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

Biography:

António Ribeiro has completed his PhD at the age of 30 years from René Descartes University, Paris, France. He is a Board member of UC-Tecnimede, an industrial-university consortium base in Coimbra and focused on new delivery sytems. He has published more than 60 papers in peer-reviewed reputed journals and several hundreds of communications around the world.  He has been serving as an editorial board member of reputed journals .          

Abstract:

Resveratrol (RSV) is a non-flavonoid polyphenol which exhibits a wide array of beneficial multi-target biological effects in preclinical studies. Besides this evidence, the far-reaching application of RSV is strongly hampered due to a low favourable pharmacokinetics behaviour attributed to its poor water solubility. This way, an unmet need to develop proper RSV delivery systems is posed, aiming for the enhancement of its bioavailability in vivo. An advanced formulation strategy able to surpass this limitation is nanotechnology, whereby Layer-by-Layer (LbL) self-assembly nanoparticles assume particular emphasis. LbL self-assembly is an encapsulation technique which is built on the sequential assembly of oppositely charged polyelectrolytes upon charged low soluble drug nanoparticles’ surface. Tunned nanocapsule-type constructions at nanoscale are obtained, fundamentally comprising a drug nanocore which is covered by a poleyelectrolyte-based multilayered nanoshell. Herein, a LbL self-assembly technique coupled with a washless polyelectrolyte approach was developed. Aqueous RSV nanoparticles composed of distinct bilayers of polyallylamine hydrochloride (PAH) as the polycation, and, dextran sulphate (DS) as the polyanion, were performed (including, 2.5 (RSV-(PAH/DS)_2.5), 5.5 (RSV-(PAH/DS)_5.5) and 7.5 (RSV-(PAH/DS)_7.5) bilayers). Homogenous particle size distributions with 150-250 nm were obtained. The most complex formulation, composed 7.5-bilayers, evidenced 219 ± 1 nm and 0.17 of polydispersity index; high electrical surface of +31 ± 0.5 mV; and a high drug content of 92 ± 2%. The modulation of the composition of the coating shell allowed the control of the RSV release pattern. Owing to such, these LbL nanoparticles are considered as a promising vehicle for the delivery of RSV.

Biography:

Michael Chandross received a Ph.D. in Physics with Electrical Engineering from MIT in 1990, and a Ph.D. in Physics from the University of Arizona in 1996.  After postdoctoral positions at SPAWAR Systems Center in San Diego, CA and Sandia National Laboratories in Albuquerque, NM, he joined the staff of Sandia in 2001, where he uses large-scale molecular dynamics simulations to understand the aging and reliability of nanomaterials. He has published more than 50 papers in peer-reviewed journals, is a fellow of the American Physical Society, and serves on the editorial boards of Lubrication Science and Tribology: Materials Surfaces and Interfaces. 

Abstract:

The tribology community presently relies on phenomenological models to describe the various seemingly disjointed steady-state regimes of metal wear. Pure metals such as gold -- frequently used in electrical contacts -- exhibit high friction and wear. In contrast, nanocrystalline metals, such as hard gold, often show much lower friction and correspondingly low wear. The engineering community has generally used a phenomenological connection between hardness and friction/wear to explain this macroscale response, and thus to guide designs. We present results of recent simulations and experiments that demonstrate a general framework for connecting materials properties (i.e. microstructural evolution) to tribological response. We present evidence that the competition between grain refinement (from cold working), grain coarsening (from stress-induced grain growth), and wear (delamination and plowing) can be used to describe transient and steady state tribological behavior of metals, alloys and composites. We will explore the seemingly disjointed steady-state friction regimes of metals and alloys, with a goal of elucidating the structure-property relationships, allowing for the engineering of tribological materials and contacts based on the kinetics of grain boundary motion.

Biography:

Dr Jérôme Labille has completed his Ph.D. in Environmental geosciences in 2003. He is a research senior scientist at French National Scientific Research Center CNRS in CEREGE lab (Aix- Marseille University, France). He is expert in the physical chemistry of aggregation, dispersion and deposition of nanoparticles in liquid systems and porous media. He coordinates the national research program Eco-SUN focused on the elaboration of safe by design sunscreen. He has published more than 40 papers in reputed journals.

Abstract:

Among nanotechnology-based products, sunscreens are of emerging concern. Nano metric titanium dioxide (TiO2) UV-blockers are advantageous in terms of sun protection and aesthetics. However from a regulatory perspective, their fate and impact are still under consideration, due to their potential influence on both consumers and the environment. At present, many gaps remain in the scientific knowledge regarding the efficacy and safety of nanomaterials used in sunscreen [2-4]. Nano metric TiO2 minerals are largely used in sunscreen since they are efficient and transparent UVblockers with both light scattering and absorption properties. From an optical aspect, little is known regarding the size and structural characteristics of the nanoparticle that optimize the resulting sunscreen. We studied this aspect by varying TiO2 primary particle size, structure, coating and concentration, using both nanomaterials currently on the market and those synthesized in-house. Our work aimed to optimize the properties of the UV blockers prior to their integration into a cosmetic formulation. Both the absorbing and scattering properties of the UV-blocker were optimised in order to get the highest sun protection factor (SPF) and transparency on the cream Prepared on purpose. The resulting sunscreens were characterised in terms of structure (nanomaterial dispersion in the emulsion) and this was related to the (SPF). The consequences of these characteristics on the overall risk of the product were also studied considering the entire lifecycle. Release and fate of the nanomaterial upon sunscreen aging were characterised and quantified.

Biography:

Shamik Ghosal has completed his Ph.D from Bhabha Atomic Research Centre (India) and has done postdoctoral studies from University of Leipzig (Germany). He is working as a Manager in MacDermid Performance Solutions. He has published more than 15 papers in reputed journals. 

Abstract:

Die attachment is one of the most important processes in the packaging of power semiconductor devices. Sintered silver has demonstrated superior properties in microelectronic packaging as compared to the traditional solders and conductive epoxies The sintering joints formed by atomic diffusion of silver nanoparticle can be processed at a temperature significantly lower than the melting temperature of the bulk and can be used for high temperature applications. The potential advantages such as high temperature stability, high electrical and thermal conductivity, good mechanical properties etc makes silver nanoparticle a promising candidate for die-attach applications.

In the present invention, we have synthesized capped silver nanoparticle and nano silver paste which can be used for pressure-less die attach applications. The percentage of capping according to thermogravimetric analysis is around 1%. TEM reveals the size of the silver nanoparticle to be around 3 nm to 80 nm. The heterogeneous particle sizes helps in sintering of the nanoparticle at a faster rate because of their large point of contact between each other which also leads to good packing fraction.  The die attach paste made from these heterogeneous size silver nanoparticles is used for pressure-less die attach applications on different metallized substrate (Au, Ag and Cu) to achieve a joint strength of 25-30 MPa when sintered at 180⁰ for 60mins. The thermal conductivity of the sintered material was around 200 W/m.K. The above results clearly shows that the nano-silver paste sintered at lower temperature has a slight edge over the traditional solder and conductive epoxies.  

Biography:

Vincent LAPINTE is an assistant professor in the polymer department of the Institute of Materials Charles Gerhardt of Montpellier (ICGM-France). His area of expertise is the synthesis and the self-organization of polymers including polyoxazolines as well as the synthesis of biobased building blocks and polymers. He has published more than 40 papers in reputed journals and 7 patents.

Abstract:

The polyoxazolines, an attractive polymers family characterized by a pseudo-peptidic structure, own bio- and hemocompatibility, low toxicity and furtivity towards immune system - basic properties for biomedical applications. They offer an additional attraction with the ability to self-assembly under various morphologies including spherical nanoparticles, nanowires using hydrogen bonds, dipolar interactions, etc.

In this study we focused on poly(2-methyl-2-oxazoline) decorated by coumarin units, able to photo-activity and able to pi-stacking and further original self-assemblies as already shown with peptides. In a previous work, we demonstrated the UV-activity and the self-organization of amphiphilic diblock and triblock copolyoxazolines in water.^(1,2) Herein, well-defined single strand helicoidal fibers were elaborated using amphiphilic graft copolymers. These polymeric filomicelles grown according to crystallization-driven self-assembly (CDSA) between polyoxazoline repetitive units and the coumarin ones. In other experimental conditions, the UV-activity of spherical nanoparticles of the same copolymers were also examined particularly the photo-cross-linking of the nanoparticle core.

Biography:

Pietro Cataldi has completed his master in Physics at the age of 25 years at Genova University. He has studied for almost two years in Berlin (Germany) at the Free University and performed its master thesis at the Physical Chemistry department in the elctron dinamics group at the Fritz-Haber-Institut der Max-Planck-Gesellschaft. He is actually a PhD student in the Smart Materials group at the Italian Institute of Technology. He has published 5 papers in reputed journals. He has a patent request pending and he participated with an oral contribution to four intrenational conferences.

Abstract:

Flexible and foldable electronic components require materials that can retain their electrical conductivity even after hard mechanical manipulations and multiple folding events[1]. Such a material was realized with two different methods exploiting the combination of all-biodegradable components (substrate and the polymer matrix) and graphene nanoplatelets (GnPs) [2,3]. A fibrous cellulose substrate was sized with a biopolymer-GnPs conductive ink rendering it electrically conductive (sheet resistance ≈10 Ω/sq). The obtained nanocomposites can be used as electrodes for surface electromyography and for terahertz electromagnetic interference shielding. With a similar approach a flexible cotton-GnPs conductive nanocomposite was realized. This material address several drawbacks related to durability and washability of wearable electronics material. Micro-cracks formed after repeated folding-unfolding events can be healed through an hot pressing process.  Such cotton based conductive composites could find several applications in smart textile industry

Biography:

Rababe SANI is PhD student from Ecole des Mines d’Albi RAPSODEE. She works on the physico-chemical transformations of ceramic materials during firing process. 

Abstract:

Number of studies has suggested the description of sintering steps during firing ceramic materials. However, these studies have shown considerable variations in the description of each step of sintering and still rare are those interested by ceramic materials produced from clay/additive mixtures. In this work, new ceramic materials have been developed using raw clay and additives matter such as Refused Derived Fuel (RDF). A multi-step kinetic model for the sintering of clay with and without RDF incorporation was developed. The sintering process of these ceramic materials was investigated by the non-isothermal thermomechanical analysis (TMA) under constant load (10g) and oxydant atmosphere. The compacted samples were heated up to 1100°C with constant-heating-rate (CHR) of 2, 5 and 10°C/min respectively. The sintering mechanisms and kinetic parameters were determined for each step. As novelty, Fraser-Suzuki deconvolution (FSD) and Kissinger-Akahira-Sunose (KAS) methods were used together to determine activation energy (Eα) for each pseudo-component during firing of clay and clay/RDF mixture respectively. The kinetic function f(α) was determined by the master-plot method and eventually the pre-exponential factor (A). Sintering of clay material was described by two steps, whereas for the clay/RDF mixture, a new viscous phase related to the physico-chemical transformation of RDF appeared. Thus, its sintering took place with three individual steps that developed in parallel. It was demonstrated that the last step of sintering related to the crystallization of spinel phase (Si₃Al₄O₁₂) was appropriately described by the Johnson-Mehl-Avrami (KJMA) equation. The ceramic material compositions and contribution of each step of sintering were discussed.

Biography:

Shintaro Fukaya received his Bachelor of Engineering degree in 2017, from Tohoku University, Sendai, Japan. He is a graduate student in Saka-Laboratory of Tohoku University.

Abstract:

The CuO nanostructure has the physical properties as remarkable increase in surface-to-volume ratio and the nanostructure is used on the various fields, such as lithium ion batteries, solar batteries and so on. Recently, the CuO nanostructure is fabricated by hydrothermal synthesis and the various fabrication techniques for CuO have been studied.

Electrochemical migration (ECM) is known as a cause of invoking insulation deterioration on the printed circuit board in high-humid and -temperature environment. Although a considerable number of studies have been reported on suppressing ECM, utilization using ECM has not really been studied so far. The previous studies of suppressing reveal that eluting metal grows as dendrites. Recent years, the concern with utilization using ECM has been growing because ECM is the low cost and green fabrication technique and the reaction is caused by DC voltage and water. The attempt has been made at fabricating the CuO nanostructure using ECM. However, it has reported that ECM stops during growth of dendrites between electrodes because dendrites form short circuit. Thus, the sustainable and large-scale fabrication for the CuO nanostructure has not been established. The purpose of this study is to demonstrate sustainable and large-scale fabrication for the CuO nanostructure using ECM. In this study, we changed experimental conditions and evaluated these results. 

Biography:

Yoshinori KODAMA is a graduate student of Osaka University in Japan.

Abstract:

Data communication volume is drastically increasing with the expansion of the global communication network. For high rate comunication, high frequency printed circuit boards made of materials having a highly dielectric property are required. Polytetrafluoroethylene (PTFE) has an excellent dielectric property but poor adhesion property to metal because of its low surface energy. For strong adhesion, PTFE and/or metal surface is roughened to obtain an anchor effect, which induces large transmission loss and low transmission rate. In this study, we aimed to modify the PTFE surface without increasing the surface roughness using atmospheric pressure plasma to improve the adhesion property to a Ag ink film. In the case of Ar plasma treatment, the Ag/PTFE adhesion strength was 0.06 N/mm and the color of the PTEE surface changed from white to red-yellow. This coloration was caused by the fluorine-conatining deposition on the plasma-treated PTFE surface and it caused low adhesion strength. To avoid the coloration, we added the O₂ or H₂ gas to Ar gas with varying the concentration (≦3%) . In the case of Ar + O₂ plasma treatment, the coloration decreased with increasing the O₂ concentration but the Ag/PTFE adhesion strength decreased to 0.0 N/mm. In the case of Ar + H₂  plasma treatment, the coloration did not occur. In addition, the Ag/PTFE adhesion strength increased to 0.55 N/mm when H₂ concentration was controlled at 0.5%. We realized the prevention of coloration and increase in the Ag/PTFE adhesion property upon control of H₂ gas concentration in Ar gas. 

Biography:

Myung-Dong Kim is a currently graduate student in School of Materials Science and Engineering at Yeungnam University, South Korea. His research topic is the ‘Joining of ceramic/metallic systems for oxygen tranport membrane applications.’

Abstract:

Reacive air brazing (RAB) is a relatively simple and inexpensive technique to hermetically seal the ceramic/ceramic and ceramic/metal joints. The joints formed by RAB generally reveal an excellent thermal cycling performance and long term stability in high temperature oxidation as well as reduced atmospheres, which can be used for the joining of oxygen transport membranes, solid oxide fuel cells, and solid state sensors, etc. Here, we used RAB technique to produce sound joints between commercially available GDC-LSM ceramics to various metallic alloys, such as AISI 310S, FeCralloy, and Crofer 22 APU. As a prerequisite, utilization of RAB rests on developing a suitable filler material so as to have reasonable wetting for both ceramic and metallic substrates. A widely used filler system based on Ag-10 wt. % CuO was used by forming a green tape through tape casting. The effects of brazing temperatures on the interfacial microstructure and mechanical properties of the GDC-LSM/metal joints were examined. Brazing was performed at different temperatures of 1000, 1050, and 1100°C for 30 min in air. The measurement of wetting angle was performed at each joining temperature to assess the degree of bonding. Interfacial microstructure and formation of various phases, cracks, voids were analyzed using SEM and EDS. Shear strength at room temperature was measured and correlated with the interfacial microstructure, mode of failure and joint thickness.

Biography:

I am a Ph.D student at School of Materials Science and Engineering, Yeungnam University. Recently, I am working on fabrication of SiC_f/SiC composites for structural nuclear reactor applications. I have published 6 papers related SiC topic as first author so far at Journal of European Ceramics and Ceramics International.

Abstract:

SiC_f/SiC for the structural components of Gen-IV fission and future fusion reactors has attracted considerable interest due to their excellent mechanical and thermal properties along with impressive post-irradiation response. Various fabrication routes (CVI, PIP, RS etc.) have already been reported with simultaneous ongoing efforts to develop newer routes that can yield improved properties. We report here a hybrid processing technique based on electrophoretic deposition (EPD) or vacuum infiltration as matrix infiltration route and subsequent hot pressing to fabricate dense and tough SiC_f/SiC. The adaptability of EPD process to fabricate tubular and planar SiC_f/SiC of varying sizes with tailorable properties has been demonstrated. Careful optimization of material-attributes, such as slurry composition, type and amount of sintering additives, pre-coated SiC fabric with PyC or dual PyC-SiC interphase and processing-attributes for e.g., AC-/DC-EPD, temperature and pressure variations etc. were performed. Addition of Al₂O₃-Y₂O₃, Al₂O₃-Sc₂O₃, and Sc-nitrate additives to facilitate liquid phase sintering in a processing window of 1650/1750°C and 10/20 MPa were attempted to obtain high densities (> 95% ρ_theo) and flexural strengths (450-500 MPa) with non-brittle and predictable flexural behavior. Subsequently, room temperature irradiation of SiC_f/SiC under 0.2 MeV H⁺ ions at a fluence level of 3×10²⁰ ions/m² were conducted. Comparative microstructural assessment of matrix, fabric and interfacial regions were undertaken to explain the observed flexural behavior of SiC_f/SiC with different additives. Subsequently, post-irradiation evolution of microstructural features, such as matrix grain size, pores, cracks, surface roughness and corresponding flexural responses, were recorded and contrasted.

Biography:

Dong Hyuk Jeong is a graduate student in the School of Materials Science and Engineering at Yeungnam University, South Korea. His current research topic is the ‘Joining of SiC_f/SiC for high temperature and nuclear reactor applications.’

Abstract:

SiC_f/SiC possesses great potential for applications in severe conditions, including high temperatures and structural components for future fusion reactors. Various fabrication techniques have been developed to fabricate SiC_f/SiC, which generally produce simple shape, such as plates and tubes. However, their practical utility can only be realized by integrating simple shapes into complex geometries. Therefore, considerable research efforts are being directed to develop filler materials, which can be employed to join SiC_f/SiC. However, SiC-based fillers being similar to the SiC_f/SiC joining body are a natural choice to preserve the outstanding properties of SiC_f/SiC. Taking this into consideration, we tried to obtain pure SiC joining filler by pyrolyzing the preceramic polymers, such as polycarbosilane(PCS) and polysilazane(PSZ). Both of PCS and PSZ were applied in a paste form followed by thermal treatment, where SiC was the main porducts along with the presence of small amount of Si₃N₄, depending on the starting material. Because cracks and pores might be generated by the vaporization of gaseous products, which can hamper the overall joining properties, careful optimization for the polymeric composition, choice of filler, heating rate, joining temperature and pressure was performed. A slow heating rate of 2°C/min was employed for the temperatures of 1600-1700°C to obtain sound and crack-free joints, while the pressure of 3.5 and 20 MPa was applied. The joining strength was estimated by 3-point bending test and correlated with the interfacial microstructure, mode of failure as well as the joint thickness.

Biography:

Nastaran Faraji is a PhD candidate at University of New South Wales. Her main research interest is performing nanoscale measurements by means of scanning probe microscopy to investigate the electronic and piezoelectric properties of semiconductor oxides.   

Abstract:

The response of individual grain boundaries in two dimensional polycrystalline ZnO platelets to visible light illumination is studied using scanning probe based techniques on the nanoscale. While many previous studies report and discuss the UV responses of ZnO, we find that even in the visible range of light below the band gap, grain boundaries are sensitive to light, this can be attributed to defect accumulation at the grain boundaries and associated photoexcitation of carriers. These findings suggest that engineered grain boundaries can be used for novel optoelectronic applications based on conductive channels in an otherwise wide-bandgap transparent material.

Biography:

Abstract:

Ce-oxide thin film coatings present unique optical properties. In this study, structural, chemical bonding and optical properties of the thin films in relation to the composition of reaction gas via sputtering process were investigated. All the thin films exhibited a polycrystalline character with cubic fluorite – structure for cerium dioxide along (111), (200) and (222) orientations. XPS analysis revealed that two oxidation states of CeO₂ and Ce₂O₃ are present in the films prepared at lower argon- oxygen flow ratios, whereas the films are totally oxidized into CeO₂ as the aforementioned ratio increases. Optical parameters (α ε₁, ε₂, n and k) derived from UV-Vis reflectance data indicate that the thin films have indirect optical band gaps in the range of 2.25 - 3.1 eV.  Density functional theory (DFT+U) implemented in the Cambridge Serial Total Energy Package (CASTEP), has been employed to model some optical properties of CeO₂ cluster at ground state. The simulated electronic density of state (DOS) of the relaxed structure of CeO₂ demonstrates a band gap agrees well with the measured optical band gap. The experimental and calculated absorption coefficient (α), have analogous trends and to some extent a similar range of values in the wave length. All in all, our theoretical findings consistently support the experimental results.

Biography:

Gérald Dujardin is « Directeur de Recherche at CNRS ». He started working on « Manipulation of single molecules with the STM » at IBM (Yorktown, USA) in 1991 with Phaedon Avouris. . Over the past years, he developed a team in Orsay which acquired experience in the electrical and optical control of atomic-scale devices. His current research interests are focused on the electrical excitation of hybrid plasmon-exciton optical nanodevices.

Abstract:

To optimize the optoelectronic properties of plasmon based nanostructures and their integration in functionalized nanodevices, it is crucial to design dedicated electrical nanosources of surface plasmons whose size is compatible with that of the studied nanostructures. Here, we report an electrical surface plasmon nanosource using inelastic electron tunneling from the tip of a scanning tunneling microscope (STM). The main advantages of STM induced surface plasmon excitation are (i) the very local excitation (10 nm) which enables precise localization of the excitation inside the nanometer size  plasmonic devices, (ii) the nature of the excitation which is equivalent to a point-like vertical dipole, (iii) the low energy electrical character (» 3 eV) of the excitation which makes nanoplasmonics compatible with nanoelectronics, and (iv) the ability to excite both localized and propagating surface plasmons with a broadband energy distribution. As an example of the integration of this electrically driven plasmon nanosource into elementary plasmonic devices we show the production of cylindrical vector beams of light from an electrically excited plasmonic lens. The plasmonic lens consists of concentric circular subwavelength slits that are etched in a thick gold film. Due to the very local electrical excitation of the plasmonic lens, a highly collimated beam with an angular divergence of less than 4° and a polarization with a cylindrical symmetry are demonstrated. The variable direction of emission is controlled by the precise positioning of the STM tip.

Biography:

Dr. Yuyan Jiang is a professor in the Institute of Engineering Thermophysics (IET), Chinese Academy of Sciences (CAS). He received a B.E. degree from Xi'an Jiaotong University (1996), a M.E. degree from Tsinghua University (1999) and a PhD from the University of Tokyo (2002). He has been a post-doctoral researcher in IIS, the University of Tokyo (2002-2005), a senior research fellow in AdvanceSoft Inc.(2005-2008) and a visiting researcher in Toyota Central R&D Labs Inc. (2008-2011). He has also been working with CD-Adapco as a senior software engineer. Dr. Jiang's research interests include the boiling heat transfer, computations of two-phase flows with phase change. He is one of the major developers of the general-purpose CFD code, FrontFlow/Red. He has published more than 70 peer reviewed journal papers and has 30 disclosed patents. In their latest study, they invented surfaces with deformable micro structures made of shape memory alloys for the enhancement and smart control of boiling.

Abstract:

Smart materials, that can change structures and/or physical-chemical properties by active or passive control, has potential applications in energy engineering. They can be used to design cute and efficient energy converting systems, e.g. waste heat generation systems made of shape-memory-alloys (SMA). The advances of electronic and aerospace engineering calls for more robust thermal management technologies that can help the devices to discharge intensive heat release and mitigate the temperature fluctuation. To this end, smart materials can take their inherent advantages in heat transfer enhancing and in providing extra measures for driving coolant flow.

In our latest studies, a novel deformable structured surface was fabricated by SMA for the enhancement of boiling heat transfer. Pool boiling heat transfer on deformable structures were performed in three fluids (ethanol, FC-72, water) with different thermal properties was explored. Comparing heat flux versus wall superheat and HTC at different fluxes with fixed geometry, it is found that deformable structure combines the merits of closed-tunnel and open-tunnel. At low heat fluxes, it can increase the numbers of nucleation sites inside the closed tunnels with bent fins and after recovering with open tunnels, the nucleation sites are activated and the bubble growth and departure is accelerated to enhance the HTC significantly. On the other hand, by choosing the appropriate time and opportunity for different fluid to open the tunnels, the deformable structures can be used to achieve adaptive-control of boiling heat transfer. In another study, researchers from POSTECH proposed a smart TiO2-coated surface (TCS) for boiling heat transfer. The surface changes its wettability with temperature. Measurement of the contact angle of a water droplet on the tested surfaces after heat treatment showed a wettability increase of TCS, a contact angle reduction from 83.1_ to 32.7_ when the heat treatment temperature changed from 100 _C to 200 _C, in other words,  TCS is hydrophobic at a low wall temperature and becomes hydrophilic as the wall temperature increases. Hydrophobicity of TCS at low wall temperatures. The TCS improved both the heat transfer coefficient near the boiling inception point at low heat flux regime, and critical heat flux at high wall temperatures. People are also developing heat transfer devices that have SMA self-driven unit for flow circulations that working with temperature differences.

The study on energy harvesting and thermal management by use of smart materials is a quite young interdiscipline research field, which is still in the initial stage. This presentation gives a critical review to the latest pioneering work. By summarizing the advancements, we propose some comments on the principles and prospect for the future development.

Biography:

Dr. Yuen Hong Tsang has completed BSc and PhD study in the School of Physics and Astronomy, The University of Manchester, UK in 2004. He is now Assistant Professor in Applied Physics Department, The Hong Kong Polytechnic University. He has published >100 SCI international journals with H-index >20 and total citation >1400. His current research interests include development of novel 2D materials, e.g. MoS₂, WS₂, etc. for laser photonics, photo-catalysis, solar energy conversion applications, e.g. photo-catalyst, solar heat absorber, saturable absorber, optical limiter, photodetection, Q-switched and mode locked lasers, etc

Abstract:

To understand and modify the nonlinear optical properties of transition metal dichalcogenides, TMDs, two-dimensional layered materials are very important research topics nowadays as they can serve as building block for developing next generation high performance micro optics and photonic devices. These materials are very compact with atomic thick layer and have natural bandgap so they can provides strong interaction with light and other favorable features e.g. broadband absorption, transparent and high carrier mobility etc. WS₂, which is a typical TMDs material, has layer number depending bandgap energy. The WS₂ bandgap energy and optical properties can be modified by varying their size, layer number and structures. The WS₂ nano materials and film in various size, layer number or film thickness are fabricated by two methods – ultrasound and sputtering. The nonlinear optical properties of different samples are then studied by using z-scan technique. We have successfully demonstrated some viable methods to tune the nonlinear absorption properties of WS₂. We also use the fabricated WS₂ film within the diode pumped solid state Nd:YVO₄ crystal laser to generate pulsed laser output. A stable pulsed laser operation is achieved by using the fabricated WS₂ saturable absorber. The average output power obtained is 19.6 mW (135 kHz). These research findings indicate strong nonlinear optical proporties of WS₂ and high potential for nonlinear optical devices. 

Biography:

Jianhua Hao is a Full Professor and Associate Head of Department of Applied Physics in the Hong Kong Polytechnic University (PolyU). He received his BSc, MSc and PhD at Huazhong University of Science and Technology. After working at Penn State University, University of Guelph and University of Hong Kong, Jianhua Hao joined the faculty in PolyU in 2006. He has published more than 200 SCI papers. He is the first inventor of several US patents. He serves as Editorial Board Member/Senior Editor for several international journals, such as Scientific Reports（NPG）and Advanced Optical Materials 

Abstract:

The ability of lanthanide ions to generate fascinating near-infrared (NIR) emissions has played important roles in optical fibre communication, semiconductor optoelectronic devices, biomedical imaging and bioanalyses. Two aspects of my group’s recent works on the lanthanide activated advanced materials and nanotechnology will be introduced. Firstly, we have developed various lanthanide doped nanocrystals for photonic and biological applications. For instance, biosensors with both high sensitivity and rapid response are greatly desired for enabling rapid and sensitive detection of various virus gene in a cost-effective way. We have developed lanthanide doped upconversion nanoprobe/nanoporous membrane to form a heterogeneous assay. Compared to the homogeneous assay, the limit of detection in the heterogeneous assay is significantly improved. Secondly, the ultimate goal of making nanoscale electronic and optoelectronic devices greatly stimulates atomically thin material and heterostructure research. We have introduced  lanthanide dopants into two-dimensional (2D) layered semiconductor nanosheet hosts and realize NIR-to-NIR down- and up-conversion photoluminescence. Importantly, the luminescence of 2D materials simply pumped by a single NIR laser diode can be extended to a wide range of NIR spectrum, including telecommunication range at 1.55 μm. By considering the abundant energy levels arisen from lanthanide ions, our works open a door to greatly extend and modulate the luminescence wavelengths of 2D semiconductors, which will benefit for not only investigating many appealing fundamental issues, but also developing novel nanophotonic devices.

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.