研究者詳細 - 川角　昌弥

Single-Walled Carbon Nanotubes Supported Pt Electrocatalyst as a Cathode Catalyst of a Single Fuel Cell with High Durability against Start-up/Shut-down Potential Cycling

Huda, M; Kawahara, T; Park, JH; Kawasumi, M; Matsuo, Y

ACS APPLIED ENERGY MATERIALS 6 巻 ( 24 ) 頁： 12226 - 12236 2023年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Applied Energy Materials

Carbon nanotubes (CNTs) have remarkable properties such as high conductivity, high porosity, and high oxidation resistance, which make them excellent candidates for supporting electrocatalysts in proton exchange membrane fuel cells (PEMFCs). In this study, high-crystallinity, high-purity single-walled carbon nanotubes (SWCNTs), which were prepared by enhanced direct injection pyrolytic synthesis (e-DIPS), were used as a support for a metal electrocatalyst. Platinum (Pt) nanoparticles of uniform size were synthesized by a facile solvothermal method and distributed evenly on the surface of the SWCNTs (Pt/SWCNT). Electrochemical measurements using cyclic voltammetry and linear sweep voltammetry showed that the Pt/SWCNT exhibited higher mass activity and specific activity compared to commercial Pt nanoparticles supported on graphitized carbon (Pt/C). A PEMFC membrane electrode assembly (MEA) utilizing Pt/SWCNT as the cathode layer (Pt/SWCNT-MEA) with low Pt loading demonstrated high-efficiency performance with power density per gram of Pt that was three times higher than that of Pt/C. Furthermore, in a durability test using a high-voltage triangular wave between 1.0 and 1.5 V to induce corrosion of the catalyst and carbon support, simulating harsh conditions of actual repeated start-up/shut-down cycles during long-term use, the Pt/SWCNT-MEA retained high performance even after 10,000 potential cycles. These results indicate that SWCNTs show promise as an excellent support material for electrocatalysts, offering high performance and durability, and thus can contribute to realizing PEMFCs with superior performance.

DOI： 10.1021/acsaem.3c01919

Highly durable graphene-encapsulated platinum-based electrocatalyst for oxygen reduction reactions synthesized by solution plasma process

Park, JH; Kim, K; Wang, XY; Huda, M; Sawada, Y; Matsuo, Y; Saito, N; Kawasumi, M

JOURNAL OF POWER SOURCES 580 巻 2023年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Power Sources

Though expensive platinum (Pt) is used as catalyst for oxygen reduction reaction (ORR) in polymer electrolyte fuel cells (PEFCs), insufficient durability remains as a bottleneck for commercialization of PEFCs. Improving both catalytic performance and durability by graphene encapsulation is an attractive strategy to solve this problem. In this study, graphene-encapsulated PtFe core-shell catalyst is synthesized with dimethyl formamide (DMF) and a pair of Pt and Fe electrodes without using any metal salts by utilizing the solution plasma (SP) process. TEM and EELS results show synthesized PtFe nanoparticles are encapsulated with close to single-layered highly crystallized graphene. Although commercial Pt/C showed significant performance degradation (ECSA −33%, MA −68%) after 50,000 cycles of accelerated durability test (ADT), PtFe core-shell catalyst shows remarkably improved durability (ECSA −13%, MA −19%) while graphene shell clearly remains. The improved durability is more prominent in the single cell test, the decrease in maximum power density after 6000 cycles of ADT was significantly lower as −1.2%, compared to that of Pt/C (−52.1%). This study introduces a novel and attractive catalyst synthesis process by the SP method followed by heat treatments and suggests graphene encapsulation can improve long-term durability of catalyst while maintaining ORR activity.

DOI： 10.1016/j.jpowsour.2023.233419

Novel solution plasma synthesis of highly durable carbon shell encapsulated platinum-based cathode catalyst for polymer electrolyte membrane fuel cells

Park, JH; Saito, N; Kawasumi, M

CARBON 214 巻 2023年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Carbon

Developing an effective method for synthesizing high-performance and durable catalysts for the oxygen reduction reaction is of great importance for cost reduction and the wide application of fuel cells. This study presents a simple and effective strategy using a plasma reaction in the liquid phase to synthesize carbon-shell-encapsulated Pt and PtFe catalysts. A carbon-shell-encapsulated PtFe catalyst alloyed with up to 29 at.% Fe exhibits a mass activity of 730 mA·mgpt−1 and a specific activity of 1772 μA cm−1, which are 2.4 and 5 times higher than that of commercial Pt/C, respectively. The carbon shell effectively maintained the low oxidation state of Pt by suppressing the formation of Pt–OH and significantly improved the durability of the catalyst in accelerated durability tests, increasing the gap in mass activity with Pt/C by a factor of up to six after 50,000 cycles. In addition, the decrease in the electrochemical surface area by the carbon shell enabled a more stable 4-electron reaction over a wide potential range. This study may provide fascinating insights into the effect of the carbon shell contributing to the improvement of the catalytic activity and durability of fuel cells as well as the novel plasma-based synthesis strategy of core-shell catalyst.

DOI： 10.1016/j.carbon.2023.118364

Efficient CO2/Electrochemical Reduction by a Robust Electrocatalyst Fabricated by Electrodeposition of Indium and Zinc over Copper Foam

Sirisomboonchai, S; Machida, H; Tran, KVB; Kawasumi, M; Norinaga, K

ACS APPLIED ENERGY MATERIALS 5 巻 ( 8 ) 頁： 9846 - 9857 2022年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Applied Energy Materials

Electrochemical reduction of CO2comprising the CO2reduction reactuib (CO2RR) and oxygen evolution reaction (OER) is one of the most promising technologies for electrification of the chemical process industry. Here, the performance of a electrocatalyst with a three-dimensional structure of InZnCu on Cu foam (CF) is presented. This electrocatalyst was fabricated by electrodeposition of In and Zn over Cu and exhibited a superior reduction of CO2to CO at a Faradaic efficiency of 93.7% at -0.7 V and an excellently long duration of 100 h. Due to the synergy of the thin In layer, the Zn nanosheets provided a high surface-active area and strong mechanical robustness during the reaction. Additionally, a two-electrode system was constructed based on the CF-modified surface, which provided valuable guidelines on the overall CO2RR-OER system for further evolution. Furthermore, due to the facile synthesis, the bimetal-layer double hydroxide (LDH) exhibited high conductivity and high OER performance. Hence, the two-electrode system assembled excellent electrocatalysts for the CO2RR-OER (InZnCu/CF||Cu(OH)2NWs@NiCo-LDH/CF) with high conversions of CO2to CO of 67% and 88% at 2 and 50 mA cm-2, respectively. Notably, the CO2RR-OER system exhibited excellent stability in a 40 h CO2conversion with a constant current density of 2 mA cm-2at an ultralow voltage of 1.59 V. Moreover, the calculation of the energy input converting CO per ton of CO2resulted in a low energy input range for further development in scalability. This overall CO2RR-OER proposes development in electrochemical CO2reduction for industrial applications.

DOI： 10.1021/acsaem.2c01564

Non-crosslinked perfluoro-polymer electrolytes with two acid groups and their properties

Synthesis and Properties of Fluorocarbon–Hydrocarbon Hybrid Block Copolymers with Perfluorosulfonimide Acid 査読有り

5 巻 ( 43 ) 頁： 27766 - 27773 2020年10月

Nanocomposites Based on Organic and Inorganic Materials and Their unique Properties and Functions

川角　昌弥

R&D Review of Toyota CRDL 50 巻 ( 2 ) 頁： 45 - 61 2019年

Properties of a Novel Imide Network Polymer Electrolyte and Fuel Cell Performance of Its Composite Membrane

Kyoko Tsusaka, Naoki Kitano, Takashi Yamamoto, Naoki Hasegawa, Akihiko Koiwai, Masaya Kawasumi

R&D Review of Toyota CRDL 49 巻 ( 4 ) 頁： 21 - 31 2018年

Imide Crosslinked Perfluorinated Proton Exchange Membranes by Gas Treatment

Tsusaka Kyoko, Yamamoto Takashi, Asano Takashi, Muto Atsuko, Hasegawa Naoki, Kawasumi Masaya

JOURNAL OF THE ELECTROCHEMICAL SOCIETY 163 巻 ( 5 ) 頁： F372 - F376 2016年

スルホン酸修飾メソポーラスシリカ(乾燥状態)のプロトンダイナミクス

蒲沢和也, 藤田悟, 荒木暢, 長谷川直樹, 川角昌弥, Madhusudan Tyagi, 杉山純

日本物理学会講演概要集 69.2.4 巻 2014年8月

Ion Conductive Organic-inorganic Hybrid Electrolyte with Meso-scale Proton Channels for Fuel Cells

Satoru Fujita, Kazuya Kamazawa, Satoru Yamamoto, Akihiko Koiwai, Shinji Inagaki, Jun Sugiyama, Masaya Kawasumi

R&D Review of Toyota CRDL 44 巻 ( 4 ) 頁： 59 - 69 2014年

Akihiro Shinohara, Kenji Kudo, Masaya Kawasumi, Yu Morimoto, Naoki Hasegawa

ECS Transactions 58 巻 ( 1 ) 頁： 253 - 259 2013年8月

Enhancement of Proton Transport by High Densification of Sulfonic Acid Groups in Highly Ordered Mesoporous Silica

Fujita Satoru, Koiwai Akihiko, Kawasumi Masaya, Inagaki Shinji

CHEMISTRY OF MATERIALS 25 巻 ( 9 ) 頁： 1584 - 1591 2013年5月

Proton conductivity under dry conditions for mesoporous silica with highly dense sulfonic acid groups

Fujita S., Kamazawa K., Yamamoto S., Tyagi M., Araki T., Sugiyama J., Hasegawa N., Kawasumi M.

Journal of Physical Chemistry C 117 巻 ( 17 ) 頁： 8727 - 8736 2013年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Physical Chemistry C

Highly dense sulfonic acid-functionalized mesoporous electrolytes with high proton conductivity under dry conditions were prepared using tetramethoxysilane and 3-mercaptopropyltrimethoxysilane in the presence of surfactants. Impedance spectroscopy and quasielastic neutron scattering measurements showed that the proton conductive properties of the mesoporous electrolytes depended significantly on the sulfonic acid densities on the surface of the mesoporous walls. This finding was also supported by molecular dynamics simulations. The proton conductivity of the mesoporous electrolyte with the highest acid density of 3.1 SO3H molecules/nm2 showed a value of 0.3 mS/cm at 433 K even under dry conditions. This value was higher than that for Nafion by about 2 orders of magnitude. Such high proton conductivity is thought to be induced by proton hopping in the hydrogen-bonded networks that were predominantly formed by neighboring sulfonic acid groups. © 2013 American Chemical Society.

DOI： 10.1021/jp307058s

Development and applications of polyolefin- and rubber-clay nanocomposites

Kato M., Usuki A., Hasegawa N., Okamoto H., Kawasumi M.

Polymer Journal 43 巻 ( 7 ) 頁： 583 - 593 2011年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Polymer Journal

A nylon 6-clay hybrid (nanocomposite, NCH) was developed by Toyota CRDL group. In the NCH, the silicate layers of clay mineral are dispersed on a nanometer level and are strongly interacted with the matrix, and then significant improvements in the mechanical properties of the material or the discovery of unexpected new properties were realized. Polypropylene (PP) is the most widely used polymer, and then an appearance of a PP-clay nanocomposite has been desired for a long time. As a PP does not include any polar groups in its backbone, it was thought that the homogeneous dispersion of the silicate layers would not be realized. But we have developed successfully PP-clay nanocomposite using organoclay and modified PP. That is, organophilic clay, PP oligomer carrying polar groups and PP were melt-blended. This is a direct polymer intercalation process for preparing polymer nanocomposites by melt compounding, a useful process from an industrial standpoint. We have also developed successfully other polyolefin polymers (polyethylene), polyolefin rubbers (ethylene-propylene elastomer, ethylene-propylene diene monomer) and nanocomposites by this direct polymer intercalation process or by techniques based on direct polymer intercalation process. These prepared polyolefin nanocomposites exhibit superior mechanical, thermal and gas barrier properties. © The Society of Polymer Science, Japan (SPSJ) All rights reserved.

DOI： 10.1038/pj.2011.44

Angular distribution of elemental composition of films deposited by laser ablation of a SrZrO3 target

フッ素・炭化水素ブロック共重合電解質膜の合成と評価

星川尚弘，篠原朗大，細川洋一，長谷川直樹，川角昌弥

高分子学会予稿集頁： 4686 - 4686 2010年

Konomi I., Motohiro T., Horii M., Kawasumi M.

Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films 26 巻 ( 6 ) 頁： 1455 - 1461 2008年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films

The angular distributions of elemental composition of films prepared by laser ablation of perovskite oxide SrZrO3 have been investigated using electron probe microanalysis with wavelength-dispersive spectroscopy. Each constituent element showed two modal distribution composed of a broad cos m θ (m=2-3) distribution and a sharp cosn θ (n=8-23) distribution. Oxygen showed a broader distribution than that of Sr and Zr. At the polar angle close to surface normal direction (polar angle <12°), Zr concentration was higher than that of Sr in vacuum whereas in oxygen-containing atmosphere their concentrations were about the same. Below oxygen pressure of 1.3 Pa, Sr and Zr concentration increased and decreased with the increase in polar angle, respectively, whereas in oxygen partial pressure of 10 Pa, both elements showed no angular dependences. Broadening of angular distribution of all the elements was observed when deposition was performed under oxygen partial pressure of 10 Pa, which is considered to be caused by collisional scatterings of more than ten times with ambient gas molecules. © 2008 American Vacuum Society.

DOI： 10.1116/1.2987952

Degradation of Perfluorinated Membranes Having Intentionally Formed Pt-Band

Electrode and Membrane Durability Issues of PEFCs

Hatanaka Tatsuya, Takeshita Tomohiro, Murata Hajime, Hasegawa Naoki, Asano Takashi, Kawasumi Masaya, Morimoto Yu

PROTON EXCHANGE MEMBRANE FUEL CELLS 8, PTS 1 AND 2 16 巻 ( 2 ) 頁： 1961 - 1965 2008年

Hasegawa Naoki, Asano Takashi, Hatanaka Tatsuya, Kawasumi Masaya, Morimoto Yu

PROTON EXCHANGE MEMBRANE FUEL CELLS 8, PTS 1 AND 2 16 巻 ( 2 ) 頁： 1713 - 1716 2008年

Study on water content of perfluorosulfonic acid ionomer membranes below water freezing point

A. Koiwai, A. Kamiya and M. Kawasumi

11 巻 ( 1 ) 頁： 587 - 587 2007年9月

Degradation of Nafion Membranes in Hydrogen Peroxide

K. Kodama, F. Miura, N. Hasegawa, M Kawasumi and Y. Morimoto

ECS Meeting Abstracts MA2005-02 巻 ( X2 - Durability and Reliability of Low-Temperature Fuel Cells and Fuel Cell Systems ) 頁： 1185 - 1185 2006年

The discovery of polymer-clay hybrids

Kawasumi M

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY 42 巻 ( 4 ) 頁： 819 - 824 2004年2月

Cell performances of direct methanol fuel cells with grafted membranes

Hatanaka T, Hasegawa N, Kamiya A, Kawasumi M, Morimoto Y, Kawahara K

FUEL 81 巻 ( 17 ) 頁： 2173 - 2176 2002年12月

Polyolefin-clay hybrids based on modified polyolefins and organophilic clay

Hasegawa N., Okamoto H., Kawasumi M., Kato M., Tsukigase A., Usuki A.

Macromolecular Materials and Engineering 280-281 巻 ( 7-8 ) 頁： 76 - 79 2000年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecular Materials and Engineering

A novel and general approach to prepare polyolefin-clay hybrids by using the maleic anhydride modified polyolefins and organophilic clay during melt-blending was reported. The silicate layers of the clay were exfoliated and homogeneously dispersed at the monolayers in the hybrids. The hybrids exhibited remarkable reinforcement compared to conventional composites filled with talc which were dispersed at micrometer level.

DOI： 10.1002/1439-2054(20000801)280:1<76::aid-mame76>3.0.co;2-#

Novel memory effect found in nematic liquid crystal/ fine particle system

Electro-Rheological Behavior of Liquid Crystal Polymers (LCPs) Dissolved in a Nematic Solvent: Dependence on Temperature and LCP Structure

Y.-C. Chiang, A. M. Jamieson, S. Campbell, T. H. Tong, N. D. Sidocky, L. C. Chien, M. Kawasumi, V. Percec

Polymer 41 巻 ( 11 ) 頁： 4127 - 4135 2000年

Preparation and mechanical properties of polystyrene-clay hybrids

Hasegawa N, Okamoto H, Kawasumi M, Usuki A

JOURNAL OF APPLIED POLYMER SCIENCE 74 巻 ( 14 ) 頁： 3359 - 3364 1999年12月

Preparation and mechanical properties of polystyrene-clay hybrids.

Hasegawa N, Okamoto H, Kawasumi M, Usuki A

ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 217 巻頁： U411 - U411 1999年3月

Liquid Crystal/Clay Mineral Composites

Masaya Kawasumi, Naoki Hasegawa, Arimitsu Usuki, Akane Okada

Applied Clay Science 15 巻 ( 1-2 ) 頁： 93 - 108 1999年

Nematic liquid crystal/clay mineral composites

Kawasumi M, Hasegawa N, Usuki A, Okada A

MATERIALS SCIENCE & ENGINEERING C-BIOMIMETIC AND SUPRAMOLECULAR SYSTEMS 6 巻 ( 2-3 ) 頁： 135 - 143 1998年11月

Preparation and mechanical properties of polypropylene-clay hybrids using a maleic anhydride-modified polypropylene oligomer

Hasegawa N, Kawasumi M, Kato M, Usuki A, Okada A

JOURNAL OF APPLIED POLYMER SCIENCE 67 巻 ( 1 ) 頁： 87 - 92 1998年1月

Preparation and mechanical properties of polypropylene-clay hybrids

Kawasumi M, Hasegawa N, Kato M, Usuki A, Okada A

MACROMOLECULES 30 巻 ( 20 ) 頁： 6333 - 6338 1997年10月

Effect of Molecular Architecture on the Electrorheological Behavior of Liquid Crystal Polymers in Nematic Solvents

Y.-C. Chiang, A. M. Jamieson, S. Campbell, Y. Lin, N. O’Sidocky, L.-C. Chien, M. Kawasumi, V. Percec

Rheologica Acta 36 巻 ( 5 ) 頁： 505 - 512 1997年

Electrorheological Behavior of Main-Chain Liquid Crystal Polymers Dissolved in Nematic Solvents

Y.-C. Chiang, A. M. Jamieson, M. Kawasumi, V. Percec

Macromolecules 30 巻 ( 7 ) 頁： 992 - 1996 1997年

Kawasumi M., Hasegawa N., Usuki A., Okada A.

Liquid Crystals 21 巻 ( 6 ) 頁： 769 - 776 1996年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Liquid Crystals

Novel liquid crystalline composites composed of a nematic two-frequency-addressing liquid crystal and organized clay mineral (about 1 wt %) have been prepared. The particles of clay mineral were dispersed homogeneously in the liquid crystal. The composite cells became transparent within 50ms when a 60 Hz electric field was applied. The transparent state was maintained after the field was switched off. It transformed into a turbid light scattering state by applying 1.5kHz electric field which caused dynamic scattering in the cell. The light transmittance of both memory states did not change after 20 h without the electric field. © 2006 Taylor & Francis.

DOI： 10.1080/02678299608032892

メモリ性PDLCの電場二周波駆動による可逆的光スイッチング

長谷川直樹, 川角昌弥, 臼杵有光, 岡田茜

液晶討論会講演予稿集 22 巻 ( 0 ) 頁： 399 - 400 1996年

記述言語：日本語掲載種別：研究論文（研究会，シンポジウム資料等）出版者・発行元：一般社団法人日本液晶学会

A memory type PDLC have been prepared by sandwiching a mixture of two-frequency-addressing liquid crystals and acrylate monomers with hydoroxy group between two glass substrates with ITO electrodes followed by the UV irradiation. This PDLC can be electrically switched between the transparent state and the light scattering state, which are maintained over months without electric field. This PDLC exhibited a polymer ball morphology according to SEM observation.

DOI： 10.11538/ekitouyokou.22.0_399

液晶/微粒子複合系におけるメモリ性電気光学効果の支配因子

川角昌弥, 長谷川直樹, 臼杵有光, 岡田茜

液晶討論会講演予稿集 22 巻 ( 0 ) 頁： 397 - 398 1996年

記述言語：日本語掲載種別：研究論文（研究会，シンポジウム資料等）出版者・発行元：一般社団法人日本液晶学会

The novel liquid crystalline composites cell based on a nematic two-frequency-driving liquid crystal and organized clay exhibited reversible and bistable electro-optic effects between the transparent and light scattering states. In this paper, the factors affecting the electro-optic effect of the composites were investigated. The wettability of the liquid crystal on the organized clay strongly affected to their memory capability. The memory effect decreased drastically with decreasing the clay content in the composites with clay content below 1 wt.%. Not only the composites themselves but also the treatment of the substrates affected to the electro-optic effect. The treatment for the homogeneous alignment gave the better memory effect for the transparent state.

DOI： 10.11538/ekitouyokou.22.0_397

Reversible electro-optical switching of a memory type pdlc memory using two-frequency-addressing liquid crystals memory on- state ii 国際誌

大学大学院における高分子教育

岡田守, 板垣秀幸, 伊藤浩一, 川上雄資, カートハウスオラフ, 川角昌弥, 金仁華

高分子 45 巻 ( 10 ) 頁： 729 - 735 1996年

Liquid crystalline composite based on a clay mineral

Kawasumi M, Usuki A, Okada A, Kurauchi T

MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY SECTION A-MOLECULAR CRYSTALS AND LIQUID CRYSTALS 281 巻頁： 91 - 103 1996年

Reversible Electro-Optical Switching of a Memory Type PDLC Memory Using Two-Frequency-Addressing Liquid Crystals

Naoki Hasegawa, Masaya Kawasumi, Arimitsu Usuki, Akane Okada

Liquid Crystals 21 巻 ( 5 ) 頁： 765 - 766 1996年

Novel memory effect found in nematic liquid crystal clay mineral composites 査読有り国際誌

Kawasumi M, Hasegawa N, Usuki A, Okada A, Kurauchi T

LIQUID CRYSTALS FOR ADVANCED TECHNOLOGIES 425 巻頁： 311 - 316 1996年

Hasegawa N., Kawasumi M., Usuki A., Okada A.

Liquid Crystals 21 巻 ( 5 ) 頁： 765 - 766 1996年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Liquid Crystals

A memory type PDLC has been prepared by sandwiching a mixture of two-frequencyaddressing liquid crystals and acrylate monomers with a hydoroxy group between two glass substrates with IT0 electrodes followed by UV irradiation. This PDLC can be electrically switched between a transparent state and a light scattering state, which are maintained over several months without electric fields. © 2006 Taylor & Francis.

DOI： 10.1080/02678299608032890

Novel preferred orientation in injection‐molded nylon 6‐clay hybrid

ナイロン6-粘土ハイブリッドの分子構造

臼杵有光, 川角昌弥, 小島由継, 岡田茜, 倉内紀雄, 小川忠男, 荒賀年美

高分子論文集 52 巻 ( 5 ) 頁： 299-304 1995年5月

Kojima Y., Usuki A., Kawasumi M., Okada A., Kurauchi T., Kamigaito O., Kaji K.

Journal of Polymer Science Part B: Polymer Physics 33 巻 ( 7 ) 頁： 1039 - 1045 1995年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Polymer Science Part B: Polymer Physics

Nylon 6‐clay hybrid (NCH) is a molecular composite of Nylon 6 and uniformly dispersed silicate monolayers of montmorillonite. In this study the preferred orientation of montmorillonite and Nylon‐6 crystallites in a thick (3 mm) injection‐molded bar of NCH has been investigated using x‐ray diffraction and electron micrography (TEM). It is clear that this bar has a triple layer structure consisting of surface, intermediate, and middle layers which have different preferred orientation. In the surface layer both the silicate monolayers and the chain axes of Nylon‐6 crystallites are parallel to the bar surface though the latter are randomly oriented within the plane. In the intermediate layer the silicate monolayers remain parallel to the bar surface but the Nylon‐6 crystallites rotate by 90° so that the chain axes would be perpendicular to the bar surface or the silicate monolayers. In the middle layer the silicate monolayers are randomly oriented around the flow axis of the NCH bar while remaining parallel to it, and the Nylon crystallites are randomly oriented around the flow axis while keeping their chain axes perpendicular to the silicate monolayers. It may be concluded that such preferred orientation of Nylon 6 crystallites is induced by the clay because the crystallites in the pure Nylon 6 bar have no preferred orientation. ©1995 John Wiley & Sons, Inc. Copyright © 1995 John Wiley & Sons, Inc.

DOI： 10.1002/polb.1995.090330707

Interaction of nylon 6‐clay surface and mechanical properties of nylon 6‐clay hybrid

Usuki A., Koiwai A., Kojima Y., Kawasumi M., Okada A., Kurauchi T., Kamigaito O.

Journal of Applied Polymer Science 55 巻 ( 1 ) 頁： 119 - 123 1995年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Applied Polymer Science

We synthesized nylon 6‐clay hybrid materials using four types of clay minerals, montmorillonite, saponite, hectrite, and synthetic mica. The mechanical properties of their injection molded specimens were measured according to ASTM. Nylon 6‐clay hybrid using montmorillonite was superior to the other hybrids in mechanical properties. This might result from the difference in the interaction between nylon molecules and silicates in the hybrids. To clarify this hypothesis, we synthesized intercalated compounds of the clay minerals with glycine as the model of the hybrids, and analyzed the interaction using 15N cross polarization magic angle spinning (CP/MAS) NMR spectroscopy. The 15N‐NMR result reveals that the positive charge density on the nitrogen of the intercalated compound based on montmorillonite was largest in all the intercalated compounds. It was suggested that montmorillonite interacted strongly with nylon 6 by ionic interaction. This ionic interaction was one of the reasons why these hybrid materials had superior mechanical properties. © 1995 John Wiley & Sons, Inc. Copyright © 1995 John Wiley & Sons, Inc.

DOI： 10.1002/app.1995.070550113

環状および樹状構造を有する液晶高分子

川角昌弥

高分子 44 巻 ( 7 ) 頁： 448 - 448 1995年

Viscoelastic Properties of Dilute Nematic Mixtures Containing Cyclic and Hyperbranched Liquid Crystal Polymers Dissolved in a Nematic Solvent

Fu‐Lung ‐L Chen, A. M. Jamieson, M. Kawasumi, V. Percec

Journal of Polymer Science Part B: Polymer Physics 33 巻 ( 8 ) 頁： 1213 - 1223 1995年

Conformational Behavior of the Spacer in a Liquid Crystalline Main-Chain Polymer in Its Nematic and Glassy States

J. Leisen, C. Boeffel, H. W. Spiess, D. Y. Yoon, M. H. Sherwood, M. Kawasumi, V. Percec

Macromolecules 28 巻 ( 20 ) 頁： 6937 - 6941 1995年

SANS Study of a Semiflexible Main Chain Liquid Crystalline Polyether

F. Hardouin, G. Sigaud, M. F. Achard, A. BrÛlet, J. P. Cotton, D. Y. Yoon, V. Percec, M. Kawasumi

Macromolecules 28 巻 ( 16 ) 頁： 5427 - 5433 1995年

ジアミン変性ナイロン６‐粘土ハイブリッドの合成と特性

臼杵有光, 川角昌弥, 小島由継, 岡田茜, 倉内紀雄

高分子論文集 52 巻 ( 7 ) 頁： 440 - 444 1995年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人高分子学会

今までに, 12-アミノラウリン酸で有機化した粘土を用い, その層間でカプロラクタムを重合し, 粘土のシリケート層が1層ごとはく離して均一に分散したナイロン6-粘土ハイブリッド (NCH) を合成した. 今回, NCHの重合時に, ジアミンを添加することにより, ナイロン6中にシリケート層が数層積層して分散した新しいハイブリッド材料が合成できた. これをジァミン変性NCHと呼ぶ. ジァミン変性NCHの力学的性質は従来のNCHに比べ, 強度, 弾性率はやや低下するが, 伸びと衝撃強度が大幅に向上した. これはNCHの合成時に, 粘土のシリケート層が, ジアミンから生成したジアンモニウムイオンで架橋して積層し, この状態でナイロン6中に分散したためと考えられる. そのためジアミン変性NCHでは, シリケート層とナイロン6の界面が減少し, 双方のイオン相互作用が低下することにより, ハイブリッド材料の強度, 弾性率が低下したと考察した.

DOI： 10.1295/koron.52.440

Molecular Structure of Nylon in Nylon 6-Clay Hybrid

Usuki A., Kawasumi M., Kojima Y., Okada A., Kurauchi T., Ogawa T., Raga T.A.

KOBUNSHI RONBUNSHU 52 巻 ( 5 ) 頁： 299 - 304 1995年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：KOBUNSHI RONBUNSHU

The molecular structure of nylon in nylon 6-clay hybrid (NCH), in which clay silicates were dispersed uniformly, was analyzed using a field desorption mass spectrometer. The main peaks of fragment ions from the mass spectrum of NCH, were classified into ion groups. Two possible molecular structures of NCH were postulated supposing different locations of the copolymerized nylon 12 monomer unit (12-aminolauric acid) which was intercalated in the clay prior to the polymerization to enhance the miscibility between the clay and nylon 6. We compared the experimental fragment ion groups with those from the expected structures. From these results, it became clear that nylon 12 monomer units did not exist only at the end of nylon 6, but also occur randomly along the nylon 6 main chain. NCH without having any 12-aminolauric acid units was proved to have improved thermal properties. © 1995, The Society of Polymer Science, Japan. All rights reserved.

DOI： 10.1295/koron.52.299

FINE-STRUCTURE OF NYLON-6-CLAY HYBRID 査読有り国際誌

KOJIMA Y, USUKI A, KAWASUMI M, OKADA A, KURAUCHI T, KAMIGAITO O, KAJI K

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS 32 巻 ( 4 ) 頁： 625 - 630 1994年3月

Molecular Recognition Directed Self-Assembly of Supramolecular Architectures

V. Percec, J. Heck, G. Johansson, D. Tomazos, M. Kawasumi, P. Chu, G. Ungar

Journal of Macromolecular Science, Part A 31 巻 ( 11 ) 頁： 1719 - 1758 1994年

Molecular Order in the Nematic Melt of a Semiflexible Polyether by Deuteron NMR

M. H. Sherwood, G. Sigaud, D. Y. Yoon, C. G. Wade, M. Kawasumi, V. Percec

Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 254 巻 ( 1 ) 頁： 455 - 468 1994年

At the Borderline Between Glassy, Crystalline and Liquid Crystalline Macrocyclics

V. Percec, M. Kawasumi

Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 238 巻 ( 1 ) 頁： 21 - 37 1994年

Toward ‘Willowlike’ Thermotropic Dendrimers 査読有り

V. Percec, P. Chu, M. Kawasumi

Macromolecules 27 巻 ( 16 ) 頁： 4441 - 4453 1994年

Molecular Recognition Directed Self-Assembly of Supramolecular Liquid Crystals

V. Percec, J. Heck, G. Johansson, D. Tomazos, M. Kawasumi, P. Chu, G. Ungar

Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 254 巻 ( 1 ) 頁： 137 - 196 1994年

SORPTION OF WATER IN NYLON-6 CLAY HYBRID

KOJIMA Y, USUKI A, KAWASUMI M, OKADA A, KURAUCHI T, KAMIGAITO O

JOURNAL OF APPLIED POLYMER SCIENCE 49 巻 ( 7 ) 頁： 1259 - 1264 1993年8月

One‐pot synthesis of nylon 6–clay hybrid 国際誌

Kojima Y., Usuki A., Kawasumi M., Okada A., Kurauchi T., Kamigaito O.

Journal of Polymer Science Part A: Polymer Chemistry 31 巻 ( 7 ) 頁： 1755 - 1758 1993年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Polymer Science Part A: Polymer Chemistry

Nylon 6–clay hybrid is a molecular composite of nylon 6 and uniformly dispersed silicate layers of montmorillonite. One‐pot synthesis of the hybrid was carried out by the following procedures. Montmorillonite was dispersed in water, and then ε‐caprolactam, acid (phosphoric acid, hydrochloric acid, benzenesulfonic acid, isophthalic acid, trichloroacetic acid, or acetic acid), and 6‐aminocaproic acid were added to the dispersion. The mixtures were reacted at 260°C for 6 h, yielding the nylon 6–clay hybrids (1potNCHs). X‐ray diffraction revealed that the silicate layers of 1potNCH by phosphoric acid were uniformly dispersed in the nylon 6 matrix. The 1potNCH had excellent mechanical properties. The strength and the modulus of the hybrid increased compared with previously reported nylon 6–clay hybrid (NCH) synthesized by montmorillonite intercalated with 12‐aminolauric acid. The heat distortion temperature (HDT) of the 1potNCH was 160°C, which was 8°C higher than that of NCH. In other 1potNCHs, montmorillonite had a smaller effect on the increase of those properties, and interlayer spacing of montmorillonite was observed at ca. 20 Å. © 1993 John Wiley & Sons, Inc. Copyright © 1993 John Wiley & Sons, Inc.

DOI： 10.1002/pola.1993.080310714

MECHANICAL-PROPERTIES OF NYLON 6-CLAY HYBRID

KOJIMA Y, USUKI A, KAWASUMI M, OKADA A, FUKUSHIMA Y, KURAUCHI T, KAMIGAITO O

JOURNAL OF MATERIALS RESEARCH 8 巻 ( 5 ) 頁： 1185 - 1189 1993年5月

SWELLING BEHAVIOR OF MONTMORILLONITE CATION EXCHANGED FOR OMEGA-AMINO ACIDS BY EPSILON-CAPROLACTAM 査読有り

USUKI A, KAWASUMI M, KOJIMA Y, OKADA A, KURAUCHI T, KAMIGAITO O

JOURNAL OF MATERIALS RESEARCH 8 巻 ( 5 ) 頁： 1174 - 1178 1993年5月

SYNTHESIS OF NYLON 6-CLAY HYBRID

USUKI A, KOJIMA Y, KAWASUMI M, OKADA A, FUKUSHIMA Y, KURAUCHI T, KAMIGAITO O

JOURNAL OF MATERIALS RESEARCH 8 巻 ( 5 ) 頁： 1179 - 1184 1993年5月

Synthesis of nylon 6–clay hybrid by montmorillonite intercalated with ϵ‐caprolactam 国際誌

Kojima Y., Usuki A., Kawasumi M., Okada A., Kurauchi T., Kamigaito O.

Journal of Polymer Science Part A: Polymer Chemistry 31 巻 ( 4 ) 頁： 983 - 986 1993年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Polymer Science Part A: Polymer Chemistry

It was found that montmorillonite was intercalated with ϵ‐caprolactam. X‐ray diffraction revealed that the chain axes of the ϵ‐caprolactam were parallel to the montmorillonite plates. The intercalated montmorillonite was swollen by molten ϵ‐caprolactam at 200°C. ϵ‐Caprolactam and 6‐aminocaproic acid (accelerator) were polymerized with the intercalated montmorillonite at 260°C for 6 h, yielding a nylon 6‐clay hybrid. X‐ray diffraction and transmission electron micrography revealed that the silicate layers of the hybrid were uniformly dispersed in the nylon 6 matrix. Mechanical properties of the hybrid were improved. The strength and the modulus of the hybrid increased compared with the previously reported nylon 6 clay‐hybrid (NCH) synthesized by montmorillonite intercalated with 12‐aminolauric acid. The heat distortion temperature (HDT) of the hybrid was 164°C, which was 12°C higher than that of NCH. © 1993 John Wiley & Sons, Inc. Copyright © 1993 John Wiley & Sons, Inc.

DOI： 10.1002/pola.1993.080310418

ナイロン６‐粘土ハイブリッドのガスバリア性

小島由継, 臼杵有光, 川角昌弥, 岡田茜, 倉内紀雄, 上垣外修己

マテリアルライフ 5 巻 ( 1/2 ) 頁： 13 - 17 1993年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：マテリアルライフ学会

ナイロン6-粘土ハイブリッド (NCH) とはナイロン6と層状粘土鉱物であるモンモリロナイト単位結晶層との分子複合材であり、ナイロン6に比べ強さ、弾性率、熱変形温度に優れている。このNCHをフィルムに成形し、ガスバリア性の評価を行った。NCHフィルム中でモンモリロナイト単位結晶層は面配向しており、その結晶化度はナイロン6に比べやや高い値を示した。モンモリロナイト量がわずか0.74vol%のNCHの気体透過係数はナイロン6の70%以下となり、ガスバリア性に優れていた。このNCHのガスバリア性はモンモリロナイト量の増加に伴い大きくなり、モンモリロナイト単位結晶層の面配向に基づく曲路率の増大によって説明できた。

DOI： 10.11338/mls1989.5.13

主鎖にメソゲン基を有する環状ポリエーテルの合成とその液晶性

川角昌弥

液晶討論会講演予稿集 19 巻 ( 0 ) 頁： 208 - 209 1993年

Liquid-Crystalline Polyethers Based on Conformational Isomerism. 31. Absence of Chiral Molecular Recognition in Irregular Linear and Macrocyclic Liquid-Crystalline Polyethers Based on 1-(4-Hydroxy-4’-Biphenylyl)-2-(4-Hydroxyphenyl) butane and α,ω-Dibromoalkanes

V. Percec, M. Kawasumi

Macromolecules 26 巻 ( 15 ) 頁： 3917 - 3928 1993年

Liquid-Crystalline Polyethers Based on Conformational Isomerism. 32. Effect of Molecular Weight on the Phase Behavior of Linear and Macrocyclic Oligoethers and of Linear Polyethers Based on 1-(4-Hydroxy-4’-biphenylyl)-2-(4-hydroxyphenyl) butane and 1,10-Dibromodecane

V. Percec, M. Kawasumi

Macromolecules 26 巻 ( 14 ) 頁： 3663 - 3675 1993年

Liquid Crystalline Polyethers Based on Conformational Isomerism. Part 28. Noncrystallizable Macrocyclics Exhibiting Enantiotropic Liquid-Crystalline Phases

V. Percec, M. Kawasumi

Chemistry of Materials 5 巻 ( 6 ) 頁： 826 - 834 1993年

機能性液晶高分子

川角昌弥

豊田中央研究所R&D レビュー 28 巻 ( 4 ) 頁： 13 - 24 1993年

Mechanical Properties of Nylon 6-Clay Hybrid 査読有り

Yoshitsugu Kojima, Arimitsu Usuki, Masaya Kawasumi, Akane Okada, Yoshiaki Fukushima, Toshio Kurauchi, Osami Kamigaito

Journal of Materials Research 8 巻 ( 5 ) 頁： 1185 - 1189 1993年

Synthesis of Nylon 6-Clay Hybrid 査読有り

Arimitsu Usuki, Yoshitsugu Kojima, Masaya Kawasumi, Akane Okada, Yoshiaki Fukushima, Toshio Kurauchi, Osami Kamigaito

Journal of Materials Research 8 巻 ( 5 ) 頁： 1179 - 1184 1993年

Swelling Behavior of Montmorillonite Cation Exchanged for ω-Amino Acids by ε-Caprolactam

Arimitsu Usuki, Masaya Kawasumi, Yoshitsugu Kojima, Akane Okada, Toshio Kurauchi, Osami Kamigaito

Journal of Materials Research 8 巻 ( 5 ) 頁： 1174 - 1178 1993年

Macrocycles with Clearing Temperatures Higher than Their Linear High-Molecular-Weight Homologues

V. Percec, M. Kawasumi

Journal of Materials Chemistry 3 巻 ( 7 ) 頁： 725 - 734 1993年

Similarities and Differences between the Mesomorphic Behavior of Oligomeric Macrocyclics and of Linear High Relative Molecular Mass Polyethers Based on 1-(4’-Hydroxybiphenyl-4-yl)-2-(4-Hydroxyphenyl) butane and Flexible Spacers

V. Percec, M. Kawasumi

Journal of the Chemical Society, Perkin Transactions 1 巻 ( 12 ) 頁： 1319 - 1334 1993年

Transformation of a Kinetically Controlled Nematic Phase of a Linear Polymer into One Which Is Thermodynamically Controlled via Cyclization

V. Percec, M. Kawasumi

Liquid Crystals 13 巻 ( 1 ) 頁： 83 - 94 1993年

Dynamic Light Scattering from Nematic Monodomains Containing Mesogenic Polymers of Differing Architectures

G. Dongfeng, A. M. Jamieson, M. Kawasumi, M. S. Lee, V. Percec

Macromolecules 25 巻 ( 8 ) 頁： 2151 - 2155 1992年

Synthesis and Characterization of a Thermotropic Nematic Liquid Crystalline Dendrimeric Polymer

V. Percec, M. Kawasumi

Advanced Materials 4 巻 ( 9 ) 頁： 572 - 576 1992年

Synthesis and Characterization of Cyclic Liquid Crystalline Oligomers Based on 1-(4-Hydroxy-4’-Biphenylyl)-2-(4-Hydroxyphenyl) butane and 1,10-Dibromodecane 査読有り

V.　Percec, M. Kawasumi, P. L. Rinaldi, V. E. Litman

Macromolecules 25 巻 ( 15 ) 頁： 3851 - 3861 1992年

Light Scattering from a Nematic Monodomain in an Electric Field Twist Elastic Constant and Viscosity Coefficient of Nematic Polymer–Solvent Mixtures

D. F. Gu, A. M. Jamieson, M. S. Lee, M. Kawasumi, V. Percec

Liquid Crystals 12 巻 ( 6 ) 頁： 961 - 971 1992年

Liquid-Crystalline Polyethers Based on Conformational Isomerism. 18. Polyethers Based on a Combined Mesogenic Unit Containing Rigid and Flexible Groups: 1-(4-Hydroxy-4’-Biphenyl)-2-(4-Hydroxyphenyl) butane

V. Percec, M. Kawasumi

Macromolecules 24 巻 ( 23 ) 頁： 6318 - 6324 1991年

Scaling law for elastic modulus in filler-reinforced composite materials 招待有り査読有り

A Koiwai, M Kawasumi, S Hyodo, T Motohiro, S Noda, O Kamigaito

"Benibana" International Symposium on How to Improve the Toughness of Polymers and Composites--Toughness, Fracture and Fatigue of Polymers and Composites 頁： 105 - 110 1990年

A solid state NMR study on crystalline forms of nylon 6

Okada A., Kawasumi M., Tajima I., Kurauchi T., Kamigaito O.

Journal of Applied Polymer Science 37 巻 ( 5 ) 頁： 1363 - 1371 1989年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Applied Polymer Science

High‐resolution 13C‐NMR spectra were studied for two different crystalline structures of nylon 6 in the solid state by the cross polarization/magic angle spinning (CP/MAS) method. Two crystalline structures, α‐form and γ‐form, gave different chemical shifts for methylene carbons. The results showed that the hydrogen bonds between intermolecular chains are stronger in the γ‐form than in the α‐form. This strongly supports the results of the X‐ray study of nylon 6 by Malta et al. Our results also showed that interamolecular delocalization of positive charges occurs in the γ‐form through hyperconjugation in which the dihedral angle between the π bond and neighboring σ bonds is 30° while no such effect can be expected in the α‐form in which the angle is 0°. Copyright © 1989 John Wiley & Sons, Inc.

DOI： 10.1002/app.1989.070370519

Vinylbenzyl-type polyamide macromer synthesized from bicyclic oxalactam. preparation and characterization of graft copolymer composed of polystyrene as a stock and hydrophilic polyamide as branches

SWELLING BEHAVIOR OF MONTMORILLONITE BY POLY-6-AMIDE 査読有り国際誌

FUKUSHIMA Y, OKADA A, KAWASUMI M, KURAUCHI T, KAMIGAITO O

CLAY MINERALS 23 巻 ( 1 ) 頁： 27 - 34 1988年3月

Hashimoto K., Sumitomo H., Kawasumi M.

Polymer Journal 17 巻 ( 9 ) 頁： 1045 - 1054 1985年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Polymer Journal

Vinylbenzyl-type polyamide macromers (1) of various average molecular weights (Mn; 3900, 5400, and 8400) were prepared by the anionic ring-opening polymerization of a bicyclic oxalactam, 8-oxa-6-azabicyclo[3.2.1]octan-7-one (abbreviated as BOL, 2) followed by a reaction with p-vinylbenzylamine. The relative reactivity of the macromer (M1) in the radical copolymerization with styrene (M2) was found to be lower than that of p-methylstyrene from the estimation of the reciprocal monomer reactivity ratio (1/r2). The resulting graft copolymer composed of a polystyrene stock and polyamide branches was characterized by structural analysis, solubility test, and determination of moisture sorption. Two kinds of transparent binary blend films, which were i) the graft copolymer and homopolystyrene and ii) the graft copolymer and polyBOL, were cast on a glass plate from the corresponding chloroform and chloroform-methanol (9:1) solutions, respectively. In the case of the former film comprising mainly polystyrene, the hydrophilic polyamide segment of the graft copolymer as a really minor component was found to be located on the glass-side surface from the contact angle measurement and the attenuated total reflection-infrared spectroscopy. © 1985 The Society of Polymer Science, Japan.

DOI： 10.1295/polymj.17.1045

Preparation of a new polyamide macromer having a vinylbenzyl group from bicyclic oxalactam and its radical copolymerization with styrene

Hashimoto K., Sumitomo H., Kawasumi M.

Polymer Bulletin 11 巻 ( 2 ) 頁： 121 - 128 1984年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Polymer Bulletin

A new polyamide macromer having a vinylbenzyl end group (1), of which molecular weight was 3700-3800, was prepared by the anionic polymerization of bicyclic oxalactam (2) followed by the reaction with p-vinylbenzylamine. Its radical copolymerization with styrene was conducted to obtain a novel graft copolymer consisting of a polystyrene stock-chain and hydrophilic polyamide branches. © 1984 Springer-Verlag.

DOI： 10.1007/BF00258018