| 藤川 茂紀（ふじかわ しげのり） | データ更新日：2023.06.20 |
教授 ／
カーボンニュートラル・エネルギー国際研究所
マルチスケール構造科学ユニット
| 1. | Vaishnav, A., Fujikawa, S., Staykov, A., Curvature Effect in Polydimethylsiloxane Interaction with CO2. Insights from Theory, JOURNAL OF PHYSICAL CHEMISTRY A, 10.1021/acs.jpca.2c07001, 127, 4, 876-885, 2023.01, [URL]. |
| 2. | 中野 健央, 藤川 茂紀, 高CO2 透過性を持つ分離膜の設計, 10.5360/membrane.47.310, 47, 6, 310-316, 2022.10, [URL], The development of CO2 capture technology is essential as a global warming mitigation technology that will lead to the suppression of climate change. Gas separation membranes have great potential for direct air capture (DAC), which captures CO2 directly from the atmosphere, as well as from large CO2 emission sources, due to their low energy consumption and small footprint. However, membrane–based DAC has never been considered because of its low CO2 permeance. Recently, there have been report of high CO2 permeance membranes which would be promising candidate for DAC process. In this review paper, the recent studies of membranes with high CO2 permeance are summarized and discuss with molecular design of membranes in addition to our recent efforts to improve CO2 selectivity of nanometer–thick freestanding membranes by chemical modification of the membrane surface.. |
| 3. | Ariyoshi, M., Fujikawa, S., Kunitake, T., Nanomembranes of Poly(dimethysiloxane) Reinforced with Carbon Nanotubes and Their Potential for CO2 Capture, CHEMISTRY LETTERS, 10.1246/cl.220296, 51, 9, 962-965, 2022.09. |
| 4. | Nakano, T., Fujikawa, S., Aryl/Heteroaryl Substituted Boron-Difluoride Complexes Bearing 2-(Isoquinol-1-yl)pyrrole Ligands Exhibiting High Luminescence Efficiency with a Large Stokes Shift, JOURNAL OF ORGANIC CHEMISTRY, 10.1021/acs.joc.2c01343, 87, 17, 11708-11721, 2022.09. |
| 5. | Gautama, Z. A. R., Hutapea, Y. A., Hwang, B., Matsuda, J., Mufundirwa, A., Sugiyama, T., Ariyoshi, M., Fujikawa, S., Lyth, S. M., Hayashi, A., Sasaki, K., Nishihara, M., Suppression of radical attack in polymer electrolyte membranes using a vinyl polymer blend interlayer with low oxygen permeability, Journal of Membrane Science, 10.1016/j.memsci.2022.120734, 658, 120734, 2022.09. |
| 6. | Matsuno, Ryosuke; Nutthon, Yokajaksusri; Miyano, Akira; Ninomiya, Kakeru; Nishibori, Maiko; Kiuchi, Hisao; Fujikawa, Shigenor; Harada, Yoshihisa; Takahara, Atsushi, Electronic Structure of Carbon Dioxide in Sylgard-184 Evaluated by Using X-ray Emission Spectroscopy, CHEMISTRY LETTERS, 10.1246/cl.220113, 51, 6, 650-653, 2022.06. |
| 7. | Nakano, T., Fujikawa, S., First synthesis of a chlorin skeleton containing thiazole and thiophene rings and its optical properties, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S1088424622500110, 26, 04, 279-285, 2022.04. |
| 8. | Chapman, Andrew; Ertekin, Elif; Kubota, Masanobu; Nagao, Akihide; Bertsch, Kaila; Macadre, Arnaud; Tsuchiyama, Toshihiro; Masamura, Takuro; Takaki, Setsuo; Komoda, Ryosuke; Dadfarnia, Mohsen; Somerday, Brian; Staykov, Alexander Tsekov; Sugimura, Joichi; Sawae, Yoshinori; Morita, Takehiro; Tanaka, Hiroyoshi; Yagi, Kazuyuki; Niste, Vlad; Saravanan, Prabakaran; Onitsuka, Shugo; Yoon, Ki-Seok; Ogo, Seiji; Matsushima, Toshinori; Tumen-Ulzii, Ganbaatar; Klotz, Dino; Nguyen, Dinh Hoa; Harrington, George; Adachi, Chihaya; Matsumoto, Hiroshige; Kwati, Leonard; Takahashi, Yukina; Kosem, Nuttavut; Ishihara, Tatsumi; Yamauchi, Miho; Saha, Bidyut Baran; Islam, Md. Amirul; Miyawaki, Jin; Sivasankaran, Harish; Kohno, Masamichi; Fujikawa, Shigenori; Selyanchyn, Roman; Tsuji, Takeshi; Higashi, Yukihiro; Kirchheim, Reiner; Sofronis, Petros.*, Achieving a Carbon Neutral Future through Advanced Functional Materials and Technologies., Chemical Communications, 95, 1, 73-103, 2022.02. |
| 9. | Miho Aryoosh, Shigenri FUJIKAWA, Toyok nitake, Robust, Hyper-Permeable Nanomembrane Composites of Poly(dimethylsiloxane) and Cellulose Nanofibers, ACS APPLIED MATERIALS & INTERFACES, 10.1021/acsami.1c19220, 13, 51, 61189-61195, 2021.12, Robust, Hyper-Permeable Nanomembrane Composites of Poly(dimethylsiloxane) and Cellulose Nanofibers. |
| 10. | Tsuji, Takeshi; Sorai, Masao; Shiga, Masashige; Fujikawa, Shigenori; Kunitake, Toyoki, Geological storage of CO2-N2-O2 mixtures produced by membrane-based direct air capture (DAC), Greenh. Gases Sci. Technol., DOI:10.1002/ghg.2099, 2021.06, Carbon capture and storage has been considered as a realistic approach to reducing atm. CO2 concns. However, the cost of capturing high-purity CO2 typically used for geol. storage (e.g., 98%) is high. Direct air capture (DAC), a technol. that exts. CO2 of relatively low-purity from the ambient atm., has been recently proposed as a means to achieve neg. CO2 emissions when the product is sequestered underground. Although the CO2 produced by DAC is of low-purity, the other gaseous components (mainly nitrogen and oxygen) are not hazardous materials like NOx and SOx that must be typically dealt with by conventional projects in coal-burning plants. Here, we evaluate geol. storage of the low-purity CO2 captured via advanced membrane-based DAC technol. The ubiquity of ambient air is important in reducing transport costs and ensuring social acceptance as the CO2 product can be both produced and stored at sites in remote areas, such as deserts and offshore platforms. We calcd. the d. of CO2-N2-O2 mixts. via mol. dynamics simulation and evaluated the cost of the low-purity CO2 storage. Our evaluation suggests that the storage of low-purity CO2 in geol. formations is environmentally acceptable and economically viable.. |
| 11. | Fujikawa, Shigenori; Selyanchyn, Roman; Kunitake, Toyoki, A new strategy for membrane-based direct air capture, Polymer Journal, DOI:10.1038/s41428-020-00429-z, 53, 1, 111-119, 2021.06, A review. Direct CO2 capture from the air, so-called direct air capture (DAC), has become inevitable to reduce the concn. of CO2 in the atm. Current DAC technologies consider only sorbent-based systems. Recently, there were reports that show ultrahigh CO2 permeances in gas sepn. membranes and thus membrane sepn. could be a potential new technol. for DAC in addn. to sorbent-based CO2 capture. The simulation of chem. processes was well established and is commonly used for the development and performance assessment of industrial chem. processes. These simulations offer a credible assessment of the feasibility of membrane-based DAC (m-DAC). In this paper, we discuss the potential of m-DAC considering the state-of-the-art performance of org. polymer membranes. The multistage membrane sepn. process was employed in process simulation to est. the energy requirements for m-DAC. Based on the anal., we propose the target membrane sepn. performance required for m-DAC with competitive energy expenses. Finally, we discuss the direction of future membrane development for DAC.. |
| 12. | Inoue, Keiki; Selyanchyn, Roman; Fujikawa, Shigenori; Ishiwari, Fumitaka; Fukushima, Takanori., Thermal and Gas Adsorption Properties of Troger's Base/Diaza-cyclooctane Hybrid Ladder Polymers., ChemNanoMat, 10.1002/cnma.202100151, 7, 7, 824-830, 2021.04, A polymer of intrinsic microporosity (PIM) consisting of Troger's base (TB) undergoes ring opening of the bicyclic amine upon N-methylation followed by alk. hydrolysis, resulting in a hybrid ladder polymer that contains diazacyclooctane (DACO) units with tert- and sec-amino groups. The hybrid ladder polymers with various TB/DACO ratios can be prepd. depending on the reaction conditions. Here we report a systematic study on the effect of DACO content on the thermal and gas adsorption properties of the hybrid ladder polymer. Using a PIM derived from 2,5-diamino-p-xylene, we prepd. hybrid ladder polymers with a DACO content ranging from 19% to 55% while having a similar mol. wt. The thermal stability of the hybrid ladder polymers, evaluated by thermogravimetric anal., is decreased with the increase in DACO content. Based on gas adsorption measurements, the increase in DACO content results in the decrease in the BET surface area but improves the gas adsorption selectivity for CO2 against N2, likely due to high basicity of the sec-amino group of DACO unit. This result demonstrates that the partial TB-to-DACO conversion of the TB-based PIM may provide a simple but useful strategy to design polymer materials that enable selective CO2 capture and/or sepn. [on SciFinder(R)]. |
| 13. | Pylypchuk, Ievgen; Selyanchyn, Roman; Budnyak, Tetyana; Zhao, Yadong; Lindstroem, Mikael; Fujikawa, Shigenori; Sevastyanova, Olena., ''Artificial wood'' lignocellulosic membranes: influence of kraft lignin on the properties and gas transport in tunicate-based nanocellulose composites., Membranes (Basel, Switz.), 10.3390/membranes11030204, 11, 3, 204, 2021.03, Nanocellulose membranes based on tunicate-derived cellulose nanofibers, starch, and 竏ｼ5% wood-derived lignin were investigated using three different types of lignin. The addn. of lignin into cellulose membranes increased the sp. surface area (from 5 to 竏ｼ50 m2/g), however the fine porous geometry of the nanocellulose with characteristic pores below 10 nm in diam. remained similar for all membranes. The permeation of H2, CO2, N2, and O2 through the membranes was investigated and a characteristic Knudsen diffusion through the membranes was obsd. at a rate proportional to the inverse of their mol. sizes. Permeability values, however, varied significantly between samples contg. different lignins, ranging from several to thousands of barrers (10-10 cm3 (STP) cm cm-2 s-1 cmHg-1cm), and were related to the obsd. morphol. and lignin distribution inside the membranes. Addnl., the addn. of ~ 5% lignin resulted in a significant increase in tensile strength from 3 GPa to 竏ｼ6-7 GPa, but did not change thermal properties (glass transition or thermal stability). Overall, the combination of plant-derived lignin as a filler or binder in cellulose-starch composites with a sea-animal derived nanocellulose presents an interesting new approach for the fabrication of membranes from abundant bio-derived materials. Future studies should focus on the optimization of these types of membranes for the selective and fast transport of gases needed for a variety of industrial sepn. processes. [on SciFinder(R)]. |
| 14. | Pylypchuk, I., Selyanchyn, R., Budnyak, T., Zhao, Y., Lindström, M., Fujikawa, S., Sevastyanova, O., "Artificial Wood" Lignocellulosic Membranes: Influence of Kraft Lignin on the Properties and Gas Transport in Tunicate-Based Nanocellulose Composites., Membrane, 10.3390/membranes11030204, 11, 3, 204, 2021.03. |
| 15. | Bayer, Thomas; Cunning, Benjamin Vaughan; Smid, Bretislav; Selyanchyn, Roman; Fujikawa, Shigenori; Sasaki, Kazunari; Lyth, Stephen Matthew, Spray deposition of sulfonated cellulose nanofibers as electrolyte membranes in fuel cells, CELLULOSE, 10.1007/s10570-020-03593-w, 28, 3, 1355-1367, 2021.02, Nanocellulose is a promising new membrane material for fuel cells, with much lower cost and environmental impact compared with Nafion or Aquivion. It is mech. strong, is an excellent hydrogen barrier and has reasonable proton cond. Here, sulfonation of cellulose nanofibers is performed to enhance the cond. (up to 2 x 10- 3 S cm- 1) without compromising the membrane integrity, and fuel cells are fabricated with 30μm-thick "paper" membranes. The hydrogen crossover current is two orders of magnitude lower than for Nafion fuel cells with equiv. thickness, but the power d. is rather low. Spray-coating is used to deposit 8μm-thick membranes directly onto the electrocatalyst layer, in a process analogous to 3D printing or additive manufg. The resulting paper fuel cell has high c.d. (> 0.8 A cm- 2) and power d. (156 mW cm- 2) under std. measurement conditions (H2/air; 80°C; 95% RH; 0.1 MPa), attributed to decreased membrane resistance. The cost of the spray-painted cellulose membranes is calcd. to be ∼ 50 $ m- 2, which is much lower than that of Nafion, even without taking into consideration economies of scale. This new concept in electrochem. energy conversion paves the way for the mass prodn. of affordable, recyclable fuel cells.. |
| 16. | Fujikawa, Shigenori; Selyanchyn, Roman; Kunitake, Toyoki., Correction: A new strategy for membrane-based direct air capture., Polym. J. (Tokyo, Jpn.), 10.1038/s41428-020-00440-4, 53, 1, 219, 2021.01, An amendment to this paper has been published and can be accessed via a link at the top of the paper. [on SciFinder(R)]. |
| 17. | Selyanchyn Olena, Selyanchyn Roman, Fujikawa, Shigenori, Critical Role of the Molecular Interface in Double-Layered Pebax-1657/PDMS Nanomembranes for Highly Efficient CO2/N2 Gas Separation, ACS Applied Materials & Interfaces, 10.1021/acsami.0c07344, 12, 29, 33196-33209, 2020.06, [URL], In this work, we deposited a CO2-selective block copolymer, Pebax-1657, as a selective layer with a thickness of 2-20 nm on the oxygen plasma-activated surface of poly(dimethylsiloxane) (PDMS) used as a gutter layer (thickness ~ 400 nm). This double-layered structure was subsequently transferred onto the polyacrylonitrile (PAN) microporous support and studied for CO2/N2 sepn. The effect of interfacial mol. arrangements between the selective and gutter layers on CO2 permeance and selectivity has been investigated. We have revealed that the gas permeance and selectivity do not follow the conventional theor. predictions for the multilayer membrane (resistance in series transport model); specifically, more selective CO2/N2 sepn. membranes were achieved with ultrathin selective layers. Detailed characterization of the chem. structure of the outermost membrane surface suggests that nanoscale blending of the ultrathin Pebax-1657 layer with O2 plasma-activated PDMS chains on the surface takes place. This nanoblending at the interface between the selective and gutter layers played a crit. role in enhancing the CO2/N2 selectivity. CO2 permeance in the developed thin-film composite membranes (TFCM) were between 1200 and 3500 gas permeance units (GPU) and the resp. CO2/N2 selectivities were between 72 and 23, providing the gas sepn. performance suitable for CO2 capture in postcombustion processes. This interpenetrating polymer interface enhanced the overall selectivity of the membrane significantly, exceeding the sepn. ability of the pristine Pebax-1657 polymer.. |
| 18. | Heeyoel Baek, Keiichiro Kashimura, Takashi Fujii, Shuntaro Tsubaki, Yuji Wada, Shigenori Fujikawa, Takuma Sato, Yasuhiro Uozumi, Yoichi M.A. Yamada, Production of Bio Hydrofined Diesel, Jet Fuel, and Carbon Monoxide from Fatty Acids Using a Silicon Nanowire Array-Supported Rhodium Nanoparticle Catalyst under Microwave Conditions, ACS Catalysis, 10.1021/acscatal.9b04784, 10, 3, 2148-2156, 2020.02, [URL], Biodiesel was efficiently produced from biomass fatty acids using renewable gas H2 and a reusable heterogeneous catalyst under low-energy-consumption microwave conditions. As the decarboxylation of fatty acids to alkanes is an important transformation in the production of bio hydrofined diesel (BHD) and jet fuel, we herein report the development of a highly active and reusable Rh nanoparticle catalyst supported by a silicon nanowire array (SiNA-Rh) and its application in the decarboxylation of fatty acids to alkanes under mild conditions. More specifically, SiNA-Rh (500 mol ppm) selectively promoted the hydrogenative decarboxylation reaction at 200 °C under microwave irradiation (∼40 W) in a H2 atmosphere (10 bar) to afford the corresponding alkanes in high yields selectively. The only coproduct observed was carbon monoxide, an important and essential staple for the chemical industry. Importantly, carbon dioxide formation was not observed. Moreover, the aldehydes were efficiently converted to alkanes by SiNA-Rh, and this catalyst was reused 20 times without any loss in catalytic activity. Finally, to investigate the effects of microwave irradiation on the enhancement of this chemical transformation based on the Si nanorod structures present in the SiNA-Rh catalyst, the effect of the microwave electric field and magnetic field in the microwave to the reaction was experimentally investigated, and the spatial distribution of the electric field intensity around the surface of the Si nanostructure was simulated using the finite element method.. |
| 19. | Linlin Li, Akihiko Takada, Wei Ma, Shigenori Fujikawa, Miho Ariyoshi, Kosuke Igata, Maiko Okajima, Tatsuo Kaneko, Atsushi Takahara, Structure and Properties of Hybrid Film Fabricated by Spin-Assisted Layer-by-Layer Assembly of Sacran and Imogolite Nanotubes, Langmuir, 10.1021/acs.langmuir.9b03626, 36, 7, 1718-1726, 2020.02, [URL], A free-standing (biomacomolecule/synthetic inorganic nanotubes) hybrid film was fabricated through an alternative layer-by-layer (LBL) assembly of sacran and imogolite nanotubes. Sacran is a natural polysaccharide extracted from the cyanobacterium Aphanothece sacrum, while imogolite is a natural tubular aluminosilicate clay found in volcano ash. The hybrid film thickness increased linearly with the number of the bilayers, because of the interaction between the negatively charged surface of sacran and the positively charged surface of imogolite. UV-vis spectroscopy indicated that the LBL film exhibited good transparency. The surface morphology of the LBL film was smooth in the micrometer scale; many imogolite nanotubes were adsorbed onto the sacran layer, while no imogolite clusters were observed. Furthermore, the structure, stability, gas permeability, and mechanical properties of the LBL films were investigated.. |
| 20. | Ryosuke Yamamoto, Shigenori Fujikawa, Nobuo Kimizuka, Polar switching of dipolar molecules confined in submicron- And micron-sized pores in polymer films, Chemistry Letters, 10.1246/cl.190917, 49, 3, 255-259, 2020.01, [URL], p-Nitroanisole (pNA) confined in submicron- and micron-sized pores in polyimide films shows enhanced dipolar polarization and polar switching characteristics in the liquid state, as revealed by hysteresis in the polarization (P)-electric field (E) curves. They reflect interface-induced orientational polarization of confined pNA molecules, i.e. inversion of molecular orientation depending on the direction of the external electric field. Such an enhanced orientational polarization is not observed for the bulk pNA nor pristine polyimide films, and interactions between the confined pNA molecules and the surface of the pores are indispensable for the polar switching phenomena.. |
| 21. | Takahiro Senzai, Shigenori Fujikawa, Fast hydrophobicity recovery of the surface-hydrophilic poly(dimethylsiloxane) films caused by rechemisorption of dimethylsiloxane derivatives, Langmuir, 10.1021/acs.langmuir.9b01448, 35, 30, 9747-9752, 2019.07, [URL], Long-term stability of the surface hydrophilicity of poly(dimethylsiloxane) (PDMS) remains a critical issue for a wide range of applications including, e.g., biomedical materials, biochip devices, and microfluidics. Although several mechanisms for recovering hydrophobicity have been proposed, none has been proven unequivocally. We discovered that the hydrophobic recovery of surface-oxidized PDMS films was accelerated when the films were stored in a closed chamber under an atmosphere containing dimethylsiloxane derivatives such as octamethylcyclotetrasiloxane, which had evaporated from the films and were detected by gas chromatography-mass spectrometry measurements. X-ray photoelectron spectroscopy and quartz crystal microbalance measurements were used to monitor the chemical deposition of the derivatives on the surface-oxidized substrates, and the formation of a hydrophobic dimethyl silicone layer rendered the oxidized surfaces hydrophobic again. In the absence of superficial hydrophilic functional groups, volatile species did not react with the surface, and the hydrophobic dimethyl silicone layer did not form. The results show that the formation of a thin layer of dimethylsiloxane derivatives by chemisorption is a new mechanism for recovering the surface hydrophobicity of PDMS films.. |
| 22. | Saravanan, Prabakaran; Selyanchyn, Roman; Tanaka, Hiroyoshi; Fujikawa, Shigenori; Lyth, Stephen Matthew; Sugimura, Joichi., The effect of oxygen on the tribology of (PEI/GO)15 multilayer solid lubricant coatings on steel substrates, Wear, 10.1016/j.wear.2019.05.035, 432-433, 102920/1-102920/7, 2019.06. |
| 23. | Selyanchyn, Roman; Fujikawa, Shigenori; Katsuta, Naohiro; Suwa, Kazuya; Kunitake, Masashi., Study of gases permeation in necklace-shaped dimethylsiloxane polymers bearing POSS cages, Membranes, 10.3390/membranes9040054, 9, 4, 54-66, 2019.04. |
| 24. | Selyanchyn, Roman; Fujikawa, Shigenori, Molecular Hybridization of Polydimethylsiloxane with Zirconia for Highly Gas Permeable Membranes, ACS Appl. Polym. Mater., 10.1021/acsapm.9b00178, 1, 5, 1165-1174, 2019.04. |
| 25. | Ishizu, Masaki; Aizawa, Miho; Akamatsu, Norihisa; Hisano, Kyohei; Fujikawa, Shigenori; Barrett, Christopher J.; Shishido, Atsushi, Effect of surface treatment on molecular alignment behavior by scanning wave photopolymerization, Appl. Phys. Express, 10.7567/1882-0786/ab040d, 12, 4, 041004/1-041004/5, 2019.03. |
| 26. | Mersha, Anteneh; Fujikawa, Shigenori, Mechanical Reinforcement of Free-Standing Polymeric Nanomembranes via Aluminosilicate Nanotube Scaffolding, ACS Appl. Polym. Mater., 10.1021/acsapm.8b00104, 1, 2, 112-117, 2019.01. |
| 27. | Takahiro Senzaki, Shigenori Fujikawa, Design of polymer coating materials for long-term hydrophilic stability of poly(dimethylsiloxane) surfaces, Chemistry Letters, 10.1246/cl.190453, 48, 9, 1152-1155, 2019.01, [URL], Poly(dimethylsiloxane) (PDMS) is often used as a base material for microfluidic devices because of its attractive shape-molding properties, elasticity, and biocompatibility. However, sufficient long-term hydrophilic stability of PDMS surfaces has not been achieved. This study provides a new molecular design for surface-coating materials that can maintain the hydrophilicity of the PDMS surface for an ultralong-term. The recovery rates of surface hydrophobicity were distinctly different for the three polymers used for coating the PDMS substrate. The polymer with the most inert functional group maintained the hydrophilic surface over one year.. |
| 28. | Shigenori Fujikawa, Miho Ariyoshi, Roman Selyanchyn, Toyoki Kunitake, Ultra-fast, selective CO2 permeation by free-standing siloxane nanomembranes, Chemistry Letters, 10.1246/cl.190558, 48, 11, 1351-1354, 2019.01, [URL], Fabrication and gas permselective behavior of free-standing polydimethylsiloxane (PDMS) nanomembranes are discussed. The largest CO2 permeance is close to 40,000 GPU (the highest one ever reported) at 34-nm membrane thickness without losing the CO2/N2 selectivity of 1012, indicating the formation of pin-hole free nanomembranes.. |
| 29. | Prabakaran Saravanan, Roman Selyanchyn, Motonori Watanabe, Shigenori Fujikawa, Hiroyoshi Tanaka, Stephen Matthew Lyth, Joichi Sugimura, Ultra-low friction of polyethylenimine / molybdenum disulfide (PEI/MoS2)15 thin films in dry nitrogen atmosphere and the effect of heat treatment, Tribology International, 10.1016/j.triboint.2018.06.003, 127, 255-263, 2018.11, [URL], The unique frictional behavior of polyethylenimine/molybdenum disulphide (PEI/MoS2)n thin films on steel substrates, deposited via the layer-by-layer (LbL) technique, is explored. The effects of gaseous atmosphere (i.e. air vs. dry nitrogen), and heat treatment of the coatings are investigated. The coefficients of friction (COFs) are reduced by factors of ca. 2 and 11 in air and N2 respectively, compared to an uncoated steel substrate. Ultra-low friction (COF 2. After heat treatment of the coating at 500 °C, the COF in air and nitrogen does not change significantly, but the coating demonstrates much higher durability. Detailed characterization of the coating and wear debris are performed to understand the origin of these tribological properties.. |
| 30. | Shiyan Feng, Shoichi Kondo, Takahiro Kaseyama, Taichi Nakazawa, Takamasa Kikuchi, Roman Selyanchyn, Shigenori Fujikawa, Liana Christiani, Kazunari Sasaki, Masamichi Nishihara, Characterization of polymer-polymer type charge-transfer (CT) blend membranes for fuel cell application, Data in Brief, 10.1016/j.dib.2018.02.031, 18, 22-29, 2018.06, [URL], The data presented in this article are related to polymer-polymer type charge-transfer blend membranes for fuel cell application. The visible spectra of the charge-transfer (CT) blend membranes indicated formation of CT complex in the blend membranes, and behavior of CT complex formation by polymers was clarified by Job plot of the visible spectra. The effect of fluorine for membrane property and fuel cell performance of CT blend membranes were evaluated by 19F NMR and overvoltage analysis, respectively.. |
| 31. | Akamatsu, Norihisa; Fukuhara, Motoyuki; Fujikawa, Shigenori; Shishido, Atsushi., Effect of hardness on surface strain of PDMS films detected by a surface labeled grating method, J. Photopolym. Sci. Technol., 10.2494/photopolymer.31.523, 31, 4, 523-526, 2018.06. |
| 32. | Shiyan Feng, Shoichi Kondo, Takahiro Kaseyama, Taichi Nakazawa, Takamasa Kikuchi, Roman Selyanchyn, Shigenori Fujikawa, Liana Christiani, Kazunari Sasaki, Masamichi Nishihara, Development of polymer-polymer type charge-transfer blend membranes for fuel cell application, Journal of Membrane Science, 10.1016/j.memsci.2017.11.025, 548, 223-231, 2018.02, [URL], We have prepared new charge-transfer (CT) complex polymer blend membranes (CT membranes), for use as high performance polymer electrolyte membranes (PEMs); with a simple and easy preparation method for application in PEFCs. In this study, electron-accepting sulfonated polyimide (SPI) and electron-donating polyether (PE), were used to develop polymer-polymer type CT membranes. The formation of CT complex in the obtained SPI/PE membranes was confirmed by visible spectroscopy. The use of flexible spacers in the PE and heat treatment of the CT membranes, enhanced the CT complex formation. SPI/PE CT membranes showed 1.9–2.2 times higher mechanical strength than the original SPI, while SPI/PE 0.33 CT membrane with heat treatment at 130 °C for 2 h showed 4.3 times higher mechanical strength than the original SPI. Hydrogen permeability through SPI/PE CT membranes was 4.1–5.4 times lower than Nafion 212 and 1.4–1.9 times lower than the original SPI membrane. We have prepared a thin SPI/PE CT membrane (10 µm thickness), that showed comparable OCV (0.88 V), similar resistance compared to Nafion 212 and demonstrated more than 10 h of durability in a fuel cell test; suggesting that SPI/PE thin CT membrane can be applied for PEFC application.. |
| 33. | Norihisa Akamatsu, Motoyuki Fukuhara, Shigenori Fujikawa, Atsushi Shishido, Effect of hardness on surface strain of PDMS films detected by a surface labeled grating method, Journal of Photopolymer Science and Technology, 10.2494/photopolymer.31.523, 31, 4, 523-526, 2018.01, [URL], In recent years, mechanical properties of flexible materials have attracted much attention for the development of stretchable electronic devices, flexible sensors and wearable biointegrated devices that would support the future ‘Internet of things’ (IoT) and ‘information technology’ (IT). For designing advanced soft devices, there is a strong demand to quantitatively analyze the deformation behavior of soft materials. Recently, a surface labeled grating method has been developed as a new tool to quantitatively measure the bending behavior of flexible films. In this study, we investigated the effect of hardness of the film to be measured on the surface strain evaluated by this method.. |
| 34. | Yoshiaki Shoji, Minsu Hwang, Haruka Sugiyama, Fumitaka Ishiwari, Kumiko Takenouchi, Ryota Osuga, Junko N. Kondo, Shigenori Fujikawa, Takanori Fukushima, Highly efficient transformation of linear poly(phenylene ethynylene)s into zigzag-shaped π-conjugated microporous polymers through boron-mediated alkyne benzannulation, Materials Chemistry Frontiers, 10.1039/c7qm00582b, 2, 4, 807-814, 2018.01, [URL], Porous polymers offer great advantages compared to other microporous materials in terms of solubility and processability. However, the design of porous polymers has suffered from the limited availability of suitable building blocks. Here we propose a conceptually new strategy for the design of porous polymers, which involves the transformation of a rigid linear polymer into a rigid zigzag polymer with a large free volume around the polymer backbone. This strategy relies on a boron-mediated alkyne benzannulation reaction, which was recently developed by our group. When the benzannulation reaction was applied to poly(phenylene ethynylene) (PPE) derivatives, a linear-to-zigzag structural transformation successfully occurred to give the corresponding p-conjugated polymers with a diarylphenanthrene unit in the main chain. As revealed by N2 adsorption experiments, while the parent PPEs were non-porous, the zigzag polymers in the solid state possessed porosity with a specific surface area of up to 366 m2 g1, where the surface area largely depended on the steric bulkiness of the substituents on the polymer. Considering the fact that a wide variety of PPE derivatives have so far been synthesized, the present strategy may open a new avenue for the development of functional porous polymers.. |
| 35. | Daisuke Kichise, Kazuma Mase, Shigenori Fujikawa, Nobuhiro Yanai, Nobuo Kimizuka, Specific uniaxial self-assembly of columnar perylene liquid crystals in au nanofin arrays, Chemistry Letters, 10.1246/cl.171228, 47, 3, 354-357, 2018.01, [URL], Self-assembly of liquid crystalline tetrakis(2-ethylhexyl) perylene-3,4,9,10-tetracarboxylate (C8PTC) in periodically aligned Au nanofin arrays (Au-NFs) is investigated. C8PTC forms columnar hexagonal liquid crystalline assemblies oriented parallel to the glass substrate, while the in-plane orientation of the long columnar axis is perpendicular to the surface of Au- NFs. This unique alignment reflects the interaction between the aromatic π-surface and the bare gold surface of NFs. This work provides a new perspective to design and control molecular selfassembly confined in the designed surface nanopatterns.. |
| 36. | Roman Selyanchyn, Miho Ariyoshi, Shigenori Fujikawa, Thickness Effect on CO2/N2 Separation in Double Layer Pebax-1657®/PDMS Membranes, Membranes, 10.3390/membranes8040121, 8, 4, 2018.01, [URL], The effect of thickness in multilayer thin-film composite membranes on gas permeation has received little attention to date, and the gas permeances of the organic polymer membranes are believed to increase by membrane thinning. Moreover, the performance of defect-free layers with known gas permeability can be effectively described using the classical resistance in series models to predict both permeance and selectivity of the composite membrane. In this work, we have investigated the Pebax®-MH1657/PDMS double layer membrane as a selective/gutter layer combination that has the potential to achieve sufficient CO2/N2 selectivity and permeance for efficient CO2 and N2 separation. CO2 and N2 transport through membranes with different thicknesses of two layers has been investigated both experimentally and with the utilization of resistance in series models. Model prediction for permeance/selectivity corresponded perfectly with experimental data for the thicker membranes. Surprisingly, a significant decrease from model predictions was observed when the thickness of the polydimethylsiloxane (PDMS) (gutter layer) became relatively small (below 2 µm thickness). Material properties changed at low thicknesses-surface treatments and influence of porous support are discussed as possible reasons for observed deviations.. |
| 37. | Roman Selyanchyn, Shigenori Fujikawa, Membrane thinning for efficient CO2 capture, Science and Technology of Advanced Materials, 10.1080/14686996.2017.1386531, 18, 1, 816-827, 2017.12, [URL], Enhancing the fluxes in gas separation membranes is required for utilizing the membranes on a mass scale for CO2 capture. Membrane thinning is one of the most promising approaches to achieve high fluxes. In addition, sophisticated molecular transport across membranes can boost gas separation performance. In this review, we attempt to summarize the current state of CO2 separation membranes, especially from the viewpoint of thinning the selective layers and the membrane itself. The gas permeation behavior of membranes with ultimate thicknesses and their future directions are discussed.. |
| 38. | Mersha, Anteneh; Selyanchyn, Roman; Fujikawa, Shigenori, Preparation of large, ultra-flexible and free-standing nanomembranes of metal oxide–polymer composite and their gas permeation properties, Clean Energy, 10.1093/ce/zkx006, 1, 1, 80-89, 2017.12. |
| 39. | Prabakaran Saravanan, Roman Selyanchyn, Hiroyoshi Tanaka, Shigenori Fujikawa, Stephen Matthew Lyth, Joichi Sugimura, Ultra-low friction between polymers and graphene oxide multilayers in nitrogen atmosphere, mediated by stable transfer film formation, Carbon, 10.1016/j.carbon.2017.06.090, 122, 395-403, 2017.10, [URL], The efficiency and lifetime of mechanical devices is significantly decreased by friction and wear, significantly contributing to global energy consumption. We previously showed that multilayer polyethyleneimine/graphene oxide thin films, (PEI/GO)15, on steel display superlubricity against a steel counterface ball. Here, the coefficient of friction (COF) and wear of (PEI/GO)15 with six different counterface polymer balls is investigated in air and in nitrogen, with particular focus on the formation of tribological transfer films. The polymers polyoxymethylene (POM), polyetheretherketone (PEEK), polyethylene (PE), poly(methyl methacrylate) (PMMA), polycarbonate (PC), and polytetrafluoroethylene (PTFE) are utilized. The COF of (PEI/GO)15 vs steel is 0.35 in both air and nitrogen. In air, the COF ranges from 0.06 to 0.17 for all polymers. Significantly, in nitrogen, four polymers (POM, PEEK, PMMA and PC) display ultra-low friction (COF ∼0.02) whilst two do not (PTFE and PE). The wear tracks and transfer films are investigated using e.g. optical microscopy, electron microscopy, and Raman mapping, and the tribological behavior is correlated to the hydrophilicity and relative hardness of the polymer balls compared to GO.. |
| 40. | Fujikawa, Shigenori; Ariyoshi, Miho; Shigyo, Eiko; Fukakusa, Chihoko; Roman, Selyanchyn; Kunitake, Toyoki, Preferential CO2 Separation Over Nitrogen by a Free-standing and Nanometer-thick Membrane, Energy Procedia, 10.1016/j.egypro.2017.03.1907, 114, 608-612, 2017.08. |
| 41. | T. Bayer, R. Selyanchyn, Shigenori Fujikawa, Kazunari Sasaki, Stephen Matthew Lyth, Spray-painted graphene oxide membrane fuel cells, Journal of Membrane Science, 10.1016/j.memsci.2017.07.012, 541, 347-357, 2017.01, [URL], Graphene oxide (GO) is potentially a useful electrolyte material for polymer electrolyte membrane fuel cells due to its high strength, excellent hydrogen gas barrier properties, hydrophilicity, and proton conducting acidic functional groups. Here, GO paper is prepared from aqueous dispersion by vacuum-filtration, and the hydrogen permeability (2 × 10−2 barrer) is measured to be 3 orders of magnitude lower than Nafion (30 barrer) at 30 °C. The in-plane and through-plane conductivities are measured to be 49.9 and 0.3 mS cm−1, respectively. This significant anisotropy is attributed to the lamellar structure of GO, and the physical anisotropy between the thickness and lateral size of the GO nanoplatelets. Interestingly, the in-plane conductivity of GO is comparable to the through-plane conductivity of Nafion. GO membrane fuel cells (GOMFCs) are fabricated. To compensate for the low in-plane conductivity of GO, whilst taking advantage of the excellent hydrogen gas barrier properties, extremely thin electrode-supported GOMFCs are prepared by spray painting GO directly onto the electrocatalyst layer. The effect of membrane thickness on cell performance is investigated. Decreasing membrane thickness by spray painting improves the power density from 3.7 mW cm−2 for a 50 μm-thick membrane-supported GOMFC, to 79 mW cm−2 for a 3 µm-thick, spray-painted membrane, electrode-supported GOMFC.. |
| 42. | Fujikawa, Shigenori; Koizumi, Mari; Taino, Akiko; Okamoto, Koichi., Fabrication and Unique Optical Properties of Two-Dimensional Silver Nanorod Arrays with Nanometer Gaps on a Silicon Substrate from a Self-Assembled Template of Diblock Copolymer., Langmuir, 10.1021/acs.langmuir.6b02934, 2016.01. |
| 43. | Saravanan, Prabakaran; Selyanchyn, Roman; Tanaka, Hiroyoshi; Darekar, Durgesh; Staykov, Aleksandar; Fujikawa, Shigenori; Lyth, Stephen Matthew; Sugimura, Joichi., Macroscale Superlubricity of Multilayer Polyethylenimine/Graphene Oxide Coatings in Different Gas Environments., ACS Appl. Mater. Interfaces, 10.1021/acsami.6b06779, 8, 40, 27179-27187, 2016.01. |
| 44. | Bayer, Thomas; Cunning, Benjamin V.; Selyanchyn, Roman; Nishihara, Masamichi; Fujikawa, Shigenori; Sasaki, Kazunari; Lyth, Stephen M., High Temperature Proton Conduction in Nanocellulose Membranes: Paper Fuel Cells., Chem. Mater., 10.1021/acs.chemmater.6b01990, 28, 13, 4805-4814, 2016.01. |
| 45. | Bayer, Thomas; Cunning, Benjamin V.; Selyanchyn, Roman; Daio, Takeshi; Nishihara, Masamichi; Fujikawa, Shigenori; Sasaki, Kazunari; Lyth, Stephen M., Alkaline anion exchange membranes based on KOH-treated multilayer graphene oxide., J. Membr. Sci., 10.1016/j.memsci.2016.02.017, 508, 51-61, 2016.01. |
| 46. | Kim, Byoungsu; Hillman, Febrian; Ariyoshi, Miho; Fujikawa, Shigenori; Kenis, Paul J. A., Effects of composition of the micro porous layer and the substrate on performance in the electrochemical reduction of CO2 to CO., J. Power Sources, 10.1016/j.jpowsour.2016.02.043, 312, 192-198, 2016.01. |
| 47. | Roman Selyanchyn, Aleksandar Staykov, Shigenori Fujikawa, Incorporation of CO2-philic moieties into a TiO2 nanomembrane for preferential CO2 separation., RSC Advances, 10.1039/C6RA18419, 6, 91, 88664-88667, 2016.01. |
| 48. | Prabakaran Saravanan, Roman Selyanchyn, Hiroyoshi Tanaka, Shigenori Fujikawa, Joichi Sugimura, Frictional behavior of (PEI/GO)x solid lubricant coatings on steel substrates in various environments, 71st Society of Tribologists and Lubrication Engineers Annual Meeting and Exhibition 2016 Society of Tribologists and Lubrication Engineers Annual Meeting and Exhibition 2016, 543-548, 2016.01. |
| 49. | Hisamitsu, Shota; Yanai, Nobuhiro; Fujikawa, Shigenori; Kimizuka, Nobuo., Photoinduced crystallization in ionic liquids: photodimerization-induced equilibrium shift and crystal patterning., Chem. Lett., 10.1246/cl.150261, 44, 7, 908-910, 2015.01. |
| 50. | Akamatsu, Norihisa; Tashiro, Wataru; Saito, Keisuke; Mamiya, Jun-ichi; Kinoshita, Motoi; Ikeda, Tomiki; Takeya, Jun; Fujikawa, Shigenori; Priimagi, Arri; Shishido, Atsushi., Facile strain analysis of largely bending films by a surface-labelled grating method., Sci. Rep., 10.1038/srep05377, 4, 5377-5377, 2014.01. |
| 51. | Kimura, Seiichro; Honda, Kuniaki; Kitamura, Keigo; Taniguch, Ikuo; Shitashima, Kiminori; Tsuji, Takeshi; Fujikawa, Shigenori., Preliminary Feasibility Study for On-Site Hydrogen Station with Distributed CO2 Capture and Storage System., Energy Procedia, 10.1016/j.egypro.2014.11.490, 63, 12th International Conference on Greenhouse Gas Control Technologies, GHGT-12, 4575-4584, 2014.01. |
| 52. | Taniguchi, Ikuo; Fujikawa, Shigenori., CO2 Separation with Nano-thick Polymeric Membrane for Pre- combustion., Energy Procedia, 10.1016/j.egypro.2014.11.025, 63, 12th International Conference on Greenhouse Gas Control Technologies, GHGT-12, 235-242, 2014.01. |
| 53. | Taniguchi, Ikuo; Ioh, Daichi; Fujikawa, Shigenori; Watanabe, Takayuki; Matsukuma, Yosuke; Minemoto, Masaki., An alternative carbon dioxide capture by electrochemical method., Chem. Lett., 10.1246/cl.140508, 43, 10, 1601-1603, 2014.01. |
| 54. | Lee, Yaerim; Maeda, Etsuo; Ho, Ya-Lun; Fujikawa, Shigenori; Delaunay, Jean-Jacques., High sensitivity refractive index sensing with strong light confinement in high-aspect-ratio U-cavity arrays., Sens. Actuators, B, 10.1016/j.snb.2014.05.033, 202, 137-143, 2014.01. |
| 55. | Taniguchi, Ikuo; Fujikawa, Shigenori., Preferential CO2 separation over H2 with poly(amidoamine) dendrimer-containing polymeric membrane., MRS Online Proc. Libr., 10.1557/opl.2014.347, 1660, Transport Properties in Nanocomposites, Taniguchi/1-Taniguchi/6, 2014.01. |
| 56. | Shao, Huaiyu; Ma, Weigang; Kohno, Masamichi; Takata, Yasuyuki; Xin, Gongbiao; Fujikawa, Shigenori; Fujino, Sayoko; Bishop, Sean; Li, Xingguo., Hydrogen storage and thermal conductivity properties of Mg-based materials with different structures., Int. J. Hydrogen Energy, 10.1016/j.ijhydene.2014.02.063, 39, 18, 9893-9898, 2014.01. |
| 57. | Patil, Bhushan; Kobayashi, Yoshiki; Fujikawa, Shigenori; Okajima, Takeyoshi; Mao, Lanqun; Ohsaka, Takeo., Direct electrochemistry and intramolecular electron transfer of ascorbate oxidase confined on L-cysteine self-assembled gold electrode., Bioelectrochemistry, 10.1016/j.bioelechem.2013.10.005, 95, 15-22, 2014.01. |
| 58. | Yamada, Yoichi M. A.; Yuyama, Yoshinari; Sato, Takuma; Fujikawa, Shigenori; Uozumi, Yasuhiro., A Palladium-Nanoparticle and Silicon-Nanowire-Array Hybrid: A Platform for Catalytic Heterogeneous Reactions., Angew. Chem., Int. Ed., 10.1002/anie.201308541, 53, 1, 127-131, 2014.01. |
| 59. | Kajitani, Takashi; Suna, Yuki; Kosaka, Atsuko; Osawa, Terutsune; Fujikawa, Shigenori; Takata, Masaki; Fukushima, Takanori; Aida, Takuzo., o-Phenylene Octamers as Surface Modifiers for Homeotropic Columnar Ordering of Discotic Liquid Crystals., J. Am. Chem. Soc., 10.1021/ja4087853, 135, 39, 14564-14567, 2013.01. |
| 60. | Koishi, Takahiro; Yasuoka, Kenji; Willow, Soohaeng Yoo; Fujikawa, Shigenori; Zeng, Xiao Cheng., Molecular Insight into Different Denaturing Efficiency of Urea, Guanidinium, and Methanol: A Comparative Simulation Study., J. Chem. Theory Comput., 10.1021/ct3010968, 9, 6, 2540-2551, 2013.01. |
| 61. | E. Maeda, Y. Lee, Y. L. Ho, Shigenori Fujikawa, J. J. Delaunay, A 3D metallic structure array for refractive index sensing with optical vortex, IEEE 26th International Conference on Micro Electro Mechanical Systems, MEMS 2013 IEEE 26th International Conference on Micro Electro Mechanical Systems, MEMS 2013, 10.1109/MEMSYS.2013.6474409, 973-976, 2013.01, [URL], A simple and large-scale fabrication technique for three dimensional structure arrays using a photolithography process was applied to realize an array of high-aspect-ratio metallic fins. The fin array enables light confinement between the high-aspect-ratio fins, thus generating optical vortices. The light confinement between the fins produces sharp dips in the reflection spectrum of the array. We show that the position of the dip wavelength is sensitive to change in the refractive index of the surrounding medium. Sensitivity to change in the refractive index was quantified by optical simulation and experimental measurements.. |
| 62. | Maeda, Etsuo; Lee, Yaerim; Kobayashi, Youjiro; Taino, Akiko; Koizumi, Mari; Fujikawa, Shigenori; Delaunay, Jean-Jacques., Sensitivity to refractive index of high-aspect-ratio nanofins with optical vortex., Nanotechnology, 10.1088/0957-4484/23/50/505502, 23, 50, 505502/1-505502/6, 2012.01. |
| 63. | Patil, Bhushan; Fujikawa, Shigenori; Okajima, Takeyoshi; Ohsaka, Takeo., Enzymatic direct electron transfer at ascorbate oxidase-modified gold electrode prepared by one-step galvanostatic method., Int. J. Electrochem. Sci., 7, 6, 5012-5019, 2012.01. |
| 64. | Kuwahara, Rempei; Fujikawa, Shigenori; Kuroiwa, Keita; Kimizuka, Nobuo., Controlled Polymerization and Self-Assembly of Halogen-Bridged Diruthenium Complexes in Organic Media and Their Dielectrophoretic Alignment., J. Am. Chem. Soc., 10.1021/ja208958t, 134, 2, 1192-1199, 2012.01. |
| 65. | Koishi, Takahiro; Yasuoka, Kenji; Fujikawa, Shigenori; Zeng, Xiao Cheng., Measurement of Contact-Angle Hysteresis for Droplets on Nanopillared Surface and in the Cassie and Wenzel States: A Molecular Dynamics Simulation Study., ACS Nano, 10.1021/nn2005393, 5, 9, 6834-6842, 2011.01. |
| 66. | Kubo, Wakana; Fujikawa, Shigenori., Preparation of gold double pillar arrangement by nano-coating lithography and development of plasmon sensors., Mirai Zairyo, 11, 5, 60-63, 2011.01. |
| 67. | Kubo, Wakana; Hayakawa, Harumi; Miyoshi, Kentaro; Fujikawa, Shigenori., Size-controlled simple fabrication of Free-standing, ultralong metal nanobelt array., J. Nanosci. Nanotechnol., 10.1166/jnn.2011.3123, 11, 1, 131-137, 2011.01. |
| 68. | Kubo, Wakana; Fujikawa, Shigenori., Au double nanopillars with nanogap for plasmonic sensor., Nano Lett., 10.1021/nl100787b, 11, 1, 8-15, 2011.01. |
| 69. | T. Koishi, Shigenori Fujikawa, Static and dynamic properties of ionic liquids, Molecular Simulation, 10.1080/08927020903536358, 36, 15, 1237-1242, 2010.12, [URL], We performed molecular dynamics (MD) simulations of ionic liquids composed of 1-butyl-3-methylimidazolium ([bmim]) cation with PF6, NO 3 and Cl anions to determine their static and dynamic properties. Large-scale simulation of 4096 ion pairs (131,072 particles in [bmim]PF 6) was performed to estimate the system-size dependence of the static and dynamic properties. The diffusion constant, which is 100 times smaller than that of a normal liquid such as water, was estimated from long-time simulations. We also performed non-equilibrium MD simulations to determine the electrical conductivity. We obtained a nonlinear relationship between the electrical current and external electric field strength.. |
| 70. | Koishi, Takahiro; Yasuoka, Kenji; Zeng, Xiao-Cheng; Fujikawa, Shigenori., Molecular dynamics simulations of urea-water binary droplets on flat and pillared hydrophobic surfaces., Faraday Discuss., 10.1039/b926919c, 146, Wetting Dynamics of Hydrophobic and Structured Surfaces, 185-193, 2010.01. |
| 71. | Kunitake, Toyoki; Fujikawa, Shigenori., Nanomembranes of solid acid electrolytes as a key component of the intermediate-temperature fuel cell., Nenryo Denchi, 9, 4, 73-78, 2010.01. |
| 72. | Kubo, Wakana; Fujikawa, Shigenori., Manipulation of a one dimensional molecular assembly of helical superstructures by dielectrophoresis., Appl. Phys. Lett., 10.1063/1.3253708, 95, 16, 163110/1-163110/3, 2009.01. |
| 73. | Koishi, Takahiro; Yasuoka, Kenji; Fujikawa, Shigenori; Ebisuzaki, Toshikazu; Zeng, Xiao Cheng., Coexistence and transition between Cassie and Wenzel state on pillared hydrophobic surface., Proc. Natl. Acad. Sci. U. S. A., 10.1073/pnas.0902027106, 106, 21, 8435-8440, 2009.01. |
| 74. | Fujikawa, Shigenori; Muto, Emi; Kunitake, Toyoki., Nanochannel Design by Molecular Imprinting on a Free-Standing Ultrathin Titania Membrane., Langmuir, 10.1021/la9014916, 25, 19, 11563-11568, 2009.01. |
| 75. | Kubo, Wakana; Fujikawa, Shigenori., Embedding of a gold nanofin array in a polymer film to create transparent, flexible and anisotropic electrodes., J. Mater. Chem., 10.1039/b819290a, 19, 15, 2154-2158, 2009.01. |
| 76. | Miyoshi, Kentaro; Fujikawa, Shigenori; Kunitake, Toyoki., Fabrication of nanoline arrays of noble metals by electroless plating and selective etching process., Colloids Surf., A, 10.1016/j.colsurfa.2007.11.041, 321, 1-3, 238-243, 2008.01. |
| 77. | Takaki, Rie; Takemoto, Hiromi; Fujikawa, Shigenori; Toyoki, Kunitake., Fabrication of nanofins of TiO2 and other metal oxides via the surface sol-gel process and selective dry etching., Colloids Surf., A, 10.1016/j.colsurfa.2007.11.040, 321, 1-3, 227-232, 2008.01. |
| 78. | Miyoshi, Kentaro; Aoki, Yoshitaka; Kunitake, Toyoki; Fujikawa, Shigenori., Facile Fabrication of Silver Nanofin Array via Electroless Plating., Langmuir, 10.1021/la703512w, 24, 8, 4205-4208, 2008.01. |
| 79. | Li, Yuanzhi; Kunitake, Toyoki; Fujikawa, Shigenori; Ozasa, Kazunari., Photoluminescence Modification in 3D-Ordered Films of Fluorescent Microspheres., Langmuir, 10.1021/la700610p, 23, 17, 9109-9113, 2007.01. |
| 80. | Matsushita, Sachiko; Fujikawa, Shigenori; Onoue, Shinya; Kunitake, Toyoki; Shimomura, Masatsugu., Rapid fabrication of a smooth hollow-spheres array., Bull. Chem. Soc. Jpn., 10.1246/bcsj.80.1226, 80, 6, 1226-1228, 2007.01. |
| 81. | Fujikawa, Shigenori; Muto, Emi; Kunitake, Toyoki., Embedding of Individual Ferritin Molecules in Large, Self-Supporting Silica Nanofilms., Langmuir, 10.1021/la0635247, 23, 8, 4629-4633, 2007.01. |
| 82. | Tetsu Narumi, Yousuke Ohno, Noriaki Okimoto, Takahiro Koishi, Atsushi Suenaga, Noriyuki Futatsugi, Ryoko Yanai, Ryutaro Himeno, Shigenori Fujikawa, Makoto Taiji, Mitsuru Ikei, A 55 TFLOPS simulation of amyloid-forming peptides from yeast prion Sup35 with the special-purpose computer system MDGRAPE-3, Proceedings of the 2006 ACM/IEEE Conference on Supercomputing, SC'06, 10.1145/1188455.1188506, 2006.12, [URL], We have achieved a sustained performance of 55 TFLOPS for molecular dynamics simulations of the amyloid fibril formation of peptides from the yeast Sup35 in an aqueous solution. For performing the calculations, we used the MDGRAPE-3 system - -a special-purpose computer system for molecular dynamics simulations. Its nominal peak performance was 415 TFLOPS for Coulomb force calculations; this is the highest-ever performance reported for classical molecular dynamics simulations. Amyloid fibril formation is known to be related to the occurrence of severe diseases such as Alzheimer's, Parkinson's, and Creutzfeldt-Jakob diseases. The Sup35 protein is a "yeast prion protein," which forms mini-crystals due to aggregation; it forms an effective platform for studying the formation process of amyloid fibrils. In these simulations, we first elucidate that the amyloid-forming peptides GNNQQNY aggregate at a higher frequency than non-amyloid-forming peptides SQNGNQQRG; further, the GNNQQNY peptides tend to form parallel two-stranded -sheets that would grow into a cross- amyloid nucleus. The results are consistent with those obtained experimentally. Furthermore, we could observe an early elongation of the amyloid nucleus. This result is expected to contribute toward a deeper understanding of the amyloid growth mechanism.. |
| 83. | Fujikawa, Shigenori; Takaki, Rie; Kunitake, Toyoki., Fabrication of Arrays of Sub-20-nm Silica Walls via Photolithography and Solution-Based Molecular Coating., Langmuir, 10.1021/la061830e, 22, 21, 9057-9061, 2006.01. |
| 84. | Li, Yuanzhi; Kunitake, Toyoki; Fujikawa, Shigenori., Efficient Fabrication and Enhanced Photocatalytic Activities of 3D-Ordered Films of Titania Hollow Spheres., J. Phys. Chem. B, 10.1021/jp061979z, 110, 26, 13000-13004, 2006.01. |
| 85. | Li, Yuanzhi; Kunitake, Toyoki; Fujikawa, Shigenori., Efficient fabrication of large, robust films of 3D-ordered polystyrene latex., Colloids Surf., A, 10.1016/j.colsurfa.2005.09.045, 275, 1-3, 209-217, 2006.01. |
| 86. | Fujikawa, Shigenori; Kunitake, Toyoki., 3D nanoarchitecture from ultrathin titania film via surface sol-gel process and photolithography., Chem. Lett., 10.1246/cl.2005.1414, 34, 10, 1414-1415, 2005.01. |
| 87. | Fujikawa, Shigenori; Takaki, Rie; Kunitake, Toyoki., Nanocopying of Individual DNA Strands and Formation of the Corresponding Surface Pattern of Titania Nanotube., Langmuir, 10.1021/la051554o, 21, 19, 8899-8904, 2005.01. |
| 88. | Kunitake, Toyoki; Fujikawa, Shigenori., Nanocopying as a Means of 3D Nanofabrication: Scope and Prospects., Aust. J. Chem., 10.1071/CH03129, 56, 10, 1001-1003, 2003.01. |
| 89. | Kunitake, Toyoki; Fujikawa, Shigenori., Three dimensional nanostructure preparation by nano-copy method., Mirai Zairyo, 3, 8, 20-27, 2003.01. |
| 90. | He, Junhui; Fujikawa, Shigenori; Kunitake, Toyoki; Nakao, Aiko., Preparation of Porous and Nonporous Silica Nanofilms from Aqueous Sodium Silicate., Chem. Mater., 10.1021/cm034253d, 15, 17, 3308-3313, 2003.01. |
| 91. | Fujikawa, Shigenori; Kunitake, Toyoki., Surface Fabrication of Hollow Nanoarchitectures of Ultrathin Titania Layers from Assembled Latex Particles and Tobacco Mosaic Viruses as Templates., Langmuir, 10.1021/la026979e, 19, 16, 6545-6552, 2003.01. |
| 92. | Fujikawa, Shigenori; Kunitake, Toyoki., Preparation of hollow structures composed of titania nanocrystal assembly., Int. J. Nanosci., 1, 5 & 6, 617-620, 2002.01. |
| 93. | He, Junhui; Ichinose, Izumi; Fujikawa, Shigenori; Kunitake, Toyoki., Synthesis of metal and metal oxide nanoparticles in the nanospace of ultrathin TiO2-gel films: role of the ion-exchange site., Int. J. Nanosci., 1, 5 & 6, 507-513, 2002.01. |
| 94. | Fujikawa, Shigenori; Kunitake, Toyoki., Surface fabrication of interconnected hollow spheres of nm-thick titania shell., Chem. Lett., 10.1246/cl.2002.1134, 11, 1134-1135, 2002.01. |
| 95. | He, Junhui; Ichinose, Izumi; Fujikawa, Shigenori; Kunitake, Toyoki; Nakao, Aiko., Reversible conversion of nanoparticles of metallic silver and silver oxide in ultrathin TiO2 films: a chemical transformation in nano-space., Chem. Commun., 10.1039/b204227b, 17, 1910-1911, 2002.01. |
| 96. | He, Junhui; Ichinose, Izumi; Fujikawa, Shigenori; Kunitake, Toyoki; Nakao, Aiko., A General, Efficient Method of Incorporation of Metal Ions into Ultrathin TiO2 Films., Chem. Mater., 10.1021/cm010880w, 14, 8, 3493-3500, 2002.01. |
| 97. | Ichinose, Izumi; He, Junhui; Fujikawa, Shigenori; Hashizume, Mineo; Huang, Jianguo; Kunitake, Toyoki., Ultrathin composite films: An indispensable resource for nanotechnology., RIKEN Rev., 37, 34-37, 2001.01. |
| 98. | Kimizuka, Nobuo; Fujikawa, Shigenori; Kunitake, Toyoki., Organization of hydrophilic nanoparticles on a hydrogel surface and their gel-assisted transfer to solid substrates., Adv. Mater., 10.1002/(SICI)1521-4095(199811)10:163.0.CO;2-T, 10, 16, 1373-1376, 1998.01. |
| 99. | Kimizuka, Nobuo; Shimizu, Masafumi; Fujikawa, Shigenori; Fujimura, Kotaro; Sano, Masahito; Kunitake, Toyoki., AFM observation of organogel nanostructures on graphite in the gel-assisted transfer technique., Chem. Lett., 10.1246/cl.1998.967, 10, 967-968, 1998.01. |
| 100. | Kimizuka, Nobuo; Fujikawa, Shigenori; Kunitake, Toyoki., Protein assembly on solid surfaces by gel-assisted transfer (GAT) technique., Chem. Lett., 10.1246/cl.1998.821, 8, 821-822, 1998.01. |
| 101. | Kimizuka, Nobuo; Fujikawa, Shigenori; Kuwahara, Hiroaki; Kunitake, Toyoki; Marsh, Andrew; Lehn, Jean-Marie., Mesoscopic supramolecular assembly of a 'Janus' molecule and a melamine derivative via complementary hydrogen bonds., J. Chem. Soc., Chem. Commun., 10.1039/C39950002103, 20, 2103-2104, 1995.01. |
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