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.