of Chemical Engineering, Delft University of Technology, The Netherlands. 2 Department of Chemistry, Carleton University, Canada.

Resume : Nanoparticles of Au supported on TiO2 have various applications in photocatalysis, plasmonics and photovoltaics. These supported materials are commonly synthesized using liquid-based techniques such as sol-gel and deposition-precipitation. These methods, while being low-cost, result in a high level of impurities and formation of Au particles with inhomogeneous size and composition. Here we present a vapor-based approach via atomic layer deposition (ALD) for controlled deposition of Au nanoparticles on TiO2. We also use the designed structures for photocatalytic degradation of pollutants. We perform a low temperature thermal ALD process using Trimethylphosphino-trimethylgold (III) and two oxidizers (ozone and water) in a fluidized bed reactor under atmospheric pressure condition. We show the effects of Au precursor saturation and oxidizing reactants on controlling the nucleation, particle size distribution and composition of the Au nanoparticles. We also investigated the effects of Au loading and particle size on the photocatalytic activity of Au/TiO2 nanoparticles. Our studies suggest that the oxidizers have an opposite effect on Au particle size distribution. A threefold enhancement in the photocatalytic activity of TiO2 is achieved when Au/TiO2 nanoparticles are used for degrading pollutants. This all vapor process provides a highly controlled and efficient method for producing Au/TiO2 particulates that meet the criteria for various applications.

Q.8.3
17:00
Authors : Agata Krywko-Cendrowska, Laurent Marot, Fouzia Boulmedais
Affiliations : Univeristy of Strasbourg, CNRS, Institut Charles Sadron UPR 22, 67000 Strasbourg, France; Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland; Univeristy of Strasbourg, CNRS, Institut Charles Sadron UPR 22, 67000 Strasbourg, France

Resume : Silver nanoparticles (AgNPs) have been attracting an increasing interest in the development of electrochemical sensors due to their high electrical conductivity and ability to the enhance the electron transfer between the sensor and the electrode. In this work we present a novel ionically-imprinted thin sensor film based on tannic acid, TA, and Ag NPs, which was tailor-designed for voltammetric tracing of aluminum ions, Al(III), in biological fluid. In the first stage, AgNPs were presynthesized via direct reduction of Ag(I) by TA resulting in tannic acid-stabilized AgNPs of size ranging between 2 and 10 nm, as observed by dynamic light scattering and transmission electron microscopy. In the following step, the Al(III) ions were added to the mixture to complex the TA molecules adsorbed on AgNPs and an anodic potential was applied to self-assemble the (TA@AgNPs) ? Al (III) complexes into a thin film on the surface of ITO electrode. The Al(III) ions imprinted on the surface of the film, were then chemically removed from the film, as monitored by cyclic voltammetry and X-ray photoelectron spectroscopy, creating vacancies ready to bind the Al(III) ions present in the analyzed fluid. The obtained film was employed for sensing of Al3 present in bovine serum. A correlation between the current value of TA-Al(III) CV peak and the concentration of Al(III) in the range corresponding to aluminum levels for a healthy individual, from 0 to 6 µg/L, was obtained. Incorporation of AgNPs resulted in an improved sensitivity of the film by three orders in magnitude in the measured Al(III) concentration.

Q.8.4
17:15
Authors : Mantas Sriubas1, Tomas Bartnikas1, Vytautas Kavali?nas1,3, Kristina Bo?kut?1, Paulius Palevi?ius2, Marius Kaminskas1, ?ilvinas Rinkevi?ius1,4, Minvydas Ragulskis2, Giedrius Laukaitis1
Affiliations : 1 Kaunas University of Technology, Physics Department, Studentu str. 50, LT-51368, Kaunas, Lithuania; 2 Kaunas University of Technology, Department of Mathematical Modeling, Studentu str. 50, LT-51368, Kaunas, Lithuania; 3 Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-Ku, Hamamatsu, Shizuoka 432-8011, Japan ; 4 Division of Theoretical Chemistry &Biology, School of Biotechnology, KTH Royal Institute of Technology, 109 61 Stockholm, Sweden;

Resume : The deposition of transition-metal nanoparticles on various oxide materials is a topic of interest due to its optical, plasmonic, and catalytical properties. The size and distribution density influence these properties. Thus, it is important to be able to form metal clusters of desired characteristics. In this work, magnetron sputtering technique is suggested to use due to the ability to control deposition parameters easily. TiO2 thin films of 200 nm thickness were deposited on room temperature (20 ºC) SiO2 substrates from two Ti targets using reactive magnetron sputtering technique. Subsequently, thin films (5 nm and 10 nm) of copper, magnesium, and nickel were formed on TiO2 thin films and Si substrates in Ar environment using the magnetron sputtering method. After deposition, metal/TiO2 thin films and metal/Si were annealed at 300 ºC, 350 ºC, 400 ºC, 450 ºC, and 500 ºC temperatures in N2 atmosphere for 1.5 h to form nanoclusters. The distribution of nanoclusters was investigated by scanning electron microscope. Different distribution of nanoclusters was observed depending on substrate type, annealing temperature, and thickness of the metal thin film. The higher density of metal nanoclusters was obtained on Si substrates due to the lower surface energy of Si in comparison to TiO2 thin films. Funding: This project has received funding from European Social Fund (project No 09.3.3-LMT-K-712-01-0162) under grant agreement with the Research Council of Lithuania (LMTLT).

Q.8.5
 
Poster Session II: Characterization and Application : Patricia Abellan and Petra de Jongh
17:30
Authors : Jatani U, Dejene B.F
Affiliations : Department of Physics, University of the Free State (QwaQwa Campus), Private Bag X13, Phuthaditjhaba, 9866, South Africa.

Resume : ZnO nanoparticles were synthesized using sol-gel method. The influence of the annealing temperature on the structural, morphological and optical properties of ZnO nanoparticles is studied. The properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL), Uv-Vis spectroscopy and EDS. XRD analysis demonstrates that the crystallinity of ZnO is improved with annealing for all growth temperatures selected (45, 55 and 65 °C) as indicated by narrower and more intensified diffraction intensities of the annealed ZnO compared to that of the as prepared particles. The average crystallite sizes of the ZnO particles increased from 29.9 nm to 33.3 nm with annealing indicating the tendency of large grain growth in the nanoparticles due to annealing. SEM micrographs showed that annealed ZnO nanoparticles aggregated and became larger in diameter compared to its as prepared counterparts. The EDS analyses, for as prepared and annealed samples indicate the purity of all the synthesized samples with no peaks other than Zn and O. The photoluminescence peak intensity ratios of ultraviolet to that of visible emission (UVPL/ VisPL) are found to increase on annealing. The UVPL/ VisPL intensities ratio range between 0.9-2.4 for the as prepared samples and 5.0-7.1 for annealed samples. Quenching of visible emission on annealing is known to be responsible for this. The red shift in both the visible and UV emission with increasing particle size due to annealing closely follows the red shift in the band edge emission, indicating that the two complement each other. The average band gap is observed to decrease from 3.25 eV to 3.22 eV with the increase in crystallite sizes occasioned by annealing. Keywords: ZnO; Nanoparticles; Sol-gel; Growth temperature, Structure, Luminescence

Q.PII.1
17:30
Authors : Adil Alshoaibi, Osama Saber
Affiliations : Physics Department, Faculty of Science, King Faisal University, Al-Hassa 31982, P.O. Box 400, Saudi Arabia Email: adshoaibi@kfu.edu.sa, +966-506933370

Resume : Zinc oxide has been shown to be suitable for many advanced applications such as water purification and solar cells. In this trend, different nanostructures of ZnO were prepared by intercalation of carbon nanotubes inside Zn-Al nanohybrid. This nanohybrid was formed through intercalation of long chain of fatty acid C18 H38 inside Zn-Al layered double hydroxides. X-ray diffraction of the interlayered spacing of Zn-Al LDH increased from 0.75 nm to 2.1 nm after intercalation with CNTs and the organic fatty acid forming CNTs-C18H38-Zn-Al nanohybrid. By treatment of the nanohybrid at high pressure and temperature, different sizes of the doped zinc oxides nanoparticles and zinc aluminum oxides nanocomposites were produced. The doped zinc oxides nanoparticles have symmetrical spherical shape with 10 nm in diameter. Zinc aluminum oxides nanocomposites have large particles with 100 nm in diameter. According to the nano size and structures, the band gap energy of these products changed from 1.8 eV to 3.2 eV to produce effective photocatalysts. Purification of water was achieved through complete decolorization and mineralization of the green pollutants from water after 176 min of irradiation of UV light using the doped zinc oxide. In case of using the nanocomposites, the green dye was completely removed after 355 min. Comparing with the results of the doped zinc oxide which prepared by usual method, these nanomaterials were very effective because water purification was achieved in a shorter time. Finally, the experimental results concluded that nanohybrids have positive impact to create effective nanoparticles for water purification using light. Biography: Adil is Chairman of Physics Department and Chairman of Mathematics and Statistics Department at King Faisal University in Saudi Arabia. Adil received his PhD in 2017 from University of Sheffield, UK from Department of Materials Science and Engineering. Adil's research is a blend of the Chemistry, Physics and Engineering of Inorganic Materials, especially oxides, which focuses on materials with interesting and/or useful electrical properties, especially ionic conductors, mixed ionic/electronic conductors, semiconductors, ferro- and di-electrics.

Q.PII.2
17:30
Authors : Fangyuan Ren, Xiaowei Yin
Affiliations : Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University

Resume : In order to optimize the dielectric performance of polymer derived SiCN ceramics (PDCs-SiCN), carbon nanowires (CNW) were deposited in SiCN by catalytic chemical vapor deposition. Microstructure evolutions, dielectric property and electromagnetic (EM) wave absorption capacity of CNW/SiCN were investigated. Results show that carbon nanowires had plentiful defects on their roughened surface and formed hierarchical network in SiCN which benefited the impedance match and generated strong conductivity and polarization loss, enhancing the absorption ability of CNW/SiCN. When CNW accounted for 5.61wt%, minimum reflection coefficient reached -51 dB with EAB of 3.0 GHz at 2.7 mm in thick, showing excellent microwave absorbing performance. The favorable microwave absorption ability could be ascribed to three aspects including enhanced conductivity loss derived from the excellent conductivity of CNW, polarization loss generated by defects, and multiple reflection loss enhanced by hierarchical network. By comparing the variation tendency between defect concentration and electrical conductivity in CNW/SiCN, it is rational to conclude that the conductivity loss dominated the dielectric loss while the polarization loss and repeated multi-reflection simultaneously worked. We have already proceeded to a study regarding the effect of heat-treatment temperature since CNW have the potential to promote the crystallization process of amorphous PDCs thereby improving their dielectric properties.

Q.PII.3
17:30
Authors : N.A. Liedienov1,2, A.V. Pashchenko1,2,3, Q. Li1, I.V. Fesych4, I.V. Zatovskyi5, A.V. Voznyak3, V.K. Prokopenko2, V.G. Pitsyuga6, G.G. Levchenko1,2
Affiliations : 1 State Key Laboratory of Superhard Materials, International Centre of Future Science of Jilin University, 130012 Changchun, China 2 Donetsk Institute for Physics and Engineering named after O. O. Galkin, NASU, 03028 Kyiv, Ukraine 3 Donetsk National University of Economy and Trade named after Michael Tugan - Baranovsky, MESU, 50005 Kryvyi Rih, Ukraine 4 Taras Shevchenko National University of Kyiv, 01030 Kyiv, Ukraine 5 College of Physics of Jilin University, 130012 Changchun, China 6 Vasyl? Stus Donetsk National University, 21021 Vinnytsia, Ukraine

Resume : Phase composition, structure, morphology, and magnetic properties of La0.6Ag0.2Mn1.2O3-? nanopowder were investigated using XRD, SEM, TEM, and magnetic methods. Magnetic nanoparticles (MNPs) of La0.6Ag0.2Mn1.2O3-? were synthesized using a nitrate pyrolysis method. MNPs have a spherical shape and are single-phase with a rhombohedral R-3c type of perovskite structure distortion. The size distribution function of MNPs is LogNormal Distribution with an average MNP size < d> = 68 ± 2 nm. On the basis of the magnetic properties analysis, average magnetic moment of manganese ? = 4.61 ?B, Curie temperature ?? = 312 ?, saturation magnetization MS = 426.8 emu/cm3, effective anisotropy constant Keff = 7123 erg/cm3, magneto-crystalline anisotropy constant K1 = 2.522?104 erg/cm3 for each MNP, exchange constant A = 3.47?10-7 erg/cm were determined. It was concluded that La0.6Ag0.2Mn1.2O3-? refers to magnetically soft material with magnetic hardness parameter k = 0.022 < < 1. The critical sizes of single-domain state (d ? 40 nm), vortex state (40 ? d ? 67 nm), and multi-domain state (d ? 67 nm) were calculated. In the narrow temperature range ?TC = 4 K near TC, giant magnetocaloric effect was detected. The absence of coercivity above blocking temperature ?? = 301 ? and the large magnetocaloric effect in weak magnetic fields H = 200?500 Oe allow to use La0.6Ag0.2Mn1.2O3-? nanopowder in intelligent hyperthermia control systems with automatic temperature stabilization within 39?43 °? range.

Q.PII.4
17:30
Authors : Nam-Woon Kim1, Dong-Kyu Lee2, and Hyunung Yu1
Affiliations : 1 Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Republic of Korea; 2 Chungbuk National University (CBNU), Cheongju 28644, Republic of Korea

Resume : Metal oxide such as ZnO and TiO2 are widely utilized in chemical sensors and photocatalysts for their redox properties related to the electron-hole pair on the metal oxide surface with analyte species. To enhance these properties, it is necessary to reduce the particle size and increase the active area. Cerium oxide is a good material for this purpose including catalysts, sensors, electrochemistry, batteries and energy storages. This study reports very efficient preparation of monodisperse cerium oxide nanorods through simple hydrothermal synthesis. Our synthetic route of cerium oxide nanorods is highly dependent on the reaction time and found to be 10 minutes for the optimum condition. The cerium oxide nanorods are further converted into nanospheres by the spontaneous assembly of cerium oxide nanoparticles onto nanorods. The TEM result shows that the nanorods are grown with high crystallinity in the < 110> direction. The cerium oxide nanorods show the growth process of the Ostwald ripening phenomenon. The cerium oxide nanorods prove to be very efficient electron mediators for use as excellent photocatalytic materials and highly sensitive chemical sensors. The chemical sensor fabricated on a carbon paper substrate shows a high sensitivity of 1.81 ?A mM-1 cm-2 and a detection limit of 6.4 ?M with a correlation coefficient of 0.950. As a result of comparing the selectivity of methanol and acetone as a chemical sensor, the selectivity of acetone is found to be very high.

Q.PII.6
17:30
Authors : Hameed Ullah (1)(2), Kabeer Ahmad Khan (2), Guerin Katia (1), Guillaume Rogez (3), Pierre Bonnet (1)
Affiliations : (1) Institut de Chimie de Clermont-Ferrand, Université Clermont Auvergne / CNRS / Sigma Clermont - France ; (2) Department of Chemistry, Hazara University - Pakistan (3) Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg / CNRS - France

Resume : Metal fluorides present many applications in sensors, batteries, actuators or optical devices. Many methods have been developed for synthesis of metal fluorides nanoparticles and their self-assembly. Among them, microemulsion method is exploited for the preparations of metal fluoride nanostructures, like self-assembled YF3 nanoparticles or BaF2 nanoparticles. Here our attention is paid to the synthesis of MnF2/MnF3 and NiF2 nanoparticles. These materials are attracting attention as conversion reaction material for Li ion batteries due to their specific capacities (554 mAh/g for NiF2 and 577 mAh/g for MnF2), and the electrochemical performance of these nanomaterials could be improved by engineering self-assemblies. In addition, the magnetic properties are also interesting, and could be modified by nanostructuration. In this talk, we present the synthesis of hydrated fluoride nanoparticles which self assembles into truncated bipyramidal structures by reverse microemulsion. The self-assemblies of nanoparticles into theses architectures are controlled by varying the reaction time and water to surfactant ratios. Few examples of nanostructuration of MnF2 and NiF2 are given in the literature. An important drawback is the formation of hydrated compounds, and the dehydration of the resulting nanomaterials remains difficult. Here, we come up with a new strategy to synthesize anhydrous fluoride nanoparticles and their self-assemblies. Hydrated materials are transformed to dehydrated ones under F2 and the self-assemblies of nanoparticles are successfully retained. The Electrochemical and magnetic properties of resulting nanomaterials have been studied.

Q.PI.7
17:30
Authors : C.S. Cojocaru b, A.L. Danilyuk a, A.V. Kukharev a, S.L. Prischepa a, c, F. Le Normand b
Affiliations : a Belarusian State University of Informatics and Radioelectronics, P. Browka 6, Minsk, 220013, Belarus b Institut de Physique et Chimie des Mat_eriaux (IPCMS), CNRS-University of Strasbourg, BP 43, 67034, Strasbourg Cedex 2, France c National Research Nuclear University (MEPhI), Kashirskoe Highway 31, Moscow, 115409, Russia

Resume : We investigate the influence of carbon nanotubes (CNT) aligned array on the magnetic properties of ensemble of densely packed Co nanoparticles (NPs) embedded inside CNT. Each CNT contains only one nanosized Co. Such a special structure was formed by catalyst chemical vapor deposition (CCVD) activated by current discharge plasma and hot filament. The Co NPs, previously deposited onto SiO2/Si substrate, acted as a catalyst. By varying the parameters of the CCVD process, we were able to also sputter the substrate instead of CNT growth. Co NPs were used as a mask and the structure of Si-based nanocones with Co NPs on the top of each cone was formed. Exhaustive investigation of the structural, morphology and crystalline properties of Co nanoparticles were performed. The magnetic properties of two kinds of samples, Co on the Si-based nanocones and Co inside CNTs, differ drastically. In the former case, the magnetic anisotropy of thin-film-type has been observed with large magnetic domains. Whereas for the Co-CNT samples ferromagnetic NPs were magnetically isolated. It was established that the magnetic anisotropy of nanosized Co plays more dominant role than the dipole interaction between Co NPs (1). The role of the CNT container in this is investigated. (1) ?Impact of aligned CNT nanotubes array on the magnetostatic isolation of closely packed ferromagnetic nanoparticles.? Danilyuk A.L., Kukharev A.V., Cojocaru C.S., Le Normand F., Prischepa S.L Carbon, 139 (2018) 1104-1116 with SI

Q.PII.9
17:30
Authors : Chutima Kongvarhodom, Pannarai Jetsadangkool, Kittima Khumsa-Ang
Affiliations : Department of Chemical Engineering, Faculty of Engineering, King Mongkut?s University of Technology Thonburi, Bangkok 10140, Thailand; Department of Chemical Engineering, Faculty of Engineering, King Mongkut?s University of Technology Thonburi, Bangkok 10140, Thailand; Canadian Nuclear Laboratories, Ontario K0J 1J0, Canada

Resume : The present study investigated the influence of microstructures on the electrochemical response of Cu-Ni alloys in Sodium Chloride solution. The Cu-Ni alloy thin films were fabricated on silicon substrates by magnetron sputtering. The X-ray diffraction (XRD) analysis and surface characterization with a scanning electron microscope (SEM) revealed that microstructures including preferred orientation of the [111] direction along the surface normal and mean crystallite size were influenced from the deposition pressure and the sputtering power. The electrochemical behaviors of these deposited films were examined by potentiodynamic polarization in 3.5 wt.% Sodium Chloride solution. Potentiodynamic polarization plots demonstrated that the corrosion current densities of deposited films were found to be related to microstructures. It could be explained by the compact morphology of the Cu-Ni alloy thin films affecting the dissolution rate, the access of corrosive species to the film and the passive layers formation on deposited films. This phenomenon which is in the context of microstructures and electrochemical behaviors of metallic alloy of Cu-Ni in chloride media indicates several interesting and fundamental relationships.

Q.PII.10
17:30
Authors : Bora Kang, Hong-Gu Jeon, Song-Ho Byeon
Affiliations : Department of Applied Chemistry, Kyung Hee University, Korea

Resume : Cu2+, which is readily absorbed in the human body from nature, is essential for human life and health, whereas it can cause neurotoxicity known as Wilson?s disease at higher concentrations. Therefore, the development of convenient detection and removal methods is of importance to monitor and maintain Cu2+ concentrations in environmental waters at lower than limited levels. Recently, we demonstrated that Cu2+ ions are readily adsorbed at the surface of GdVO4:Eu nanoparticles (NPs) in aqueous media and that (trace amounts of) Cu2+ can filter the emitted light to quench the fluorescence of GdVO4:Eu. Because such a filter effect can effectively occur only if the absorption band of the metal ion is complementarily overlapped with the emission bands of GdVO4:Eu, highly selective and sensitive fluorescence quenching can be achieved by the Cu2+ ion adsorption. To improve the efficiency and convenience of Cu2+ removal from environmental waters, a tailoring technique has been developed to construct a recyclable film covered with YVO4:Eu NPs. Thus, the film of Eu3+-doped layered yttrium hydroxide (LYH:Eu) nanosheets was directly grown on the slide glass substrate using the chemical bath deposition technique, where LYH:Eu sheets are preferably oriented perpendicular to the substrate surface. The as-prepared films have the microscale hierarchical surfaces composed of LYH sheets. YVO4:Eu nanoparticles were then tailored at the edge of LYH:Eu nanosheet in an aqueous Na3VO4 solution. This tailoring method can immobilize NPs to keep from aggregating. The luminescence quenching of YVO4:Eu NPs by the filter effect of adsorbed Cu2+ ions was useful for the luminescent ?turn-off? adsorbent film for Cu2+ ions. The tailor-made films in the present work exhibited a high performance and satisfactory practicability and recyclability for detecting and removing Cu2+ ions.

Q.PII.11
17:30
Authors : Mika Kawai, Tetsu Mitsumata
Affiliations : Mika Kawai, Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan, ALCA, Japan Science and Technology Agency, Tokyo 102-0076, Japan: Tetsu Mitsumata, Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan, ALCA, Japan Science and Technology Agency, Tokyo 102-0076, Japan

Resume : Polymer gel containing magnetic particles is a stimuli-responsive gel that viscoelastic properties can be controlled by applying magnetic fields. We have fabricated magnetoelastic soft materials with various polymer matrices thus far, and succeeded to fabricate a magnetic hydrogel that demonstrates drastic and reversible changes in dynamic modulus without using strong magnetic fields. The magnetic hydrogel exhibits drastic changes in storage modulus even at high modulus. At zero magnetic field, the storage modulus for magnetic gel is low with an order of ~104 Pa although the gel contains large amount of particles (volume fraction ~0.30), indicating the random dispersion of magnetic particles. Magnetic particles align to the magnetic lines of force and form a chain structure under magnetic fields, resulting in high storage modulus exceeding 4 MPa. In this paper, we present the magnetic response of storage modulus, morphological changes by magnetic fields, and the interaction between carrageenan and magnetic particles. The origin of significant magnetorheological effect for carrageenan magnetic gels is discussed.

Q.PII.12
17:30
Authors : Azmira Jannat, Jian Zhen Ou
Affiliations : School of Engineering, RMIT University, Melbourne, Australia

Resume : Nitrogen dioxide (NO2) is a gas species that play a vital role in particular industrial, farming, and healthcare sectors. However, there are still significant challenges for NO2 sensing at low detection limits, especially in the presence of other interfering gases. The NO2 selectivity of current gas-sensing technologies is significantly traded-off with their sensitivity and reversibility as well as fabrication and operating costs [1-5]. In this work, we present essential progress for selective and reversible NO2 sensing by demonstrating an economic sensing platform based on the charge transfer between physisorbed NO2 gas molecules and two-dimensional (2D) tin sulfide (SnS) flakes at room temperature. An extraordinary response factor of ~36 is demonstrated to ultralow 150 parts per billion (ppb) NO2 at room temperature, within the physisorption temperature bands for SnS. The device shows high sensitivity and superior selectivity to NO2 at operating temperatures of less than 140o C, which are well below those of chemisorptive and ion conductive NO2 sensors with much more low selectivity [5-8]. The demonstrated 2D SnS based sensing device holds the most significant potential for producing future commercial low-cost, sensitive, and selective NO2 gas sensors.

Q.PII.13
17:30
Authors : P Natarajan,[a], A Shalabny, [a], S Sadhujan, [a], A Idlibi, [a] M Y Bashouti [a],[b],*
Affiliations : [a] Department of Solar Energy and Environmental Physics, Swiss Institute for Dryland Environmental and Energy Research, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshset Ben-Gurion 8499000, Israel. [b] The IlSe-Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beersheva, 8410501, Israel. ? P Natarajan and A Shalabny are equally contributed.

Resume : Anisotropic synthesis of two-dimensional (2D) monocrystalline Au flakes attracts significant interest due to its importance toward the future development of optical nanocircuitry for high-speed communication and quantum computation applications. In this study, 2D Au microplates were synthesized by seedless aniline assisted polyol reduction with anisotropic control of the polyaniline oxidation states (PAOS) that form in-situ. Three different PAOS were identified by a novel algorithm based on subtraction deconvolution of UV-vis spectra: A (372 nm), B (680 nm), and C (530 nm). Time-dependent UV-Vis Spectra and SEM images of Au nanostructures showed that PAOS controls the 2D flake shape, size, and crystallization parameters. Different growth regimes associated with relevant growth mechanism (protonation, deprotonation and thermal decomposition) were resolved. Specifically, we found that state A is responsible for the nucleation of gold from the AuCl4- solution (region i), state B is responsible for the aggregation of the nucleation sites (region ii), and state C is responsible for the 2D shape of the microplate and for the control of Au monocrystalline flake growth (region iii). We used a time-resolved deconvolution model for the solution-growth of nanomaterials, which accurately describes the charge transitions (intra and inter transitions) and growth regimes by effective permittivity parameter in solutions. In terms of the development of a basic understanding of PAOS, deconvolution, and Au flake formation, our approach and our promising results provide inspiration for anisotropic investigations of other metals and their syntheses with desired properties and monocrystallinity for optoelectronic applications.

Q.PII.14
17:30
Authors : Mei-Hwa Lee1, Cheng-Chih Lin?, Chih-Kai Chan3 and Hung-Yin Lin3,*
Affiliations : 1Department of Materials Science and Engineering, I-Shou University, Kaohsiung 84001, Taiwan; ?Division of Pulmonary Medicine, Department of Internal Medicine, Armed-Forces Zuoying General Hospital, Kaohsiung 81342, Taiwan; 3Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81148, Taiwan

Resume : Induced pluripotent stem cells (iPSCs) are typically derived by reprogramming factors, eg. Oct4, Sox2, cMyc and Klf4. However, the genomic integration of the transcription factors may have the risk of mutations being inserted into the target cell?s genome. Recently, clustered regularly interspaced short palindromic repeats associated protein 9 (CRISPR/Cas9) system has been employed to edit genomes. In this work, the molecular imprinting of peptide on chitosan is optimized with various imprinting template or chitosan concentrations. These magnetic peptide-imprinted chitosan nanoparticles (MPIC NPs) are then characterized by dynamic light scattering (DLS), high performance liquid chromatography (HPLC), Brunauer-Emmett-Teller (BET) and superconducting quantum interference device (SQUID) analysis. Finally, mutated clustered regularly interspaced short palindromic repeats associated protein 9 (CRISPR/dCas9) without endonuclease activity is produced by the transfection of plasmid to HEK293T cells. The adsorption of dCas9 protein are monitored by both total protein kits and Cas9 staining. These MPIC NPs are employed to deliver the dCas9 nuclease complexed with a synthetic guide RNA (gRNA) into HEK293T cells to activate their Oct4 gene expression, which are examined by quantitative real-time polymerase chain reaction (qRT-PCR) and staining of Oct4 and Cas9. ACKNOWLEDGEMENTS: We appreciate financial supports from Ministry of Science and Technology of ROC under Contract nos. MOST 106-2221-E-390 -013 -MY3, MOST 106-2314-B-390 -001 -MY2 and MOST 107-2923-M-390 -001 -MY3. REFERENCES: 1. M.-H. Lee, C.-C. Leu, C.-C. Lin, Y.-F. Tseng, H.-Y. Lin* and C.-N. Yang*, Gold-decorated magnetic nanoparticles modified with hairpin-shaped DNA for fluorometric discrimination of single-base mismatch DNA, Microchimica Acta, 186:80 (2019) 2. M.-H. Lee, J. L. Thomas, C.-L. Liao, S. Jurcevic, T. Crnogorac-Jurcevic and H.-Y. Lin*, Epitope Recognition of Peptide-imprinted Polymers for Regenerating Protein 1 (REG1), Separation and Purification Technology, 192, 213-219 (2018) 3. M.-H. Lee, J. L. Thomas, J.-Z. Chen, J.-S. Jan and H.-Y. Lin*, Activation of Tumor Suppressor p53 Gene Expression by Magnetic Thymine-imprinted Chitosan Nanoparticles, Chemical Communications, 52, 2137-2140 (2016) 4. M.-H. Lee, J. L. Thomas, Y.-C. Chen, H.-Y. Wang and H.-Y. Lin*, Hydrolysis of Magnetic Amylase-imprinted Poly(ethylene-co-vinyl alcohol) Composite Nanoparticles, ACS Applied Materials & Interfaces, 4, 916-921 (2012) 5. M.-H. Lee, J. L. Thomas, M.-H. Ho, C. Yuan and H.-Y. Lin*, Synthesis of Magnetic Molecularly Imprinted Poly(ethylene-co-vinyl alcohol) Nanoparticles and Their Uses in the Extraction and Sensing of Target Molecules in Urine, ACS Applied Materials & Interfaces, 2, 1729-1736 (2010)

Q.PII.15
17:30
Authors : Daniel Avram a b, Claudiu Colbea a, Mihaela Florea c, Ioana Porosnicu a b *, Carmen Tiseanu
Affiliations : a National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG-36, RO 76900 Bucharest-Magurele, Romania b University of Bucharest, Faculty of Physics, 405 Atomistilor Street, 077125 Magurele-Ilfov, Romania c National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele-Ilfov, Romania

Resume : Over the last years, luminescence thermometry has emerged as an exciting field of research due to its potential in nanotechnology, biomedicine, photonics and microelectronic applications [1]. We present a simple approach to obtain a luminescence nanothermometer operating in the near infrared (NIR) range (1000-1700 nm) by use of binary mixtures, Ho - Y2O3 + Er - Y2O3 and Ho - Y2O3 + Nd - Y2O3 nanoparticles [2]. The thermometry properties were assessed in terms of emission shape, intensity, excitation wavelength, dynamics, acquisition mode and weight ratio of the binary mixture [3]. The temperature evolution of the emission shape was monitored in the range of 297 - 472?K. For the binary mixture of Ho - Y2O3 + Er - Y2O3 with 3: 1 weight ratio, the maximum relative sensitivity was of 1%K-1 under 536.8 nm excitation [2]. Further, to extend the excitation wavelength from visible range to the first biological window, we assessed the Er, Ho, Yb codoped Y2O3 nanoparticles. For this system, under 905 nm excitation, a maximum relative sensitivity of 1.4-1.5 % K-1 was obtained, among the best values obtained to date for lanthanide based near infrared luminescent thermometers. References: [1] L. Carlos, F. Palacio, Thermometry at the nanoscale: techniques and selected applications, Thermometry Nanoscale Tech. Sel. Appl. 38, 2016, 124-166 [2] D. Avram, C. Colbea, M. Florea, C. Tiseanu, Highly-sensitive near infrared luminescent nanothermometers based on binary mixture. Journal of Alloys and Compounds, 785, 2019, 250-259. [3] D. Avram, C. Tiseanu, Thermometry properties of Er, Yb?Gd2O2S microparticles: dependence on the excitation mode (cw versus pulsed excitation) and excitation wavelength (980 nm versus 1500 nm). Methods and applications in fluorescence, 6(2), 2018, 025004.

Q.PII.16
17:30
Authors : Hui Jin Jung, You Jung Chung, Rosemarie Wilton, Chang H. Lee, Byung Il Lee, Jinyoung Im, Elena A. Rozhkova, Chan Beum Park, and Joonseok Lee*
Affiliations : H. J. Jung, Prof. J. S. LeeMolecular Recognition Research Center, Korea Institute of Science and Technology (KIST), Division of Nano and Information Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea; Y. J. Chung, Dr. C. H. Lee, Dr. B. I. Lee, Prof. C. B. Park Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 335 Science Road, Daejeon 305?701, Republic of Korea; J. Im, Dr. H. Kang Gwangju Center, Korea Basic Science Institute (KBSI), Gwangju, Republic of Korea; Dr. R. Wilton Biosciences, Argonne National Laboratory, Argonne, Illinois 60439, United States; Dr. E. A. Rozhkova Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States; H. J. Jung, Prof. J. H. Choi Department of Chemistry, Korea University, Seoul 02841, Republic of Korea;

Resume : The abnormal accumulation of ?-amyloid (A?) peptide aggregates in the brain is a hallmark of Alzheimer?s disease (AD). Because the self-assembled A? aggregates cause the cell death and brain atrophy by interfering with neuronal communications, numerous efforts to suppress A? aggregation and attenuate A?-induced toxicity have been progressed. Here, we developed novel A? nanosponges that consist of anti-A? single chain variable fragments (scFv) and ultra-large porous silica nanostructures for targeting and eliminating aggregative A? monomers. The presence of the A? nanosponges exhibits notable declines of the A? peptide aggregate through the scFv?s binding affinity to A? peptides. The biocompatible A? nanosponges show the significant enhanced cell viability and mitigation on A? neurotoxicity. After an intracerebral direct injection of A? nanosponges into an AD mouse brain, the brain slices show apparent suppression on A? plaque formations in comparison with the non-treated region. As a result, the A? nanosponges having remarkable therapeutic potentials for A? clearance in vitro and in vivo, are attractive candidates for AD treatments.

Q.PII.17
17:30
Authors : Kota Nagura, Naoki Komatsu, Rui Tamura
Affiliations : Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, JAPAN

Resume : We have prepared various all-organic magnetic soft materials containing a cyclic nitroxide radical moiety as a spin source [1]. In this talk, we report the preparation of all-organic magnetic nanoemulsions composed of the non-ionic surfactant and the hydrophobic nitroxide radical compound [2]. The properties of the nanoemulsions have been investigated by small angle neutron scattering (SANS) and dynamic light scattering (DLS) analyses, EPR spectroscopy, and MRI method. The nanoemulsions showed high colloidal stability, high reduction resistance to ascorbic acid, low cytotoxicity and an enough contrast enhancement in the proton longitudinal relaxation time (T1)-weighted MR images in (-)-PBS in vitro and in vivo. Furthermore, an additional hydrophobic anticancer drug such as Taxol® was simultaneously encapsulated inside the nanoemulsions. We expect that the drug-loaded nanoemulsions can be used as a biocompatible magnetic drug carrier for MRI-visible targeted delivery system. [1] a) Uchida, Y.et al. J. Mater. Chem. 2009, 19, 6877; b) Uchida, Y. et al. J. Am. Chem. Soc. 2010, 132, 9746; c) Takemoto, Y. et al. Soft Matter 2015, 11, 5563 [2] K. Nagura, N. Komatsu, R. Tamura, et al., Chem. Eur. J., 23, 15713 (2017); K. Nagura, N. Komatsu, R. Tamura, et al., Nanotechnology, 30, 224002 (2019); K. Nagura, N. Komatsu, R. Tamura, et al., Pharmaceutics, 11, 42 (2019).

Q.PII.18
17:30
Authors : Hohyeong Kim, Heungyeol Lee
Affiliations : Korea Institute of Industrial Technology, Incheon 21999, Korea

Resume : The electrochemical metallization of non-conductors, including plastics, elastomers, and glass is one of the key processes in electronics and automotive applications. Electroless plating on non-conductors is a chemically complex process and different processing steps are needed for each substrate. However, etching solution and a catalyst such as palladium are commonly used for good adhesion of the metallic layer to the substrate and initiating the electroless plating on non-conductive surfaces. In this work, we report the experimental studies on electroless plating of non-conductors such as silicone rubber, glass and PET films using silica sol-gel catalyst without etching process to reduce environmental pollutant. The results show that silica sol-gel coating layers containing palladium effectively catalyze electroless nickel plating on various substrates and the nickel deposits remained without failure after tape tests.

Q.PII.19
17:30
Authors : Valerio Gulino, Laura Barberis, Peter Ngene, Marcello Baricco, Petra E. de Jongh
Affiliations : (V. Gulino, Presenting Author, valerio.gulino@unito.it) Department of Chemistry and Inter-departmental Center Nanostructured Interfaces and Surfaces (NIS), University of Turin, Via Pietro Giuria 7, 10125 Torino, Italy; (L. Barberis) Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands; (P. Ngene) Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands; (M. Baricco) Department of Chemistry and Inter-departmental Center Nanostructured Interfaces and Surfaces (NIS), University of Turin, Via Pietro Giuria 7, 10125 Torino, Italy; (P. E. de Jongh) Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands;

Resume : Complex hydrides (e.g. LiBH4) are suggested as solid-state electrolytes. LiBH4 shows different polymorphs, the stable phase at room temperature (RT) is orthorhombic and has a low ionic conductivity. However, the hexagonal phase, which is stable at temperatures above 110 °C, has a remarkable high ionic conductivity (~10-3 Scm-1 at 120 °C). A promising approach to enhance the Li-ion conductivity of LiBH4 at RT is the development of new interfaces by ball milling it with oxide nanoparticles. In this work, the effect of adding oxide nanoparticles to LiBH4 by ball milling, on the Li-ion conductivity has been investigated by Electrochemical Impedance Spectroscopy. Firstly, the effect of the mixture composition on Li-ion conductivity in the LiBH4-SiO2 system was analysed. Li-ion conductivity was enhanced for all the composite conductors. The sample containing 20 v/v% of SiO2 showed the highest conductivity (2.2 × 10^-5 S/cm at RT, about tree orders of magnitude higher than LiBH4), and the lowest activation energy. A clear effect of the SiO2 volume fraction was observed, and a tentative explanation for this dependence will be discussed. Different oxides, i.e. CaO, MgO, ZrO2 and TiO2 and Al2O3, were tested and all increased the Li-ion conductivity of the LiBH4 at room temperature, achieving the highest conductivities for the samples containing ZrO2 and MgO (1.3 × 10^-4 S/cm and 1.0 × 10^-4 S/cm, respectively). The reason for the influence of the nature of the oxide is the topic of ongoing investigation. We illustrate that the addition of oxide nanoparticles to LiBH4 offers promising candidates for Li-based solid state electrolytes.

Q.PII.20
17:30
Authors : Ashok D. Ugale, Govind G. Umarji, Sung Hyeon Jung, Nishad G. Deshpande, Wonyoung Lee, Hyung Koun Cho, and Ji-Beom Yoo*
Affiliations : Ashok D. Ugale, Ji-Beom Yoo Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 440-746, Republic of Korea E-mail: jbyoo@skku.edu Nishad G. Deshpande, Sung Hyeon Jung, Hyung Koun Cho, Ji-Beom Yoo Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, 440-746, Republic of Korea Govind G. Umarji, Wonyoung Lee Department of Mechanical Engineering, Sungkyunkwan University, Suwon, 440-746, Republic of Korea

Resume : Gas sensor devices that operate at room temperature (RT) and detect toxic gases are currently more focused in wearable electronics for monitoring the environmental pollution and human health. In this regards, graphene and its derivatives are promising material possessing the prerequisite properties necessary to design advanced sensor devices. Therefore, the present study reports on continuous, strong and flexible graphene oxide (GO) fibers composed of oriented GO sheets that were synthesized by transforming a prealigned liquid crystalline GO solution using a simple wet-spinning assembly. GO fibers were chemically reduced (rGO) for gas sensing. Further, Nitrogen-doped (NrGO) and ZnO-incorporated rGO (ZrGO) fibers were achieved by hydrothermal assisted chemical reduction of GO fibers. A combinatorial ZnO nanoparticles and flower morphology was achieved on the surface of ZrGO fibers. This kind of mixed morphology not only provided more surface-area but also render more catalytic active sites for quicker interactions of the gas molecules, thereby enhancing the gas sensing performance as compared to rGO and NrGO fibers. The fiber sensors were able to detect minimum levels of 1.5 and 8 ppm of NO2 and H2S gas, respectively. Interestingly, the sensing performance of the ZrGO sensor was higher by 8 and 24 fold for NO2 and H2S, respectively, compared to rGO. The sensors exhibited characteristic response patterns for NO2 and H2S, showing excellent selectivity. This work opens a new way for the application of flexible, wearable, robust, lightweight, cheap, and room temperature chemical sensors, that can detect hazardous gases.

Q.PII.21
17:30
Authors : Alina Maria Holban1,2, Alexandru Mihai Grumezescu2, Valentina Grumezescu3, Lia Mara Ditu1, Carmen Curutiu1, Veronica Lazar1, Mariana Carmen Chifiriuc1, Bogdan Stefan Vasile2, Ecaterina Andronescu2
Affiliations : 1 Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Romania; 2 Faculty of Applied Chemistry and Materials Science, Politehnica University of Bucharest, Romania; 3 Laser-Surface-Plasma Interactions Laboratory, Lasers Department, National Institute for Lasers, Plasma and Radiation Physics, Magurele, Romania

Resume : Biofilms are multicellular microbial communities which can develop on any surface, tissue or interface and present a real ecological, industrial and medical challenge. Clinical biofilms are up to 3000 times more resistant to antimicrobial drugs as free-floating bacteria and represent a high risk for patients with implantable devices. The purpose of this study was to develop and characterize the antimicrobial potential of essential oils functionalized silver (Ag)-based core-shell nanoparticles (NPs) and nanocoatings. A Gram positive (Staphylococcus aureus) and a Gram negative (Pseudomonas aeruginosa) monospecific clinical biofilm model was used. AgNPs were functionalized with Eugenia caryophyllata, Eucalyptus globulus and Cinnamomum verum essential oils and thin coatings were obtained by matrix assisted pulsed laser evaporation (MAPLE) technique. Antimicrobial impact of the NPs was established by minimum inhibitory concentration (MIC) assay and antibiofilm activity by a microdilution crystal violet adapted method and viable count. Results revealed that the obtained NPs have low MICs and are highly efficient in both S. aureus and P.aeruginosa planctonic cultures. Regarding biofilms, these nanoparticles have the ability to inhibit biofilms formation when used at MIC/2 doses, but also to inhibit pre-formed biofilms in a microbial strain and NP type dependent manner. E. caryophyllata functionalized AgNPs proved the most significant antibiofilm effect, this being correlated with the significant inhibition of biofilm formation of this nanosystem also on the MAPLE ? obtained thin coating. The antibiofilm effect of the prepared nanocoatings is mantained for at least 72h. This study demonstrates that core-shell NPs containing essential oils represent an efficient and ecological strategy to fight biofilms and these nanosystems may be used to prepare bioactive coatings to avoid device-related infections.

Q.PII.22
17:30
Authors : Jeyanthinath Mayandi, Ragavendran Venkatesan,Terje Finstad, Vishnukanthan Venkatachalapathy
Affiliations : Department of Materials Science, School of Chemistry, Madurai Kamaraj University, Madurai-625 021, India. Department of Physics/Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo, Norway; Department of Materials Science, School of Chemistry, Madurai Kamaraj University, Madurai-625 021, India; Department of Physics/Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo, Norway; Department of Physics/Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo, Norway Department of Materials Science, National Research Nuclear University ?MEPhI?, 31 Kashirskoe sh, Moscow, Russian Federation;

Resume : Semiconductor nanomaterials can also be used in degrading organic pollutants that cause environmental hazard. Photocatalysis is effective in degrading numerous organic substances. Silicon (Si) nanostructures appear to be potentially remarkable photocatalysts and degradation agents because of their extremely large surface areas and small energy gaps, which enable large optical absorption. Fabrication of large area Si nanostructures supported on bulk crystalline silicon for photo-catalytic application utilizing low cost upgraded metallurgical grade Si wafer. Photo-catalytic degradation of organic effluents (dyes) from textile industry is systematically investigated using the Si nanostructures. The reusability of Si based photo-catalyst and methods to increase its recycling lifetime are studied. In this study, porous silicon is formed my electrochemical etching and we use the surface of the porous Silicon as a degrading agent of an organic dye, methylene blue under direct sunlight. This approach represents a simple, low-cost, environmental friendly method for decomposition of organic pollutants. The SEM image revels the structure of formed porous silicon and from the absorption spectra we can infer the degradation of methylene blue is fivefold form the initial position (it decrease from 1.0 to 0.2). The (C0 ? C)/C gives the removal ratio/time/ removal ratio plot gives the significance of the dye degradation.

Q.PII.23
17:30
Authors : Jamuna K. Vaishnav and Tushar Kanti Mukherjee
Affiliations : Indian Institute of Technology Indore (IITI)

Resume : Fundamental understanding and precise control of complex nonradiative processes in the nanoscale system find significant interest in recent times due to their importance in various nanophotonics applications. Here we have systematically investigated the mechanism behind photoluminescence (PL) quenching of mercaptosuccinic acid (MSA) capped CdTe QDs in the near field of gold and silver nanoparticles (Au and Ag NPs) by using steady-state and time-resolved photoluminescence (PL) spectroscopy. Resonance coupling between excitonic emission and localized surface plasmon resonance (LSPR) of Au NPs has been tuned by varying the size of QDs. Herein, three differently sized MSA-capped CdTe QDs have been synthesized namely, 2.1 ± 0.7, 3.1 ± 0.4, and 3.9 ± 0.3 nm with emission in green, yellow and red region of the electromagnetic spectrum, respectively. It has been observed that both the luminescence intensity and lifetime of green QDs quench significantly in the near field of 20 nm sized Au NPs. In contrast, the luminescent intensity and lifetime of yellow and red QDs remain unaltered in the presence of Au NPs. Moreover, it has been observed that ligand exchange at the surface of Au NPs with Poly(ethylene glycol) methyl ether thiol (PEG-SH) decreases the quenching efficiency of the green QD-Au NP pair significantly. In addition, the extent of quenching strongly depends on the excitation wavelength. The observed quenching is more efficient at the excitation wavelength close to the LSPR of Au NP. These results have been explained on the basis of a size-dependent nanometal surface energy transfer (NSET) model by incorporating the changes in the complex dielectric function and the absorptivity of the Au NP. On the contrary, irrespective of the sizes of QDs, significant PL quenching has been observed in the presence of 10 nm sized citrate-capped Ag NPs as a consequence of photoinduced electron transfer (PET). The present findings of size and wavelength-dependent long-range nonradiative electromagnetic coupling in hybrid QD-metal NP system can be useful to understand and optimize the performance of various nanophotonic devices.

Q.PII.24
17:30
Authors : Maria Cristina Bartha, Alina Crisan, Aurel Leca, Petru Palade, Nicu Iacob
Affiliations : National Institute of Materials Physics (NIMP) Magurele, 077125, Romania

Resume : Multiple valence oxides, containing rare earth elements, remained of permanent interest in the last years, especially for their capacity to form diverse structures with various compositions showing a wide variety of compositional elemental ratios for each particular type processed under correctly selected sintering conditions. The control of these compositions led to a large number of applications and an enormous body of research, as promoting the composition and peculiar structures as key factors to be tailored to produce precisely the desired properties [1-4]. Our goal was to tailor (based on prediction and reasoning) new materials with perovskite structure based on rare earth by a non-conventional and very modern processing route. An element of originality was that, for the first time were used molecular crystals as precursors for obtaining the REFeO3 , with (RE= Tb, Gd, Ho, Dy) perovskite structures. All morpho-structural and properties investigations were performed compared to similar compounds obtained by classical method (solid state synthesis). A significant improvement in nanoparticles size was observed, decreasing from about 300 nm (classical processing) to about 30-40 nm (molecular crystal precursors). Mossbauer spectra analysis revealed that all investigated samples were magnetically ordered at room temperature.Isomeric shift (IS) values are approximately the same and correspond to Fe3 ions in high spin state. The analysis of hysteresis curves specific to the 4 compounds shows the presence of an antiferromagnetic behavior at low temperatures, which is also maintained at room temperature. These behaviors have been interpreted in terms of a strong magnetic couplings between the two sublattices of the Fe / RE ions. Bibliography 1. Aharony, A. and E. Pytte, 1983, Phys. Rev. 27, 5872. Ali N., M. P., Hill, S. Labroo, and J. E. Greedan, 1989, J.Solid State Chem. 83, 178. 2. Matsuhira, K., C. Sekine, C. Paulsen, and Y. Hinatsu, 2004, J. Magn. Magn. Matter. 272, E981. 3. Gozar A, Logvenov G, Kourkoutis LF, Bollinger AT, Giannuzzi LA, et al. 2008. Nature 455:782?85. 4. Pinna, N., Niederberger, M.: Angew. Chem. Int. Ed. 47, 5292?5304 (2008).

Q.PII.25
17:30
Authors : Bruno P. Falcão1*, Joaquim P. Leitão1, Maria R. Soares2, Lídia Ricardo3, Hugo Águas3, Rodrigo Martins3, Rui N. Pereira1,4
Affiliations : 1 Departamento de Física & I3N, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal 2 Laboratório Central de Análises, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal 3 CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, CEMOP-UNINOVA, 2829-516 Caparica, Portugal 4 Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany * Corresponding author: bfalcao@ua.pt

Resume : The investigation of lattice-strain effects in nanoparticles (NPs) is fundamental for the materialization of NP-based nanotechnologies. In the present work, we conduct a comprehensive investigation of lattice strain in crystalline Si NPs, which appears upon oxidation under ambient conditions. Si NPs are currently attracting much interest due to the unique chemical and physical properties of Si at the nanoscale and the environmental inertness, biocompatibility, and high abundance of the silicon element. From monitoring the time evolution of surface oxidation with Raman and infrared spectroscopies, we find a clear correlation between the formation of the surface oxide and appearance of compressive strain in the crystalline core of the Si NPs. This surface-dependent lattice strain increases continuously as the oxidation progresses. By comparing experimental variations of the Raman spectra with theoretical predictions using an improved phonon confinement model [1], we infer that strain is negligible in H-terminated Si NPs with sizes of ~3 nm and that after long-term oxidation the compressive stress induced by the oxide shell is estimated to be 1.2 GPa. These findings link the time-dependent oxidation phenomenon with the experimental observation of compressive strain in Si NPs, clarifying contradicting results found in the literature, and demonstrate a simple route for the deconvolution of confinement and strain effects in low-dimensional structures using Raman spectroscopy. [1] B. Falcão et al., Phys. Rev. B 98, 195406 (2018)

Q.PII.26
17:30
Authors : Wenjuan Cui, Tapani A. Pakkanen
Affiliations : Department of Chemistry, University of Eastern Finland, P.O.Box 111, Joensuu, FI-80101, Finland

Resume : Nanoparticle-modified structures are common to provide important functionalities for many industrial applications. Under subzero conditions, it is critical to inhibit and delay the interaction between solid objects and ice. Superhydrophobic structures (SHS), including lotus and petal surfaces, are considered potential materials due to the water repellency. Here, hydrophobic silica nanoparticle-modified polyvinylidene fluoride coatings were prepared with tunable wettability. The icephobic performance was evaluated fully with several observation techniques at -10?C. Results show that the icephobic performance of nanoparticle-modified coatings lowers with increasing hydrophobicity. The ice adhesion strength is controlled by mechanical interlocking in the textures and stress concentrator induced by air cushions. The stress concentrator used to reduce ice adhesion is better on the lotus surface than on the petal surface. The lotus and petal surfaces lose their superhydrophobicity in a condensation environment, being less useful for anti-icing due to poor humidity tolerance. Apart from the SHS with excessive mechanical interlocking, the ice adhesion values of all other modified coatings are linearly related to the contact angle hysteresis. Smooth hydrophobic surfaces were found to be better icephobic materials compared to rough surfaces. The intrinsic surface energy of smooth surfaces is significantly linear with the ice adhesion. High freezing delay times were found for smooth low-density polyethylene resin and fluorinated surfaces.

Q.PII.27
17:30
Authors : Patricia Abellan, Jay A. LaVerne, Ashish Bhattarai, Grant E. Johnson, Fredrik S. Hage, Wayne P. Hess, Rik Brydson, Patrick Z. El-Khoury, Quentin M. Ramasse
Affiliations : SuperSTEM Laboratory, Daresbury, U.K.; Radiation Laboratory, University of Notre Dame, Notre Dame, U.S.A.; Pacific Northwest National Laboratory, Richland, U.S.A; Pacific Northwest National Laboratory, Richland, U.S.A; SuperSTEM Laboratory, Daresbury, U.K.; Pacific Northwest National Laboratory, Richland, U.S.A; University of Leeds, Leeds, U.K.; Pacific Northwest National Laboratory, Richland, U.S.A; SuperSTEM Laboratory, Daresbury, U.K.

Resume : The properties of nanoparticles (NPs) functionalized with organic molecules are determined by the interaction between the individual NP surface and the molecules. This interaction is complex and represents a considerable characterization challenge. The elucidation of the mechanisms of quenching or enhancement of particular excited states of molecules in functionalized NPs, including plasmon-supporting NPs, ideally requires a combined energy and spatial resolution to resolve all: the fine structure spectra of electronic excitations, surface plasmons and the local structural and chemical variations at the molecular level. STEM is able to provide sub-angstrom spatial resolution using Cs-correction, local chemical identification, if using microscopes equipped with electron energy loss spectrometers or information on chemical bonds, bandgaps and vibrational states if using a new generation of monochromated scopes (less than 20 meV).[1, 2] The high sensitivity of solid organic molecules to ionizing radiation presents a severe practical limitation. In this contribution, I will discuss electron microcopy methods for the study of metal - organic molecule interactions in nanoparticles. These tools can aid the design of NP-based materials for better biodistribution, higher optical yields at relevant wavelengths, sensing selectivity or selective radiosensitizing effects. References: [1] Krivanek, O. L.; Lovejoy, T. C.; Dellby, N.; Aoki, T.; Carpenter, R.; Rez, P.; Soignard, E.; Zhu, J.; Batson, P. E.; Lagos, M. J. Nature 2014, 514, (7521), 209. [2] Krivanek, O. L.; Ursin, J. P.; Bacon, N. J.; Corbin, G. J.; Dellby, N.; Hrncirik, P.; Murfitt, M. F.; Own, C. S.; Szilagyi, Z. S. Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences 2009, 367, (1903), 3683-3697.

Q.PII.28
17:30
Authors : Gilles R. Bourret, Oliver Diwald,
Affiliations : Department of Chemistry and Physics of Materials, University of Salzburg, Jakob-Haringer-Strasse 2a, A-5020 Salzburg;

Resume : The implementation of nanostructured metal oxides and hydroxides into functional and catalytic materials requires knowledge about their growth and stability in changing chemical environments. Tailored metal oxide particle systems with interface properties which are accessible to experimental methods are indispensable model systems in this regard.[1] This presentation deals with examples where structure-property relationships have between established for metal oxide nanocrystals and their transformation behaviour in different water containing environments.[2,3] Particle interface functionalization processes via the gas- or the liquid phase will be compared. Moreover, we learned that adsorbed water originating from the storage of Magnesium oxide nanoparticle powders in air gives rise to significant particle morphology changes at elevated processing temperatures. Under such conditions, protrusions form on (100) terraces in parallel to the formation of step edges and vicinal surfaces which, at lower magnifications, give rise to the appearance of rounded grains which are made up from cubic building blocks. Related local structures can accommodate important new functionalities which are beneficial for sintering and microstructure evolution, on the one hand, or related to catalytic activity, on the other. [1] T. Berger and O. Diwald, ?Defects in Metal Oxide Nanoparticle Powders?, in Defects at Oxide Surfaces, ed. J. Jupille and G. Thornton, Springer International Publishing, ISBN: 978-3-319-14366-8, 2015. [2] G.R. Bourret and O. Diwald, J. Mater. Res. 34, 428-441, 2019. [3] D. Thomele et al. Angew. Chem. Int. Ed. 56, 1407-1410, 2017.

Q.PII.29
17:30
Authors : Piotr Nowak (a), Katarzyna Zakrzewska (a), Anna Kusior (b), Agnieszka Lacz (b), Marta Radecka (b), Hubert Haranczyk (c), Karol Kubat (c), Kazimierz Kowalski (d)
Affiliations : (a) Faculty of Computer Science, Electronics and Telecommunications, AGH University of Science and Technology, al. Mickiewicza 30, Kraków, Poland ; (b) Faculty of Materials Science and Ceramics, AGH University of Science and Technology, al. Mickiewicza 30, Kraków, Poland; (c) Marian Smoluchowski Institute of Physics, Jagiellonian University, ul. Lojasiewicza 11, Kraków, Poland ; (d) Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, Kraków, Poland.

Resume : Titanium dioxide is one of the most commonly used metal oxides in gas sensors both reducing and oxidizing gases. The presence of water molecules is an important factor affecting the electrical properties of TiO2 [1]. Even a small change in relative humidity can cause a significant change in the conductivity of TiO2. 1H-Nuclear Magnetic Resonance (1H-NMR) allows one to investigate the influence of water molecules on TiO2 structure and observe different water fractions bound to the TiO2 surface [2,3]. 1H-NMR measurements of rutile nanopowder were carried out in controlled relative humidity (2-100%) using the Bruker Avance III 300, Bruker Biospin, spectrometer (B0 = 7 T, f = 300 MHz , transmitter power = 400 W; pulse = 2.2 μs; bandwidths 300 kHz). The recorded 1H-NMR spectra were superpositions of one Gaussian component (half-width ~ 30 kHz) coming from protons bound to solid matrix (protons of hydroxyl groups directly bound to TiO2 surface) and since one till four (with the increased hydration level) Lorentzian components coming from mobile protons. The Lorentzian lines differ in half-widths and peak positions of water fractions according to molecular mobility (very tightly, tightly, and loosely, and finally very loosely bound water fraction) and to the magnetic environment. Acknowledgements: National Science Centre, Poland 2016/23/B/ST7/00894 project is acknowledged. [1] Kusior A., Radecka M., Zych Ł. et al. Sens. Actuators, B Chemical 189, 251-259, (2013) [2] Nosaka, A.Y, Fujiwara T., Yagi H., et al. J. Phys. Chem. B, 26, 9121-9125, (2004) [3] Soria J., Sanz J., Sobrados I., et al., J. Phys. Chem. C, 111 ,28, 10590-10596, (2007)

Q.PII.30
17:30
Authors : Rolf Beerthuis, Lisette Pompe, Krijn de Jong, Petra E. de Jongh
Affiliations : Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands

Resume : Methanol is essential to produce chemicals such as acetic acid, alkyl acrylates and various olefins. Over 65 million metric tons of methanol are produced each year by Cu(ZnOx)-catalyzed hydrogenation of CO and CO2. However, fundamentals such as the nature of the active site, the effect of particle size, and the origin of the ZnOx promoter effect are still being debated.[1-3] Recently, a DFT study predicted a strong decrease in activity for particle sizes below 20 nm, due to loss of effectiveness of the ZnOx promotion.[2] Our group was the first to publish experimental results on the dependency of turn-over frequency (TOF) on particle size, showing decreasing activities for particles below 8 nm.[3] Although structure sensitivity was postulated as an underlying cause, the results for unpromoted Cu particles were inconclusive, leaving space for an alternative explanation via the effectiveness of the ZnOx promoter. These previous studies applied employed different supports, mostly metal oxides, to allow variation of the particle size. However, the nature of the support may affect the efficiency of Cu and ZnOx, thus obscuring intrinsic particle size effects. In this study, we utilized carbon as an inert catalyst support to elucidate the particle size effects for both Cu and CuZnOx.

Q.PII.31
17:30
Authors : Anatoliy Titenko1, Lesya Demchenko2, Larisa Kozlova1, Mustafa Babanli3, Sergiy Sidorenko2, Sayami Huseynov3
Affiliations : 1 Institute of Magnetism, National Academy of Sciences and Ministry of Education and Science of Ukraine, 36-b, Vernadskoho Blvd, Kyiv, Ukraine, 2 National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", 37, Peremohy Ave, Kyiv, Ukraine 3 Azerbaijan State University of Oil and Industry, Azadliq Ave, 20, Baku, Azerbaijan

Resume : For a long time Fe?Ni?Co-based alloys with a various combination of different doping components, in which thermoelastic martensite transformations occurs, occupy leading positions in reversible deformation effects. The Fe-Ni-Co-Ti alloy system belongs to the family of new smart ferromagnetic materials exhibiting the shape memory effect and superelasticity. The long-lasting study of the martensite transformation in Fe-Ni-Co-Ti alloys has given the opportunity to find the conditions of its reversibility. When ageing of austenite, the formation of homogeneously distributed coherent with the surrounding matrix spherical nanoparticles occurs. The particles including in austenite retain coherency with the crystal lattice of martensite, that leads to its tetragonality. It makes easier the coherent connection of the austenite and martensite lattices and decreases the level of strains between them that determines the proceeding of thermoelastic martensite transformation. The degree of tetragonality ?/? of such martensite is caused by the superposition of strain fields from coherent nanoparticles within the martensite twin due to the fact that the thickness of martensite twins is much larger than the average distance between the nanoparticles. By means of the proper selection of the alloy composition and their ageing, it has been managed to obtain in the above alloys the thermoelastic transformation with hysteresis from 250 to 20 ?. An increasing the degree of tetragonality ?/? of the crystal lattice ?f martensite results in narrowing hysteresis of martensite transformation. Narrower hysteresis corresponds to the martensite with thinner plates.

Q.PII.32
17:30
Authors : Hye Ryeon Yun,Hoi Jin Yoon,Sunho Jeong1,Seung-Yun Lee*
Affiliations : Hanbat National University;Korea Research Institute of Chemical Technology1

Resume : There has been a growing interest in alternative energies, due to the depletion of fossil fuels, and the environmental impact caused by CO2 emissions. As a result, there is an increased focus on various alternative energy sources, such as solar and hydroelectric energy. Solar cells have been used in many application as an eco-friendly and efficient power source. In addition to their own functions of energy conversion, semi-transparent solar cells are considered one of the most promising components in building integrated photovoltaic (BIPV) systems. Semi-transparent Si solar cells, prepared based on mature Si thin-film technology, have drawn much attention as an important semi-transparent solar cell. In order to commercialize the semi-transparent Si solar cells, both improved aesthetics and increased efficiency are required. We have previously reported colored and semi-transparent Ag nanoparticle layers, which resulted in color variation and efficiency improvement of semi-transparent Si solar cells. In this study, we investigate the effect of spin coating parameters on the optical properties of Ag nanoparticle layers, and propose a mechanism to explain the change in reflectance and transmittance with variation in the two independent parameters. The Ag nanoparticle layers were formed by the spin coating of colloid solutions on substrates. The reflectance and transmittance of the nanoparticle layers were measured using an Uv?Vis spectrophotometer. It was confirmed that the saturation of the reflectance and transmittance at high spin speeds is closely related to the liquid thickness dependent on the reciprocals of spin coating variables.

Q.PII.33
Start atSubject View AllNum.Add
09:00 Plenary Session (Main Hall)    
12:30 Lunch break    
 
Optical Nanomaterials : Paola Ceroni
14:00
Authors : Paola Luches
Affiliations : Consiglio Nazionale delle Ricerche, Istituto Nanoscienze, Via G. Campi 213/a, 41125 Modena, Italy

Resume : The coupling of plasmonic metal nanoparticles (NPs) and oxides represents a promising strategy to sensitize wide band gap materials to visible light, and convert solar energy into chemical or electric energy. This possibility is of great relevance for a wide range of applications, like for example sensors, photocatalysts, or photovoltaic devices. The decay of localized surface plasmon resonances (LSPRs) in the metal NPs, occurring on fs time scales, may involve a relevant energy and/or charge transfer to the neighboring oxide and it may lead to modifications of the material properties on much longer time scales, which can be exploited in the applications. An understanding of the mechanisms for plasmonic energy transfer is very relevant for a knowledge-driven optimization of this important class of functional materials. Mass-selected Ag NPs, grown by magnetron sputtering with inert gas aggregation, combined with cerium oxide were chosen as a model system to probe the modifications of the oxide after LSPR excitation. The used physical synthesis method allowed to easily tune the system architecture and to maximize the expected effects. Femtosecond transient absorption spectroscopy was used to probe the dynamics of charge carrier relaxation after the excitation of the LSPRs in the Ag NPs and to evaluate the efficiency of the plasmon-mediated electron transfer from the Ag NPs to the cerium oxide matrix [1]. [1] J. S. Pelli Cresi et al., Nanoscale (2019), doi: 10.1039/C9NR01390C

Q.9.1
14:30
Authors : M.Urbain (1), F.Riporto (1), K.Bredillet (1), R.Le Dantec (1), S.Beauquis (1), V.Monnier (2), Y.Chevolot (2), C.Galez (1), Y.Mugnier (1)
Affiliations : (1) Université Savoie Mont Blanc, SYMME, F-74000, Annecy, France ; (2) Université de Lyon, Ecole Centrale de Lyon, UMR CNRS 5270, Institut des Nanotechnologies de Lyon, F-69134, Ecully, France

Resume : Lithium niobate is an excellent nonlinear optical material. One of the recent and very promising applications is the use of LiNbO3 nanoparticles as bioimaging probes to image cells by taking advantage of their Second Harmonic Generation (SHG) properties [1,2]. Such properties, in terms of brightness, depend on the particle size and shape, hence the importance of controlling them. Use of sol-gel precursors (alkoxides) combined with a solvothermal process leads to the synthesis of quite monodispersed single crystalline LiNbO3 nanoparticles with an average size down to 30nm. The variation of some experimental parameters either related to precursors or to solution processing (temperature, solvent, additives) has allowed to change the particle morphology from platelet-like to almost spherical. Particular attention has thus been paid to the understanding of reaction and growth mechanisms. The orientation-averaged SHG response of the synthesized nanoparticles has also been characterized [3]. Finally, Er-doping of these particles has been achieved leading to a simultaneous emission of SHG and upconversion signals after excitation in the near-IR. [1] Staedler, D. ; Magouroux, T. ; Hadji, R. ; Joulaud, C. ; et al. ACS Nano 2012, 6 2542-2549 [2] Slenders, E. ; Bove?, H. ; Urbain, M ; Mugnier, Y. ; et al. J. Phys. Chem. Lett. 2018, 9, 6112?6118 [3] Riporto, J. ; Urbain, M. ; Mugnier, Y. ; Multian, V. ; et al. Opt. Mat. Express 2019, 9, 1955-1966

Q.9.2
14:45
Authors : Sylvain Regny, Kévin Bredillet, Jérémy Riporto, Yannick Mugnier, Ronan Le Dantec, Isabelle Gautier-Luneau, Géraldine Dantelle
Affiliations : Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France Sylvain Regny Isabelle Gautier-Luneau Géraldine Dantelle Université Savoie Mont Blanc, SYMME, F?74000, Annecy, France Kévin Bredillet Jérémy Riporto Yannick Mugnier Ronan Le Dantec

Resume : Harmonic nanoparticles (HNPs) (BaTiO3 [1], KNbO3 [2], LiNbO3 [3] or BiFeO3 [4]) are widely studied as Second Harmonic Generation (SHG) nanoprobes for bio-imaging as they can be excited in the 0.7-1.3 ?m near-infrared range (corresponding to the 1st and 2nd biological transparency windows) thus allowing deep tissue imaging and high-spatial resolution related to the two-photon absorption process. With the booming of nanomedicine, the search for new HNPs with multifunctional properties is of high interest. We present here our work on the development of both luminescent and SHG-active ?-La(IO3)3 nanocrystals doped with Yb3+ and Er3+ [5]. ?-La(IO3)3 is a known noncentrosymmetric compound, which was synthesized at the micron scale by hydrothermal method [6]. It was shown to exhibit non-linear optical properties with a SHG efficiency similar to that of the reference compound, namely lithium iodate (?-LiIO3). In the context of bio-imaging, we developed a microwave-assisted hydrothermal method to synthesize ?-La(IO3)3 nanocrystals with high crystal quality. By controlling various synthesis parameters (temperature, time, stoichiometry ?), well-crystallized undoped and Yb3+,Er3+-doped SHG-active ?-La(IO3)3 nanocrystals of circa 30 nm were obtained, as characterized by TEM. The SHG efficiency was quantitatively assessed from second-harmonic scattering experiments at 1064 nm. It results in relatively high ?d? coefficients measured at 8.2 ± 2.0 pm.V-1 for undoped ?-La(IO3)3, a value comparable to that of the state-of-the-art HNPs. For Yb3+,Er3+-doped nanocrystals excited at 980nm, SHG as well as photoluminescence by up-conversion (UC) were simultaneously observed. As expected, the UC process is enhanced in codoped nanocrystals after excitation of the Yb3+ ions, acting as the sensitizer, and energy transfer to the Er3+ ones. The emission is situated at 525 nm and 546 nm and corresponds to the 2H11/2 ? 4I15/2 and 4S3/2 ? 4I15/2 electronic transitions of Er3+. Because of the non-resonant and resonant nature of the SHG and up-conversion (UC) processes, respectively, the intensity ratio between SHG and UC is readily changed according to the excitation wavelength and a possible competition between each mechanism will be discussed under resonant conditions. [1] Hsieh, C. L.; Grange, R.; Pu, Y.; Psaltis, D. Biomaterials. 2010, 31, 2272-2277 [2] Ladj, R.; Magouroux, T.; Eissa, M.; Dubled, M.; Mugnier, Y.; Le Dantec, R.; Galez, C.; Valour, J. P.; Fessi, H.; Elaissari, A. Colloids Surf. A. 2013, 439, 131-137 [3] Staedler, D.; Magouroux, T.; Hadji, R.; Joulaud, C.; Extermann, J.; Scwung, S.; Passemard, S.; Kasparian, C.; Clarke, G.; Gerrmann, M.; Le Dantec, R.; Mugnier, Y.; Rytz, D.; Ciepielewski, D.; Galez, C.; Gerber-Lemaire, S.; Juillerat-Jeanneret, L.; Bonacina, L.; Wolf, J. P. ACS Nano. 2012, 6, 2542-2549 [4] Staedler, D.; Passemard, S.; Magouroux, T.; Rogov, A.; Maguire, C. M.; Mohamed, B. M.; Schwung, S.; Rytz, D.; Jüstel, T.; Hwu, S.; Mugnier, Y.; Le Dantec, R.; Volkov, Y.; Gerber-Lemaire, S.; Prina-Mello, A.; Bonacine, L.; Wolf, J. P. Nanomedicine. 2015, 11, 815-824 [5] Regny, S.; Riporto, J.; Mugnier, Y.; Le Dantec, R.; Kodjikian, S.; Pairis, S.; Gautier-Luneau, I.; Dantelle, G. Inorg. Chem. 2019, 58, 1647-1656 [6] Taouti, M. B.; Suffren, Y.; Leynaud, O.; Benbertal, D.; Brenier, A.; Gautier-Luneau, I. Inorg. Chem. 2015, 54, 3608-3618

Q.9.3
15:00
Authors : T.Popelá? (1), K.K?sová (1), P. Ceroni (2)
Affiliations : 1-Institute of Physics of the ASCR, v.v.i., Cukrovarnická 10, 162 00 Prague 6, Czech Republic; 2-Department of Chemistry ?G. Ciamician?, University of Bologna, Via Selmi 2, 40126 Bologna, Italy

Resume : Si nanocrystals (SiNC) can be relatively efficient light emitters despite their indirect bandgap. Their attributes (e. g. light-emission efficiency) depend heavily on surface passivation. Various schemes were exploited over the years, however, the functionalization with diphenylanthracene (DPA) is quite new in the SiNC field. Here, the DPA molecules function as molecular antennae in order to improve the absorption in the 340 nm - 400 nm range and then transfer the energy to SiNCs, which has a potential benefit in e.g. light-harvesting applications. The DPA-functionalized samples were compared with SiNCs prepared by the same method passivated by dodecene. In order to elucidate the full role of DPA on the SiNCs surface, we employed a range of optical methods such as quantum yield, time-resolved photoluminescence (PL), excitation spectra measurements, etc. We were able to detect a fast (PL decay ~ ns) blue band [1] as well as a slow (PL decay ~ 100 us) red band typical for SiNCs. We found out that the PL of SiNCs passivated by DPA differs markedly compared to the dodecene passivated ones: 1) blue band PL is greatly enhanced, 2) the blue band?s behavior changes with respect to excitation wavelength 3) decays of the red and blue band changes their character. We will discuss the influence of DPA and the underlying energy transfers between NCs and DPA describing the above mentioned results. [1] J. Valenta et al 2008 New J. Phys. 10 073022

Q.9.4
15:15
Authors : Christian Rein, Sara Engberg, Jens Wenzel Andreasen
Affiliations : C. Rein & J. W. Andreasen: Technical University of Denmark, Department of Energy Conversion and Storage, Frederiksborgvej 399, 4000 Roskilde, Denmark. S. Engberg: Technical University of Denmark, Department of Photonics Engineering, Frederiksborgvej 399, 4000 Roskilde, Denmark.

Resume : Copper-zinc-tin-sulfide (CZTS with standard stoichiometry of Cu2ZnSnS4) is a cheap, earth-abundant and non-toxic photovoltaic material for 3rd generation solar cells. Unfortunately, conventional CZTS solar cell fabrication relies on an architecture, adopted from earlier solar cell generations, which depends on an energy-intensive high temperature annealing process in a sulfur or selenium atmosphere. We want to present a more environmentally-friendly approach where CZTS is synthesized in nanoparticle (NP) form at room temperature. The method is shown to be compositionally robust and able to produce S2--stabilized carbon-free nanoparticle inks that are suitable for an absorber layer in solar cells. No organic residues from the process were detected. The metal-composition and the occurrence of secondary phases is here correlated with synthesis conditions: By utilizing a reactant concentration of Cu/Sn < 1.8 and Sn(II) as tin-source it is possible to avoid the formation of copper sulfide-phases, which are detrimental for the solar cell performance when present in the final absorber layer. With nanoparticle sizes approaching the Bohr radius for CZTS, the band gap can be broadened up to 1.7 eV. In addition, the conditions for forming stable, carbon-free aqueous inks of such CZTS NPs and the effect of the stabilizing ammonium/sulfide-ion concentration on the quality of the deposited absorber layer are investigated. The use of room temperature synthesis and stable aqueous ink formulations make the method suitable for roll-to-roll fabrication and upscaling.

Q.9.5
15:30 Coffee break    
 
Plasmonic Nanoparticles : Paola Luches
16:00
Authors : Andrea Baldi
Affiliations : DIFFER - Dutch Institute for Fundamental Energy Research

Resume : Metal nanoparticles can sustain localized surface plasmon resonances, which are light-driven resonant oscillations of their free electrons. Thanks to their strong spectral dependence on the nanoparticle size, shape, composition, and dielectric environment these resonances can be used as nanoscale probes for a large range of chemical and physical processes. Furthermore, their non-radiative decay into ?hot? charge carriers and heat can be exploited to accelerate and modify chemical reactions at the metal nanoparticle surface. In the present talk, I will show how we use plasmon resonances in noble metal nanoparticles to study hydrogen absorption in individual metal nanocrystals [1-3], probe charge equilibration across metal/semiconductor interfaces [4], and drive the synthesis of hierarchical nanostructures in solution, using both photo-thermal effects and non-thermal processes such as near-field enhancement and hot charge carrier injection [5]. [1] A. Baldi, T. C. Narayan, A.-L. Koh, and J. A. Dionne, Nature Mater. 13, 1143-1148 (2014) [2] T. C. Narayan, A. Baldi, A.-L. Koh, R. Sinclair, and J. A. Dionne, Nature Mater. 15, 768?774 (2016) [3] T. C. Narayan, F. Hayee, A. Baldi, A.-L. Koh, R. Sinclair, and J. A. Dionne, Nature Comm. 8, 14020 (2017) [4] M. Parente, S. Sheikholeslami, G. V. Naik, J. Dionne, and A. Baldi, J. Phys. Chem. C 122, 23631-23638 (2018) [5] R. Kamarudheen, G. W. Castellanos, L. P. J. Kamp, H. J. H. Clercx, and A. Baldi, ACS Nano 12, 8447-8455 (2018)

Q.10.1
16:30
Authors : Hyun Huh, Hoa Duc Trinh, Dokyung Lee, Sangwoon Yoon*
Affiliations : Chung-Ang University

Resume : Hot-electron chemistry at gold nanoparticle (AuNP) surfaces has received much attention recently because its under-standing provides a basis for plasmonic photocatalysis and photovoltaics. Nonradiative decay of excited surface plas-mons produces energetic hot charge carriers that transfer to adsorbate molecules and induce chemical reactions. Such plasmon-driven reactions, however, have been limited to a few systems, notably the dimerization of 4-aminobenzenethiol to 4,4?-dimercaptoazobenzene. In this work, we explore a new class of plasmon-driven reactions associated with a unimolecular bond-cleavage process. We unveil the mechanism of the decarboxylation reaction of 4-mercaptobenzoic acid and extend the mechanism to account for the ?-cleavage reaction of 4-mercaptobenzyl alcohol. Combining the construction of well-controlled nanogap systems and sensitive Raman spectroscopy with methodical changes of experimental conditions (laser wavelengths, interface materials, pH, ambient gases, etc.), we track the hot charge carriers from the formation to the transfer to reactants, which provides insights into how plasmon excitation eventually leads to the C?C bond cleavage of the molecules in the nanogap.

Q.10.2
16:45
Authors : N. Gordillo, S. Catalán-Gómez, J.L. Pau, A. Redondo-Cubero
Affiliations : Microelectronics Lab. Department of Applied Physics, Universidad Autónoma de Madrid E-28049 Madrid, Spain

Resume : Gallium and indium nanoparticles (NPs) have attracted a lot of interest in the last years for biosensing and photonic devices [1,2], since they provide a wide tunability of their localized surface plasmon resonance (LSPR) energy, from the UV to the IR spectral region. Interestingly, these NPs develop a native thin oxide on the surface that preserves the metal from the environment [3]. Furthermore, the thickness of the oxide layer can be increased by thermal processes, tuning the core-shell architecture and modifying the plasmon resonance with the annealing time and temperature [4]. In this work, we use Joule-effect thermal evaporation to produce hybrid structures made of Ga and In NPs on Si substrates. These complex structures of mixed NPs present a spectrally broad plasmonic absorption that can be optically tuned with a wide range of photon energies from UV to IR regions with a full width at half maximum range of ~ 400 to 800 nm. The surface morphology was characterized by means of scanning electron microscopy. The LSPRs were determined by spectroscopic ellipsometry and compared with discrete dipole approximation simulations. These results explore the benefits and limits of hybridization, in new platforms for optical sensing devices. 1. A. García Marín et al., Biosens. Bioelectron. 74, 1069 (2015) 2. Y. Kumamoto et al., ACS Photonics 1, 598 (2014). 3. K.A. Willets et al., Annu. Rev. Phys. Chem. 58, 267 (2007) 4. S. Catalán-Gómez et al., Nanotechnology 29 (2018) 355707)

Q.10.3
17:00
Authors : Z. Zolnai, D. Zámbó, D. P. Szekrényes, and A. Deák
Affiliations : Centre for Energy Research, Institute of Technical Physics and Materials Science (MFA), Konkoly-Thege M. út 29-33, H-1121 Budapest, Hungary

Resume : In the surface plasmon resonance (SPR) of metal nanoparticles (NPs) the linewidth is determined by radiative and nonradiative damping terms. So far less attention was paid to give an overview of the different semi-empirical scaling factors reported for the radiation damping of spheroidal NPs. In this work we use a local field approach and the kinetic equation method to estimate the linewidth of radiative damping of SPR. As we found the linewidth increases quadratically with the radius of spherical NPs while for nanorods significantly larger radiation damping is found for the transversal than for the longitudinal SPR band. So far this effect induced by shape anisotropy has not been discussed in detail. We also show that the shape of gold nanodiscs can be successfully modelled with prolate spheroids in radiation damping calculations. We also investigate the effect of the underlying substrate. The radiation damping is evaluated for NPs supported on glass, ITO, and Si, i.e., substrates with significantly different refractive indexes. In this case the effect of the anisotropic dielectric environment is taken into account through an effective dielectric constant extracted from the substrate induced mirror charge model. We compare the values resulted by the kinetic equation method to previously reported values of the semi-empirical radiation damping factor and reveal correspondence between these two parameters. In general good agreement is found between calculations and experiments.

Q.10.4
18:00 Graduate Student Awards Ceremony and Reception (Main Hall)    
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Luminescent Nanoparticles : Petra Szilagyi
09:00
Authors : Paola Ceroni
Affiliations : Department of Chemistry "Giacomo Ciamician" - University of Bologna

Resume : Silicon nanocrystals (SiNCs) in the quantum size range (2-12 nm) can be made as viable light emitters with emission wavelength that can be tuned from the near-infrared (NIR) into the visible by decreasing their size.[1, 2] Silicon nanocrystals, produced by thermal disproportionation of silicon oxide, were co-passivated with dodecene and different organic chromophores, e.g. pyrene,[3] porphyrin,[4] or benzothiadiazole chromophores.[5] Excitation of the organic chromophores results in an efficient energy transfer to the nanocrystal core: this is the working principle of a light harvesting antenna. This approach enabled us to circumvent the drawback of the low molar absorption coefficient of SiNCs. The investigated hybrid material exhibits high quantum yield also in the NIR spectral region with lifetime in the µs range. This research has potential applications in bioimaging, taking advantage of time-gated luminescence microscopy to enhance image resolution and in solar energy conversion, e.g. luminescent solar concentrators, thanks to the apparent large Stokes shift. [1] Y. Yu, G. Fan, A. Fermi, R. Mazzaro, V. Morandi, P. Ceroni, D.-M. Smilgies, B. A Korgel, J. Phys. Chem. C, 2017, 121, 23240 [2] R. Mazzaro, F. Romano, P. Ceroni, PhysChemChemPhys 2017, 19, 26507 [3] M. Locritani, Y. Yu, G. Bergamini, J. K. Molloy, M. Baroncini, B. A. Korgel, P. Ceroni, J. Phys. Chem. Lett. 2014, 5, 3325. [4] A. Fermi, M. Locritani, G. Di Carlo, M. Pizzotti, S. Caramori, Y. Yu, B. A. Korgel, G. Bergamini, P. Ceroni, Faraday Discussion 2015, 185, 481. [5] L. Ravotto, Q. Chen, Y. Ma, S. A. Vinogradov, M. Locritani, G. Bergamini, F. Negri, Y. Yu, B. A. Korgel, P. Ceroni, Chem. 2017, 2, 550.

Q.11.1
09:30
Authors : Chukova O.1, Nedilko S.A.1, Nedilko S.G.1, Slepets A.1, Voitenko T.1, Androulidaki M.2, Papadopoulos A.2, Stratakis E.2
Affiliations : 1 - Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, Kyiv 01601, Ukraine. E-mail: chukova@univ.kiev.ua; 2 - Institute of Electronic Structure & Laser (IESL) of Foundation for Research & Technology Hellas (FORTH), Heraklion 711 10 Crete, Greece

Resume : Lanthanum vanadate nanoparticles doped with europium and erbium ions and co-doped with calcium ions were prepared by aqueous nitrate-citrate sol-gel synthesis route taking citric acid as a complexing agent. Phase composition, crystal lattice parameters and microstructure of the synthesized samples were studied by various methods. The XRD analysis has revealed dependence of crystal structure on dopants concentration: monoclinic monazite-type structure for low dopant concentration and tetragonal zircon-type structure for high dopant concentration. The photoluminescence spectra showed narrow lines caused by f-f transitions in the rare earth dopants. Distributions of these lines intensity differ for the samples with different concentrations for both Er3 and Eu3 ions. This effect can be related with different symmetry of the rare earth ions sites in the monoclinic and tetragonal crystal phases. It was shown that crystal structures of the samples also effects on intensity and distribution of the lines intensity in emission spectra. This work has received funding from Ministry of Education and Science of Ukraine and from the EU-H2020 grant No 654360 within the framework of the NFFA-Europe Transnational Access Activity.

Q.11.2
09:45
Authors : Benedetta Del Secco, Luca Ravotto, Tatiana V. Esipova, Sergei A. Vinogradov, Damiano Genovese, Nelsi Zaccheroni, Enrico Rampazzo, Luca Prodi
Affiliations : Department of Chemistry ?Giacomo Ciamician?, University of Bologna, Via Selmi 2,40126 Bologna, Italy Departments of Biochemistry and Biophysics and of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA

Resume : The development of nanotechnologies in the field of medicine has opened up the design of synergic tools where therapeutic and diagnostic features can be combined in a single nanostructure. In this framework, silica nanoparticles (NPs) with a polymeric soft shell and a dye-doped silica hard core (Pluronic-Silica nanoparticles (PluS NPs), patented in 2011 by L.Prodi et al) are versatile nanomaterials, and all the experimental results, so far, are in favours of their benign nature in biomedical applications. The advantages of these NPs include their ease of preparation, inexpensive starting materials and the possibility to functionalize them or to load them with various doping agents especially luminescent species or drugs. However,the solubility of the doping agent(s) imposes constraints on the choice of the reaction system and hence limits the range of molecules that can be included in the NPs.We succeeded in overcoming this problem, improving the current state of the art of the synthetic strategies based on Pluronic F127, by enabling the synthesis in the presence of large amounts of organic solvents We obtained nanoparticles doped with large amounts of water-insoluble silane derivatized metallo-porphyrins developing four different NPs able to act as a chemosensor (nanosensors) for molecular oxygen. Moreover, our synthetic strategy is versatile for many applications allowing the future development of new silica nanosystem also for imaging, drug delivery or catalysis

Q.11.3
10:00
Authors : Stanislav V. Zabotnov (1), Fedor V. Kashaev (1), Anastasiia V. Skobelkina (1), Denis E. Presnov (1), Daria A. Kurakina (2), Aleksandr V. Khilov (2), Ekaterina A. Sergeeva (2), Mikhail Yu. Kirillin (2), Leonid A. Golovan (1)
Affiliations : (1) Lomonosov Moscow State University, Faculty of Physics, 1/2 Leninskie Gory, Moscow, 119991 Russia; (2) Institute of Applied Physics RAS, 46 Uljanov str., Nizhny Novgorod, 603950 Russia

Resume : Currently silicon nanostructures, besides having high potential for novel micro- and nanoelectronic devices development, are perspective agents for biomedical applications as well [1,2]. In the present work we study the ensembles of nanoparticles fabricated through picosecond laser ablation in distilled water in the course of irradiation of monocrystalline and porous silicon, and silicon micropowders. The size of such particles varies from 2 to 300 nm depending on the type of target used for ablation. Analysis of the produced nanoparticles Raman spectra revealed high level of their crystallinity: more than 88% for all cases. Spectrophotometry measurements of the fabricated silicon nanoparticles revealed relatively high scattering coefficient in the spectral range 400 ? 1000 nm. Optical coherence tomography imaging of the suspensions drops administered on agar gel surfaces indicated high efficiency of the nanoparticles as contrast agents providing contrast up to 30 dB. The reported results demonstrated the perspectives of fabricated nanoparticles suspensions as agents for controlling optical properties in photonics and biomedical applications. The work was financially supported by the Russian Science Foundation (project #19-12-00192). [1] V. Stojanovi?, F. Cunin, J.O. Durand, et al. J. Mater. Chem. B, 4, 7050 (2016). [2] O.I. Ksenofontova, A.V. Vasin, V.V. Egorov, et al. Tech. Phys., 59, 66 (2014).

Q.11.4
10:15
Authors : Ungula J, Dejene B F
Affiliations : Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba, 9866, South Africa.

Resume : ZnO nanoparticles were synthesized by Sol-gel method at different temperatures. The effects of growth temperature on the structure and optical properties of ZnO nanostructures were investigated in detail. Temperature is an important thermodynamic factor that plays a key role in controlling the growth rate of a crystal, the morphology and aspect ratio of ZnO nanostructures. The characterization of the nanoparticles with Scanning Electron Microscopy (SEM) showed that at low temperatures (35 °C and 45ºC) needle like particles were observed. As the growth temperature increases to 75 °C, Spherical particles are formed. The particle size, lattice parameters and crystal structures of the nanoparticles are characterized by X-ray diffraction (XRD). The average crystallite sizes have been found to increase with the increase in growth temperatures from 27.6 nm to 34.2 nm. Results of XRD showed a systematic shift in peak positions towards lower 2? values with the increase in growth temperatures caused by change in lattice parameters. The intensity of the DLE band, as observed, from photoluminescence spectra decreased with the increase in growth temperature. The estimated band gap reduced from 3.31 eV to 3.24 eV with the increase in the growth temperature. Keywords: ZnO; Nanoparticles; Sol-gel; Annealing temperature, Morphology, Luminescence

Q.11.5
10:30 Coffee break    
 
Modelling and Simulation : Zineb Saghi
11:00
Authors : Aleksandra Jankowska and Magdalena BIrowska
Affiliations : University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland

Resume : The metal phosphorus trichalcogenides (MPX3) are the van der Waals layered materials, which have been widely studied in the bulk form [1]. Since the graphene has been successfully exfoliated, atomically-thin layered materials have captured great attention of the scientific community, due to the wide range of unique properties not observed in th bulk counterparts. The 2D metal phosphorus trichalcogenides are of special note in future magnetic and spintronic device applications. In addition, mixed compositions of metallic cations (M) can result in in enhancement of various properties, e.g. better electrocatalytic performance and water splitting has been previously observed for CoNiPS3 material [2]. Hence, the potential applications of MPX3 could be extended. In this study, we present the results of extensive first principles calculations of the mixed MnxNi1-xPS3 systems. Our studies are based on the ab initio calculations in the framework of the density functional theory (DFT), with the generalized gradient approximation with U correction (GGA U) for the exchange-correlation density functional, and the weak van der Waals forces included, as implemented in the numerical package VASP. The structural, energetic and magnetic properties of MnxNi1-xPS3 monolayers for different metallic compositions x, and different arrangement of spins on the manganese and nickel atoms will be presented. All of the presented results will be compared to NiPS3 and MnPS3 monolayers and theirs bulk counterparts. The research was supported in part by PL-GRID Infrastructure, and computing facilities of the Interdisciplinary Centre of Modelling of the University of Warsaw. The work has been funded by the NCN grant SONATA (no. UMO-2016/23/D/ST3/03446). [1] R. Brec, Solid State lonics 22, 1986, 3. [2] Q. Liang et al., Adv. Funct. Mater. 28, 2018, 1805075.

Q.12.1
11:15
Authors : Ilya S. Popov, Nataliya S. Kozhevnikova, Andrey S. Vorokh, Andrey N. Enyashin
Affiliations : Institute of Solid State Chemistry UB RAS, Ekaterinburg, Russia

Resume : The CdS nanoparticles possess a number of unique photocatalytic and optical properties. The application of such nanoparticles can be expanded further by increasing their resistance to agglomeration and oxidation by embedding them into glasses or an amorphous SiO2. The synthesis technique for obtaining of CdS nanoparticles in glass proceeds in two stages: glass melting and secondary heat treatment. However, no comprehensive information on the phase equilibrium and the structure of the interface between the nanoparticles and the glass can be found to date. Therefore, we conduct a theoretical survey for the core@shell CdS@SiO2 nanoparticle system by means of the MD simulations. The study is carried out using an in-house code with the pair potentials. CdS core and SiO2 shell had stoichiometric compositions and diameter of 4 nm and thickness of 2 nm, respectively. The models of CdS core in both the wurtzite and sphalerite phase were considered. Simulations were performed on 0.1 ns time intervals at temperatures from 300 to 1200K. The results show that the CdS sphalerite core may be thermodynamically slightly more stable than the wurtzite core. However, at elevated temperatures, the sphalerite core gets progressively amorphized. According to results, the CdS wurtzite core should crystallize first from the glass matrix under high-temperature conditions. The results are compared with the CdS@TiO2 system. Authors acknowledge the Russian Science Foundation (project ?17-79-20165).

Q.12.2
11:30
Authors : Maurizio Coden, Barbara Fresch
Affiliations : Università degli studi di Padova; Università degli studi di Padova

Resume : Most of the applications of semiconductor quantum dots (QDs) are not based on isolated QDs but on a molecular or solid-like assembly of nanocrystals. Therefore, the collective opto-electronic properties of QD materials is influenced by mutual interdot interactions. Moreover, exciton energy transfer and electronic coupling are hampered in colloidal QD aggregates because of the nanoparticle isolation due to the capping ligands that reduce the charge carrier extraction and mobility. Understanding if and how the electronic density of the excitonic states spreads into the ligand shell is essential to understand their photophysics and to engineering ligands promoting interdot excitonic coupling and electronic energy transfer. We address this issue by performing all-atom calculations in models of colloidal QD dimers at the DFT and TD-DFT level of theory. Magic sizes (CdSe)13 and (CdSe)33 QD units are linked by phenyl-dithiocarbamate (PDTC), recently proposed as exciton delocalizing ligand. We show that in the (CdSe)13-PDTC-(CdSe)13 dimer, the formation of interdot delocalized exciton is analogous to the formation of Frenkel exciton in molecular systems but the energy scale of the inter-unit electronic coupling is substantially smaller than those typical of molecular aggregates. In the hetero-dimer (CdSe)13-PDTC-(CdSe)13 excitations are not delocalized but charge transfer states appear at accessible energies. The nature of the coupling is discussed, coulombic contributions are found to dominate even at the smaller surface to surface distance. The validity of the widely used dipole-dipole approximation is critically analyzed.

Q.12.3
11:45
Authors : Petra Matunová, Vít Jirásek, Bohuslav Rezek
Affiliations : Faculty of Electrical Engineering, Czech Technical University, Technická 2, Prague 6, 166 27, Czech Republic, Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, Prague 6, 162 00, Czech Republic; Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, Prague 6, 162 00, Czech Republic; Faculty of Electrical Engineering, Czech Technical University, Technická 2, Prague 6, 166 27, Czech Republic, Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, Prague 6, 162 00, Czech Republic;

Resume : Finding novel flexible materials for renewable energy generation is increasing in importance to meet the modern society requirements. Diamond nanoparticles denoted as nanodiamonds (NDs) possess numerous beneficial material properties and are envisioned for a wide range of applications. Blending NDs with organic materials into organic-inorganic composites could provide new beneficial properties for solar cells, in contrast with the well-established but not ideally cost-effective and adaptable silicon photovoltaics. In this work, complexes of polypyrrole (PPy) organic dye covalently grafted to ND surfaces are investigated by atomic scale density functional theory (DFT) computations with a view to their structural and electronic properties. We consider NDs terminated with oxygen, hydroxyl, carboxyl, anhydride, as well as amorphous carbon (a-C:H, a-C:O). Thereby the theoretical model is brought close to real nanodiamonds. We observe spatially separated HOMO and LUMO and favorable energetic level alignment at the ND-PPy interface for the majority of the oxidized NDs. This feature is also retained for NDs with the amorphous surface layer. Excited states are computed by time-dependent DFT (TDDFT) to analyze how the electronic configuration can promote dissociation of excitons, for instance in photovoltaic applications. The computed results thus provide guidance for the synthesis of real ND-PPy composites. We acknowledge financial support from the CVUT student project SGS18/179/OHK4/3T/13 and European Regional Development Fund project CZ.02.1.01/0.0/0.0/15_003/0000464.

Q.12.4
12:00
Authors : Tu C. Le
Affiliations : School of Engineering, RMIT University, GPO Box 2476, Melbourne, VIC 3001, Australia

Resume : Machine learning methods are efficient tools to develop novel materials for different applications. They are fast, resource efficient, versatile, and low cost. They produce reliable, repeatable results, uncover hidden insights through learning from trends in the data, and are essential synergistic elements of any experimental project, especially those that generate high volumes of multi-dimension data using high throughput experiments. This presentation will provide examples of how these efficient approaches, coupled with a strong understanding of molecular properties and interactions, can generate useful and robust models for ?smart?, self-assembling amphiphiles for targeted drug delivery. This approach also allows the determination of factors that significantly affect the materials properties and therefore allow the design of new materials or optimization of existing materials.

Q.12.5
12:15 Lunch break    

Symposium organizers
Luca PASQUINIUniversity of Bologna

Department of Physics and Astronomy, Viale Berti-Pichat 6/2, Bologna, Italy

luca.pasquini@unibo.it
Patricia ABELLANInstitute of Materials Jean Rouxel, CNRS - UMR 6502

Physics of Materials and Nanostructures Group, 2 rue de la Houssinière, BP32229, 44322 Nantes cedex 3, France

pabellan2@gmail.com
Petra DE JONGHUtrecht University

Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands

P.E.deJongh@uu.nl
Petra SZILAGYIQueen Mary University of London

Mile End Road, E1 4NS London, U.K.

p.szilagyi@qmul.ac.uk