13^th International Conference on Advanced Materials and Nanotechnology October 26-28, 2017 Osaka, Japan

Biography:

Dr. Kai-Ming Ho has completed his PhD from University of California, Berkeley in 1978. He is currently a Distinguished Professor in Liberal Arts and Sciences at Iowa State University and Fellow of American Physical Society since 1995.

Abstract:

Material informatics is a new initiative which has attracted a lot of attention in recent scientific research. The basic strategy is to construct comprehensive data sets and use machine learning to solve a wide variety of problems in material design and discovery. In pursuit of this goal, a key element is the quality and completeness of the databases used. Recent advance in the development of crystal structure prediction algorithms has made it a complementary and more efficient approach to explore the structure/phase space in materials using computers. In this talk, we discuss the importance of the structural motifs and motif-networks in crystal structure predictions. Correspondingly, powerful methods are developed to improve the sampling of the low-energy structure landscape. Applications to the Li/Na-ion battery cathode materials, in particular A_nFeSiO₄ (n=1 and 2; A = Li and Na) [1-5] and LiFePO₄ [6-7], will be presented. 

Biography:

Professor My Ali El Khakani is the leader of the “NanoMat” Group, he founded in 1998 at the Institut National de la Recherche Scientifique (Centre-Energie, Materiaux et Telecommunications, Canada; www.wmt.inrs.ca). His R&D activities cover the inter-related fields of laser/plasma based synthesis, modification, nanoassembly and characterizations of nanostructured materials (including nanotubes, nanoparticles and ultrathin films) and their applications for advanced photo/electronic devices, functional coatings, and electro-photo-catalysis. He has published more than 190 refereed publications in prestigious journals (his current google scholar H index is 36), and co-holds 5 patents. The results of his R&D work have been disseminated in more than 250 international conferences and in numerous invited keynote talks/seminars. He has served on many international R&D steering committees and scientific advisory boards for various public and private R&D funding agencies (from Canada, USA, South America, and Europe). He has been a member of several international scientific advisory boards and/or session chair at international conferences. He has served on the editorial board of sensors letters, and he is currently member of the editorial board of the ISRN-Nanotechnology and Scientific Reports-NPG journals. He is also a regular reviewer for more than 25 refereed scientific journals

Abstract:

We will recall first the unique features of the pulsed laser deposition (PLD) technique and its latitude to synthesize either 0D and 1D nanomaterials or nanohybrid (NH) structures. Secondly, the PLD technique will be shown to be highly effective for the physical synthesis of highly crystalline PbS nanoparticles (NPs) onto various substrates with the latitude to tailor their size, and hence their bandgap over the 0.75-1.45 eV through quantum confinement effects.¹ Finally, we will show that the PLD is very appropriate for the decoration of 1D nanomaterials (e.g., single-wall carbon nanotubes (SWCNTs) or TiO₂ nanorods (NRs)) by PbS-NPs leading to the formation of a novel class of nanohybrid materials. The achieved SWCNT/PbS-NPs nanohybrids were straightforwardly integrated into photoconductive (PC) devices exhibiting unprecedented photo-response values (~700 % and ~1400 % at 633 and 405 nm, respectively).²  On the other hand, the TiO₂–NRs/SWCNTs nanostructures were integrated into nano-heterojunction PV devices of which PCE was as high as 5.3%.³ The high-purity of the PbS NPs along with their intimate bonding to the 1D structures (without the use of any bridging ligands) are key factors to ensure a highly efficient charge transfer between PbS-NPs and SWCNTs. This particular architecture is believed to be responsible for the remarkable PC/PV properties of these PLD synthesized nanohybrid materials, where the occurrence of multi-exciton generation (MEG) has been recently pointed out.

Biography:

Jungup Park has completed his PhD in chemical engineering from the University fo Texas at Austin. Currently, he is a senior researcher at the Chemicals R&D center at Samyang Corp

Abstract:

Owing to excellent heat resistance and physical properties (especially, impact strength), as well as transparency, polycarbonates (PC) have been used widely in various applications such as electronics, construction materials, and automotive components. Certain applications such as product exterior casings for electronics and headlamp reflectors require additional heat resistance due to their constant exposure to heat. We, at Samyang Corp., developed new oligomer structures consisting of polyester compounds along with its synthesizing technique. We synthesized the oligomers with varying molecular weights by altering the experimental conditions and investigated the mathematical relathionships between the experimental conditions and the molecular weight of the oligomer. These novel oligomers exhibit high heat resistance due to its rigid structure; moreover, a block copolymer containg the polyester oligomer along with polycarbonate features a higher heat resistance capability compared to the regular PC

Biography:

Marko Soderžnik has completed his PhD at Jožef Stefan International Postgraduate School, Ljubljana, Slovenia. He investigated Nd-Fe-B permanent magnets and the influence of the grain-boundary diffusion process on the magnetic properties and the microstructure. He was a post-doctoral researcher at the National Institute for Materials Science in Tsukuba, Japan where he was studying magnetic domains and now he is a post-doctoral researcher at Jožef Stefan Institute, Ljubljana, Slovenia. He is a author or co-author of more than 30 scientific contributions and patents and currently leader of post-doctoral research project, funded by the Slovenian Research Agency.

Abstract:

With their high performance, Nd-Fe-B sintered permanent magnets are the most promising candidates for a variety of transportation application. Heavy rare earths (HRE), such as Dy or Tb are inevitably used in Nd-Fe-B permanent magnets that exhibit high magnetic performance at elevated temperatures. Particularly, high coercivity of the magnets is important to oppose high demagnetization fields, caused in the electromotor. Drastic reduction of Dy- or Tb-consumption was achieved by using the grain-boundary diffusion process initiated by the electrophoretic deposition of nano TbF₃ particles. At the same time, the magnetic properties remained unaffected. Commercially available Nd-Fe-B magnets were coated by EPD with nano TbF₃. Scanning electron microscopy revealed uniform layer of nano TbF₃ which was well attached to the surface of the magnet. Good adhesion of powder is one of the main quality parameters for the successful grain-boundary diffusion process. Compared to simple dip-coating, EPD gives better adhesion of TbF₃ powder and consequently higher coercivity after the GBDP. The coercivity achieved after the EPD-based GBDP was 1536 kA/m at 75 °C, which is nearly twice that of the uncoated sintered magnet and 1.5 times higher than that for the uncoated magnet exposed to the same heat treatment. To measure the accurate amounts of the elements, especially Tb, the chemical composition was determined with induction coupled plasma optical electron spectroscopy (ICP-OES). The microstructural investigation was done with a high resolution field emission SEM. Core-shell-type microstructure was formed after the processing.

Biography:

Aitber Bizhanov has completed his PhD from National University of Sciemce and Technology MISIS (Moscow). He is the official representative of JC Steele and Sons, INC (NC, USA)- world largest producer of the equipment for Stiff Extrusion Agglomeration. He has published more than 45 papers in reputed journals and owns more than 15 patents in metallurgical applcations of Stiff Extrusion Agglomeration. Results of R&D have evidently propved that this technology which had been widely used for brick-making can be very efficient for the utilization of anthropogenic and natural iron-containing materials for iron and steelmaking. Aitbe Bizhanov invstigated the mechanisms of the reduction of briquettes in Blast Furnace, in Submerged Electric Arc Furnace and in the Direct Reduced Iron Reactors. He is an authors of new term BREX which is being used internationally to describe extruded briuettes. 

Abstract:

Stiff Vacuum Extrusion  (SVE) - new agglomeration technology has been successfully applied for the briquetting of natural and anthropogenic raw-materials of the ferrous metallurgy. The results of the investigation of the Extrusion Briquettes (BREX) metallurgical properties showed that they can be efficiently used as the charge components of Blast Furnaces (BF), Direct Reduction Iron (DRI) reactors and Submerged Electric Arc Furnaces (EAF). The behavior of BREX under the reduction conditions has been investigated. The mechanism of the hot strength has been described. The examples of the industrial application of SVE for BFs and the results of the full-scale trials of SVE for DRI and Ferro Alloys production are represented in details. Evaluation of the prospects of the application of carbon containing BREX made of natural and anthropogenic raw materials in BF production is given.

Biography:

Väino Sammelselg has completed his PhD in 1989 from Institute of Physics of the Estonian Academy of Sciences. He is professor of inorganic chemistry and head of Materials Science department of the University of Tartu, Estonia. His research areas are materials chemistry, thin film and surface technologies, incl. (ultra)thin protective and functional coatings, (nano)materials characterization and testing. He has published more than 150 papers in reputed journals, has h index 30, and is co-author of several patents, he is member of ECS and MRS.

Abstract:

In the presentation two novel types of composite ultrathin coatings engineered for corrosion protection will be introduced: the first, for anodizable metals, and the second for widely used stainless steels, both biocompatible. The first type coating, its technology and performance will be introduced on an example of easily corroding Al2024 alloy, the coating is patented (GB2509335 - Corrosion resistant coatings and a method of preparing such coatings) and its study results are sent for publication. The technology consists of special anodizing of the substrate surface and top coating of nanometric metal oxide layers using atomic layer deposition (ALD) method. In result, a corrosion protection composite ≥1 µm thick coating is formed. The coating worked well in salt solution immersion (7000 h) and salt spray (1000 h) standard tests. The second type of sub-micron thick coating consists of nanometric graphene oxide interface layer and added ALD laminated top layer. Its performance was demonstrated on AISI 304 (see DOI: 10.1016/j.corsci.2016.01.013). The coating withstood well in 30 days’ immersion test in salt solution. The role of the graphene interlayer and the development of ALD technology for the corrosion protection will be discussed in the presentation.

Biography:

Jian MENG has completed his PhD in 2002 from Toyohashi University of Technology. He is the Professor, director of light alloy research group, State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. He has published more than 115 papers in reputed journals, Authorized patents 36 and has been serving as an editorial board member of J. Rare Earths.

Abstract:

There exists a threshold stress identified as 38 MPa through the commonly adopted threshold stress approach in the studied alloy, and the true stress exponent n and the activation energy Q are approximately 7 and 217 kJ/mol, respectively, under stresses of 75-110 MPa and at temperatures of 185-215 °C. After creep, no discernable changes were observed on components, shapes, sizes, and distributions of the dominant phases identified as Al₁₁RE₃ and C36, and also the grain sizes, except that the lattice parameters of the C36 phase were decreased and numerous C15 particles precipitated in the grain interior during creep deformation. Under relatively lower stresses, the operative creep mechanism is cross-slip of <a> dislocations in ALaX422 alloy, while both cross-slip of <a> dislocations and climb of <c> and <c + a> dislocations under relatively higher stresses. Also, both twinning, precipitates of C15 phase, and twin-twin interaction of different {10.2} twin variants are closely related to the creep behavior of the studied alloy. The underlying causes of why substituting half RE of AE44 alloy with Ca resulted in significant deterioration on creep resistance but without changes on creep mechanisms, were revealed as the thermally instability of the C36 phase whose lattice parameter decrease will promote grain boundary sliding, and the precipitation of the disc C15 particles which provides more interfaces that allow for basal gliding of <a> dislocations. In addition, dislocation substructure observations reveal that the rate-controlling creep mechanism is dislocation cross-slip at relatively low stresses while both dislocation cross-slip and climb at relatively high stresses.

Biography:

D. F. Pessoa is mechanical engineer and MSc in materials science from Federal University of Rio Grande do Sul. He worked more than 8 years in the automotive field. Moreover, Pessoa worked 4 years as scientific researcher in the Fraunhofer Institute for Material and Beam Technology and at the meantime as guest researcher in the Technical University of Dresden where Pessoa developed his PhD studies. He has published 8 papers, was awarded in 2010 by the Society of Automotive Engineers in the SAE International Congress & Exhibition and has been serving as a reviewer of a reputed journal.

Abstract:

In order to evaluate the true durability of a material or component a sufficiently high number of fatigue tests performed at a number of cycles higher than the classical fatigue limit must be executed, which, in turn, implies that normally pronounced time consumption and high costs are involved. This issue can be addressed using high frequency test systems, allowing the performance of cyclic loading tests in high to very high cycle fatigue regime in a reasonable time. However, the likely influences of the test frequency on the material response must be considered. For this reason and because metastable austenitic steels are well known for their strain rate sensitivity, the steel AISI 304 was analyzed regarding the influence of load frequency on the cyclic response and fatigue behavior. Fatigue tests were performed at load frequencies of 100 Hz and 1000 Hz using two resonance pulsation test stands, as well as by means of a servo-hydraulic test machine at 1 Hz and 50 Hz. The cyclic deformation behavior was characterized based on the evaluation of stress-strain hysteresis loops and temperature measurements. The deformation-induced phase transformation from γ-austenite to α'-martensite was globally and locally evaluated by means of magneto-inductive measurements and EBSD analysis, respectively. The analyses showed that higher amounts of α'-martensite and lower plastic strain amplitudes are observed when the cyclic experiments are carried out at lower frequency, promoting higher fatigue strengths.

Biography:

Prof. Hong completed his Ph.D. in Dept. of Materials Science and Engineering at Northwestern University in 1984. After R&D experience at Stanford University as a research associate, he joined Korea Advanced Institute of Science and Technology (KAIST) as a professor in 1986, directing research and education on nanomaterials and nanocomposites. Prof. Hong pioneered to develop frontier technologies for fabrication processes and applications of multi-functional nanocomposites. Prof. Hong had served as the President of the Korea Society for Composite Materials (KSCM) and the Director for Basic Science and Engineering at National Research Foundation (NRF). Prof. Hong has published 242 international journal papers and registered 146 patents mainly in areas of nanomaterials and nanocomposites.

Abstract:

Carbon nanomaterials, such as carbon nanotube (CNT) and graphene, are promising fillers for nanocomposite materials due to their excellent mechanical and functional properties. Previous researches on carbon nanomaterials filled nanocomposites have shown limited enhancement of properties due to strong agglomeration of the carbon nanomaterials and poor interfacial bonding between the carbon nanomaterials and matrices. In this presentation, a novel fabrication process, named as molecular-level mixing process, is introduced to fabricate carbon nanomaterials filled nanocomposites in order to maximize the effect of filler addition in various matrices. The molecular level mixing process has been proved to realize homogeneous dispersion of nanomaterials with strong interfacial bonding with matrices. Various types of carbon nanomaterials filled nanocomposites with remarkably enhanced mechanical, electrical and electro-chemical properties show a wide scope of possible applications such as strong and tough structural materials, EMI shielding materials, flexible and stretchable conductors, electrodes for energy storage devices and organic photovoltaic cells etc.

Biography:

Prof. Choi is Inha Fellow Professor at Inha University, Korea with BS from Seoul National University and Ph. D. in Chemical Engineering from Carnegie Mellon University. He joined Department of Polymer Science and Engineering at Inha University in 1988, and his research interests cover soft matter materials and complex fluids including electrorheology, magnetorheology, and polymer rheology. He is a member of Korean Academy of Science and Technology and a recipient of numerous scientific achievement awards including “World Class Research Front Award and Thomson Scientific Citation Laureate 2007 and the 2016 Top 300 Most Cited Researchers in Materials Science and Engineering by Elsevier Scopus Data.

Abstract:

Carbon nanotubes (CNTs) have received great attentions with their extraordinarily fascinating behaviors such as structural, mechanical, optical and electrical properties. They can be added into various polymers as fillers to prepare advanced functional polymeric composites. However, due to their intrinsically poor dispersibility, achieving a uniform dispersion is generally difficult. As one of the effective methods, milling processes are introduced to reduce the original size of the nanotubes to improve dispersion, especially in the case of CNT suspension rheology for potential battery applications. With interesting functionalities under external fields  implying typical flow fields of laminar flow with most cases of rheological aspects and electrical and magnetic fields, electro-responsive electrorheological (ER) characteristics of polymer/CNT composite systems from material rheological viewpoint are examined for various CNT composite particles with polystyrene and PMMA. Interesting characteristics of their ER suspensions include yield stress, flow curve behavior and dielectric analysis. As for magneto-responsive magnetorheological (MR) materials, we coated the surface of soft-magnetic carbonyl iron particles with CNT along with polymers to produce their favourable core-shell structure with apparently decreased particle density for better dispersion, and then characterized their MR characteristics under magnetic fields applied. 

Biography:

Bongjun Yeom received his PhD from Seoul National University and postdoctoral studies from University of Michigan. He currently works at Department of Chemical Engineering, Myongji University as assistant professor. He has published more than 25 papers in the research fields of nanocomposites and plasmonic nanomaterials.

Abstract:

We can learn how nature produces hierarchical micro-nanostructures for realization of specific functions. Superb mechanical properties as well as unique optical properties can be distinguished examples. These examples have inspired researchers to develop and design new arificial materials. Structural organization with parallel stacking of nanosheets was found in internal structure of nacre of abalone shell and it presents strong and tough mechanical properties. On the other hand, the vertically orientation of nanostructures are also ubiquitous in biocomposites such as teeth and seashells. In this presentation two types of nanocomposites will be presented, planar shaped nanocomposites with silica layer and vertically oriented nanocomposites with ZnO nanopillars. We demonstrated that 2D and 3D structural organization of nanomaterials can show enhancements of mechanical properties which can exceed limit of conventional nanocomposites.

Biography:

Addis Lemessa Jembere has completed his Masters of Science in Process Engineering, from Bahir Dar Institute of Technology, Bahir Dar University Bahir Dar, Ethiopia. He is the Lecturer of Bahir Dar University, in the Department of Chemical Engineering. 

Abstract:

The ultimate objective of this experimental analysis is to prospect the possibility of replacing inorganic filler (which consumes exhaustive energy) by organic filler. In this study investigation on the utilization of Rice husk Ash Silica (RHAS) as filler in vehicle tire tread part was examined. Silica was synthesized from rice husk ash by using a method based on alkaline extraction followed by acid precipitation. Effects of extraction temperature, retention time and NaOH concentration as a digesting agent were investigated to get the best possible silica yield. The maximum yield was noted at the interaction of 60^oC, 1.5hrs and 2.5 Molarities with the silica purity of 83.7% by weight. The maximum silica yield obtained was further subjected to different characterization techniques by means of AAS, XRD, BET, FTIR and DSC. Rheological and mechanical testing was performed on the formulated (12 PHR) compounded rubber vulcanizates filled with RHAS and COS (commercial silica) independently. The curing characteristics at 175^oC on RHAS and COS filled rubber were examined with an oscillating disk Rheometer. It was eminent that the rubber composite products reinforced with RHAS had shorter scorch time (T’10) at 1.20 minutes which caused a premature vulcanization than the COS filled rubber composite, improving the time required to start the vulcanization. Though, the optimum curing time (T’90) showed retardation due to the possible interaction of silica with the accelerators making it unavailable for cure reaction. The maximum torque for the RHAS was 13.49 d.Nm. Overall mechanical properties like hardness, young’s modulus, abrasion resistance of rubber products reinforced with RHAS was better than COS filled rubber composite

Biography:

Rodrigo Poblete is a Chilean engineer. He has a PhD in Environmental Engineering from the Universidad de Sevilla (Spain) and has a Master's degree in Thermal Energy Systems from the same university. Rodrigo Poblete has expertise in landfill leachate treatment and the use of waste materials for this purpose. He works as a professor at Universidad Católica del Norte (Coquimbo, Chile) where he researches and teaches on this topic and the use of waste materials as byproducts. He is also the director of the Master of Environmental Management program at Universidad Católica del Norte.

Abstract:

A set of experiments were carried out in order to establish and evaluate the potential of a new activated carbon, produced from coffee waste in adsorption process, in the depuration of landfill leachate, a toxic waste water. Different reagents were studied in the activation of carbon: HCl, HCl + H₂O₂, H₃PO₄, H₃PO₄ + H₂O₂, all with an impregnation rate of 1:1. The activated carbon that showed the best global results was activated with H₃PO₄, obtaining a 51.0%, 24.4%, 32.8%, 66.0%, 81.0% and 97.1% elimination of chemical oxygen demand, color, ammonia, total chlorine, bromine and copper, respectively. This activated carbon has a total pore area of 4.85 m²/g and a median pore diameter of 65.32 micrometers. When different loads of this carbon were placed in a stirrer system in contact with landfill leachate, with the aim of evaluating the effect of the adsorption load and contact time, the concentration of ammonia decreased from the beginning of the adsorption process to the end of it and the removal of ammonia increased with the increase in the adsorbent load. However the trend of the amount adsorbed per unit mass decreased with increased dosage. The model Freundlich equilibrium isotherm fits experimental data adequately, giving R² values of 0.95, 1/n of 0.5183 and a k value of 7.08*10^-5 L/g, being favorable for adsorption process.

Biography:

Profesor Reifsnider is a graduate of the Johns Hopkins University in the general field of materials, and has served on the faculties of Virginia Tech, University of Connecticut, University of South Carolina, and the University of Texas. He is Director of the Institute of Predictive Performance

Abstract:

Biography:

Abderrazzak Douhal is a Professor at the University of Castilla La Mancha (Toledo, Spain). His present research is deserved to the study of photoevents in condensed phase, molecular pockets and pores of chemical and biological systems, advanced hybrid materials based on zeolites, mesoporous materials and metal-organic frameworks, and perovskites-based solar cells using different techniques of ultrafast spectroscopy and single molecule fluorescence microscopy. He has published more than 160 scientific contributions. He served as a member of the editorial boards of Chem. Phys. Lett., and is being of J. Photochem. Photobiol. A. Chem., and of Inter. J. Photo-energy. He is member of RSEQ, GRUFO, EPA, IUPAC, IAAM and AAAS.

Abstract:

Metal-Organic Frameworks (MOFs), a class of crystalline porous compounds, have emerged as smart materials with a wide range of uses and applications. Among them, luminescent MOFs have gained great attention owing to their applicability in optoelectronic devices, as fluorescent sensors or photocatalyst systems [1-3]. In this Lecture, I will talk about the results exploring the spectroscopic and photodynamical properties of a serie of Zr-based MOFs, and their possible uses in nanophotonics, photocatalysis and detection of explosive molecules[4-7]. Firstly, we investigated the photoproperties of Zr-NDC MOF, which is made of Zr-clusters and 2,6-naphthalene dicarboxylate linkers [4]. The absorption and emission properties of this MOF are mainly due to the naphthalene linkers, with a well-defined vibrational absorption and emission bands. Moreover, the interaction of neighboring linkers induces the formation of excimers, reflected in a red-shifted broad emission band. A detailed photodynamic study reveals a multiexponential behavior with three time constants assigned to excimers formation, monomers and excimers lifetimes. With this in mind, we have incorporated different dyes (Coumarin 153, Nile Red and DCM) into the MOF porous structure, in order to investigate the possibility of energy transfer processes from excited MOF to the trapped dyes [5]. Upon MOF excitation, we have observed and unraveled the mechanism of energy transfer to the trapped dyes. By controlling the amount of the dye incorporated into the MOF, we have synthesized two white light emitting materials, one containing a mixture of Coumarin 153 and Nile Red, and the other by adding DCM to the MOF. Both materials emit cool white light with CIE coordinates (0.32, 0.34 and 0.32, 0.31) very near to the ideal ones (0.33, 0.33)

Biography:

The experimentally determined data – enthalpy and entropy – of the grain boundary segregation of substitutional solutes of 14^th and 15^th groups of the Periodic Table, i.e. silicon, phosphorus, tin and antimony, in α-iron are compared. The consequences of the grain boundary segregation of these elements for the intergranular strengthening or embrittlement are also shown and discussed from the point of view of the values of the segregation enthalpy and entropy. It is documented that all these solutes except silicon segregate at the grain boundaries interstitially at enhanced temperatures although substitutional segregation is preferred at zero K. It is shown  that this controversy can be explained on basis of so called enthalpy-entropy compensation effect. Despite some variations, the values of the strengthening/embrittling Gibbs energy of all solutes are nearly linearly dependent on the differences in the sublimation energies of the host and solute.

Abstract:

Pavel Lejček has completed his PhD in 1983 from Academy of Sciences of the Czech Republic. He obtaind the Alexander-von-Humboldt research award in 1989 at the Max-Planc-Institute for Metals Research, Stuttgart/Germany. He is the senior scientist at the Institute of Physics, Academy of Sciences of the Czech Republic and full professor at the University of Chemistry and Technology in Prague, Czech Republic. He has published more than 200 original papers and reviews in reputed journals and has been serving as an editorial board member of repute. He is also author of the book “Grain boundary segregation in metals” 

Biography:

The experimentally determined data – enthalpy and entropy – of the grain boundary segregation of substitutional solutes of 14^th and 15^th groups of the Periodic Table, i.e. silicon, phosphorus, tin and antimony, in α-iron are compared. The consequences of the grain boundary segregation of these elements for the intergranular strengthening or embrittlement are also shown and discussed from the point of view of the values of the segregation enthalpy and entropy. It is documented that all these solutes except silicon segregate at the grain boundaries interstitially at enhanced temperatures although substitutional segregation is preferred at zero K. It is shown  that this controversy can be explained on basis of so called enthalpy-entropy compensation effect. Despite some variations, the values of the strengthening/embrittling Gibbs energy of all solutes are nearly linearly dependent on the differences in the sublimation energies of the host and solute.

Abstract:

Pavel Lejček has completed his PhD in 1983 from Academy of Sciences of the Czech Republic. He obtaind the Alexander-von-Humboldt research award in 1989 at the Max-Planc-Institute for Metals Research, Stuttgart/Germany. He is the senior scientist at the Institute of Physics, Academy of Sciences of the Czech Republic and full professor at the University of Chemistry and Technology in Prague, Czech Republic. He has published more than 200 original papers and reviews in reputed journals and has been serving as an editorial board member of repute. He is also author of the book “Grain boundary segregation in metals” 

Biography:

Cadmium selenide (CdSe) quantum dots (QDs) were prepared by solvothermal route. Subsequently a inorganic QDs-organic semiconductor (copper phthalocyanine) nanocomposite (i.e CuPc:CdSe nanocomposites) were produced by different concentration of QDs varied in CuPc. The nanocomposite thin films have been prepared by means of spin coating technique. The optical, structural and morphological properties of nanocomposite films have been investigated. The transmission electron microscopy (TEM) confirmed the formation of QDs having average size of ~ 4 nm. The X-ray diffraction pattern exhibits cubic crystal structure of CdSe with reflection to (111), (220) and (311) at 25.4áµ’, 42.2áµ’ and 49.6áµ’ respectively. The additional peak observed at lower angle at 6.9áµ’ in nanocomposite thin films are associated to CuPc. The field emission scanning electron microscopy (FESEM) observed that surface morphology varied in increasing concentration of CdSe QDs. The obtained nanocomposite show significant improvement in the thermal stability as compared to the pure CuPc indicated by thermo-gravimetric analysis (TGA) in thermograph. The effect in the Raman spectra of composites samples gives a confirm evidence of homogenous dispersion of CdSe in the CuPc matrix and their strong interaction between them to promotes charge transfer property. The success of reaction between composite was confirmed by Fourier transform infrared spectroscopy (FTIR). The photo physical properties were studied using UV - visible spectroscopy. The enhancement of the optical absorption in visible region for nanocomposite layer was observed with increasing the concentration of CdSe in CuPc. This composite may obtain the maximized interface between QDs and polymer for efficient charge separation and enhance the charge transport. Such nanocomposite films for potential application in fabrication of hybrid solar cell with improved power conversion efficiency. 

Abstract:

Ganesh Bhand is a senior research fellow (UGC-BSR) in the department of physics of Savitribai Phule Pune University, Pune (India). He is pursuing his PhD under the supervision of Dr. N. B. Chaure, Department of Physics, Savitribai Phule Pune University. He has completed his M. Phil from the same university. His field of research is “Metal and semiconductor nanostructure for hybrid organic – inorganic solar cell”. Presently, he is working on the synthesis and characterization of Au, Ag, CdSe, and CdTe nanostructure through wet chemical and solvothermal routes for solar cell applications.