Biography: Dr. Kazuo Umemura is a full professor of Tokyo University of Science. His specialty is biophysics, especially, nanobioscience and nanobiotechnology. One of his recent interests is nanoscopic research of hybrids of biomolecules and carbon nanotubes (CNTs). Unique structures and physical/chemical properties of the hybrids are promising in biological applications such as nanobiosensors and drug delivery.
Dr. Umemura received his B.S. degree in Physics from Nagoya University. His M.S. and Ph.D. degrees were given from Tokyo Institute of Technology. After working at several institutes/universities as a researcher in Japan and in China, he became a professor of Tokyo University of Science. Kagurazaka campus of Tokyo University of Science is located at the center of Tokyo, so five subway/railway lines reach in front of the campus.
Title of Speech: Nanobiosensing using near-infrared spectroscopy of bioconjugates of carbon nanotubes
Abstract: Specific mechanical properties, electrical properties, and optical properties of carbon nanotubes (CTNs) have tremendous potentials for various applications including biological and medical applications such as DNA sensors and drug delivery carriers. In particular, single-walled CNTs (SWCNTs) reveal specific near-infrared (NIR) absorbance and NIR photoluminescence (PL). Chirality of SWCNTs is one of the key factors to establish the SWCNT nanotechnology. For biological and medical applications, solubilization of SWCNTs is one of the important techniques. In general, water soluble organic molecules are attached on SWCNT surfaces.
In this talk, several fundamental studies to maximize the specific physicochemical properties of SWCNTs for biological applications will be introduced. Because SWCNT surfaces can be decorated with various organic molecules, the SWCNT nanobiosensing method can be applied to many research fields.
Biography: Dr. Xiaohong Zhu is currently a full professor at Department of Materials Science, Sichuan University, China. Dr. Zhu received his BSc degree in Materials Physics from Sichuan University in 2000 and PhD degree in Condensed Matter Physics from the Institute of Physics, Chinese Academy of Sciences in 2006. After that, he did 3-year postdoctoral research at CNRS and CEA in France, and then joined Sichuan University as a professor in 2009. From April 2012 to April 2013, he was also a research scholar at the Department of Physics & Department of Materials Science and Engineering, University of California, Berkeley, USA. He was selected as a New Century Excellent Talent in University of China in 2009 and an Outstanding Young Scientific and Technological Leader of Sichuan Province, China in 2011. Dr. Zhu’s research interests include mainly graphene-based electrode materials and novel solid-state electrolytes for energy storage devices (supercapacitors and lithium-ion batteries), piezoelectric ceramics, as well as multifunctional oxide thin films and related electronic devices. Until now, he has authored/co-authored more than 80 SCI-indexed papers and 2 scientific books.
Title of Speech: Graphene-based electrode materials for supercapacitors
Abstract: Graphene has attracted much attention since it was firstly stripped from graphite by two physicists in 2004, and the supercapacitor based on graphene has obtained wide attention and much investment as well. However, there are many problems to solve in practical application of graphene-based supercapacitors, for instance, how to reduce the cost and simplify the fabrication process and how to improve further the electrochemical performance. In this talk, I will present our recent breakthroughs in fabricating graphene-based electrode materials for high-performance supercapacitors. First of all, to avoid graphene restacking, we come up with a pumping paper process, that is, when we use force to draw the paper from a small pore, the paper would fold. So here, we report a novel strategy to prepare wrinkled flower-like graphene through a simple suction filtration process. The wrinkled flower-like graphene shows a high specific capacitance of 272 F g-1 and a perfect capacitance retention of 99.5% after 2,000 times of charging/discharging cycles. Second, graphene/MnO2 and graphene/Ni(OH)2 composites with high electrochemical performance are prepared. Last but not least, 3D hierarchical porous carbon-based electrode materials (3DHPCs) with a composite structure are prepared from a biomass waste, sheep manure, by a facile carbonization and activation process without using any additional template. Benefiting from the composite structure, the ions experience a variety of environments, i.e., graphene-like sheets, nanotube- and microtube-like pores coexist in the same material, which, in turn, contribute significantly to the excellent electrochemical properties of supercapacitors, comprising high specific capacitance, outstanding rate capability and excellent long cycle stability. The specific capacitance at large current densities of 1 A g-1 and 50 A g-1 reaches as high as 486 F g-1 and 411 F g-1, respectively, in 6 M KOH electrolyte. Furthermore, the supercapacitor device based on 3DHPCs shows a superior cycle stability with almost 100% retention of the initial specific capacitance after 10,000 cycles; in addition, it yields a Ragone curve with high energy and power density combinations of 57.08 Wh kg-1 at 25.37 kW kg-1.
Biography: Prof. Jong Hak Kim received his Ph.D. degree in Chemical Engineering department of Yonsei University, South Korea in 2003. He worked as a postdoctoral researcher in the department of materials science and engineering at Massachusetts Institute of Technology (MIT) until he joined Yonsei University in 2005 as an assistant professor. He is now a full professor of Chemical and Biomolecular Engineering department in Yonsei University. His current research interests include the design and synthesis of graft copolymers and their applications to gas separation membranes and polymer electrolyte for electrochemical devices. He has a publication record of over 270 papers in refereed international journals such as Adv. Mater., Adv. Funct. Mater., ChemSusChem, ACS Appl. Mater. Interfaces, J. Membr. Sci., Chem. Eng. J. and etc. The sum of the times cited is 5785 and h-index is 42.
Title of Speech: Graft Copolymers for Solar Energy and Gas Separation Membranes
Abstract: Recently, concerns about global warming and its seriousness have increased greatly with the escalated global emissions of carbon dioxide. Many studies have been pursued on carbon capture and separation technologies based on membranes. Also, photovoltaics have received great attention as a renewable energy system, which can possibly replace conventional fossil fuel combustion. Our group has been working on the use of amphiphilic graft copolymers for gas separation membrane as well as photovoltaics solar energy. It should be noted that graft copolymers are more advantageous than block copolymers due to economical and simple synthetic method. For example, the graft copolymer consisting of poly(vinyl chloride)-graft-poly(oxyethylene methacrylate) (PVC-g-POEM) was synthesized via atom transfer radical polymerization (ATRP) with a copper/ligand complex that functions as a reaction catalyst. Mesoporous perovskite with a high porosity and interfacial properties were synthesized via a solvothermal reaction using PVC-g-POEM as a structure-directing agent. Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS) is a widely used conductive polymer in various electronic devices. We also reported the first use of PEDOT-PSS to enhance carbon capture performance of all-polymeric membranes. Also, we first report the structural orientation of an amphiphilic crystalline polymer to a highly ordered microphase-separated lamellar structure on a hydrophobic surface. It is formed by the surface graft polymerization of poly(ethylene glycol)behenyl ether methacrylate onto poly(trimethylsilyl) propyne in the presence of allylamine. In particular, allylamine plays a pivotal role in controlling the crystalline phase, configuration and permeation property. The resulting materials are effectively used to improve the CO2 capture property of membranes. Upon the optimization of the reaction conditions, a high CO2 permeability of 501 Barrer and a CO2/N2 ideal selectivity of 77.2 are obtained, which exceed the Robeson upper bound limit.
Biography: Dr. Shu YIN received a B. S. degree in inorganic chemical engineering from the Dalian University of Technology in 1987. He received a M. S. degree in chemical metallurgy from the Institute of Chemical Metallurgy (ICM, latterly Institute of Process and Engineering, IPE), Chinese Academy of Science in 1990, then worked as a research associate for 2 years at ICM. He came to Japan and worked as a research fellow in the Hydrothermal Chemistry Research Laboratory (Prof. N.Yamasaki’s Group), Kochi University in 1992, then became a research assistant at the Institute for Chemical Reaction Science (ICRS, Prof.T.Sato’s group), Tohoku University during 1995-1997. He received a Ph.D. degree in applied chemistry from Tohoku University (research period shortened) in 1999. He has been a research assistant at the ICRS in 1999, then a lecture and associate professor at the Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University in 2005, and then a full-time professor in 2016. He is also an affiliate professor of eight Chinese Universities / Institutes (Lanzhou University; Dalian University of Technology; Guangxi Research Institute of Chemical Industry, Huaqiao University, Taiyuan University of Technology, Sichuan University, Beijing University of Technology, University of Science and Technology Beijing / State Key Laboratory of Rare Earth Resource Utilization). He has authored more than 440 original research papers, contributed 25 book chapters/ review papers and 22 patents. His research papers were cited more than 9140 times and showed a citation h-index = 53. His research interests include morphological control of nanostructured materials, photocatalytic materials, UV-shielding materials, hydrothermal / solvothermal process, soft chemical synthesis etc.. Prof. Yin has received various awards, including “Functional Materials Scientist Award(2009)”, “Excellent Academic Photograph Award(2005)”, “The 40th Harada Award(2000)”. “The 59th Academic Award of the Society of Inorganic Materials Japan (2015)”, and “The 69th CerSJ Awards for Academic Achievements in Ceramic Science and Technology (2015)”.
Title of Speech: Synthesis of Nanostructure-Controllable Nitrides / Oxynitrides and their Novel Applications
Abstract: Nitrides and oxynitrides have attracted many researcher’s attentions, because of their novel functionalities. The physical-chemical properties of the materials greatly affecte by their morphology, particle size, specific surface area and crystalline facets etc. It is accepted that hydrothermal or solvothermal method has become a promising way for the synthesis of inorganic functional materials, because of the possibility for producing nano-size crystals with soft agglomeration, and controlling the phase composition or morphology by optimizing reaction conditions. In order to develop novel functionality of nitride materials, nanostructure control is an interesting topic. However, for normal synthesis process, it is quite difficult to prepare morphology / particle size controllable nitrides directly. In the present talk, environmental friendly low-temperature synthesis of the products with controllable particle size and morphologies will be introduced. Some novel properties such as photocatalytic activity and hydrogen gas sensing performance of the nitrides and oxynitrides will be introduced also.
In a typical synthesis process for morphological control, the precursors with various morphologies synthesized by hydrothermal process were utilized for the nitridation treatment. As an example, GaN was prepared from α–GaOOH precursors by a direct nitridation method under NH3 flow. The nitridation was carried out at various temperatures to obtain GaN with different oxygen contents, which played important role to H2 gas sensing response. Although the oxides showed very limited gas sensing property, the nitrides showed quite enhanced sensing sensitivity.The sensor devices also showed high stability and repeatable property after being exposed in H2 gas at high temperatures. Furthermore, the morphology controllable aluminum nitride such as needle-like, nest-like and plate-like AlN were also successfully synthesized by the similar manner. The plate-like morphology had the lowest shrinkage completing temperature, indicating its quite different sintering behavior compare with other morphologies. On the other hand, in order to synthesis the nitrides and oxytrides with nanoscale particle size, the addition of acetylene black during the hydrothermal process is an effective way. As an example, the Gallium oxynitride (GaON) nanoparticles could be successfully synthesized through hydrothermal treatment of an aqueous solution containing Ga(NO3)3 together with hexamethylenetetramine and acetylene black., followed by calcination and then nitridation in ammonium gas atmosphere. The presence of acetylene black in the hydrothermal treatment is an effective way for the synthesis of nanosize of particles even followed by high temperature calcination and nitridation treatment. The obtained GaON nanoparticles show a higher photocatalytic NOx decomposition activity than that of bulk GaON, because of their small particle size and high specific surface area.
Biography: Dr. Mikio Ito is an associate professor in the Center for Atomic and Molecular Technologies, Graduate School of Engineering, Osaka University, Japan. He obtained his master’s(1994) and Doctor’s degrees(1997) in Engineering from Osaka University. His research focuses on development of materials processing, mainly powder processing, for functional materials with excellent performances, such as hard magnetic materials, thermoelectric materials etc. So far, he has produced nearly 140 publications. His resent research also focuses on SPS processing, and he is trying to clarify the effects of directly applied current sintering using SPS on densification behaviors of metal and ceramic powders.
Title of Speech: Rapid and energy-saving sintering of electrically conductive powders by directly applied current heating
Abstract: The thermoelectric β-FeSi2 sintered body was synthesized by SPS (spark plasma sintering) using graphite punches and an electrically nonconductive quartz glass die, which we call as “directly applied current sintering”. In this process, the applied current is entirely put into a powder compact. The densification behaviour during heating and thermoelectric properties of the sample were compared to those of a sample sintered by the conventional SPS using graphite punches and a graphite die. When the electrically conductive Fe-Si alloy powder was sintered by directly applied current heating, the densification of a powder compact was significantly promoted and the density of a sintered body became higher than those of the sample sintered by the conventional SPS. It was also found that the sintering process in a quartz glass die was progressed by applying lower power consumption as compared to sintering in the conventional graphite die, leading to a significantly energy-saving sintering processing. The relative density of a compound sintered in a quartz die at 1173 K for 5 min was 96.9 %, which is almost the same as 97.3 % of the sample sintered by the conventional SPS at 1208 K for 10 min. The sample sintered by this modified SPS process showed the thermal conductivity smaller than the sample prepared in the conventional SPS process because of its finer microstructure. On the other hand, the electrical resistivity and the Seebeck coefficient of this sample were slightly reduced and enhanced, respectively, resulting in the significantly lager figure of merit as compared to the conventionally sintered sample.