Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 2nd International Conference and Exhibition on Materials Science and Chemistry Berlin, Germany.

Day 1 :

  • Materials Science and Engineering | Materials Chemistry in Developing Areas | Formulating Materials Chemistry
Location: Berlin, Germany
Speaker
Biography:

Hisayoshi Kobayashi is a Professor of Kyoto Institute of Technology. He got his Doctor's degree at Kyoto University in 1982 from Prof. Kenichi Fukui. His field is theoretical analysis of catalysis of metal and metal oxide surfaces. He got Award for Younger Researchers from the Catalysis Society of Japan in 1989, and the BCSJ Award Article from the Chemical Society of Japan in 2007. Shinya Higashimoto is Associate Professor of Osaka Institute of Technology. He received his Doctor's degree of Engineering at Osaka Prefecture University in 2000. His field is catalysis and photo-electrochemical phenomena on the metal-oxide and/or semiconductor surfaces.

Abstract:

The selective photocatalytic oxidation of benzyl alcohol by O2 on the TiO2 surface was theoretically studied by DFT calculations. Experimentally, it is well known that (1) benzyl alcohol is oxidized to benzaldehyde, but not further oxidized to benzoic acid, and (2) TiO2 surface itself is insensitive for the visible light, but becomes sensitive by benzyl alcohol adsorption. These phenomena were clarified by the plane wave based DFT calculations. Dehydroxylated and partially hydroxylated TiO2 with an anatase TiO2 (101) crystal face were modeled with a slab of Ti16O32 and Ti16O32(OH)H, respectively. It was found that the interaction of benzyl alcohol with the hydroxylated TiO2 surface significantly induces the formation of the alkoxide species, of which the donative orbitals hybridized with the O2p orbital in the valence band (VB) of the TiO2. The visible light response is attributed to the electronic transition from the donor levels created by the alkoxide species to the conduction band (CB). The dissociation of methylene C-H in the alkoxide was assisted by O2, and this process was confirmed to be the rate-determining step. Furthermore, the hydro-peroxide (OOH) species formed by O2 reduction can also oxidize another benzyl alcohol into benzaldehyde together with Ti-OH regeneration. It was thus clearly demonstrated that two benzaldehyde molecules were formed from two benzyl alcohols and one O2 molecule on the TiO2 photocatalys.

Speaker
Biography:

Patrick Grant completed his PhD at the age of 24 from Oxford University where he then undertook postdoctoral studies. He is now the Vesuvius Chair of Materials, Head of the Department of Materials at Oxford University, and leader of the Processing of Advanced Materials group that researches new processes for advanced structural and functional materials. He has published more than 200 papers journals, has 7 patents, and was elected to the Royal Academy of Engineering in 2010.

Abstract:

The development of electrochemical energy storage devices such as supercapacitors and Li ion batteries (LiB's) has been led by electrochemists, resulting in steady improvements in key performance metrics such as energy density, cycle life, etc. Over the same period, the production of electrochemical cells in which the positive and negative electrodes are slurry cast composites has accelerated to reach nearly 5 B pa. For a given electrochemical system, the optimisation of the electrode microstructure in these devices has been empirical, inferred from exhaustive electrochemical testing, and advanced principally by varying the average fractions of the different materials (actives, binder, conductivity enhancers, porosity, etc.) in the composite electrode. Arguably, the penetration of exciting new energy storage chemistries has been slowed and constrained by a lack of optimisation tools that account for the complexities of electrode dynamics and their degradation, and the absence of a flexible manufacturing technology for the fabrication of designed, structured electrodes with spatially varying properties.

This talk will provide an overview of recent efforts of the Oxford group to develop new processing routes that allow better micro- and meso-scale control of the electrode structure in both supercapacitors and batteries. Examples will be given of how these new approaches to electrode manufacturing can both enhance existing electrochemical systems and facilitate new systems that are otherwise difficult. Reference will be made to the cost-effectiveness and scalability of approaches, and the key insights and data that are needed from modelling and in-situ experiments to guide the future manufacture of optmised electrodes.

Speaker
Biography:

Leonard Brillson received his A.B. from Princeton University and his Ph.D. from the University of Pennsylvania. He has published over 350 journal articles and 4 books. He is a Fellow of the Institute of Electrical and Electronics Engineers, the Materials Research Society, the American Institute of Physics, the American Association for the Advancement of Science, and the AVS Science & Technology Society as well as a recipient of the Gaede-Langmuir Award. Prior to joining Ohio State University, he directed Xerox Corporation’s Materials Research Laboratory and had responsibility for Xerox Rochester’s long-range physical science and technology programs.

Abstract:

Spatially-resolved cathodoluminescence spectroscopy has contributed significant new information to our understanding of native point defects in ZnO micro- and nanoscale structures. This presentation will review representative examples of this work and the new perspectives gained from spatially resolving these defects both laterally and depth-wise. Results obtained from many groups worldwide include studies of Schottky diodes, polycrystalline, ceramics, nanostructures, and microwires. The nature and spatial distribution of native point defects in these materials together with their strong dependence on growth and processing suggest new avenues for their control in transport and optoelectronic device structures. A key aspect of ZnO-based materials and applications is the nature, spatial distribution, and electronic impact of native point defects. These features are particularly important at the micro- and nanoscale, where their physical properties can dominate charge carrier transport and electronic contacts. Starting from the optical identification of specific defects already discussed in the literature, this talk focuses on the new defect information provided by spatially-localized cathodoluminescence spectroscopy (CLS). This technique has unique advantages in measuring key defect features. Spatially-resolved CLS has now shown that: (1) native point defects are present inside these structures and not just on their surfaces; (2) their nature and distribution depend on the specific growth method used to create them; and (3) they can strongly affect nanoscale transport and device properties. These studies suggest many new avenues to understand and control defects in ZnO and may be of more general significance as spatially-resolved cathodoluminescence spectroscopy extends to other semiconductors and device structures.

Speaker
Biography:

Daniel E. Lazo completed his Bachelor’s degree from the University of Lima, Peru, and his Master’s from Purdue University, West Lafayette, USA. He is currently pursuing his Phd degree in Extractive Metallurgy at the Western Australia School of Mines, Curtin University, Australia. He has work experiences in Peru, USA and Australia. It was during his stint at a mining operation in South America where he got interested in pursuing postgraduate studies in mineral processing and hydrometallurgy.

Abstract:

Daniel E. Lazo completed his Bachelor’s degree from the University of Lima, Peru, and his Master’s from Purdue University, West Lafayette, USA. He is currently pursuing his Phd degree in Extractive Metallurgy at the Western Australia School of Mines, Curtin University, Australia. He has work experiences in Peru, USA and Australia. It was during his stint at a mining operation in South America where he got interested in pursuing postgraduate studies in mineral processing and hydrometallurgy.

Speaker
Biography:

Dr. Valentin Valtchev is Research Director at the Laboratory of Catalysis and Spectroscopy (LCS) in Caen, France and “Thousand Talents” Professor at the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry in Jilin University, P. R. China. His research involves synthesis and modification of zeolites and other porous solids that can be used for catalysis, separation and molecular recognition. He has published more than 200 papers, a number of review articles and book chapters, 6 books and 21 patents.

Dr. Valtchev is recipient of: “Baron Axel Cronstedt” award (2014) of the Federation of European Zeolite Associations; “Donald Breck” award (2016) of the International Zeolite Association; and “La Recherche 2016: Chimie” in France.

In 2016 Valentin Valtchev was elected President of the International Zeolite Association.

Abstract:

Porous materials are those permeable to fluids due to the presence of pores. Amongst different groups of materials the zeolite type materials has the biggest impact on the modern society. Zeolites are crystalline microporous crystals with well define pores with size below 2 nm, large micropore volume and specific surface area, tunable active sites and unique shape selectivity. These properties make zeolites indispensable catalysts and molecular sieves in petroleum refining, petrochemical industry, protection of the environment and as a component of different products used in the household. In the future, their impact will widen and be felt in the processing of heavier fossil and renewable feedstocks, optical and medical applications. The diversified feedstocks, together with the changes in the products demand and environmental regulations, make the design and engineering of zeolite based materials a complex task. In order to address new challenges detail insights in the structure-property relationship of zeolite molecular sieves are indispensable. The talk will provide an overview of the current developments in the field of zeolite-type materials. Both, in-situ and post-synthesis methods of modification of zeolite molecular sieves will be addressed. The advances in the understanding of the nucleation/crystal growth process will be discussed and example how the new knowledge serve to obtain zeolites with predetermined properties will be given. Post-synthesis methods for control of the physicochemical properties of zeolites will also be addressed. For instance, a drawback in the use of zeolites is the restricted diffusion, which is commonly associated with the sub-nanometer size of their pores where the active sites are located. The post-synthesis methods that allow overcoming this roadblock to the more efficient use of zeolites will be overviewed. Finally the complementarily between in-situ and post-synthesis methods with the goal to overcome the natural limits and obtain unique zeolitic materials will be addressed.

Speaker
Biography:

Rénal Backov obtained his PhD in 1997 at the University of Montpellier, France while being a post-doc fellow at the University of Florida, USA 2001. Full Professor since 2010 at the University of Bordeaux his  research focuses on the rational design of advanced  materials through combining physical chemistry of complex fluids and chemistry. He formalized the concept of Integrative Chemistry in 2006 and was Laureate of the French Chemical Society in 2013. With more than 140 articles and 300 contributed papers, his research encompasses the domains of energy conversion and storage, drug delivery, sensors, heterogeneous catalysis, photocatalysis, etc.

Abstract:

Chemical sciences are on continuous evolution offering more and more complex synthetic strategies that rely on emerging inter- and trans-disciplinary action modes. In this context, beyond the ability of constructing advanced functional materials we demonstrate how the Integrative Chemistry allows positioning chemical reactors within the geometric space. When it turns to energy dedicated advanced materials we will focused on oxide monoliths bearing hierarchical porosity. We will see first how through enzymatic engineering we can trigger biodiesel generation bearing unprecedented TON and TOF catalytic efficiency. Secondly when going from silica foams, used as hard templates, toward carbonaceous ones we will see how we can generate outstanding enzymatic biofuel cells, Li-ion and Li-S performant and stable battery electrodes. Also we will see that it is possible to trigger hydrogen storage and reversibility based on Li(BH4) confinements. Novel Bacteria-based bioreactors will be discussed.

Speaker
Biography:

Graduated in Biological Sciences, Master in Biochemistry by the Institute of Chemistry (UFRJ) and Doctorate in Technology of Chemical and Biochemical Processes - Chemical Engineering by the School of Chemistry (UFRJ). He is currently an adjunct professor at the Federal University of Rio de Janeiro - Campus Macaé / Professor Aluísio Teixeira, ministering disciplines in the area of ​​Analytical Chemistry. He has developed projects with exopolysaccharides of marine cyanobacteria for application as antifouling in anticorrosive paints. He is currently Coordinator of the Group of Bioelectroanalytics and Advanced Materials at UFRJ-Campus Macaé and develops research in the area of ​​quantification of heavy metals in different samples using electroanalytical methods, electrode construction and modified sensors for interaction with different macromolecules, study and development of anticorrosive coatings and development of films by electropolymerization with natural marine products.

Abstract:

The anticorrosive and antifouling performance of copper oxide-based organic coatings incorporated with microbial exopolysaccharides (EPS) was studied using electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) after immersion in water produced by oil wells and in natura seawater. EPS incorporation in the paint did not influence the coating's final anticorrosive behavior. Moreover, no bacterial adhesion occurred during the immersion period in the presence of EPS, indicating the biopolymer as a promising biocide for the antifouling paint sector.

Speaker
Biography:

Hisayoshi Kobayashi is a Professor of Kyoto Institute of Technology. He got his Doctor's degree at Kyoto University in 1982 from Prof. Kenichi Fukui. His field is theoretical analysis of catalysis of metal and metal oxide surfaces. He got Award for Younger Researchers from the Catalysis Society of Japan in 1989, and the BCSJ Award Article from the Chemical Society of Japan in 2007. Hiroaki Tada received his Dr. degree in engineering from Kyoto University in 1991. After worked at Nippon Sheet Glass Co., he joined to Kinki University in 1997, and became a Professor in 2004.

Abstract:

Photoelectrochemical experiments and DFT calculations indicated that visible-light irradiation of the CdS quantum dots (QDs)−TiO2 direct coupling system (CdS/TiO2) causes the electron injection in two paths: The inter-CB electron transfer from CdS to TiO2 (path 1) and that the electron transfer from the valence band (VB) of CdS into the conduction band (CB) of TiO2 (path 2). Path 2 can be induced by the sub-bandgap excitation of CdS QDs to extend the spectral response of the CdS/TiO2 system. For path 2 as well as path 1 to effectively work, CdS QDs should be directly deposited on the TiO2 surface with high coverage.

According to the guideline, a photocatalytic growth of the preformed seed (PCGS) technique has been developed. Transmission electron microscopy observation and X-ray photoelectron spectroscopy measurements of the CdS/TiO2 prepared by the PCGS technique indicated that the TiO2 surface is highly covered by CdS QDs. The technique was applied to mesoporous TiO2 nanocrystalline films (mp-TiO2) to yield CdS/mp-TiO2. CdS QD-sensitized photoelectrochemical (QD-SPEC) cells with a structure of CdS/mp-TiO2 (photoanode)|aqueous sulfide solution|Ag/AgCl (reference electrode)|Pt (cathode) were fabricated. The rate of hydrogen (H2) generation in the QD-SPEC cell under illumination of simulated sunlight (AM 1.5, 1 sun, λ > 430 nm) increases with an increase in the TiO2-surface coverage by CdS QDs. We also show that the sub-bandgap excitation of a directly coupled CdSe quantum dot–TiO2 system induces electron injection from CdSe levels to the conduction band of TiO2.

  • Materials Synthesis and Characterization | Insilico Materials Chemistry | Regenerative Materials Chemistry
Location: Berlin, Germany
Speaker
Biography:

42 years-old, University of Bordeaux associate professor-HDR, over 70 publications in international journals. She is a specialist of luminescence of inorganic doped compounds. V. Jubera has been working as an associate professor at the ICMCB-CNRS, University of Bordeaux for 14 years. Her research topic deals with the structure-luminescence properties of crystallized materials. The luminescence spectroscopy is performed to evaluate the potentiality of phosphors for displays, lighting, sensing or lasers materials. She has been developing in the Institute, topics on the synthesis and characterization of massive (single crystals, transparent ceramics) innovative compounds as well as nano-powders. Her activities is fully included and supported by the competitiveness cluster ”Routes des Lasers” and the cluster Laphia (IDEX Univ. de Bordeaux).

Abstract:

Considerable efforts have been carried out to develop new tools and research efforts in the domain of functionalized materials (information, lighting, communication, energy etc). As an illustration, to correlate the optical response of a material to another of its property is possible through the monitoring of the luminescence.

(i) Modifications of the doping element local environment is associated to crystal field strength modification. For instance, divalent manganese radiative transitions can be observed from the green to the red ranges. Synthesis control route makes possible a red to green luminescence switch of manganese doped spinel treated at high temperature in relation with the cation migration through the host lattice. In other matrices, external factors induce unit cell symmetry transition. This effect can also be observed in rare earth doped compounds as Eu3+ doped sesquioxyde .

(ii) Irradiation energy is also an efficiency factor which can initiate redox processus. The oxidation of europium +II to europium +III state results in a shift from blue to red emission. UV irradiation of cerium doped Indium elpasolite matrix leads to the decrease of the doping element emission in favor of a bright orange emission. The corresponding redox process is reversible under adequate irradiation or heat treatment temperature. Such local modification can easily be detected over the visible range.

(iii) Emission of ZnO are strongly related to synthetic routes. Low operating temperature can result in the appearing of surface and bulk defects. Their existence impacts not only the emission wavelength but also its stability under specific atmosphere.

Finally, luminescence spectroscopy is not only a technique to register the spectral distribution of the excitation or emission radiative de-excitation, it is also an efficient tool to highlight the influence of external factors and to record the history of a materials.

Speaker
Biography:

Stéphane Cordier is specialist in crystal chemistry and cluster-based compounds (http://orcid.org/0000-0003-0707-3774). He has developed methodologies that aim at using cluster-based ceramics for the design of hybrid nanomaterials and in particular cluster-based copolymers. His research covers a continuum from fundamental research -in order to correlate physical properties to crystal and electronic structures of solid state compounds- to the integration of inorganic clusters onto functional surfaces or in optoelectronic devices. He has in charge the Group Solid State Chemistry and Materials (https://iscr.univ-rennes1.fr/csm/) from the Institut des Sciences Chimiques de Rennes.

Abstract:

Metal atom clusters are aggregates of metal atoms held together by metal-metal bonds. Mo6 octahedral clusters are stabilized by inner ligands (Li) in face-capping positions and apical ligands (La) in terminal positions to form [M6Li8La6]n- units. On one hand, the concept of [M6Li8La6]n- unit constitutes a useful virtual object to describe the crystal and electronic structures of cluster-based solid state compounds. On the other hand, the dissolution of solids affords discrete [M6Li8La6]n- units in solution that constitute real and handleable molecular objects with unique physico-structural properties usable as building blocks in the elaboration and structuration of molecular assemblies and nanomaterials. The delocalization of electrons on all the metal centers leads to specific physical properties as for instance luminescence and even photocatalytic properties.

Optical properties of [Mo6Li8La6]2- octahedral cluster units are characterized by a large absorption window from UV to visible and a large emission window from 550 nm to the NIR region. Thus, such clusters can be used as red phosphorescent dyes for many potential applications including nanoparticles for biolabelling, liquid crystals and luminescent nanocomposites for lighting and displays. Cs2Mo6Xi8Xa6 (X = Cl, Br and I) ternary compounds are prepared by solid state chemistry route at high temperature. Interestingly, these ceramics are soluble in many common solvent affording functional [Mo6Xi8Xa6]2- cluster units that can be further use as building blocks for the design of hybrid co-polymers. Cluster based hybrid co-polymers associate the mechanical and shaping properties of the organic matrices along with the phosphorescent properties of inorganic metallic clusters. We will present here (i) the origin of dual emission of Mo6 cluster based compounds and (ii) several examples of potential applications of nanomaterials based on the incorporation of [Mo6Xi8La6]2- cluster units in organic polymers (i.e. oxygen sensors and optical waveguides).

Alain DEMOURGUES

ICMCB-CNRS-University of Bordeaux ,France

Title: New Cerium and Praseodymium-based oxides as redox catalysts
Speaker
Biography:

Dr Alain DEMOURGUES is working at ICMCB-CNRS-UPR9048 since october 1993 as Research Fellow. He became Research Director at CNRS in october 2008. He received IBM-France award in 1993 (Young scientist in Materials Science) and SFC (Société Française de Chimie) award in 2003 (Solid State Chemistry division). He is consulting scientist since 1998 at RHODIA-SOLVAY in the field of Solid State Chemistry, Redox and opto-electronic properties. He contributes to 128 publications (h-index 23) and 9 patents and gave 39 invited conference and 30 in international symposia. He was in charge of 20 industrial contracts and directed 19 PhD students. He is in charge of fluorine chemistry/inorganic fluorides unit (CNRS platform ‘Fluomat’) and cross functional axis related to exploratory solid state chemistry.

Abstract:

In the last 20 years, intense efforts deal with the environmental impact decrease of the automotive exhaust gases. Highly severe regulations led to design new materials for CO, unburnt hydrocarbons oxidation and for the NOx reduction from industrial sources, especially from diesel automotive engines. Diesel Oxidation Catalysts (DOC) have then been developed to oxidize CO, hydrocarbons and NO, in order to reach the NO2/NOx ratios suitable for the downstream system of Selective Catalytic Reduction (SCR) of NOx by ammonia. Therefore, Rare-earth oxides (REO) involving mixed valence states such as Ce4+/Ce3+, Pr4+/Pr3+ and Tb4+/Tb3+ exhibit the best acid, basic and redox properties (with high oxygen availability and mobility) to fulfill the requirements of enhanced catalysts. Considering that Tb4O7 is too expensive for extended industrial applications, the objective is to finely tune the composition, structure, texture, oxygen mobility and storage of Ce/Pr/Zr based oxides to design effective and robust catalysts for DOC and SCR. Recent studies have evidenced that a fine tuning of some chemical CeO2-ZrO2-Pr6O11 compositions  can stabilize Pr4+/Pr3+ rates associated with oxygen vacancies leading to high OSC, oxygen mobility, thermal stability up to 1400°C and surface areas varying between 80 and 40 m2/g at 700°C. Moreover, preliminary catalytic results for DOC application revealed outstanding properties without any PGM (Platinum Group Metal). Neutron and X-Ray diffraction analysis during the redox cycle reveal the occurrence of oxygen vacancies ordering depending on the Pr4+/Pr3+ and Ce4+/Ce3+ atomic ratios  determined by magnetic measurements and XANES analysis.

Speaker
Biography:

Dr. Viktor Balema’s expertise includes new materials development in academic and industrial environment. The main focus of his research during the last decade has been on the energy conversion and storage materials, and non-conventional materials preparation techniques, including solvent-free mechanochemistry.  For a decade, between 2006 and 2016, Dr. Balema was directing Hard Materials Market Segment and Materials Science R&D at Sigma-Aldrich Co.  In August of 2016, he joined the Ames Laboratory - led research consortium CaloriCoolTM where he directs the materials development group.  Dr. Balema has served as expert- reviewer for the US Department of Energy, NSF, U.S. Civilian Research and Development Foundation (CRDF), ACS Petroleum Research Fund and a variety of peer reviewed scientific journals. He has also acted as section chair at annual MRS meetings and other conferences.

Abstract:

The presentation addresses the mechanochemical approach to solid-state synthesis, which proved to be indispensable for the solvent-free preparation of a great variety of molecular, ionic and metallic solid materials.  The talk specifically focuses on the solid-state synthesis of rare earth-based metal organic frameworks (MOFs), which have a potential for becoming materials of choice for low temperature magnetocaloric systems that are under development at CaloriCoolTM.  CaloriCoolTM  is a newly established research consortium, which discovers, develops and deploys materials for magneto- electro- and elastocaloric cooling.  It is a part of the DOE’s Energy Materials Network (EMN) designed to accelerate innovation around the clean energy industries by addressing pressing materials challenges ranging from early development to manufacturing.

In the course of our research, we showed that the mechanochemical approach can be successfully applied to the preparation of MIL-78-type Metal Organic Frameworks. Contrary to the previous reports, the presence of a liquid (liquid assisted grinding) is not essential for the process.  Thus obtained Gd-, Tb- and Dy- based MOFs showed short range magnetic order below 20 K; no long range order was observed down to 2 K. The magnetocaloric effect of Gd-based material was found to be comparable to the best known cryogenic refrigerants.

Our further investigations revealed that the mechanochemical methodology can be extended onto other rare earth-based hybrid organic-inorganic materials with substantial magnetocaloric effect at cryogenic temperatures. We also found that a catalyst which improves efficiency of mechanically driven reactions.

CaloriCoolTM is supported by the United States Department of Energy, Office of Energy Efficiency and Renewable Energy though its Advanced Manufacturing and Building Technologies Offices.  Ames Laboratory is supported by the Office of Science, Basic Energy Sciences Programs and operated by Iowa State University under contract No. DE-AC02-07CH11358 with the United States Department of Energy.

Weichun Pan

Zhejiang Gognshang University School of Food and Biotechnology, PRC

Title: Salting-in effect on muscle protein extracted from the giant squid (Dosidicusgigas)
Speaker
Biography:

Dr. Pan has completed his PhD at the age of 36 years from the University of Houston and continued his postdoctoral studies at the same school. Then he went to Tohoku University serving as a researcher. He is the chiar of Applied Chemistry Department. He has published more than 20 papers in reputed journals.

Abstract:

The salting-in effect of muscle protein is a well-known phenomenon in food science but is hard to explain by conventional theories. Myofibrillar protein extracted from the giant squid (Dosidicusgigas) was selected as a model muscle protein to study this mechanism in potassium chloride (KCl) solutions. Studies have reported changes in the secondary structures of myofibrillar protein molecules caused by concentrated salt, particularly in the conformation of the paramyosin molecule. Zeta-potential determinations showed that these secondary structures have modified protein molecule surfaces. As salt concentration increased from 0.1 to 0.5M, the zeta-potential of the myofibrillar protein molecules fell from −7.24±0.82 to −9.99±1.65 mV. Meanwhile, the corresponding second virial coefficient increased from –85.43±3.8×10-7 to –3.45±1.3 × 10-7 mol mL g-2. Based on the extended law of corresponding states, the reducing attractive interactions cause protein solubility to rise. Determining the solubility in alternating KCl concentrations also demonstrated that this conformational change was reversible.

Speaker
Biography:

42 years-old, University of Bordeaux associate professor-HDR, over 70 publications in international journals. She is a specialist of luminescence of inorganic doped compounds. V. Jubera has been working as an associate professor at the ICMCB-CNRS, University of Bordeaux for 14 years. Her research topic deals with the structure-luminescence properties of crystallized materials. The luminescence spectroscopy is performed to evaluate the potentiality of phosphors for displays, lighting, sensing or lasers materials. She has been developing in the Institute, topics on the synthesis and characterization of massive (single crystals, transparent ceramics) innovative compounds as well as nano-powders. Her activities is fully included and supported by the competitiveness cluster ”Routes des Lasers” and the cluster Laphia (IDEX Univ. de Bordeaux).

Abstract:

Recent developments in fast sintering processes makes possible to highly densify refractive materials. The application of these techniques in order to obtain transparent laser materials is promising and satisfying efficiencies have been recorded [1-4]. Concerning the Spark Plasma sintering process, the main constraint is to control the grain growth so as to avoid anisotropy and diffusion in the ceramic, thus cubic matrices are preferred.

The lattice of the Y3NbO7 phase is very interesting as it adopts a cubic symmetry being capable of incorporating a high proportion of rare earth doping elements, without charge compensation requirements. The oxygen vacancies are tolerated between 21-28% of niobium over cations (Nb/(Nb+Y)) ratio [5].

We propose to expose the structural study and luminescence properties of Eu3+ doped Y3NbO7 sintered by SPS. Indeed, the fast and high crystallization rate of the phase results in a composite pellet in which two different compositions in the solid solution range are stabilized. This result shows an unexpected lack of miscibility in the phase diagram which reflects the fact that the final composition is driven by the SPS conditions and the ratio between niobium and yttrium elements.

Speaker
Biography:

Dr. M. Olaru has a Ph.D within the field of synthesis of polyurethanes with different functional groups at “Gh. Asachi” Technical University from Iasi, Romania. She has a scientific experience embodied in over 35 papers published in reputed international/national scientific journals, 1 book and 4 chapter books published in national/international publishing houses, 1 patent, collaborator in over 15 national and 2 international projects, managerial experience gained through the coordination of 1 national and two international projects; scientific domains: photochemistry, polyurethanes, hybrid nanocomposites, cultural heritage, antimicrobial coatings;  experience in synthesis and experimental data analysis.

Abstract:

Statement of the Problem: Knowledge about pigments applied in all types of paintings, especially in the case of ancient ones, is of great importance from both art history and conservation perspectives. Usually paint surfaces consist of several complex multilayers that can be altered due to aging or various degradation factors. The deterioration depends either on the paintings surrounding conditions or on the nature of the interactions between the constituting components. Identification of pigments and other materials employed in the creation of the paintings is necessary in order to acquire information regarding their provenance, author's painting style and methods or date of production. All these information is of major importance in selecting the most appropriate materials and methods for the artwork's future restoration. Nicolae Grigorescu is the most representative Romanian painter, being considered the founder of modern Romanian painting and the most important Romanian impressionist. He generated a comprehensive, original and unitary creation, spanning over almost 4000 paintings and drawings. Although his paintings rank first place in top 100 bestselling Romanian painters, there is no comprehensive work dealing with the identification and structural characterization of the pigments and materials used by him. The combination of various mobile, non-invasive techniques (IR reflectography technique, optical microscopy, XRF, Raman and NIR spectroscopies) and lab-based devices (FTIR and XPS spectroscopies, SEM-EDX microscopy) lead to the first exhaustive investigation of pigments and materials used by the famous Romanian painter Nicolae Grigorescu in three cultural heritage paintings. The study of a large number of spots and samples allowed a rigorous analysis and a far-reaching insight into his work. Conclusion & Significance: The present work is the first scientific paper that proves the use of natural ultramarine by a painter belonging to the impressionist school.

Speaker
Biography:

Dr Olivier TOULEMONDE is working at the Institute for Solid State Chemistry Bordeaux (ICMCB) – CNRS - Université de Bordeaux since october 2005 as Assistant Professor. He became Associate Professor at University of Bordeaux in october 2006. His work is devoted to the study of the relationships between the nuclear structure and the magnetic properties of oxides materials and he especially highlights the key roles played by the charge transfert between transition metal cation. He is member of the cross functional axis related to exploratory solid state chemistry at ICMCB and elected member of the “Materials Chemistry” section of the CNRS since 2016.

Abstract:

Transition metal oxides with ABO3 and A2BO4 are known as perovskite-type and K2NiF4 type structures respectively. First, their ability to undergo reversible oxydo-reductions chemical reaction are technologically very attractive as electrodes in fuel cells (SOFC), as oxygen storage materials in anaerobic processes and as three way catalysts (TWC’s).  In addition, it is the control of oxygen released and/or up taken that opens ways towards huge change of their physical properties such as metal / insulator transition and/or antiferromagnetic to ferromagnetic transition.

When a single transition metal is introduced on the B crystallographic site, its oxidation state is indeed in direct relationship with the oxygen content. However, when two transition metal cations are introduced on the B crystallographic site, our recent results highlight that their relative oxidation states are closely related to a metal to metal charge transfer giving unexpected oxidation states distribution.

In SrFe0.5Co0.5O3-y materials, we highlight that the distribution of cobalt and iron oxidation states is heterogeneous, indicating that oxidation of cobalt cation requires higher oxidation potential than for the iron ones. We emphasize the correlation in between the exhibited paramagnetic to ferromagnetic transition around room temperature and oxidation state distributions and, used that fact to better analyze the giant exchange bias like properties exhibited by SrFe0.25Co0.75O2.63 material (see figure).

The influence of oxygen annealing in the electronic states for (Cu1-X MoX)Sr2RECu2O7+d (RE = Y, Er, Tm) has also been investigated. The predominance of the MoV oxidation state over the MoVI one on as-synthesized phases has been shown. But, annealing under flowing oxygen enhances both the MoVI and CuII amounts indicating molybdenum to copper charge transfer. Interestingly, the redox reaction related to the molybdenum to copper charge transfer is associated with a non-superconducting state to a superconducting state phase transition.

Speaker
Biography:

Varlei Rodrigues has completed his PhD at the age of 28 years from Universidade Estadual de Campinas and postdoctoral studies from Ecole Polytechnique Fédérale de Lausanne. He has published more than 25 papers in reputed.

Abstract:

The preeminent control, manipulation and analysis of liquids at the submillimeter scale in microfluidics devices allowed the integration of research fields with emergent technologies such as lab-on-chips and organ-on-chips. Microfluidic devices based on Poly-Dimethylsiloxane (PDMS) shown a plethora of experimental possibilities due to good transparency, flexibility and ability to adhere reversibly and irreversibly to distinct materials, however, its cost and handling directed the field to search for new options. The simple, fast and efficient prototyping process offered by 3D printing technology makes the technique suitable across diverse applications, emerging it as an alternative to the traditional approaches. We will present the use of a home-made fused deposition modelling 3D printer for rapid prototyping of microchannels in Poly-Lactic Acid (PLA). We were able to 3D-print sealed PLA microchannels, achieving important features, such as good transparency, use of a thermoplastic (PLA) alternative to Poly-Dimethylsiloxane (PDMS) and easy integration of other materials during printing. In particular, flexible interdigitated electrodes were easily integrated within the microchannel, creating a microfluidic device within less than one hour. Finally, the 3D printing technology potentiates the field with more creative ideas and alternative materials for a rapid prototyping of complex structures, paving the way to more abundant developments.