2022/12/02 更新

写真a

ミヤタケ ケンジ
宮武 健治
Scopus 論文情報  
論文数: 0  Citation: 0  h-index: 28

Citation Countは当該年に発表した論文の被引用数

所属
理工学術院 大学院先進理工学研究科
職名
教授(任期付)

学内研究所・附属機関兼任歴

  • 2020年
    -
    2022年

    理工学術院総合研究所   兼任研究員

学位

  • Waseda University   Doctor of Engineering

  • 早稲田大学   工学博士

経歴

  • 2020年04月
    -
     

    早稲田大学   教授

  • 2009年04月
    -
     

    山梨大学   教授

所属学協会

  •  
     
     

    日本MRS

  •  
     
     

    水素科学技術連携研究会

  •  
     
     

    Royal Society of Chemistry

  •  
     
     

    燃料電池開発情報センター

  •  
     
     

    日本化学会

  •  
     
     

    高分子学会

  •  
     
     

    電気化学会

  •  
     
     

    American Chemical Society

  •  
     
     

    International Society of Electrochemistry

▼全件表示

 

研究分野

  • 高分子材料

論文

  • Quaternary Ammonium-biphosphate Ion-pair Based Copolymers with Continuous H+ Transport Channels for High-temperature Proton Exchange Membrane

    J. Jiang, Z. Li, M. Xiao, S. Wang, K. Miyatake, Y. Meng

    JOURNAL OF MEMBRANE SCIENCE   660   120878  2022年08月  [査読有り]

    DOI

    Scopus

  • Tuning Hydrophobic Composition in Terpolymer-based Anion Exchange Membranes to Balance Conductivity and Stability

    Y. Ozawa, Y. Shirase, K. Otsuji, K. Miyatake

    Molecular Systems Design & Engineering   7 ( 7 ) 798 - 808  2022年07月  [査読有り]

    DOI

    Scopus

  • Tandem Effect of Two Sulfophenylene Groups in Aromatic Polymers for Fuel Cell Membranes

    L. Guo, K. Miyatake

    ACS Applied Energy Materials   5   5525 - 5530  2022年06月  [査読有り]

    DOI

    Scopus

  • Sulfonated and Fluorinated Aromatic Terpolymers as Proton Conductive Membranes: Synthesis, Structure, and Properties

    R. Kumao, K. Miyatake

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   95 ( 5 ) 707 - 712  2022年05月  [査読有り]

    DOI

    Scopus

  • Properties and Morphologies of Anion Exchange Membranes with Different Lengths of Fluorinated Hydrophobic Chains

    Y. Shirase, A. Matsumoto, K. L. Lim, D. A. Tryk, K. Miyatake, J. Inukai

    ACS Omega   7   13577 - 13587  2022年05月  [査読有り]

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Well-designed Polyphenylene PEMs with High Proton Conductivity and Chemical and Mechanical Durability for Fuel Cell

    F. Liu, K. Miyatake

    Journal of Materials Chemistry A   10 ( 14 ) 7660 - 7667  2022年04月  [査読有り]

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Protocol for Synthesis and Characterization of ePTFE Reinforced, Sulfonated Polyphenylene in the Application to Proton Exchange Membrane Fuel Cells

    Z. Long, K. Miyatake

    STAR Protocols   3   101049  2022年03月  [査読有り]

    DOI

    Scopus

  • Highly conductive and alkaline stable partially fluorinated anion exchange membranes for alkaline fuel cells: Effect of ammonium head groups

    Ahmed Mohamed Ahmed Mahmoud, Kenji Miyatake

    JOURNAL OF MEMBRANE SCIENCE   643   120072  2022年03月  [査読有り]

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • Effect of Water Management in Membrane and Cathode Catalyst Layers on Suppressing the Performance Hysteresis Phenomenon in Anion-Exchange Membrane Fuel Cells

    K. Otsuji, Y. Shirase, T. Asakawa, N. Yokota, K. Nagase, W. Xu, P. Song, S. Wang, D. A. Tryk, K. Kakinuma, J. Inukai, K. Miyatake, M. Uchida

    JOURNAL OF POWER SOURCES   522   230997  2022年02月  [査読有り]

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • An Aromatic Ionomer in the Anode Catalyst Layer Improves the Start-up Durability of Polymer Electrolyte Fuel Cells

    T. Tanaka, M. Uchida, K. Miyatake

    Energy Advances   1   38 - 44  2022年01月  [査読有り]

    DOI

  • Poly(para-phenylene) Ionomer Membranes: Effect of Methyl and Trifluoromethyl Substituents

    L. Fanghua, J. Ahn, J. Miyake, K. Miyatake

    Polymer Chemistry   12   6101 - 6109  2021年11月  [査読有り]

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • ePTFE Reinforced, Sulfonated Aromatic Polymer Membranes Enable Durable, High-temperature Operable PEMFCs

    Z. Long, K. Miyatake

    iScience   24   102962  2021年09月  [査読有り]

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • Reinforced Polyphenylene Ionomer Membranes Exhibiting High Fuel Cell Performance and Mechanical Durability

    J. Miyake, T. Watanabe, H. Shintani, Y. Sugawara, M. Uchida, K. Miyatake

    ACS Mater. Au   1   81 - 88  2021年09月  [査読有り]

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • Wet/dry Cycle Durability of Polyphenylene Ionomer Membranes in PEFC

    T. Tanaka, H. Shintani, Y. Sugawara, A. Masuda, N. Sato, M. Uchida, K. Miyatake

    J. Power Sources Adv.   10   100063  2021年08月  [査読有り]

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Tailoring the Hydrophilic and Hydrophobic Reaction Fields of the Electrode Interface on Single Crystal Pt Electrodes for Hydrogen Evolution/Oxidation Reactions

    S. Tanaka, S. Takaya, T. Kumeda, N. Hoshi, K. Miyatake, M. Nakamura

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   46 ( 55 ) 28078 - 28086  2021年08月  [査読有り]

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • High Performance Fuel Cell Operable at 120 °C Using Polyphenylene Ionomer Membranes with Improved Interfacial Compatibility

    Z. Long, K. Miyatake

    ACS Applied Materials & Interfaces   13   15366 - 15372  2021年04月  [査読有り]

    DOI

    Scopus

    12
    被引用数
    (Scopus)
  • リチャージャブル燃料電池

    宮武 健治, 小柳 津研一, 三宅 純平

    水素エネルギーシステム   46   6 - 11  2021年03月  [査読有り]  [招待有り]

  • 高速移動水素による次世代創蓄電デバイスの設計

    宮武健治

    まてりあ   60   161 - 164  2021年03月  [査読有り]  [招待有り]

  • Performance Hysteresis Phenomena of Anion Exchange Membrane Fuel Cells Using an Fe-N-C Cathode Catalyst and an In-house-developed Polymer Electrolyte

    K. Otsuji, N. Yokota, D. A. Tryk, K. Kakinuma, K. Miyatake, M. Uchida

    J. Power Sources   487   229407  2021年01月  [査読有り]

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Anion Exchange Membranes Containing No β-Hydrogen Atoms on Ammonium Groups: Synthesis, Properties, and Alkaline Stability

    D. Koronka, K. Miyatake

    RSC Advances   11   1030 - 1038  2021年01月  [査読有り]

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Structural Investigation of Sulfonated Polyphenylene Ionomers for the Design of Better Performing Proton-Conductive Membranes

    K. Shiino, T. Otomo, T. Yamada, H. Arima, K. Hiroi, S. Takata, J. Miyake, K. Miyatake

    ACS Appl. Polym. Mater.   2 ( 12 ) 5558 - 5565  2020年12月  [査読有り]

    DOI

    Scopus

    13
    被引用数
    (Scopus)
  • Ladder-type Sulfonated Poly(arylene perfluoroalkylene)s for High Performance Proton Exchange Membrane Fuel Cells

    Z. Long, J. Miyake, K. Miyatake

    RSC Advances   10   41058 - 41064  2020年11月  [査読有り]

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Rechargeable Proton Exchange Membrane Fuel Cell Containing an Intrinsic Hydrogen Storage Polymer

    J. Miyake, Y. Ogawa, T. Tanaka, J. Ahn, K. Oka, K. Oyaizu, K. Miyatake

    Comm. Chem.   3 ( 1 ) 138  2020年10月  [査読有り]

    DOI

    Scopus

    21
    被引用数
    (Scopus)
  • アルカリ形燃料電池:アニオン膜型の現状と課題へのアプローチ

    宮武 健治

    燃料電池   19   67 - 71  2020年08月  [査読有り]  [招待有り]

  • Proton Exchange Membranes Containing Densely Sulfonated Quinquephenylene Groups for High Performance and Durable Fuel Cells

    Z. Long, J. Miyake, K. Miyatake

    J. Mater. Chem. A   8   12134 - 12140  2020年06月  [査読有り]

    DOI

    Scopus

    18
    被引用数
    (Scopus)
  • "Sublayered Thin Films of Hydrated Anion Exchange Ionomer for Fuel Cells Formed on SiO2 and Pt Substrates Analyzed by Neutron Reflectometry under Controlled Temperature and Humidity Conditions

    T. Kimura, T. Kawamoto, M. Aoki, T. Mizusawa, N. L. Yamada, K. Miyatake, J. Inukai

    Langmuir   36 ( 18 ) 4995 - 4963  2020年05月  [査読有り]  [国際誌]

    DOI PubMed

    Scopus

    7
    被引用数
    (Scopus)
  • アニオン導電性高分子薄膜の設計とアルカリ形燃料電池への展開

    三宅 純平, 宮武 健治

    高分子   69 ( 3 ) 110 - 111  2020年03月

  • Sulfonated Poly(arylene perfluoroalkylene) Terpolymers as Novel Proton Exchange Membranes for High Performance Fuel Cells

    Z. Long, J. Miyake, K. Miyatake

    Bull. Chem. Soc. Jpn.   93 ( 3 ) 338 - 344  2020年03月  [査読有り]

    DOI

  • Differences in the Synthetic Method Affected Copolymer Sequence and Membrane Properties of Sulfonated Polymers

    I. Hosaka, T. Sawano, T. Kimura, A. Matsumoto, J. Miyake, K. Miyatake

    Bull. Chem. Soc. Jpn   93 ( 3 ) 393 - 398  2020年03月  [査読有り]

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Highly Anion Conductive Polymers: How Do Hexafluoroisopropylidene Groups Affect Membrane Properties and Alkaline Fuel Cell Performance?

    T. Kimura, A. Matsumoto, J. Inukai, K. Miyatake

    ACS Appl. Energy Mater.   3 ( 1 ) 469 - 477  2020年01月  [査読有り]

    DOI

    Scopus

    21
    被引用数
    (Scopus)
  • Partially Fluorinated Copolymers Containing Pendant Piperidinium Head Groups as Anion Exchange Membranes for Alkaline Fuel Cells

    D. Koronka, A. Matsumoto, K. Otsuji, K. Miyatake

    RSC Advances   9   37391 - 37402  2019年12月  [査読有り]

    DOI

    Scopus

    16
    被引用数
    (Scopus)
  • Partially Fluorinated Polyphenylene Ionomers as Proton Exchange Membranes for Fuel Cells: Effect of Pendant Multi-sulfophenylene Groups

    Z. Long, J. Miyake, K. Miyatake

    ACS Appl. Energy Mater.   2   7527 - 7534  2019年10月  [査読有り]

    DOI

    Scopus

    18
    被引用数
    (Scopus)
  • プロトン導電性高分子薄膜の設計と燃料電池への応用

    三宅 純平, 宮武 健治

    化学と工業   72 ( 8 ) 665 - 667  2019年08月

  • In-Plane Distribution of Water inside Nafion Thin Film Analyzed by Neutron Reflectivity at Temperature of 80 °C and Relative Humidity of 30-80% Based on 4-Layered Structural Model

    T. Kawamoto, M. Aoki, T. Kimura, T. Mizusawa, N. L. Yamada, J. Miyake, K. Miyatake, J. Inukai

    Jpn. J. Appl. Phys.   58   SIID01  2019年07月  [査読有り]

    DOI

    Scopus

    10
    被引用数
    (Scopus)
  • 炭化水素系電解質膜の開発状況

    宮武 健治

    工業材料   7   24 - 27  2019年07月  [招待有り]

  • Highly Stable Polyphenylene Ionomer Membrane from Dichlorobiphenyls

    K. Shiino, J. Miyake, K. Miyatake

    Chem. Commun.   55   7073 - 7076  2019年07月  [査読有り]

    DOI

    Scopus

    16
    被引用数
    (Scopus)
  • "Quaternized Poly(arylene perfluoroalkylene)s (QPAFs) for Alkaline Fuel Cells – A Perspective

    J. Miyake, K. Miyatake

    Sustainable Energy Fuels   3   1916 - 1928  2019年05月  [査読有り]  [招待有り]

    DOI

    Scopus

    15
    被引用数
    (Scopus)
  • Effect of Alkanediol Additives on the Properties of Polyphenylene-Based Proton Exchange Membranes

    Z. Long, Y. Zhang, J. Miyake, K. Miyatake

    Industrial & Engineering Chemistry Research   58   9915 - 9920  2019年05月  [査読有り]

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • Effect of Cross-linking on the Properties of Partially Fluorinated Anion Exchange Membranes

    D. Koronka, A. M, A. Mahmoud, K. Miyatake

    J. Polym. Sci. A: Polym. Chem.   57   1059 - 1069  2019年04月  [査読有り]

    DOI

    Scopus

    11
    被引用数
    (Scopus)
  • Durability of Newly Developed Polyphenylene-based Ionomer Membranes in Polymer Electrolyte Fuel cells: Accelerated Stress Evaluation

    R. Shimizu, K. Otsuji, A. Masuda, N. Sato, M. Kusakabe, A. Iiyama, K. Miyatake, M. Uchida

    J. Electrochem Soc   166 ( 7 ) F3105 - F3110  2019年04月  [査読有り]

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • Chemically Stable, Highly Anion Conductive Polymers Composed of Quinquephenylene and Pendant Ammonium Groups

    R. Akiyama, N. Yokota, K. Miyatake

    Macromolecules   52   2131 - 2138  2019年04月  [査読有り]

    DOI

    Scopus

    31
    被引用数
    (Scopus)
  • Sublayered Structures of Hydrated Nafion Thin Film Formed by Casting on Pt Substrate Analyzed by X-ray Absorption Spectroscopy under Ambient Conditions and Neutron Reflectometry at Temperature of 80 °C and Relative Humidity of 30-80%

    T. Kawamoto, M. Aoki, T. Kimura, P. Chinapang, T. Mizusawa, N. L. Yamada, F. Nemoto, T. Watanabe, H. Tanida, M. Matsumoto, H. Imai, J. Miyake, K. Miyatake, J. Inukai

    Electrochemistry   87 ( 5 ) 270 - 275  2019年  [査読有り]

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • Structurally Well-Defined Anion Exchange Membranes Containing Perfluoroalkyl and Ammonium-Functionalized Fluorenyl Groups

    M. Ozawa, T. Kimura, K. Otsuji, R. Akiyama, J. Miyake, M. Uchida, J. Inukai, K. Miyatake

    ACS Omega   3 ( 11 ) 16413 - 16419  2018年11月  [査読有り]  [国際誌]

    DOI PubMed

    Scopus

    12
    被引用数
    (Scopus)
  • Sulfonated Aromatic Polymers Containing Hexafluoroisopropylidene Groups: Simple but Effective Structure for Fuel Cell Membranes

    J. Ahn, R. Shimizu, K. Miyatake

    J. Mater. Chem. A   6   24625 - 24632  2018年11月  [査読有り]

    DOI

    Scopus

    25
    被引用数
    (Scopus)
  • 革新的な芳香族系電解質膜の開発

    三宅 純平, 宮武 健治

    クリーンエネルギー   9   24 - 28  2018年09月  [招待有り]

  • Sulfonated Terpolymers Containing Alkylene and Perfluoroalkylene Groups: Effect of Aliphatic Groups on Membrane Properties and Interface with the Catalyst Layers

    J. Ahn, K. Miyatake

    ACS Appl. Energy Mater.   1   3965 - 3972  2018年08月  [査読有り]

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • アルカリ形燃料電池の高性能化を目指したアニオン導電性薄膜の開発

    宮武 健治

    分離技術   4   8 - 13  2018年08月  [招待有り]

  • PtNi Alloy Nanoparticles Prepared by Nanocapsule Method for ORR Catalysts in Alkaline Media

    K. Miyatake, Y. Shimizu

    Bull. Chem. Soc. Jpn.   91   1495 - 1497  2018年08月  [査読有り]

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Optimization of Pendant Chain Length in Partially Fluorinated Aromatic Anion Exchange Membranes for Alkaline Fuel Cells

    A. M, A. Mahmoud, K. Miyatake

    J. Mater. Chem. A   6   14400 - 14409  2018年07月  [査読有り]

    DOI

    Scopus

    51
    被引用数
    (Scopus)
  • Structurally Well-Defined Anion Conductive Aromatic Copolymers: Effect of the Side-Chain Length

    Ryo Akiyama, Naoki Yokota, Kanji Otsuji, Kenji Miyatake

    Macromolecules   51 ( 9 ) 3394 - 3404  2018年05月  [査読有り]

     概要を見る

    For improving the alkaline stability and other properties of aromatic semiblock copolymer [QPE-bl-11a(C1)] membranes containing benzyltrimethylammonium groups, several novel hydrophilic monomers with different side-chain lengths and substitution positions were designed and synthesized for the polymerization. The pendant-type preaminated copolymers PE-bl-11s were quaternized using iodomethane to obtain the target QPE-bl-11s with well-defined chemical structure. In TEM analyses, QPE-bl-11a(C3) and QPE-bl-11a(C5) membranes with propyl and pentyl side-chains, respectively, showed more developed phase-separated morphology with greater hydrophilic domains (ca. 10-20 nm in width) than that of the C1 equivalent. The phase separation was more distinct and larger for the QPE-bl-11a membranes linked with p-phenylene groups in the hydrophilic part than for the QPE-bl-11b membranes with m-phenylene groups. In particular, QPE-bl-11b(C5) membrane exhibited considerably smaller hydrophilic/hydrophobic domains compared to those of the other membranes. After the alkaline stability test in 1 M KOH aqueous solution at 60 °C for 1000 h, the remaining conductivity was better as increasing the side-chain length: 34% for QPE-bl-11a(C1), 54% for QPE-bl-11a(C3), and 72% for QPE-bl-11a(C5) at 60 °C. The results suggest that the pendant alkyl chains could improve the alkaline stability and the main-chain bond position could improve morphology, water utilization, and mechanical properties of QPE-bl-11 membranes. An H2/O2 fuel cell with QPE-bl-11 membrane showed 139 mW cm-2 of the maximum power density at 0.28 A cm-2 of the current density.

    DOI

    Scopus

    36
    被引用数
    (Scopus)
  • Sulfonated Phenylene/Quinquephenylene/Perfluoroalkylene Terpolymers as Proton Exchange Membranes for Fuel Cells

    Y. Zhang, J. Miyake, R. Akiyama, R. Shimizu, K. Miyatake

    ACS Appl. Energy Mater.   1   1008 - 1015  2018年03月  [査読有り]

    DOI

    Scopus

    25
    被引用数
    (Scopus)
  • Remarkable Reinforcement Effect in Sulfonated Aromatic Polymers as Fuel Cell Membrane

    J. Miyake, M. Kusakabe, A. Tsutsumida, K. Miyatake

    ACS Appl. Energy Mater.   1   1233 - 1238  2018年03月  [査読有り]

    DOI

    Scopus

    28
    被引用数
    (Scopus)
  • 次世代燃料電池用の電解質膜の課題と可能性

    三宅純平, 宮武健治

    電気化学   86  2018年03月

  • Phase separation and ion conductivity in the bulk and at the surface of anion exchange membranes with different ion exchange capacities at different humidities

    Taro Kimura, Ryo Akiyama, Kenji Miyatake, Junji Inukai

    Journal of Power Sources   375   397 - 403  2018年01月  [査読有り]

     概要を見る

    For higher performances of anion exchange membrane (AEM) fuel cells, understanding the phase-separated structures inside AEMs is essential, as well as those at the catalyst layer/membrane interfaces. The AEMs based on quaternized aromatic semi-block copolymers with different ion exchange capacities (IECs) were systematically investigated. With IECs of 1.23 and 1.95 mequiv g−1, the water uptakes at room temperature were 37% and 98%, and the anion conductivities 23.6 and 71.4 mS cm−1, respectively. The increases were not proportional to the IEC. Images obtained by transmission electron microscopy in vacuum were similar with both IEC values, but the development of a clear phase separation in humidified nitrogen was observed in the profiles only with 1.95 mequiv g−1obtained by small-angle X-ray scattering. At the temperature of 40 °C and the relative humidity (RH) of 30%, the average currents observed at the tip apex by current-sensing atomic force microscopy were &lt
    0.5 and 10 pA with 1.23 and 1.95 mequiv g−1, respectively, and those at 70% RH were 10 and 15 pA, respectively. The humidity gave a larger influence on the bulk structure with 1.95 mequiv g−1, whereas a larger influence on the surface conductivity with 1.23 mequiv g−1.

    DOI

    Scopus

    17
    被引用数
    (Scopus)
  • Versatile synthesis of sulfonated aromatic copolymers using NiBr2

    Ibuki Hosaka, Masato Kusakabe, Kenji Miyatake

    Chemistry Letters   47 ( 2 ) 257 - 259  2018年  [査読有り]

     概要を見る

    In this research, copolymerization reaction of sulfonated dichlorobenzene and dichloro-Terminated aromatic oligomer was investigated for the preparation of sulfonated copolymers as proton conductive membranes. We found that a versatile synthetic method without using costly Ni(0) catalyst, where NiBr2 could be reduced to Ni(0) with Zn in situ during the copolymerization reaction, was applicable. The resulting copolymer had comparable molecular weight and proton conductivity to those of the copolymers prepared by the previous method using Ni(0).

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Robust anion conductive polymers containing perfluoroalkylene and pendant ammonium groups for high performance fuel cells

    Hideaki Ono, Taro Kimura, Aoi Takano, Koichiro Asazawa, Junpei Miyake, Junji Inukai, Kenji Miyatake

    JOURNAL OF MATERIALS CHEMISTRY A   5 ( 47 ) 24804 - 24812  2017年12月  [査読有り]

     概要を見る

    A novel series of ammonium-containing copolymers (QPAF-4) were designed and synthesized as anion exchange membranes for alkaline fuel cell applications. The copolymers were prepared via a nickel promoted polycondensation reaction with high molecular weights (M-w = 72.7-276.4 kDa as precursors) and were composed of perfluoroalkylene and fluorenyl groups with pendant ammonium groups. The QPAF-4 membrane with optimized copolymer composition and ion exchange capacity exhibited high hydroxide ion conductivity (86.2 mS cm(-1) in water at 80 degrees C) and excellent mechanical properties (large elongation at break = 269%). A severe alkaline stability test of the QPAF-4 membranes in 1 M KOH at 80 degrees C for 1000 h and the post-test analyses of the H-1 NMR spectra, solubility, and mechanical properties revealed minor, or no, changes in the chemical structure and properties. Alkaline fuel cells using the QPAF-4 membrane were operated using hydrazine as a fuel and oxygen or air as oxidant to achieve the high maximum power density of 515 mW cm(-2). The durability of the membrane was also confirmed in the operating fuel cell at a constant current density for longer than 1000 h.

    DOI

    Scopus

    62
    被引用数
    (Scopus)
  • Durability and degradation analysis of hydrocarbon ionomer membranes in polymer electrolyte fuel cells accelerated stress evaluation

    Ryo Shimizu, Junichi Tsuji, Nobuyuki Sato, Jun Takano, Shunsuke Itami, Masato Kusakabe, Kenji Miyatake, Akihiro Iiyama, Makoto Uchida

    JOURNAL OF POWER SOURCES   367   63 - 71  2017年11月  [査読有り]

     概要を見る

    The chemical durabilities of two proton-conducting hydrocarbon polymer electrolyte membranes, sulfonated benzophenone poly(arylene ether ketone) (SPK) semiblocic copolymer and sulfonated phenylene poly(arylene ether ketone) (SPP) semiblocic copolymer are evaluated under accelerated open circuit voltage (OCV) conditions in a polymer electrolyte fuel cell (PEFC). Post-test characterization of the membrane electrodes assemblies (MEAs) is carried out via gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy. These results are compared with those of the initial MEAs. The SPP cell shows the highest OCV at 1000 h, and, in the post-test analysis, the SPP membrane retains up to 80% of the original molecular weight, based on the GPC results, and 90% of the hydrophilic structure, based on the NMR results. The hydrophilic structure of the SPP membrane is more stable after the durability evaluation than that of the SPK. From these results, the SPP membrane, with its simple hydrophilic structure, which does not include ketone groups, is seen to be significantly more resistant to radical attack. This structure leads to high chemical durability and thus impedes the chemical decomposition of the membrane. (C) 2017 The Author(s). Published by Elsevier B.V.

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    14
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  • Copolymers Composed of Perfluoroalkyl and Ammonium-Functionalized Fluorenyl Groups as Chemically Stable Anion Exchange Membranes

    Mizuki Ozawa, Taro Kimura, Ryo Akiyama, Junpei Miyake, Junji Inukai, Kenji Miyatake

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   90 ( 10 ) 1088 - 1094  2017年10月  [査読有り]

     概要を見る

    We report synthesis and properties of a novel series of ammonium-functionalized perfluoroalkylene/aromatic copolymers. In particular, the effect of number and position of ammonium groups on the properties of the copolymer thin membranes was investigated. Fluorenylidene biphenylene groups were used as a scaffold for the ammonium groups. By controlling the chloromethylation reaction conditions, the ammonium groups could be introduced up to 4.0 per fluorenylidene biphenylene unit, resulting in the ion exchange capacity (IEC) of the resulting copolymers ranging from 1.0 to 1.8 meq g(-1). The copolymers provided bendable and transparent membranes by solution casting. The membranes exhibited phase-separated morphology based on the hydrophilic/hydrophobic differences in the copolymer components. A copolymer membrane with IEC = 1.0 meq g(-1) showed high hydroxide ion conductivity (ca. 70mS cm(-1)) at 80 degrees C in water and good alkaline stability in 1M KOH aq. over 1000 h at 60 degrees C. The membrane showed only minor degradation after the long-term alkaline stability test.

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    7
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  • Design of flexible polyphenylene proton-conducting membrane for next-generation fuel cells

    Junpei Miyake, Ryunosuke Taki, Takashi Mochizuki, Ryo Shimizu, Ryo Akiyama, Makoto Uchida, Kenji Miyatake

    SCIENCE ADVANCES   3 ( 10 ) eaao0476  2017年10月  [査読有り]

     概要を見る

    Proton exchange membrane fuel cells (PEMFCs) are promising devices for clean power generation in automotive, stationary, and portable applications. Perfluorosulfonic acid (PFSA) ionomers (for example, Nafion) have been the benchmark PEMs; however, several problems, including high gas permeability, low thermal stability, high production cost, and environmental incompatibility, limit thewidespread dissemination of PEMFCs. It is believed that fluorine-free PEMs can potentially address all of these issues; however, none of these membranes have simultaneously met the criteria for both high performance (for example, proton conductivity) and durability (for example, mechanical and chemical stability). We present a polyphenylene-based PEM (SPP-QP) that fulfills the required properties for fuel cell applications. The newly designed PEM exhibits very high proton conductivity, excellent membrane flexibility, low gas permeability, and extremely high stability, with negligible degradation even under accelerated degradation conditions, which has never been achieved with existing fluorine-free PEMs. The polyphenylene PEM also exhibits reasonably high fuel cell performance, with excellent durability under practical conditions. This new PEM extends the limits of existing fluorine-free proton-conductive materials and will help to realize the next generation of PEMFCs via cost reduction as well as the performance improvement compared to the present PFSA-based PEMFC systems.

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    126
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  • Theoretical Investigation of the H2O2-Induced Degradation Mechanism of Hydrated Nafion Membrane via Ether-Linkage Dissociation

    T. Tsuneda, R. K. Singh, A. Iiyama, K. Miyatake

    ACS Omega   2   4053 - 4064  2017年08月  [査読有り]

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    26
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  • Fluorine-free sulfonated aromatic polymers as proton exchange membranes

    Junpei Miyake, Kenji Miyatake

    POLYMER JOURNAL   49 ( 6 ) 487 - 495  2017年06月  [査読有り]

     概要を見る

    The recent progress of our research on proton exchange membranes (PEMs) for fuel cell applications is reviewed. In particular, we focus on fluorine-free sulfonated aromatic polymers as alternatives to the benchmark perfluorosulfonic acid ionomer (e.g., Nafion) PEMs. Most fluorine-free sulfonated aromatic polymers require improved proton conductivity (at high temperatures and low humidity) and chemical and mechanical stability. To address these issues, a wide range of molecular structures and their sequences were investigated. First, the effect of molecular structure on the membrane properties of sulfonated multiblock copoly(arylene ether)s is discussed. We emphasize that phosphine oxide moieties might improve chemical stability; however, aromatic ether linkages in the hydrophilic block are not suitable because oxidative degradation and excess water swelling followed by mechanical failure is essentially inevitable. We then developed a novel polymer synthetic method, an intrapolymer Heck reaction, to ladderize aromatic ether linkages in the hydrophilic block. The ladderized rigid hydrophilic structure is an effective molecular design for balancing proton conductivity and mechanical stability. We then discuss two types of segmented copolymers based on the rigid hydrophilic structural design via a Ni-mediated coupling reaction; the hydrophilic structures are sulfonated phenylene and sulfonated benzophenone. We found that the traditional multiblock structure as well as any additional polar groups (e.g., ether, sulfone, ketone) in the hydrophilic sections are not necessary for improving the membrane properties that are important for fuel cell applications, such as proton conductivity and chemical and mechanical stability. The results indicate that fluorine-free aromatic PEMs are a potentially applicable class of ionomers for the next generation of proton exchange membrane fuel cells.

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    43
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  • High Hydroxide Ion Conductivity with Enhanced Alkaline Stability of Partially Fluorinated and Quaternized Aromatic Copolymers as Anion Exchange Membranes

    Ahmed Mohamed Ahmed Mahmoud, Ahmed Mohamed Mohamed Elsaghier, Kanji Otsuji, Kenji Miyatake

    MACROMOLECULES   50 ( 11 ) 4256 - 4266  2017年06月  [査読有り]

     概要を見る

    For enhancing hydroxide ion conductivity, alkaline stability, and fuel cell performance of quaternaized aromatic/perfluoroaklyl copolymer (QPAF) membranes, ammonium groups attached to the polymer backbone have been investigated. The ammonium groups included dimethyl-butylamine (DMBA), dimethylhexylamine (DMHA), and 1,2dimethylimidazole (DMIm) groups in comparison to the trimethylammonium (TMA) group. DMBA turned to be the optimum ammonium group for QPAF membranes in terms of its high hydroxide ion conductivity based on well-connected and larger phase-separated morphology than that of QPAF-TMA with similar ion exchange capacity (IEC) value. QPAF-DMBA (IEC = 1.33 mequiv g(-1)) exhibited the highest hydroxide ion conductivity among the tested membranes up to 152 mS cm(-2) in water at 80 degrees C, which was 1.6 times higher than that of QPAFTMA (95 mS cm(-1)). In addition, QPAF-DMBA exhibited reasonable alkaline stability in 1 M KOH at 60 degrees C for 1000 h. The remaining conductivity was 44 mS cm(-1) (58%) for QPAF-DMBA, while that for QPAF-TMA was 1.0 mS cm(-1) (1%). QPAFDMBA (IEC = 1.09 mequiv g(-1)) exhibited excellent stability in 1 M KOH at 80 degrees C without change in the ion conductivity (22 mS cm(-1)) for 500 h. The post-test membranes exhibited a minor degradation in QPAF-DMBA as suggested by FT-IR spectra and DMA analyses. An H-2/O-2 fuel cell was operated with the QPAF-DMBA membrane to achieve the maximum power density of 167 mW cm(-2) at the current density of 0.42 A cm(-2), which was higher than that (138 mW cm(-2)) for QPAF-TMA membrane under the same operating conditions.

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    89
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  • Pt/Co Alloy Nanoparticles Prepared by Nanocapsule Method Exhibit a High Oxygen Reduction Reaction Activity in Alkaline Media

    K. Miyatake, Y. Shimizu

    ACS Omega   2   2085 - 2089  2017年05月  [査読有り]

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    15
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  • Partially Fluorinated and Ammonium-Functionalized Terpolymers: Effect of Aliphatic Groups on the Properties of Anion Conductive Membranes

    Hideaki Ono, Junpei Miyake, Kenji Miyatake

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   55 ( 8 ) 1442 - 1450  2017年04月  [査読有り]

     概要を見る

    Synthesis and properties of a series of ammonium-containing terpolymers (QPAF-3) as anion conductive membranes are reported. The QPAF-3s composed of perfluoroalkylene, alkylene, and ammonium-functionalized phenylene groups without heteroatom linkages in the main chain were synthesized via nickel-mediated polycondensation reaction, followed by chloromethylation, quaternization, and ion exchange reactions. Self-standing, bendable membranes were obtained by solution casting. The QPAF-3 membrane with optimized terpolymer composition and ion exchange capacity (1.46 meq g(-1)) showed high hydroxide ion conductivity (123 mS cm(-1) in water at 80 degrees C). The alkaline stability test in 1 M KOH for 1000 h at 80 degrees C and the posttest analysis with IR spectra and tensile strength suggested that ammoniumgroups were likely to be decomposed while the polymer main chain was chemically more robust. The presence of the alkylene groups in the terpolymers lowered solubility, glass transition temperature, and elongation property of the resulting membranes. (C) 2017 Wiley Periodicals, Inc.

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    12
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  • Anion Conductive Polymers Containing Aliphatic and Ammonium-functionalized Fluorene Groups

    Manai Shimada, Ryo Akiyama, Hideaki Ono, Junpei Miyake, Kenji Miyatake

    CHEMISTRY LETTERS   46 ( 3 ) 374 - 377  2017年03月  [査読有り]

     概要を見る

    A novel series of anion conductive polymers, quaternized poly(phenylene alkylene)s (QPAs), were synthesized and characterized. Because of the unique main chain structure composed of alkylene and ammonium-functionalized fluorene groups, QPA thin membranes exhibited high ion conductivity and good chemical and mechanical stabilities.

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    2
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  • Durability of Sulfonated Phenylene Poly(Arylene Ether Ketone) Semiblock Copolymer Membrane in Wet-Dry Cycling for PEFCs

    Hiroshi Ishikawa, Yusuke Fujita, Junichi Tsuji, Masato Kusakabe, Junpei Miyake, Yasushi Sugawara, Kenji Miyatake, Makoto Uchida

    JOURNAL OF THE ELECTROCHEMICAL SOCIETY   164 ( 12 ) F1204 - F1210  2017年  [査読有り]

     概要を見る

    The mechanical durability of sulfonated poly (phenylene) (SPP) membrane, used for polymer electrolyte fuel cells (PEFCs), is evaluated by the United States Department of Energy (USDOE) stress protocol involving wet-dry cycling, and the degradation is analyzed specifically by comparing with sulfonated poly(arylene ether ketone) (SPK) membrane. Initially, the SPP membrane exhibits 2-fold higher stiffness and 50% lower dimensional change ratio than the SPK membrane. In durability cycling, the SPP membrane lasts more than 20,000 wet-dry cycles without mechanical failure, which is more than 5-fold better durability than that for the SPK membrane. Higher mechanical strength and lower dimensional change can reduce both irreversible membrane deformation and mechanical stress attributed to the membrane swelling and shrinking. In post-test analyses, the SPP membrane is found to rupture in the peripheral region of the membrane electrode assemblies. The SPP membrane maintains only 10% of the elongation at break in the peripheral region but 50% in the electrode region, compared with the pristine condition. It is most likely that the membrane deteriorates in the peripheral region due to stress concentration by cell compression and membrane deformation during wet-dry cycling. (185 words) (C) The Author(s) 2017. Published by ECS. All rights reserved.

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    10
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  • Mechanism of H2O2 Decomposition by Triphenylphosphine Oxide

    Takao Tsuneda, Junpei Miyake, Kenji Miyatake

    ACS Omega   3 ( 1 ) 259 - 265  2017年  [査読有り]

     概要を見る

    A decomposition mechanism of H2O2 by triphenylphosphine oxide (TPPO) is presented. TPPO is often incorporated in proton-exchange membrane electrolytes as a moiety to inhibit the H2O2-induced degradation of the membranes. However, it has not been revealed how TPPO decreases the concentration of free H2O2 in the membranes. Following the experimental X-ray structures, the TPPO dimer capturing two H2O2 molecules was used as the calculation model. The vibrational spectrum calculations for various hydration numbers show that this model correctly reproduces the spectral peaks of TPPO capturing H2O2. On the basis of this model, the H2O2 decomposition mechanism by the TPPO dimer was searched. It was consequently found that this reaction proceeds through three steps: (1) Hydrogen transfer from H2O2 to the P=O bond of TPPO, (2) Hydrogen transfer from the -OOH group to the -OH group, and (3) O-O bond formation between O2 groups. The calculated vibrational spectra for the reactants and intermediates indicated that the first and second steps are activated by vibrational excitations. Moreover, the third step giving low barrier heights is considered to proceed through two reaction paths: directly producing the O2 molecule or going through an HOOOH intermediate. Interestingly, this reaction mechanism was found to use the violation of the octet rule for the P=O double bond, resulting in the strong H2O2 binding of TPPO.

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    14
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  • Experimental and Theoretical Infrared Spectroscopic Study on Hydrated Nafion Membrane

    Raman K. Singh, Keiji Kunimatsu, Kenji Miyatake, Takao Tsuneda

    MACROMOLECULES   49 ( 17 ) 6621 - 6629  2016年09月  [査読有り]

     概要を見る

    A collaborative experimental and theoretical study on the dependence of the infrared (IR) spectrum of hydrated Nafion,electrolyte membrane on the hydration number is investigated in great detail. Experimental time-resolved attenuated total reflection Fourier transform IR spectroscopic results show that Nafion membrane has a unique IR peak intensity dependence on the hydration number. Calculated IR spectra indicate that this unique IR peak intensity dependence is correctly reproduced not for the singly hydrated Nafion but for the doubly hydrated Nafion. This result strongly supports the relay mechanism of the proton conductance, in which protonated water dusters are relayed by the side chains through the doubly hydrated sulfonic acid groups under low humidity conditions.

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    48
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  • Effect of Surface Ion Conductivity of Anion Exchange Membranes on Fuel Cell Performance

    Masanori Hara, Taro Kimura, Takuya Nakamura, Manai Shimada, Hideaki Ono, Shigefumi Shimada, Kenji Miyatake, Makoto Uchida, Junji Inukai, Masahiro Watanabe

    LANGMUIR   32 ( 37 ) 9557 - 9565  2016年09月  [査読有り]

     概要を見る

    Anion conductivity at the surfaces of two anion-exchange membranes (AEMs), quaternized ammonium poly(arylene ether) multiblock copolymer(QPE-bl-3) and quaternized ammonium poly(arylene perfluoro-alkylene) copolymer (QPAF-1), synthesized by our group was investigated using current-sensing atomic force microscopy under purified air at various relative humidities. The anion-conducting spots were distributed inhomogeneously on the surface Of QPE-bl-3, and the total areas of the anion-conducting spots and the current at each spot increased with humidity. The anion-conductive areas on QPAF-1 were found on the entire surface even at a low humidity. Distribution of the anion-conducting spots on the membrane was found to directly affect the performance of an AEM fuel cell.

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    14
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  • Simple, Effective Molecular Strategy for the Design of Fuel Cell Membranes: Combination of Perfluoroalkyl and Sulfonated Phenylene Groups

    Takashi Mochizuki, Makoto Uchida, Kenji Miyatake

    ACS ENERGY LETTERS   1 ( 2 ) 348 - 352  2016年08月  [査読有り]

     概要を見る

    Proton-conducting membranes are key materials in polymer electrolyte fuel cells. In addition to high proton conductivity and durability, a membrane must also support good electrocatalytic performance of the catalyst layer at the membrane electrode interface. We herein propose an effective molecular approach to the design of high-performance proton-conducting membranes designed for fuel cell applications. Our new copolymer (SPAF) is a simple combination of perfluoroalkylene and sulfonated phenylene groups. Because this ionomer membrane exhibits a well-controlled finely phase-separated morphology, based on the distinct hydrophilic hydrophobic differences along with the polymer chain, it functions well in an operating fuel cell with good durability under practical conditions. The advantages of this ionomer, unlike typical perfluorosulfonic acid ionomers (e.g., Nafion), include easy synthesis and versatility in molecular structure, enabling the fine-tuning of membrane properties.

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    27
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  • Effect of Thermal Crosslinking on the Properties of Sulfonated Poly(phenylene sulfone)s as Proton Conductive Membranes

    Y. Zhang, J.-D. Kim, K. Miyatake

    J. Appl. Polym. Sci.   133   44218  2016年08月  [査読有り]

  • Use of a Sub-Gasket and Soft Gas Diffusion Layer to Mitigate Mechanical Degradation of a Hydrocarbon Membrane for Polymer Electrolyte Fuel Cells in Wet-Dry Cycling

    H. Ishikawa, T. Teramoto, Y. Ueyama, Y. Sugawara, Y. Sakiyama, M. Kusakabe, K. Miyatake, M. Uchida

    J. Power Sources   325   35 - 41  2016年07月  [査読有り]

  • Anion Conductive Aromatic Copolymers from Dimethylaminomethylated Monomers: Synthesis, Properties and Applications in Alkaline Fuel Cells

    R. Akiyama, N. Yokota, E. Nishino, K. Asazawa, K. Miyatake

    Macromolecules   49   4480 - 4489  2016年07月  [査読有り]

  • Anion-exchange Membranes Containing Fluorinated Poly(arylene ether)s: Properties and Application in Pt-free Hydrazine Fuel Cell

    Eriko Nishino, Junko Yamada, Koichiro Asazawa, Susumu Yamaguchi, Manai Shimada, Junpei Miyake, Kenji Miyatake

    CHEMISTRY LETTERS   45 ( 6 ) 664 - 666  2016年06月  [査読有り]

     概要を見る

    The properties of anion-exchange membranes composed of fluorinated block copoly(arylene ether)s, QPE-b1-3, were investigated. QPE-b1-3 membranes exhibited high chemical stability under accelerated testing conditions. Reasonably high fuel cell performance was obtained with QPE-b1-3, hydrazine hydrate as a fuel, and non-platinum catalysts.

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    3
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  • Effect of Sulfonated Triphenylphosphine Oxide Groups in Aromatic Block Copolymers as Proton-exchange Membranes

    Junpei Miyake, Ibuki Hosaka, Kenji Miyatake

    CHEMISTRY LETTERS   45 ( 1 ) 33 - 35  2016年01月  [査読有り]

     概要を見る

    The introduction of sulfonated triphenylphosphine oxide moieties improved the oxidative stability of aromatic block copolymer membranes, while other factors such as water affinity also played an important role in determining the membrane properties.

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    5
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  • Effect of ammonium groups on the properties of anion conductive membranes based on partially fluorinated aromatic polymers

    Ahmed Mohamed Ahmed Mahmoud, Ahmed Mohamed Mohamed Elsaghier, Kenji Miyatake

    RSC ADVANCES   6 ( 33 ) 27862 - 27870  2016年  [査読有り]

     概要を見る

    A series of anion exchange membranes (QPE-bl-9) based on a partially fluorinated hydrophobic segment and oligophenylene as scaffolds for ammonium cations were synthesized to evaluate the effect of the various ammonium groups derived from trimethyl amine (TMA), dimethyl hexyl amine (DMHA), methyl imidazole (MIm), dimethyl imidazole (DMIm), tributyl amine (TBA), and dicyclohexyl methyl amine (DCHMA) on the membrane properties. QPE-bl-9 membranes were well characterized by H-1 NMR spectroscopy, in which all the peaks were assigned to the supposed structure. The TEM images of QPE-bl-9-TMA, -MIm, -DMIm and -DMHA membranes showed small hydrophilic/hydrophobic phase separated morphology (hydrophilic domains 1-3 nm). QPE-bl-9-TMA (1.6 mequiv. g(-1)) exhibited the highest hydroxide ion conductivity (101 mS cm(-1) at 80 degrees C) among the tested membranes, followed by QPE-bl-9-DMHA (62 mS cm(-1)) and QPE-bl-9-DMIm (62 mS cm(-1)). The alkaline stability of the membranes was tested in 1 M KOH at 60 degrees C for 1000 h. QPE-bl-9-TMA exhibited the highest retention of the conductivity (58%), which was higher than that of the Tokuyama A201 anion exchange membrane (29%). The post stability test IR analyses suggested that the major degradation mechanism of the QPE-bl-9 membranes in alkaline solution involved the decomposition of the ammonium groups. The QPE-bl-9 membranes retained their mechanical stability after the stability test, as proved by DMA analyses.

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    16
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  • Analysis of the Gold/Polymer Electrolyte Membrane Interface by Polarization-Modulated ATR-FTIR Spectroscopy

    Keiji Kunimatsu, Kenji Miyatake, Shigehito Deki, Hiroyuki Uchida, Masahiro Watanabe

    JOURNAL OF PHYSICAL CHEMISTRY C   119 ( 29 ) 16754 - 16761  2015年07月  [査読有り]

     概要を見る

    We developed a new FTIR system with two polarizers in its optics in order to conduct polarization-modulated measurements. Polarization characteristics were examined for the Kretschmann polarization-modulated attenuated total reflectance (ATR) configuration by the use of gold-sputtered films of 10-100 nm thickness on Ge and ZnSe prisms. The marked increase of the polarization characteristics for Au film thicknesses below 30-40 nm is closely associated with a large reflectivity decrease of the p-polarized radiation. A cast film of sulfonated block poly(arylene ether sulfone ketone) membrane was formed on the Au film, and the interfacial spectra were acquired by the use of the ATR FTIR system. The interfacial spectra resemble those of the ATR spectra of the bulk membrane but exhibited strong dependence of the intensity and line shape of the vibrational modes on the Au thickness. The dependence is closely associated with a change of the polarization characteristics of the interface. Electromagnetic as well as chemical effects were concluded to be responsible for the band anomalies and enhancement.

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    5
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  • A Proton Conductive Aromatic Block Copolymer Containing Dibenzofuran Moieties

    Junpei Miyake, Masaki Saito, Ryo Akiyama, Masahiro Watanabe, Kenji Miyatake

    CHEMISTRY LETTERS   44 ( 7 ) 964 - 966  2015年07月  [査読有り]

     概要を見る

    A rigid, planar dibenzofuran in the hydrophobic parts provided sulfonated aromatic block copolymer with improved membrane properties, i.e., well-developed phase separation, effective water uptake, high proton conductivity, and moderate mechanical strength at wide range of humidity.

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    6
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  • Effects of SiO2 Nanoparticles Incorporated into Poly(Arylene Ether Sulfone Ketone) Multiblock Copolymer Electrolyte Membranes on Fuel Cell Performance at Low Humidity

    Masaru Sakamoto, Shinji Nohara, Kenji Miyatake, Makoto Uchida, Masahiro Watanabe, Hiroyuki Uchida

    ELECTROCHEMISTRY   83 ( 3 ) 150 - 154  2015年03月  [査読有り]

     概要を見る

    To improve the performances of fuel cells at low humidity, we have prepared composite electrolyte membranes by incorporating SiO2 nanoparticles into poly(arylene ether sulfone ketone) (SPESK) membrane. SiO2 particles were able to be dispersed in SPESK highly uniformly on the nanometer scale by the use of a commercial SiO2-dimethylacetamide sol. The SiO2/SPESK cell exhibited improved I-E performance at 53% relative humidity (RH) and 80 degrees C. It was found that such an improvement was due to the reduction of the ohmic resistance and the oxygentransport overpotential at high current densities, probably because the SiO2 nanoparticles promoted the backdiffusion of water generated at the cathode catalyst layer toward the anode. Both the ohmic resistance and the oxygen-transport overpotential were reduced further by using a thin (ca. 12 mu m) SiO2/SPESK membrane, resulting in remarkably high performances at 53% RH and 30% RH. (C) The Electrochemical Society of Japan, All rights reserved.

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    6
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  • Synthesis and properties of sulfonated block poly(arylene ether)s containing m-terphenyl groups as proton conductive membranes

    Junpei Miyake, Mayu Sakai, Masaru Sakamoto, Masahiro Watanabe, Kenji Miyatake

    JOURNAL OF MEMBRANE SCIENCE   476   156 - 161  2015年02月  [査読有り]

     概要を見る

    We have utilized rn-terphenyl (MTP) moiety as a component of hydrophobic blocks for sulfonated multiblock poly(arylene ether) copolymers. For this purpose, bisphenol-type MTP monomer was polymerized with bis(4-fluorophenyl)sullone to obtain hydroxyl-terminated hydrophobic oligomers, which were copolymerized with sulfonated hydrophilic blocks to obtain the targeted multiblock copolymers. The block copolymers possessed high apparent molecular weight (M-w=74-180 kDa) and gave bendable membranes by solution casting. Transmission electron microscopic (TEM) images revealed that the membranes exhibited hydrophilic/hydrophobic phase separated morphology with distinct interfaces. The domain sizes were dependent on the compositions of the multiblock copolymers, indicating the sequenced structure is responsible for the morphology. The introduction of MTP moieties in the hydrophobic blocks resulted in the membrane with the higher ion exchange capacity (IEC) value (2.13 meq/g) and higher proton conductivity (ca. 320 mS/cm at 80 degrees C and 90% relative humidity) than that of the previous polymers sharing the same hydrophilic but different hydrophobic (p biphenyl, BP) moieties (1.69 meq/g, ca. 200 mS/cm under the same conditions, respectively). In contrast, humidity dependence of dynamic mechanical properties in MTP membranes was similar to BE membranes, suggesting the introduction of MTP moieties in the hydrophobic segments has minor impact on the mechanical stability and its dependence on the humidity. (C) 2014 Elsevier B.V. All rights reserved.

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    27
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  • Anion exchange membranes composed of perfluoroalkylene chains and ammonium-functionalized oligophenylenes

    Hideaki Ono, Junpei Miyake, Shigehumi Shimada, Makoto Uchida, Kenji Miyatake

    JOURNAL OF MATERIALS CHEMISTRY A   3 ( 43 ) 21779 - 21788  2015年  [査読有り]

     概要を見る

    A novel & series of ammonium-containing copoIymers (QPAFs) were synthesized as anion exchange membranes for aIkaIine fueI cell appEications. The precursor copoIymers (A/l = 28.3-90.1 kDa) composed of perfluoroaIkyIene and phenyIene groups were obtained by a nick& promoted poIycondensation reaction. ChIoromethyEation and quaternization reactions of the precursors provided thin and ductlle QPAF membranes with ion exchange capacity (IEC) ranging from 0.79 to 1.74 meq g-1. The QPAF membranes exhibited a phase-separated morphoIogy based on the hydrophiIic/hydrophobic differences in the main chain structure. The QPAF membrane with an optimized copoIymer composition and IEC = 1.26 meq g(-1) showed high hydroxide ion conductivity (95.5 mS cm(-1) in water at 80 degrees C), excellent mechanicaI properties (Large eIongation at break (218%)), and reasonabIe aIkaIine stabiIity at 80 degrees C. An aIkaIine fueI cell using the QPAF as the membrane and eIectrode binder achieved the maximum power density of 139 mW cm-2 at a current density of 420 mA cm(-2).

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    58
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  • Synthesis and Properties of Sulfonated and Brominated Poly(arylene ether)s as Proton Conductive Membranes

    Takayuki Hoshi, Junpei Miyake, Masahiro Watanabe, Kenji Miyatake

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   88 ( 1 ) 183 - 191  2015年01月  [査読有り]

     概要を見る

    A novel series of poly(arylene ether sulfone ketone) multiblock copolymers containing sulfonic acid and bromine groups in the hydrophilic blocks were synthesized and characterized. The copolymers were high molecular weight (M-n = 21-98 kDa, M-w = 234-357 kDa) and provided bendable and transparent membranes by solution casting. The bromine groups caused slight decrease in the proton conductivity at low humidity, however, were effective in improving the mechanical properties as confirmed by dynamic mechanical analyses and tensile tests.

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    1
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  • A sulfonated polybenzophenone/polyimide copolymer as a novel proton exchange membrane

    Takahiro Miyahara, Junpei Miyake, Soichi Matsuno, Masahiro Watanabe, Kenji Miyatake

    RSC ADVANCES   5 ( 62 ) 50082 - 50086  2015年  [査読有り]

     概要を見る

    A sulfonated polybenzophenone/polyimide block copolymer membrane exhibited high proton conductivity, good dimensional and mechanical stabilities, and low gas permeability, which are attractive for fuel cell applications.

    DOI

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    12
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  • Aromatic Copolymers Containing Ammonium-Functionalized Oligophenylene Moieties as Highly Anion Conductive Membranes

    Naoki Yokota, Manai Shimada, Hideaki Ono, Ryo Akiyama, Eriko Nishino, Koichiro Asazawa, Junpei Miyake, Masahiro Watanabe, Kenji Miyatake

    MACROMOLECULES   47 ( 23 ) 8238 - 8246  2014年12月  [査読有り]

     概要を見る

    The synthesis and properties of anion conductive aromatic copolymers containing oligophenylene moieties as a scaffold for quaternized ammonium groups are reported. Our new hydrophilic components consist of a chemically robust oligophenylene main chain modified with a high density of ionic groups. A partially fluorinated oligo(arylene ether) was employed as a hydrophobic block. The targeted copolymers (QPE-bl-9) were synthesized via nickel-mediated coupling polymerization, followed by chloromethylation, quaternization, and ion exchange reactions. QPE-bl-9 provided tough, bendable membranes by solution casting. The resulting membrane with the highest ion exchange capacity (IEC = 2.0 mequiv g(-1)) exhibited high hydroxide ion conductivity (138 mS cm(-1)) in water at 80 degrees C. Reasonable alkaline stability of QPE-bl-9 membrane was confirmed in 1 M KOH aqueous solution for 1000 h at 40 degrees C. A noble metal-free fuel cell with QPE-bl-9 used as the membrane and electrode binder was successfully operated. A maximum power density of 510 mW cm(-2) was achieved at a current density of 1.20 A cm(-2) with hydrazine as the fuel and O-2 as the xidant.

    DOI

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    59
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  • Carbon Segregation-Induced Highly Metallic Ni Nanoparticles for Electrocatalytic Oxidation of Hydrazine in Alkaline Media

    Tae-Yeol Jeon, Masahiro Watanabe, Kenji Miyatake

    ACS APPLIED MATERIALS & INTERFACES   6 ( 21 ) 18445 - 18449  2014年11月  [査読有り]

     概要を見る

    The important roles of Ni in electrocatalytic reactions such as hydrazine oxidation are limited largely by high oxidation states because of its intrinsically high oxophilicity. Here, we report the synthesis and properties of highly metallic Ni nanoparticles (NPs) on carbon black supports. We discovered that the heat treatment of as-prepared Ni NPs with an average particle size of 5.8 nm produced highly metallic Ni NPs covered with thin carbon shells, with negligible particle coarsening. The carbon shells were formed by the segregation of carbons in the Ni lattice to the surface of the Ni NPs, leaving highly metallic Ni NPs. X-ray photoelectron spectroscopic analyses revealed that the atomic ratio of metallic Ni increased from 19.2 to 71.7% as a result of the heat treatment. The NPs exhibited higher electrocatalytic activities toward the hydrazine oxidation reaction in alkaline solution, as compared to those of the as-prepared Ni NPs and commercial Ni powders.

    DOI

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    37
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  • Anion Conductive Aromatic Block Copolymers Containing Diphenyl Ether or Sulfide Groups for Application to Alkaline Fuel Cells

    Naoki Yokota, Hideaki Ono, Junpei Miyake, Eriko Nishino, Koichiro Asazawa, Masahiro Watanabe, Kenji Miyatake

    ACS APPLIED MATERIALS & INTERFACES   6 ( 19 ) 17044 - 17052  2014年10月  [査読有り]

     概要を見る

    A novel series of aromatic block copolymers composed of fluorinated phenylene and biphenylene groups and diphenyl ether (QPE-bl-5) or diphenyl sulfide (QPE-bl-6) groups as a scaffold for quaternized ammonium groups is reported. The block copolymers were synthesized via aromatic nucleophilic substitution polycondensation, chloromethylation, quaternization, and ion exchange reactions. The block copolymers were soluble in organic solvents and provided thin and bendable membranes by solution casting. The membranes exhibited well-developed phase-separated morphology based on the hydrophilic/hydrophobic block copolymer structure. The membranes exhibited mechanical stability as confirmed by DMA (dynamic mechanical analyses) and low gas and hydrazine permeability. The QPE-bl-5 membrane with the highest ion exchange capacity (IEC = 2.1 mequiv g(-1)) exhibited high hydroxide ion conductivity (62 mS cm(-1)) in water at 80 degrees C. A noble metal-free fuel cell was fabricated with the QPE-bl-5 as the membrane and electrode binder. The fuel cell operated with hydrazine as a fuel exhibited a maximum power density of 176 mW cm(-2) at a current density of 451 mA cm(-2).

    DOI

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    41
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  • Double-Layer Ionomer Membrane for Improving Fuel Cell Performance

    Takashi Mochizuki, Makoto Uchida, Hiroyuki Uchida, Masahiro Watanabe, Kenji Miyatake

    ACS APPLIED MATERIALS & INTERFACES   6 ( 16 ) 13894 - 13899  2014年08月  [査読有り]

     概要を見る

    A double-layer ionomer membrane, thin-layer Nafion (perfluorinated sulfonic acid polymer) on a sulfonated aromatic block copolymer (SPK-bl-1), was prepared for improving fuel cell performance. Each component of the double-layer membrane showed similar phase-separated morphologies to those of the original membranes. A fuel cell with the double-layer membrane exhibited lower ohmic resistance and higher cathode performance than those with the original SPK-bl-1 membrane despite their comparable water uptake and proton conductivity. Detailed electrochemical analyses of fuel cell data suggested that the thin Nafion interlayer contributed to improving the interfacial contact between the SPK-bl-1 membrane and the cathode catalyst layer and to mitigating excessive drying of the membrane. The results provide new insight on designing high-performance fuel cells with nonfluorinated ionomer membranes such as sulfonated aromatic polymers.

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    18
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  • Effects of Incorporation of SiO2 Nanoparticles into Sulfonated Polyimide Electrolyte Membranes on Fuel Cell Performance under Low Humidity Conditions

    Masaru Sakamoto, Shinji Nohara, Kenji Miyatake, Makoto Uchida, Masahiro Watanabe, Hiroyuki Uchida

    ELECTROCHIMICA ACTA   137   213 - 218  2014年08月  [査読有り]

     概要を見る

    We have developed new composite membranes of sulfonated polyimide containing triazole-groups (SPI-8) as a matrix ionomer and SiO2 nanoparticles. The incorporation of SiO2 nanoparticles remarkably improved the fuel cell performances during low humidity operation at 53% RH and 80 degrees C. Among the cells with SPI-8 membranes with uniformly dispersed SiO2 from 0 to 15 wt%, the single cell with 10 wt% SiO2/SPI-8 was found to exhibit the highest I - E performance, with the highest mass activity at 0.85 V and the smallest oxygen-transport overpotential (O-2-gain) as well as the lowest ohmic resistance. This strongly indicates that SiO2 nanoparticles were able to promote the back-diffusion of water produced in the cathode catalyst layer to the anode catalyst layer, maintaining high Water content in the membrane during the operation. It was found that the cell with a bilayer SPI-8 membrane having 10 wt% SiO2 in the anode-side layer and 3 wt% SiO2 in the cathode-side layer exhibited performance superior to that with a uniform dispersion of 10 wt%SiO2, especially in the higher current density region at low RH, which can be ascribed with certainty to the fact that the concentration gradient of SiO2 in the SPI-8 led to enhancement of the back-diffusion of water through the membrane (C) 2014 Elsevier Ltd. All rights reserved.

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    24
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  • Proton Conductive Areas on Sulfonated Poly(Arylene Ketone) Multiblock Copolymer Electrolyte Membrane Studied by Current-Sensing Atomic Force Microscopy

    Masaya Hara, Takahiro Miyahara, Takayuki Hoshi, Jiwei Ma, Masanori Hara, Kenji Miyatake, Junji Inukai, Nicolas Alonso-Vante, Masahiro Watanabe

    ELECTROCHEMISTRY   82 ( 5 ) 369 - 375  2014年05月  [査読有り]

     概要を見る

    Proton conductive spots on the membrane surface of sulfonated poly(arylene ketone) multiblock copolymer were investigated by current-sensing atomic force microscopy (CS-AFM) under the hydrogen atmosphere with changing relative humidity, temperature, and bias voltage. The bright spots, where the hydrophilic clusters should be effectively connected inside the membrane, were distributed rather inhomogeneously on the surface at low temperature and humidity but became more homogeneous at higher temperature and humidity. The average diameter of the spots was approximately 10 nm at 40% RH, which increased to 13 nm at 70% RH. The total area of the proton conducting spots, as well as current at each spot, on the membrane surface increased at high humidity and temperature. In addition, the diameter of the proton-conductive spots and the ratio of proton-conductive area on the membrane surface continuously increased with increasing the bias voltage. This increase of the conducting area and the current should be related to the change of the bulk ionic conductivity. (C) The Electrochemical Society of Japan, All rights reserved.

    DOI

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    7
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  • Reversible/irreversible increase in proton-conductive areas on proton-exchange-membrane surface by applying voltage using current-sensing atomic force microscope

    Masanori Hara, Hattori Daiki, Junji Inukai, Masaya Hara, Kenji Miyatake, Masahiro Watanabe

    JOURNAL OF ELECTROANALYTICAL CHEMISTRY   716   158 - 163  2014年03月

     概要を見る

    By using a current-sensing atomic force microscope (CS-AFM) under a hydrogen atmosphere, microscopic proton-conductive areas on the membrane surface of sulfonated poly(arylene ether sulfone ketone) block copolymer were investigated. With increasing the bias voltage during the CS-AFM scans, the number and the diameter of proton-conductive spots on the membrane surface continuously increased. Both reversible/irreversible changes in the proton-conductive area on the surface were found. The reversible change indicates that the proton-conductive paths are dynamically rearranged during the power generation in a polymer electrolyte fuel cell. The irreversible change might be related to the enhancement of the performance of the membrane electrode assemblies after being "conditioned" prior to the operation. (C) 2013 Elsevier B.V. All rights reserved.

    DOI

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    10
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  • Effect of Ammonium Groups on the Properties and Alkaline Stability of Poly(arylene ether)-Based Anion Exchange Membranes

    Junpei Miyake, Keita Fukasawa, Masahiro Watanabe, Kenji Miyatake

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   52 ( 3 ) 383 - 389  2014年02月  [査読有り]

     概要を見る

    Five kinds of ammonium groups functionalized partially fluorinated poly(arylene ether) block copolymer membranes were prepared for investigating the structure-property relationship as anion exchange membranes (AEMs). Consequently, the pyridine (PYR)-modified membrane showed the highest alkaline and hydrazine stability in terms of the conductivity, water uptake, and dry weight. The chloromethylated precursor block copolymers were reacted with amines, such as trimethylamine, N-butyldimethylamine, 1-methylimidazole, 1,2-dimethylimidazole, and PYR to provide the target quaternized poly(arylene ether)s. The structures of the polymers, as well as model compounds and oligomers were well characterized by H-1 NMR spectra. The obtained AEMs were subjected to water uptake and hydroxide ion conductivity measurements and stabilities in aqueous alkaline and hydrazine media. The pyridinium-functionalized quaternized polymers membrane showed the highest alkaline and hydrazine stability with minor losses in the conductivity, water uptake, and dry weight. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 383-389

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    47
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  • Intrapolymer Heck reaction for proton conductive ladder-type aromatic block copolymers

    Junpei Miyake, Masahiro Watanabe, Kenji Miyatake

    RSC ADVANCES   4 ( 40 ) 21049 - 21053  2014年  [査読有り]

     概要を見る

    A novel polymer synthetic method, the intrapolymer Heck reaction, provided ladder-type ionomer membranes with excellent proton conductivity (221 mS cm(-1) at 80 degrees C and 90% relative humidity) and mechanical strength over a wide range of humidity (ca. 0-90% relative humidity) at 80 degrees C.

    DOI

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    9
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  • Sulfonated poly(arylene ether phosphine oxide ketone) block copolymers as oxidatively stable proton conductive membranes

    Junpei Miyake, Masahiro Watanabe, Kenji Miyatake

    ACS Applied Materials and Interfaces   5 ( 13 ) 5903 - 5907  2013年07月  [査読有り]

     概要を見る

    The introduction of triphenylphosphine oxide moiety into the hydrophilic segments of aromatic multiblock copolymers provided outstanding oxidative stability and high proton conductivity. Our designed multiblock copolymers are composed of highly sulfonated phenylene ether phosphine oxide ketone units as hydrophilic blocks and phenylene ether biphenylene sulfone units as hydrophobic blocks. High molecular weight block copolymers (Mw = 204-309 kDa and Mn = 72-94 kDa) with different copolymer compositions (number of repeat unit in the hydrophobic blocks, X = 30, and that of hydrophilic blocks, Y = 4, 6, or 8) were synthesized, resulting in self-standing, transparent, and bendable membranes by solution-casting. The block copolymer membranes exhibited well-developed hydrophilic/hydrophobic phase separation, high proton conductivity, and excellent oxidative stability due to the highly sulfonated hydrophilic blocks, which contained phenylene rings with sulfonic acid groups and electron-withdrawing phosphine oxide or ketone groups. © 2013 American Chemical Society.

    DOI

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    43
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  • Synthesis and Properties of Partially Fluorinated Poly(arylene ether) Block Copolymers Containing Ammonium Groups as Anion Conductive Membranes

    Hideaki Ono, Junpei Miyake, Byungchan Bae, Masahiro Watanabe, Kenji Miyatake

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   86 ( 5 ) 663 - 670  2013年05月  [査読有り]

     概要を見る

    Synthesis and properties of aromatic block copolymers containing fluorinated phenylene and biphenylene groups and ammonium-substituted fluorene groups are reported. High-molecular-weight poly(arylene ether) block copolymers were prepared from the corresponding telechelic oligomers and were chloromethylated. Quaternization reaction of the chloromethylated precursors with trimethylamine provided the title ammonium-substituted block copolymers (QPE-b1-4). The QPE-b1-4 membrane with the highest ion-exchange capacity (IEC = 1.3 mequiv g(-1)) showed high hydroxide ion conductivity (45 mS cm(-1)) at 80 degrees C due to its phase-separated morphology with interconnected ion-transporting pathway. The accelerated stability test in aqueous KOH solution containing hydrazine revealed that the ammonium groups decomposed to certain extent while the polymer main chains were rather robust to maintain the self-supporting membranes.

    DOI

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    12
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  • Imaging individual proton-conducting spots on sulfonated multiblock-copolymer membrane under controlled hydrogen atmosphere by current-sensing atomic force microscopy.

    Masanori Hara, Daiki Hattori, Junji Inukai, Byungchan Bae, Takayuki Hoshi, Masaya Hara, Kenji Miyatake, Masahiro Watanabe

    The journal of physical chemistry. B   117 ( 14 ) 3892 - 9  2013年04月  [国際誌]

     概要を見る

    The proton-conductive spots on the membrane surface of sulfonated poly(arylene ether) multiblock copolymer were successfully imaged by current-sensing atomic force microscopy under hydrogen atmosphere at various temperatures and humidities. These spots should be connected to the proton-conductive paths inside the membrane. The average diameter of the spots was approximately 12 nm, consistent with the size of hydrophilic domains observed by transmission electron microscopy. The size of the proton-conducting spots was almost unchanged regardless of the temperature and humidity, whereas the number of the spots increased at higher humidity; the total area of the proton-conducting spots increased accordingly on the membrane surface. This increase in the conducting area at high humidity should be related to the bulk ionic conductivity measured by impedance spectroscopy.

    DOI PubMed

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    12
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  • ATR-FTIR Analysis of the State of Water in a Sulfonated Block Poly(arylene ether sulfone ketone) Membrane and Proton Conductivity Measurement during the Hydration/Dehydration Cycle

    Keiji Kunimatsu, Kiyoshi Yagi, Byungchan Bae, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    JOURNAL OF PHYSICAL CHEMISTRY C   117 ( 8 ) 3762 - 3771  2013年02月  [査読有り]

     概要を見る

    We have conducted combined time-resolved ATR-FTIR and proton conductivity measurements of a sulfonated block poly(arylene ether sulfone ketone) membrane, to be called a SPE-bl-1 membrane hereafter, during the hydration/dehydration cycle at room temperature. The result was discussed in comparison with the Nafion NRE211 membrane. Dissociation of the sulfonic acid groups and conductivity change were interpreted in terms of different states of water in the membrane characterized by delta(HOH) bands at 1705 and 1637 cm(-1), respectively. The former is assigned to hydrated protons produced by the dissociation followed by hydration. Proton conductivity increases significantly, over 0.1-0.2 S cm(-1), after the dissociation is completed at the initial stage of hydration, which is common to both membranes. The 1637 cm(-1) band contains contributions from the water in the proton conduction channels as well as some water which is hydrogen bonded to the polar groups in the SPE-bl-1 membrane such as ether (COC), sulfonyl (O=S=O), and carbonyl (C=O). The presence of the latter water lowers the effectiveness of the water in promoting proton conduction in the membrane. It is concluded that incomplete dissociation of the sulfonic acid groups coupled by the lower effectiveness is contributing to the lower proton conductivity of SPE-bl-1 than Nafion NRE211 at low hydration levels.

    DOI

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    12
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  • Proton conductive aromatic block copolymers from a new bistriazole monomer

    Ryo Akiyama, Daigo Hirayama, Masaki Saito, Junpei Miyake, Masahiro Watanabe, Kenji Miyatake

    RSC ADVANCES   3 ( 43 ) 20202 - 20208  2013年  [査読有り]

     概要を見る

    We have designed and synthesized a new bistriazole compound, 3,3'-(1,3-phenylene)bis[4-phenyl-5-(4-fluorophenyl)-4H-1,2,4-triazole], as a comonomer for a series of sulfonated block poly(arylene ether) copolymers. The bistriazole was successfully synthesized from isophthalic dihydrazide and 4-fluorobenzoyl chloride via bisoxadiazole. The bistriazole monomer was polymerized with 4,4'-biphenol or 4,4'-dihydroxydiphenyl ether to obtain hydroxyl-terminated hydrophobic oligomers, which were copolymerized with sulfonated oligomers to obtain the title block copolymers. The block copolymers were high-molecular-weight (M-w = 91-500 kDa) and provided tough and bendable membranes by solution casting. Because of the sequenced block copolymer structures, the membranes exhibited hydrophilic/hydrophobic phase-separated morphology as confirmed by scanning transmission electron microscopic (STEM) images. The membranes showed proton conductivity under humidified conditions; the highest proton conductivity was 6 x 10(-2) S cm(-1) at 95% relative humidity (RH) and 80 degrees C. The membranes were mechanically stable with high storage moduli (ca. 10(9) Pa) and loss moduli (ca. 10(8) Pa). These mechanical properties were independent on the ion exchange capacity (IEC) of the membranes. The triazole groups were effective in improving the mechanical and oxidative stability of the sulfonated poly(arylene ether) block copolymer membranes.

    DOI

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    7
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  • Complete NMR assignment of a sulfonated aromatic block copolymer via heteronuclear single-quantum correlation, heteronuclear multiple-bond correlation and heteronuclear single-quantum correlation total correlation spectroscopy

    Mari Takasaki, Kazuo Kimura, Yoshitsugu Nakagawa, Nobuyuki Sato, Byungchan Bae, Kenji Miyatake, Masahiro Watanabe

    POLYMER JOURNAL   44 ( 8 ) 845 - 849  2012年08月  [査読有り]

     概要を見る

    A sulfonated aromatic block copolymer (SABC), consisting of hydrophobic and hydrophilic blocks, was analyzed by heteronuclear single-quantum correlation (HSQC), heteronuclear multiple-bond correlation (HMBC) and HSQC total correlation spectroscopy (HSQC-TOCSY). Because of its complicated chemical structure with five different phenylene rings, 12 types of H-1 signals and 24 types of C-13 signals were observed in a narrow chemical shift range (7.0-8.0 p p.m. for H-1 and 118-162 p.p.m. for C-13). To improve the H-1 signal separation, the temperature conditions for the H-1 nuclear magnetic resonance (NMR) experiments were optimized. Moreover, H-1 and C-13 NMR signal assignments for the hydrophobic blocks were performed using HSQC and HMBC, with reference to the assignments of a model oligomer. For the hydrophilic blocks, furthermore, HSQC-TOCSY techniques were applied. As a result of these studies, complete H-1 and C-13 NMR signal assignments were made for the SABC. The ion-exchange capacity (IEC) and the copolymerization composition were calculated using the H-1 NMR assignments for the SABC, and the IEC value obtained in this way was consistent with that obtained via titration. Polymer Journal (2012) 44, 845-849; doi:10.1038/pj.2012.125; published online 20 June 2012

    DOI

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    4
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  • Sulfonated Polybenzophenone/Poly(arylene ether) Block Copolymer Membranes for Fuel Cell Applications

    Takahiro Miyahara, Tetsuji Hayano, Soichi Matsuno, Masahiro Watanabe, Kenji Miyatake

    ACS APPLIED MATERIALS & INTERFACES   4 ( 6 ) 2881 - 2884  2012年06月  [査読有り]

     概要を見る

    Sulfonated polybenzophenone/poly(arylene ether) block copolymers were designed and synthesized via Ni-mediated coupling polymerization. The block copolymers were obtained as high-molecular-weight (M-n = 70-110 kDa, M-W = 150-230 kDa) with low polydispersity index (M-W/M-n = 2.0-2.3). The block copolymer membranes showed well-developed hydrophilic/hydrophobic phase separation and high proton conductivity and low gas permeability. The membrane showed better fuel cell performance and durability compared with those with Nafion, state-of-the-art proton conducting membrane.

    DOI

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    75
    被引用数
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  • Durability of sulfonated polyimide membrane in humidity cycling for fuel cell applications

    Kenji Miyatake, Hiroshi Furuya, Manabu Tanaka, Masahiro Watanabe

    JOURNAL OF POWER SOURCES   204   74 - 78  2012年04月  [査読有り]

     概要を見る

    An aromatic proton conductive polymer, sulfonated polyimide copolymer membrane, was tested in humidity cycling under the conditions simulating fuel cell operation. The membrane was exposed periodically (every 2 min) to dry (nominal 0% relative humidity) and wet (100% relative humidity) at 80 C, similar to the United States Department of Energy (US DOE) protocol for proton exchange membrane fuel cells. The membrane was durable for 10,000 cycles without mechanical failure. Post-test analyses by H-1 NMR spectra and gel permeation chromatography (GPC) revealed that the membrane was hydrolyzed to some extent during the cycling test while mechanical properties and gas impermeability were only slightly deteriorated. (C) 2011 Elsevier B.V. All rights reserved.

    DOI

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    37
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  • Synthesis and Properties of Sulfonated Poly(arylene ether) Block Copolymers as Proton Conductive Membranes

    Takayuki Hoshi, Byungchan Bae, Masahiro Watanabe, Kenji Miyatake

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   85 ( 3 ) 389 - 396  2012年03月  [査読有り]

     概要を見る

    A new series of poly(arylene ether sulfone) multiblock copolymers were synthesized by polycondensation of linear and rigid hydrophobic and densely sulfonated hydrophilic oligomers. Thin membranes were prepared therefrom by solution casting and their properties were compared with those of Nation and other poly(arylene ether sulfone) multiblock copolymers containing perfluorinated biphenylene moieties. The membranes showed good water affinity, high proton conductivity, low hydrogen and oxygen permeability, high mechanical strength, and reasonable oxidative stability. These properties are attractive as an electrolyte for polymer electrolyte membrane fuel cells. It was found that the perfluofinated biphenylene moieties as connecting groups for hydrophilic and hydrophobic blocks affected only slightly the properties of poly(arylene ether sulfone) multiblock copolymer membranes.

    DOI

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    9
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  • Preparation and Fuel Cell Performance of Catalyst Layers Using Sulfonated Polyimide Ionomers

    Takuya Omata, Manabu Tanaka, Kenji Miyatake, Makoto Uchida, Hiroyuki Uchida, Masahiro Watanabe

    ACS APPLIED MATERIALS & INTERFACES   4 ( 2 ) 730 - 737  2012年02月  [査読有り]

     概要を見る

    Sulfonated polyimide (SPI-8) ionomers were used as binders in the catalyst layers, and their fuel cell performance was evaluated. SPI-8 ionomers functioned well in the anode with only minor overpotential even at low humidity (50% relative humidity (RH)). In contrast, the cathode performance was significantly dependent on the content and molecular weight of the ionomers and humidity of the supplied gases. Higher molecular weight of the ionomer caused larger potential drop at high current density at 80 and 100% RH since oxygen supply and/or water discharge became insufficient due to higher water uptake (swelling) of the ionomer. Similar results were obtained at higher ionomer content, because of the increase of thickness in the catalyst layer. The mass transport was improved with decreasing humidity, however, proton conductivity became lower. While the maximum values of j(@0.70) (v) for all membrane electrode assemblies (MBAs) were ca. 0.35 A/cm(2), each electrode could have the different appropriate operating conditions The results suggest that the parameters such as oxygen supply, proton conductivity, and water uptake and discharge need to be carefully optimized in, the catalyst layers for achieving reasonable cathode performance with hydrocarbon ionomers.

    DOI

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    29
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  • Effect of platinum loading on fuel cell cathode performance using hydrocarbon ionomers as binders

    Takuya Omata, Makoto Uchida, Hiroyuki Uchida, Masahiro Watanabe, Kenji Miyatake

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   14 ( 48 ) 16713 - 16718  2012年  [査読有り]

     概要を見る

    The effect of platinum loading on cathode performance in hydrogen/oxygen fuel cells was investigated using perfluorosulfonic acid (Nafion), sulfonated polyimide (SPI-8) and sulfonated poly(phenylene ether ether ketone) (SPEEK) ionomers as the electrode binder. By lowering the platinum loading, the cathode polarization decreased for MEAs using SPI-8 and SPEEK binders at high humidity (90-100% RH (relative humidity)) due to an improvement of mass transport (oxygen supply and/or water discharge) in the catalyst layer. In contrast, at humidity lower than 80% RH, the effect of platinum loading on the cathode performance differed between these two hydrocarbon (HC) ionomers. When SPI-8 was used as the binder, the cathode polarization increased when lowering the platinum loading due to an increase of activation overpotential. When SPEEK was used as the binder, the effect of platinum loading on the cathode performance was smaller. Such differences can be ascribed to the specific adsorbability of these hydrocarbon binders on the platinum catalyst at low humidity. These results point to crucial factors in achieving higher performance at low platinum loadings and low humidity using HC binders.

    DOI

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    7
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  • Block poly(arylene ether sulfone ketone)s containing densely sulfonated linear hydrophilic segments as proton conductive membranes

    Kenji Miyatake, Daigo Hirayama, Byungchan Bae, Masahiro Watanabe

    POLYMER CHEMISTRY   3 ( 9 ) 2517 - 2522  2012年  [査読有り]

     概要を見る

    Synthesis and properties of aromatic block copolymers composed of highly sulfonated phenylene ether sulfone ketone units as hydrophilic blocks and phenylene ether biphenyene sulfone units as hydrophobic blocks are reported. High molecular weight block copolymers 4 (M-w = 275-362 kDa and M-n = 76-144 kDa) with different compositions (number of repeat unit in the hydrophobic blocks (X) = 15, 30, or 60, and that of hydrophilic blocks (Y) = 4, 8, or 12) were synthesized. Transparent and bendable membranes were obtained by casting from the solution of 4. Due to the rigid rod-like structure of the hydrophilic blocks, the nanophase-separated morphology was not as distinct as that of the conventional sulfonated aromatic block copolymer membranes. Highly sulfonated hydrophilic blocks, which contained phenylene rings with sulfonic acid groups and electron-withdrawing sulfone or ketone groups, contributed to the high proton conductivity and improved oxidative stability of 4 membranes. The 4 (X60Y12) membrane with low IEC (1.18 mequiv g(-1)) showed comparable or higher conductivity than that of Nafion at >80% relative humidity (RH).

    DOI

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    37
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  • Synthesis of superacid-modified poly(arylene ether sulfone)s via post-bromination

    Takuya Shimura, Masahiro Watanabe, Kenji Miyatake

    RSC ADVANCES   2 ( 12 ) 5199 - 5204  2012年  [査読有り]

     概要を見る

    A versatile synthetic method of superacid-modified poly(arylene ether sulfone)s via post-bromination has been developed. Three kinds of high molecular weight poly(arylene ether sulfone)s, in which differences lie in the main chain structures, were synthesized and brominated. Careful control of the reaction conditions enabled selective and quantitative bromination of the polymers. The bromo groups were converted to superacid groups via Ullmann coupling reaction to obtain the title ionomers (FSPE-1a, 1b, and 1c). The chemical structure and the ion exchange capacity (IEC) of the FSPE-1s were characterized by H-1 and F-19 NMR spectra. Tough, flexible, and transparent membranes with IEC ranging from 0.87 to 1.09 meq g(-1) were obtained by solution casting. The FSPE-1 membranes showed comparable properties (chemical stability, phase-separated morphology, water absorbability, and proton conductivity,) to those of our previous version of the superacid-modified poly(arylene ether sulfone) (FSPE) synthesized from brominated monomers (pre-bromination method). The advantages of the post-bromination method have been proven by significant improvement in the mechanical strength of the FSPE-1 membranes since it could provide superacid-modified aromatic ionomers with much higher molecular weight.

    DOI

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    10
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  • Temperature dependence of the water distribution inside a Nafion membrane in an operating polymer electrolyte fuel cell. A micro-Raman study

    Masanori Hara, Junji Inukai, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    ELECTROCHIMICA ACTA   58   449 - 455  2011年12月  [査読有り]

     概要を見る

    In situ confocal micro-Raman spectroscopy was used to probe the interior of the electrolyte membrane of a polymer electrolyte fuel cell (PEFC) at various temperatures (40-110 degrees C) and humidities (dry-90% RH). No changes in the Raman spectra for functional groups involved in the polymer were found under humidified and dry conditions, except for the sulfonic acid group. With increasing relative humidity, the band intensity for S-O stretching (nu(S-O)) in the latter increased, and the peak shifted toward lower wavenumber. By analyzing the Raman peaks, water distributions through the Nafion membrane thickness were successfully evaluated in the operating PEFC. It was found that the back-diffusion of water produced at the cathode to the anode, humidifying the membrane, was clearly detectable, and also the rate of water transport in the membrane increased with increasing cell temperature. (C) 2011 Elsevier Ltd. All rights reserved.

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  • Synthesis and Properties of Sulfonated Poly(arylene ether)s Containing Azole Groups

    Byungchan Bae, Shinya Kawamura, Kenji Miyatake, Masahiro Watanabe

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   49 ( 17 ) 3863 - 3873  2011年09月  [査読有り]

     概要を見る

    Random and multiblock sulfonated poly(arylene ether sulfone)s (SPEs) containing various azole groups such as oxadiazole and triazole were synthesized and characterized for fuel cell application. Successful preparation of SPE membranes depended on the structure of azole groups, which affected solubility of precursors and the resulting SPEs. Although oxadiazole groups were incorporated into hydrophobic component, they were found to be hydrophilic to give higher proton conductivity. Introduction of oxadiazole groups into random SPE gave comparable proton conductivity to that of Nafion NRE at >60% relative humidity at 80 degrees C. Block copolymer structure further increased the proton diffusion coefficient without increasing ion exchange capacity. Hydrolytic and oxidative stability of the SPE membranes was affected by both hydrophilic and hydrophobic components. Oxadiazole groups gave negative impact on hydrolytic and mechanical stability to the SPE membranes. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 3863 3873, 2011

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  • Sulfonated Poly(arylene ether sulfone ketone) Multiblock Copolymers with Highly Sulfonated Blocks. Long-Term Fuel Cell Operation and Post-Test Analyses

    Byungchan Bae, Kenji Miyatake, Makoto Uchida, Hiroyuki Uchida, Yoko Sakiyama, Takeou Okanishi, Masahiro Watanabe

    ACS APPLIED MATERIALS & INTERFACES   3 ( 7 ) 2786 - 2793  2011年07月  [査読有り]

     概要を見る

    The stability of poly(arylene ether sulfone ketone) (SPESK) multiblock copolymer membranes having highly sulfonatecl hydrophilic blocks was tested in an operating fuel cell. The electrochemical properties and drain water were monitored during the test, followed by post-test analyses of the membrane. During a 2000-h fuel cell operation test at 80 degrees C and 53% RH (relative humidity) and with a constant current density (0.2 A cm(-2)), the cell voltage showed minor losses, with slight increases in the resistance. In the drain water, anions such as formate, acetate, and sulfate were observed. Post-test analyses of the chemical structure by NMR and IR spectra revealed that the sulfonated fluorenyl group with ether linkage was the most likely to have degraded during the long-term operation, producing these small molecules. The minor oxidative degradation only slightly affected the proton conductivity, water uptake, and phase-separated morphology.

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  • Sulfonated Block Poly(arylene ether sulfone) Membranes for Fuel Cell Applications via Oligomeric Sulfonation

    Byungchan Bae, Takayuki Hoshi, Kenji Miyatake, Masahiro Watanabe

    MACROMOLECULES   44 ( 10 ) 3884 - 3892  2011年05月  [査読有り]

     概要を見る

    Poly(arylene ether sulfone) multiblock copoly. were synthesized via oligomeric sulfonation. The successful oligomeric sulfonation enabled multiblock copolymer membranes with different hydrophobic block moiety (biphenyl and naphthalene units). High local concentration of sulfonic acid groups within the hydrophilic blocks enhanced the phase separation between hydrophilic and hydrophobic moiety. Rigid, nonpolar, and planar hydrophobic moiety such as naphthalene groups were effective in increasing proton conductivity and decreasing gas permeability. The multiblock copolymers with naphthalene hydrophobic units with IEC = 2.01 mequiv/g showed comparable proton conductivity to Nafion NRE 212 membrane (0.91 mequiv/g) at >40% RH. The longer blocks were found to increase a characteristic factor (ratio of the proton conductivity to the water volume fraction) as well as phase separation. The membrane showed relatively low oxidative stability under Fenton's test conditions due to higher water uptake and swelling. However, low gas permeability could compensate this drawback for fuel cell applications.

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  • ATR-FTIR Study of Water in Nafion Membrane Combined with Proton Conductivity Measurements during Hydration/Dehydration Cycle

    Keiji Kunimatsu, Byungchan Bae, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    JOURNAL OF PHYSICAL CHEMISTRY B   115 ( 15 ) 4315 - 4321  2011年04月  [査読有り]

     概要を見る

    We have conducted combined time-resolved attenuated total reflection Fourier transform infrared (ATR-FTIR) and proton conductivity measurements of Nafion NRE211 membrane during hydration/dehydration cycles at room temperature. Conductivity change was interpreted in terms of different states of water in the membrane based on its delta(HOH) vibrational spectra. It was found that hydration of a dry membrane leads first to complete dissociation of the sulfonic acid groups to liberate hydrated protons, which are isolated from each other and have delta(HOH) vibrational frequency around 1740 cm(-1). The initial hydration is not accompanied by a significant increase of the proton conductivity. Further hydration gives rise to a rapid increase of the conductivity in proportion to intensity of a new delta(HOH) band around 1630 cm(-1). This was interpreted in terms of formation of channels of weakly hydrogen-bonded water to combine the isolated hydrophilic domains containing hydrated protons and hydrated sulfonate ions produced during the initial stage of hydration. Upon dehydration, proton conductivity drops first very rapidly due to loss of the weakly hydrogen bonded water from the channels to leave hydrophilic domains isolated in the membrane. Dehydration of the protons proceeds very slowly after significant loss of the proton conductivity.

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  • Luminescent Sensory Polymer Coating Composed of Platinumporphyrin and Poly(trimethylsilylpropyne) for Real-Time Oxygen Visualization in Operating PEFCs

    Tsuyoshi Hyakutake, Yuta Ishigami, Junji Kato, Junji Inukai, Kenji Miyatake, Hiroyuki Nishide, Masahiro Watanabe

    MACROMOLECULAR CHEMISTRY AND PHYSICS   212 ( 1 ) 42 - 47  2011年01月

     概要を見る

    A luminescent PtTFP/PMSP polymer coating was prepared for the oxygen partial pressure visualization inside a PEFC. PMSP formed a smooth and tough coating as a highly oxygen-permeable matrix with a thickness of ca. 2 mu m in which the PtTFP was homogeneously dispersed. The coating displayed a strong red luminescence with significantly decreasing intensity upon increasing oxygen partial pressure. The sensitivity for the oxygen partial pressure was high and the analytical curve of the sensor polymer coating was undisturbed by external factors. The PtTFP/PMSP sensor was coated on the surface of a cathode gas diffusion layer on the air flow channel inside PEFC. The oxygen-pressure distribution in the air flow channel was successfully visualized while operating the PEFC.

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  • Polybenzimidazole block sulfonated poly(arylene ether sulfone) ionomers

    Feifei Ng, Byungchan Bae, Kenji Miyatake, Masahiro Watanabe

    CHEMICAL COMMUNICATIONS   47 ( 31 ) 8895 - 8897  2011年  [査読有り]

     概要を見る

    Novel ionomers based on polybenzimidazole block sulfonated poly(arylene ether sulfone) show excellent thermal properties. The ionic aggregation of sulfonic acid groups leads to well-developed phase separated morphology and thus high proton conductivity at wide humidity range, up to 65 mS cm(-1) at 90% relative humidity.

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  • Synthesis and Properties of Multiblock Copoly(arylene ether)s Containing Superacid Groups for Fuel Cell Membranes

    Takefumi Mikami, Kenji Miyatake, Masahiro Watanabe

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   49 ( 2 ) 452 - 464  2011年01月  [査読有り]

     概要を見る

    A series of block copoly(arylene ether)s containing pendant superacid groups were synthesized, and their properties were investigated for fuel cell applications. Two series of telechelic oligomers, iodo-substituted oligo(arylene ether ketone)s and oligo(arylene ether sulfone)s, were synthesized. The degree of oligomerization and the end groups were controlled by changing the feed ratio of the monomers. The nucleophilic substitution polymerization of the two oligomers provided iodo-substituted precursor block copolymers. The iodo groups were converted to perfluorosulfonic acid groups via the Ullmann coupling reaction. The high degree of perfluorosulfonation (up to 83%) was achieved by optimizing the reaction conditions. Tough and bendable membranes were prepared by solution casting. The ionomer membranes exhibited characteristic hydrophilic/hydrophobic phase separation with large hydrophilic clusters (ca. 10 nm), which were different from that of our previous random copolymers with similar molecular structure. The block copolymer structure was found to be effective in improving the proton-conducting behavior of the superacid-modified poly(arylene ether) ionomer membranes without increasing the ion exchange capacity (IEC). The highest proton conductivity was 0.13 S/cm at 80 degrees C, 90% relative humidity, for the block copolymer ionomer membrane with IEC = 1.29 mequiv/g. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 452-464, 2011

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  • Rechargeable Proton Exchange Membrane Fuel Cell Containing an Intrinsic Hydrogen Storage Polymer

    J. Miyake, Y. Ogawa, T. Tanaka, J. Ahn, K. Oka, K. Oyaizu, K. Miyatake

    Comm. Chem.   3 ( 1 ) 138  2010年10月  [査読有り]

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  • Synthesis, Properties, and Fuel Cell Performance of Perfluorosulfonated Poly(arylene ether)s

    Takuya Shimura, Kenji Miyatake, Masahiro Watanabe

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   83 ( 8 ) 960 - 968  2010年08月  [査読有り]

     概要を見る

    Poly(arylene ether)s containing superacid groups (FSPEs) were synthesized as proton conducting membranes for fuel cell applications. To obtain the title ionomers, a series of brominated poly(arylene ether)s were synthesized and perfluorosulfonated via Ullmann coupling. The chemical structure and the ion exchange capacity (IEC) of the FSPEs were characterized by H-1 and F-19 NMR spectra. Tough, flexible, and transparent membranes with the IEC ranging from 0.34 to 1.29 mequiv g(-1) were obtained by solution casting. The FSPE membranes did not show obvious glass transition behavior up to the decomposition temperature (180 degrees C). Microscopic analyses revealed homogeneous and well-connected ionic clusters for the high IEC membrane. Compared to conventional sulfonated poly(arylene ether) membranes, the FSPE membranes showed much higher proton conductivity. The highest proton conductivity of 0.07S cm(-1) was achieved at 80 degrees C and 86% relative humidity (RH) with the IEC = 1.29 mequiv g(-1) membrane. A fuel cell using the FSPE membrane showed comparable performance to that of a Nafion cell at 78% RH and 80 degrees C.

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  • Sulfonated Poly(arylene ether sulfone ketone) Multiblock Copolymers with Highly Sulfonated Block. Fuel Cell Performance

    Byungchan Bae, Takeshi Yoda, Kenji Miyatake, Makoto Uchida, Hiroyuki Uchida, Masahiro Watanabe

    JOURNAL OF PHYSICAL CHEMISTRY B   114 ( 32 ) 10481 - 10487  2010年08月  [査読有り]

     概要を見る

    Poly(arylene ether sulfone ketone) (SPESK) multiblock copolymers having highly sulfonated hydrophilic blocks were synthesized and the fuel cell performance with the copolymers was investigated. A membrane electrode assembly (MEA) using an SPESK ionomer with an ion exchange capacity of 1.8 mequiv g(-1) as membrane and Nafion as the electrode binder showed comparable fuel cell performance and ohmic resistance to that using a Nafion NRE 211 membrane at 80 degrees C and 30% relative humidity (RH). A Nafion-free, all-SPESK MEA using SPESK as both the membrane and the binder was operable at 100 degrees C and 50% RH. The fuel cell performance was limited not only by the proton conductivity of the SPESK membrane but also by the low water flux through the membrane and specific adsorption of the ionomer on the platinum catalyst.

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  • Proton Conductive Polyimide lonomer Membranes: Effect of NH, OH, and COOH Groups

    Jumpei Saito, Manabu Tanaka, Kenji Miyatake, Masahiro Watanabe

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   48 ( 13 ) 2846 - 2854  2010年07月  [査読有り]

     概要を見る

    A new series of sulfonated polyimide (SPI) copolymers containing NH, OH, or COOH groups were synthesized by the polycondensation of 1,4,5,8-naphthalnetetracarboxylic dianhydride, 3,3'-bis(sulfopropoxy)-4,4'-diaminobiphenyl, and 3-(4-aminophenyl)-5-(3-aminophenyl)-1H-1,2,4-triazole (SPI-8-m), 3,5-bis(4-aminophenyl)-1H-1,2,4-triazole (SPI-8-p), 3,6-diaminocarbazole (SPI-9), 3,5-diamino-1H-1,2,4-triazole (SPI-10), bis(3-aminopropyl)-amine (SPI-11), 2,6-diaminopurine (SPI-12), 2,4-diamino-6-hydroxyprymidine (SPI-13), or 3,5-bis(4-aminophenoxy)benzoic acid (SPI-14). The obtained SPIs were soluble in polar organic solvents and gave tough and flexible membranes by solution casting. The SPI membranes having NH and COOH groups showed high thermal (decomposition temperature approximate to 1200 degrees C) and mechanical (maximum stress >22 MPa) stability. Introducing NH groups, especially triazole and carbazole groups, was effective in improving proton conductive properties of SPI membranes at low humidity. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2846 2854, 2010

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  • Poly(arylene ether)s Containing Superacid Groups as Proton Exchange Membranes

    Takefumi Mikami, Kenji Miyatake, Masahiro Watanabe

    ACS APPLIED MATERIALS & INTERFACES   2 ( 6 ) 1714 - 1721  2010年06月  [査読有り]

     概要を見る

    A series of poly(arylene ether)s containing pendant superacid groups on fluorenyl groups were synthesized and their properties were investigated for fuel cell applications. Poly(arylene ether)s containing iodo groups were synthesized by the polymerization of 2,7-diiodo-9,9-bis(4-hydroxyphenyl)fluorene with difluorinated compounds such as decafluorobiphenyl, bis(4-fluorophenyl)sulfone, and bis(4-fluorophenyl)ketone, under nucleophilic substitution conditions. The iodo groups on the fluorenyl groups were converted to perfluorosulfonic acid groups via the Ullmann coupling reaction. The degree of perfluorosulfonation was controlled to be up to 92%, which corresponds to an ion exchange capacity (IEC) of 1.52 meq/g. The ionomers yielded flexible, ductile membranes by solution casting. The ionomer membranes exhibited a characteristic hydrophilic/hydrophobic phase separation, with small interconnected hydrophilic clusters (2-3 nm), which is similar to that of the benchmark perfluorinated membrane (Nafion). The aromatic ionomers containing superacid groups showed much higher proton conductivities than those of the conventional sulfonated aromatic ionomers with similar main chain structures. Fuel cell performance with the superacidic ionomer membranes was also tested.

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  • Gas diffusion electrodes containing sulfonated poly (arylene ether) ionomer for polymer electrolyte fuel cells Part 2. Improvement of the cathode performance

    Takeshi Yoda, Takuya Shimura, Byungchan Bae, Kenji Miyatake, Makoto Uchida, Hiroyuki Uchida, Masahiro Watanabe

    ELECTROCHIMICA ACTA   55 ( 10 ) 3464 - 3470  2010年04月  [査読有り]

     概要を見る

    The performances of gas diffusion electrodes (GDEs) containing Pt/C catalyst (48 wt.% and 68 wt.%-Pt) and sulfonated poly (arylene ether) (SPAE) ionomer (ion exchange capacity, IEC = 1.8 and 2.5 meq g(-1)) as a proton-conducting binder (SPAE-GDE) were examined in a PEFC at 80 degrees C and relative humidities (RH) from 60% to 100%. Based on our analyses in Part 1, we have succeeded in improving the cathode performance over the whole range of current densities examined by using a high Pt-loading for the catalyst (68 wt.%-Pt/C), in place of the previously used 48 wt.% one, for the reduction of thickness of the catalyst layer, which enabled us to increase the O(2) gas diffusion rate and to suppress the adsorption of the SPAE binder on the Pt surface via an effective utilization of generated water. The performance, especially at low RH, was improved further by employing an SPAE binder with a lower IEC, 1.8 meq g(-1) [SPAE(1.8)]. It was demonstrated by cyclic voltammetry that the specific adsorption of the sulfonate or organic moiety on the Pt surface was indeed suppressed for the case of SPAE(1.8). Hence, for the SPAE-GDEs, the use of a high Pt-loading catalyst, together with a binder with an appropriate IEC, is very important. (C) 2010 Elsevier Ltd. All rights reserved.

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  • Sulfonated Poly(arylene ether sulfone ketone) Multiblock Copolymers with Highly Sulfonated Block. Synthesis and Properties

    Byungchan Bae, Kenji Miyatake, Masahiro Watanabe

    MACROMOLECULES   43 ( 6 ) 2684 - 2691  2010年03月  [査読有り]

     概要を見る

    Poly(arylene ether sulfone ketone) (SPESK) multiblock copolymer membranes having highly sulfonated hydrophilic blocks were synthesized. The degree of polymerization of hydrophobic blocks (X) was controlled to be 15, 30, and 60 and that of hydrophilic blocks ( Y) to be 4, 8, 12, and 16. Morphological observation by scanning transmission microscopy (STEM) and small-angle X-ray scattering (SAXS) showed that high local concentration of sulfonic acid groups within the hydrophilic blocks enhanced phase separation between the hydrophobic and hydrophilic blocks. Rodlike hydrophilic aggregates were found to be interconnected very well, which resulted in high proton conductivity even at low relative humidity (RH). The ionomer membrane with X30 Y8 and 1.86 mequiv/g of ion exchange capacity (IEC) showed 0.03 S/cm at 80 degrees C and 40% RH, which was a comparable or higher proton conductivity than that of the state-of-the-art perfluorinated ionomer (Nation) membrane. The longer blocks induced higher proton conductivity; however, excessively long block length offset mechanical properties. Low hydrogen and oxygen permeability was also observed.

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  • Anion Conductive Aromatic Ionomers Containing Fluorenyl Groups

    Manabu Tanaka, Masaki Koike, Kenji Miyatake, Masahiro Watanabe

    MACROMOLECULES   43 ( 6 ) 2657 - 2659  2010年03月  [査読有り]

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  • Proton-Conductive Aromatic Ionomers Containing Highly Sulfonated Blocks for High-Temperature-Operable Fuel Cells

    Byungchan Bae, Takeshi Yoda, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION   49 ( 2 ) 317 - 320  2010年  [査読有り]

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  • Gas diffusion electrodes containing sulfonated poly (arylene ether) ionomer for PEFCs Part 1. Effect of humidity on the cathode performance

    Takeshi Yoda, Takuya Shimura, Byungchan Bae, Kenji Miyatake, Makoto Uchida, Hiroyuki Uchida, Masahiro Watanabe

    ELECTROCHIMICA ACTA   54 ( 18 ) 4328 - 4333  2009年07月  [査読有り]

     概要を見る

    Gas diffusion electrodes (GDEs) containing Pt/C catalyst and sulfonated poly (arylene ether) (SPAE) ionomer as a proton conducting binder (SPAE-GDE) were prepared. The cathode performances were evaluated in a PEFC at 80 degrees C and relative humidities (RH) from 60 to 100%. The value of the electrochemical active surface area (ECA) of 65 m(2) g(-1) for the SPAE-GDE. which was measured by cyclic voltammetry at 100%-RH and 40 degrees C, was nearly the same as that for a Nafion-GDE. In contrast, the RH-dependencies of the performance indices (Such as mass activity at 0.9 V, Tafel slope, or current density at 0.7 V) at the SPAE-GDE were very large and distinct from those for the conventional Nafion-GDE. With decreasing RH, the mass activity at the Nafion-GDE decreased monotonically, whereas that at the SPAE-GDE reached a maximum at 88%-RH and decreased steeply below 78%-RH. predominantly due to a strong adsorption of functional groups, probably sulfonate groups, in the SPAE on the Pt catalyst surface. However, at 88-100%-RH, the concentration polarization became significant for current densities j > 0.1 A cm(-2) due to excessive swelling of the SPAE ionomer. Strategies to improve the performance of SPAE-GDEs have been elucidated. (C) 2009 Elsevier Ltd. All rights reserved.

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  • Synthesis and Properties of Sulfonated Block Copolymers Having Fluorenyl Groups for Fuel-Cell Applications

    Byungchan Bae, Kenji Miyatake, Masahiro Watanabe

    ACS APPLIED MATERIALS & INTERFACES   1 ( 6 ) 1279 - 1286  2009年06月  [査読有り]

     概要を見る

    A series of sulfonated poly(arylene ether sulfone)s (SPES) block copolymers containing fluorenyl groups were synthesized. Bis(4-fluorophenyl)sulfone (FPS) and 2,2-bis(4-hydroxy-3,5-dimethylpheny)propane were used-as comonomers for hydrophobic blocks, whereas FPS and 9,9-bis(4-hydroxyphenyl)fluorene were used as hydrophilic blocks. Sulfonation with chlorosulfonic acid gave sulfonated block copolymers with molecular Weight (M(w)) higher than 150 kDa. Proton conductivity of the SPE block copolymer with the ion exchange capacity (IEC) = 2.20 mequiv/g was 0.14 S/cm [80% relative humidity (RH)] and 0;02 S/cm (40% RH) at 80 degrees C, which is higher or comparable to that of a perfluorinated ionomer (Nafion) membrane. The longer hydrophilic and hydrophobic blocks resulted in higher water uptake and higher proton conductivity; Scanning transmission electron microscopy observation revealed that phase separation of the SPE block copolymers was more pronounced than that of the SPE random copolymers. The SPE block copolymer membranes showed higher mechanical properties than those of the random ones. With these properties, the SPE block copolymer membranes seem promising for fuel-cell applications.

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  • Oxygen Reduction at the Pt/Carbon Black-Polyimide Ionomer Interface

    Kenji Miyatake, Takuya Omata, Donald A. Tryk, Hiroyuki Uchida, Masahiro Watanabe

    JOURNAL OF PHYSICAL CHEMISTRY C   113 ( 18 ) 7772 - 7778  2009年05月  [査読有り]

     概要を見る

    We have investigated the oxygen reduction reaction (ORR) at the interface of Pt nanoparticles dispersed on carbon black (Pt/CB) with a sulfonated polyimide ionomer layer (SPI-8). The electrochemical experiments were carried out in air-saturated 0.1 M HClO(4) aqueous solution at 25 degrees C via the rotating ring disk electrode technique. Slow-sweep (5 mV s(-1)) hydrodynamic voltammetry yielded accurate estimates of the activity of the Pt catalysts under steady state conditions. It was found that the ORR was purely kinetically controlled provided that the polyimide ionomer layer covering the Pt/CB catalysts was thinner than 0.05 mu m (threshold thickness) for higher potentials. When thicker than 0.05 mu m, the oxygen diffusion limitation through the ionomer was non-negligible for potentials lower than 0.8 V vs the reversible hydrogen electrode, RHE. The threshold thickness was approximately half of that for a similar perfluorinated ionomer(Nafion)-coated Pt/CB (Nafion-PUCB) electrode. The hydrogen peroxide yield, P(H(2)O(2)), was lower than 0.6% of the overall ORR current in the 0.7-+0.8 V vs RHE range for the SPI-8-Pt/CB electrodes, which was somewhat lower than that for the Nafion-Pt/CB ones. In particular, P(H(2)O(2)) was negligibly low (<0.2%) when the polyimide ionomer layer was thinner than 0.05 mu m. The low P(H(2)O(2)) is favorable for fuel cell applications, since hydrogen peroxide is regarded as one of the major factors responsible for the degradation of fuel cell constituent materials such as the ionomer binder in the catalyst layers, the ionomer membrane itself, and the carbon support.

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  • Effect of the Hydrophobic Component on the Properties of Sulfonated Poly(arylene ether sulfone)s

    Byungchan Bae, Kenji Miyatake, Masahiro Watanabe

    MACROMOLECULES   42 ( 6 ) 1873 - 1880  2009年03月  [査読有り]

     概要を見る

    Four kinds of sulfonated poly(arylene ether sulfone)s containing hydrophobic component of different size was synthesized by the copolymerization of disodium 3,3'-disulfo-4,4'-difluorophenyl sulfone and 4,4'-difluorophenyl sulfone with 2,2-bis(2-hydroxy-5-biphenylyl)propane (SPE1), 4,4'-dihydroxytetraphenylmethane (SPE2), 9,9-bis(4-hydroxyphenyl)fluorene (SPE3), or 2,7-dihydroxynaphthalene (SPE4) under nucleophilic aromatic substitution conditions. The copolymer composition was set at 45-70 mol % of 3,3'-disulfo-4,4'-difluorophenyl sulfone in order to achieve similar ion exchange capacity (ca. 2.0 mequiv/g) for all the sulfonated copolymers SPE1-4. The copolymers were of high molecular weight (M(n) = 150-220 kDa; M(w) = 310-695 kDa) to give tough and flexible membranes by Solution casting. STEM observation revealed that small hydrophobic components (SPE3 and SPE4) induced larger water cluster than bulky hydrophobic ones (SPE1 and SPE2). The small hydrophobic components induced high proton conductivities and proton diffusion coefficients as well as low water swelling. SPE4 membrane showed the highest proton conductivity at 50-80 degrees C and 10-90% RH among the four SPEs membranes. The smaller hydrophobic component was also effective in terms of gas permeation and mechanical properties for fuel cell applications.

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  • Aromatic ionomers with superacid groups

    Kenji Miyatake, Takuya Shimura, Takefumi Mikami, Masahiro Watanabe

    CHEMICAL COMMUNICATIONS   ( 42 ) 6403 - 6405  2009年  [査読有り]

     概要を見る

    Aromatic polymers containing perfluorosulfonic acid groups show well-developed and interconnected ionic clusters, and thus high proton conductivity at wide humidity range.

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  • Poly(arylene ether) Block Copolymer Membranes: Synthesis, Properties and Durability

    Byungchan Bae, Kenji Miyatake, Masahiro Watanabe

    PROTON EXCHANGE MEMBRANE FUEL CELLS 9   25 ( 1 ) 415 - 422  2009年  [査読有り]

     概要を見る

    Poly(arylene ether sulfone)s (SPEs) block copolymers containing fluorenyl groups were synthesized for fuel cell applications. Post-sulfonation of the polymers by chlorosulfonic acid gave sulfonated block copolymers having highly sulfonated hydrophilic block. SPE block copolymer membrane with the ion exchange capacity (IEC) = 2.20 meq/g showed proton conductivity, 0.14 S/cm (80% RH) and 0.02 S/cm (40% RH) at 80 degrees C, which is higher or comparable to that of perfluorinated ionomer (Nafion (R)) membrane. STEM observation of Ag-stained membranes revealed that phase separation of the SPE block copolymers was more developed than that of the SPE random copolymers. Long-term hydrolytic stability of these membranes has been confirmed.

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  • Poly(arylene ether) ionomers containing sulfofluorenyl groups: Effect of electron-withdrawing groups on the properties

    Takuya Shimura, Kenji Miyatake, Masahiro Watanabe

    EUROPEAN POLYMER JOURNAL   44 ( 12 ) 4054 - 4062  2008年12月  [査読有り]

     概要を見る

    For polymer electrolyte membrane fuel cell (PEMFC) applications, the effect of electron-withdrawing groups on the properties of sulfonated poly(arylene ether) (SPE) ionomer membranes was investigated. A series of poly(arylene ether)s containing fluorenyl groups and electron-withdrawing groups (sulfone, nitrile, or fluorine) was synthesized, which were sulfonated with chlorosulfonic acid using a flow reactor to obtain the title ionomers. The ionomers had high molecular weight (M(n) > 77 kDa, M(w) > 238 kDa) and gave tough, ductile membranes by solution casting. The ion exchange capacity (IEC) of the membranes ranged from 1.6 to 3.5 mequiv/g as determined by titration. The electron-withdrawing groups did not appear to affect the thermal properties (decomposition temperature higher than 200 degrees C). The presence of nitrile groups, especially at positions meta to the ether linkages, improved the oxidative stability of the SPE membranes, while it led to a deterioration of the hydrolytic stability. The perfluorinated biphenylene groups were effective in providing high mechanical strength with reasonable dimensional change, probably due to a somewhat decreased water absorbability. The SPE membrane containing sulfone groups showed the highest proton conductivity (10(-3)-10(-1) S/cm) at 20-93% RH (relative humidity) and 80 degrees C. The nitrile-containing SPE membrane showed smaller apparent activation energies for oxygen and hydrogen permeability and is thus considered to be a possible candidate for applications in PEMFCs. (C) 2008 Elsevier Ltd. All rights reserved.

    DOI

    Scopus

    26
    被引用数
    (Scopus)
  • Substituents effect on the properties of sulfonated polyimide copolymers

    Kenji Miyatake, Tomohiro Yasuda, Masahiro Watanabe

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   46 ( 13 ) 4469 - 4478  2008年07月  [査読有り]

     概要を見る

    A series of sulfonated polyimide (SPI) copolymers containing methyl, methoxy, or fluorine groups were synthesized to elucidate the substituents effect on their proton conducting properties as well as thermal, hydrolytic, and oxidative stability for polymer electrolyte membrane fuel cell applications. SPIs of high molecular weight (M-w > 200 kDa, M-n > 80 kDa) along with the ion exchange capacity (IEC) varying between 1.34 and 1.91 mequiv/g were obtained, which gave tough, ductile, and flexible membranes by solution, casting. The thermal properties of the SPIs were dominated by the electronic structure of the sulfonated aromatic rings. The electron-donating methyl groups lowered the thermal decomposition temperature. The hydrolytic and oxidative stability was roughly in the order of IEC (the higher IEC membranes were less stable). Fluorine groups, either as -F or -CF3, had negative effect on the hydrolytic and oxidative stability. In the water uptake and proton conductivity, hydrophobic components are rather more influential than the substituents. It was found out that the SPI(5, 8, 0.7) containing bis(phenoxy)biphenylene sulfone moieties as a rigid hydrophobic component showed the best balanced properties in terms of the stability and the proton conductivity for its rather low IEC. (c) 2008 Wiley Periodicals, Inc.

    DOI

    Scopus

    28
    被引用数
    (Scopus)
  • Synthesis and properties of polyimide ionomers containing 1H-1,2,4-triazole groups

    Jumpei Saito, Kenji Miyatake, Masahiro Watanabe

    MACROMOLECULES   41 ( 7 ) 2415 - 2420  2008年04月  [査読有り]

     概要を見る

    A series of sulfonated polyimide copolymers containing 1H-1,2,4-triazole groups in the main chains were synthesized as proton-conducting membranes for fuel cell applications. Polycondensation of triazole-containing dianiline, acid-functionalized benzidine, and naphthalenetetracarboxylic dianhydride gave the title polyimide ionomers. The ionomers were high molecular weight (M-w > 100 kDa, M-n > 20 kDa) to give tough and flexible membranes by Solution casting. The ion exchange capacity (IEC) of the membranes ranged from 1.10 to 2.68 mequiv/g as confirmed by H-1 NMR analyses and titration. Comparison with the other polyimide ionomer membranes revealed that introducing triazole groups caused better thermal stability (decomposition temperature of ca. 200 degrees C), comparable hydrolytic and oxidative stability, and better mechanical properties. Although NH groups did not function as ion exchange sites, the triazole-containing membrane,; showed slightly higher proton conductivity. The highest proton conductivity (0.3 S/cm at 88% RH) was obtained for the high IEC (2.68 mequiv/g) ionomer membrane. The ionomer membranes showed low hydrogen and oxygen permeability under dry and wet conditions.

    DOI

    Scopus

    95
    被引用数
    (Scopus)
  • Sulfonated poly(arylene ether sulfone) ionomers containing fluorenyl groups for fuel cell applications

    Byungchan Bae, Kenji Miyatake, Masahiro Watanabe

    JOURNAL OF MEMBRANE SCIENCE   310 ( 1-2 ) 110 - 118  2008年03月  [査読有り]

     概要を見る

    A series of sulfonated poly(arylene ether sulfone)s (SPEs) containing fluorenyl groups as bulky components were synthesized and characterized for fuel cell applications. Introduction of disodium 3,3'-disulfo-4,4'-difluorophenyl sulfone (SFPS) monomer gave ionomers with high acidity and accordingly high proton conductivity as well as high proton diffusion coefficient (D,) at low humidity. The membrane of SPE60 (where the number denotes mole percentage of the component containing sulfonic acid groups; IEC (ion exchange capacity) = 1.68 mequiv./g) exhibited high proton conductivity of 4.6 x 10(-3) S/cm at 40% RH and 80 degrees C, which is one order of magnitude higher than that (6 x 10(-4) S/cm) of our previous SPE (SPE-1, IEC = 1.58 mequiv./g). D, of SPE60 membrane was ca. 4 times higher than that of the SPE-1 membrane at low water volume fraction. SPE membranes showed good oxidative and hydrolytic stability as well as favorable thermal and mechanical properties. Small-angle X-ray scattering analyses showed that the phase separation of SPE membranes was much less developed than that of the perfluorinated Nafion membrane which accounts for lower hydrogen and oxygen permeability of the former membranes. (C) 2007 Elsevier B.V. All rights reserved.

    DOI

    Scopus

    62
    被引用数
    (Scopus)
  • Direct visualization of oxygen distribution in operating fuel cells.

    Junji Inukai, Kenji Miyatake, Kenji Takada, Masahiro Watanabe, Tsuyoshi Hyakutake, Hiroyuki Nishide, Yuzo Nagumo, Masayuki Watanabe, Makoto Aoki, Hiroshi Takano

    Angewandte Chemie (International ed. in English)   47 ( 15 ) 2792 - 5  2008年  [国際誌]

    DOI PubMed

    Scopus

    35
    被引用数
    (Scopus)
  • Tuned polymer electrolyte membranes based on aromatic polyethers for fuel cell applications

    Kenji Miyatake, Yohei Chikashige, Eiji Higuchi, Masahiro Watanabe

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   129 ( 13 ) 3879 - 3887  2007年04月  [査読有り]

     概要を見る

    Poly(arylene ether sulfone)-based ionomers containing sulfofluorenyl groups have been synthesized for applications to polymer electrolyte membrane fuel cells (PEMFCs). In order to achieve high proton conductivity and chemical, mechanical, and dimensional stability, the molecular structure of the ionomers has been optimized. Tough, flexible, and transparent membranes were obtained from a series of modified ionomers containing methyl groups with the ion-exchange capacity (IEC) ranging from 1.32 to 3.26 meq/g. Isopropylidene tetramethylbiphenylene moieties were more effective than the methyl-substituted fluorenyl groups in giving a high-IEC ionomer membrane with substantial stability to hydrolysis and oxidation. Dimensional stability was significantly improved for the methyl-substituted ionomer membranes compared to that of the non-methylated ones. This new ionomer membrane showed comparable proton conductivity to that of the perfluorinated ionomer membrane (Nafion 112) under a wide range of conditions (80-120 degrees C and 20-93% relative humidity (RH)). The highest proton conductivity of 0.3 S/cm was obtained at 80 degrees C and 93% RH. Although there is a decline of proton conductivity with time, after 10 000 h the proton conductivities were still at acceptable levels for fuel cell operation. The membranes retained their strength, flexibility, and high molecular weight after 10 000 h. Microscopic analyses revealed well-connected ionic clusters for the high-IEC membrane. A fuel cell operated using the polyether ionomer membrane showed better performance than that of Nafion at a low humidity of 20% RH and high temperature of 90 degrees C. Unlike the other hydrocarbon ionomers, the present membrane showed a lower resistance than expected from its conductivity, indicating superior water-holding capability at high temperature and low humidity.

    DOI

    Scopus

    326
    被引用数
    (Scopus)
  • Effect of cross-linking on polyimide ionomer membranes

    Kenji Miyatake, Naoki Asano, Takahiro Tombe, Masahiro Watanabe

    ELECTROCHEMISTRY   75 ( 2 ) 122 - 125  2007年02月  [査読有り]

     概要を見る

    In order to improve the stability and the proton conductivity of sulfonated polyimide ionomer membranes, effect of cross-linking has been investigated. The cross-linking moieties have been introduced into the ionomer structure by applying 2 mol% of trifunctional monomer in the polymerization reaction. Tough, flexible, and processable membranes were obtained by solution casting. Among the three cross-linking agents investigated, tris(aminoethyl)amine (TE) was the most effective to improve the membrane properties. Having high ion exchange capacity (2.33 meq/g), the cross-linked SPI-5TE showed good stability to the oxidative and hydrolytic degradation, superior mechanical strength, and high proton conductivity at low humidity conditions. Low methanol permeation of the cross-linked SPI-5TE membrane than the uncross-linked SPI-5 and Nafion 112 membranes has been confirmed.

  • Synthesis and properties of a polyimide containing pendant sulfophenoxypropoxy groups

    Kenji Miyatake, Tomohiro Yasuda, Michiko Hirai, Masato Nanasawa, Masahiro Watanabe

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   45 ( 1 ) 157 - 163  2007年01月  [査読有り]

    DOI

    Scopus

    82
    被引用数
    (Scopus)
  • Branched and cross-linked proton conductive poly(arylene ether sulfone) ionomers: Synthesis and properties

    Yohei Chikashige, Yoshiki Chikyu, Kenji Miyatake, Masahiro Watanabe

    MACROMOLECULAR CHEMISTRY AND PHYSICS   207 ( 15 ) 1334 - 1343  2006年08月  [査読有り]

     概要を見る

    A series of branched and cross-linked poly (arylene ether sulfone) ionomers containing sulfofluorenyl groups, 2b-e were synthesized in order to investigate the effect of these chemical modifications on the properties. Ionomers 2b-e gave a flexible, ductile, and transparent membrane by casting from DMAc solution. The branching and cross-linking were effective to improve the dimensional stability under wet conditions without losing their high thermal, oxidative, and hydrolytic stability. The cross-linked ionomer 2e (IEC=2.63 meq.g(-1)) membrane showed high proton conductivity of 0.2 S.cm(-1) at 87% RH and 0.02 S.cm(-1) at 57% RH. The branched ionomer 2b membrane was durable in proton conductivity for almost 2 months without any chemical degradation.

    DOI

    Scopus

    38
    被引用数
    (Scopus)
  • Investigation of direct methanol fuel cell performance of sulfonated polyimide membrane

    Jung Min Song, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    ELECTROCHIMICA ACTA   51 ( 21 ) 4497 - 4504  2006年06月  [査読有り]

     概要を見る

    Sulfonated polyimide (SPI) membranes have been evaluated as electrolyte membranes in direct methanol fuel cells (DMFCs). The membrane-electrode assembly (MEA) was made by hot-pressing the membrane, an anode and a cathode, catalyzed with PtRu/CB (PtRu dispersed on carbon black) and Pt/CB bound with Nafion((R)) ionomer, respectively. The performance of the cell based on SPI was compared with that of Nafion((R)) 112 in various operation conditions such as cell temperature (T(cell)), cathode relative humidity (RH), and methanol concentration (C(MeOH)). The methanol crossover at the cell based on SPI was a half of Nafion((R)) 112, resulting in the improved cell efficiency. Advantage of the use of SPI became much distinctive from the conventional Nafion((R)) 112 when the DMFC was operated at a higher Tee or a higher C(MeOH). (c) 2005 Elsevier Ltd. All rights reserved.

    DOI

    Scopus

    36
    被引用数
    (Scopus)
  • Emerging membrane materials for high temperature polymer electrolyte fuel cells: durable hydrocarbon ionomers

    Kenji Miyatake, Masahiro Watanabe

    JOURNAL OF MATERIALS CHEMISTRY   16 ( 46 ) 4465 - 4467  2006年  [査読有り]

     概要を見る

    Proton conducting membranes are key materials in polymer electrolyte fuel cells (PEFCs). Perfluorinated ionomers have been state-of-the-art for decades, but challenges remain for the high temperature operation of fuel cells. We present herein our approaches toward durable and high temperature-operable ionomer membranes using non-fluorinated aromatic polyimide copolymers combined with aliphatic building blocks.

    DOI

    Scopus

    49
    被引用数
    (Scopus)
  • Polyimide electrolyte membranes having fluorenyl and sulfopropoxy groups for high temperature PEFCs

    H Zhou, K Miyatake, M Watanabe

    FUEL CELLS   5 ( 2 ) 296 - 301  2005年04月  [査読有り]

     概要を見る

    A series of novel polyimide electrolyte copolymers (SPPI-X) containing fluorenyl and sulfopropoxy groups were synthesized. The copolymer composition (X: molar percentage of the fluorenyl groups) was set from 0-60 mol% so that the ion exchange capacity of the electrolyte membrane ranged from 1.3 to 2.9 meq g(-1). Tough and flexible membranes, with the typical polyimide brown colour, were obtained by casting from the polymer solution. The SPPI membranes are thermally stable up to 220 T without glass transition, melting, and decomposition under a dry nitrogen atmosphere. Sulfopropoxy groups are effective at improving oxidative stability in Fenton's reagent since the main polymer chains are separated from sulfonic acid groups and are less susceptible to hydrophilic attack by the oxidative radical species. A high mechanical strength, with 53 MPa of the maximum stress at break and 15% of strain, was confirmed for SPPI-30 membrane. The proton conductivity of the SPPI membranes was higher than 0.1 S cm(-1) at temperatures from 40 to 120 degrees C. The long term proton conductivity stability (ca. 1,000 h) was also confirmed at 120 degrees C, to prove the possible availability of the membrane materials for high temperature PEFC applications.

    DOI

    Scopus

    27
    被引用数
    (Scopus)
  • Synthesis and properties of novel sulfonated poly(phenylene ether)

    K Miyatake, H Zhou, M Watanabe

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   43 ( 8 ) 1741 - 1744  2005年04月  [査読有り]

    DOI

    Scopus

    17
    被引用数
    (Scopus)
  • Proton conductive polyimide electrolytes containing trifluoromethyl groups: Synthesis, properties, and DMFC performance

    K Miyatake, H Zhou, T Matsuo, H Uchida, M Watanabe

    MACROMOLECULES   37 ( 13 ) 4961 - 4966  2004年06月  [査読有り]

     概要を見る

    A series of sulfonated polyimide copolymers (FSPIH-X; X refers to molar percentage of his(trifluoromethyl)biphenylene content) with X from 0 to 60 mol % were synthesized, of which electrolyte properties were investigated and compared to those of the perfluorinated ionomer (Nafion 112). FSPIH-X membranes are thermally stable with no glass transition temperature observed below the decomposition temperature (280 degreesC). Oxidative stability of the membranes is improved with an increase in the content of trifluoromethyl substituents in the copolymer structure. FSPIH-60 endured for more than 9 h in Fenton's reagent at 80 degreesC. Bis(trifluoromethyl)biphenylene groups with the molecular size of 6.1 Angstrom make each polymer chain separate and produce space to hold water molecules despite their hydrophobic property so that the maximum water uptake was observed for FSPIH-20. Unlike the fluorene groups containing polyimides (SPIH-X), a strong water confinement effect was not obtained for FSPIH-X. The optimum composition of bis(trifluoromethyl)biphenylene groups was 30 mol %, and the FSPIH-30 membrane showed higher proton conductivity than 0.2 S cm(-1) at 30-140 degreesC. A direct methanol fuel cell (DMFC) using FSPIH-30 membrane has revealed that the methanol crossover through the membrane equivalent to the current density of methanol oxidation at cathode (j(CH3OH)) is 64 mA/cm(2) and merely 30% of that of Nafion 112 at open-circuit potential. A terminal voltage of 0.38 V was obtained at 200 mA/cm(2) by the operation at 80 and 90 degreesC with supplying dry and humidified oxygen.

    DOI

    Scopus

    172
    被引用数
    (Scopus)
  • Proton conductive polyimide electrolytes containing fluorenyl groups: Synthesis, properties, and branching effect

    K Miyatake, H Zhou, M Watanabe

    MACROMOLECULES   37 ( 13 ) 4956 - 4960  2004年06月  [査読有り]

     概要を見る

    Novel sulfonated polyimide copolymers as electrolytes for high-temperature fuel cell applications are reported. A series of sulfonated polyimide copolymers (SPIH-X; X refers to molar percentage of fluorenyl content) containing 0-60 mol % of fluorenyl groups as hydrophobic component were synthesized, of which electrolyte properties were investigated and compared to those of the perfluorinated ionomer (Nafion 112). High-molecular-weight copolymers with good film-forming capability were obtained. Thermal stability with decomposition temperature of ca. 280 degreesC and no glass transition temperature was confirmed for the copolymers. SPIH shows unique water uptake behavior with the maximum value of 57 wt % at X = 30. Water molecules absorbed in the electrolyte membrane with this specific composition do not evaporate easily so that the high proton conductivity of 1.67 S cm(-1) was obtained at 120 degreesC and 100% RH. The branching and cross-linking of SPIH-30 were carried out by applying 2 mol % of trifunctional monomer (melamine) in the polymerization and by electron beam irradiation upon the membrane. The branching and cross-linking are effective to improve oxidative stability and mechanical strength. Although the proton conductivity decreases slightly by the branching and cross-linking, it still remains at the comparable level to that of Nafion 112.

    DOI

    Scopus

    159
    被引用数
    (Scopus)
  • Novel sulfonated poly(arylene ether): A proton conductive polymer electrolyte designed for fuel cells

    K Miyatake, Y Chikashige, M Watanabe

    MACROMOLECULES   36 ( 26 ) 9691 - 9693  2003年12月  [査読有り]

    DOI

    Scopus

    204
    被引用数
    (Scopus)

▼全件表示

書籍等出版物

  • 高速・局所移動水素、リチャージャブル燃料電池

    宮武健治( 担当: 共著)

    共立出版  2022年01月

  • Polymer Electrolyte Membranes: Design for Fuel Cells in Acidic Media

    K. Miyatake( 担当: 単著)

    Elsevier  2018年11月

Misc

  • 中性子反射率測定によるSiO2,PtおよびC基板上のナフィオン薄膜の含水構造

    川本鉄平, 青木誠, 木村太郎, CHINAPANG P., 水沢多鶴子, 山田悟史, 根本文也, 渡辺剛, 谷田肇, 松本匡史, 今井英人, 三宅純平, 宮武健治, 犬飼潤治

    電池討論会PDF要旨集(CD-ROM)   60th  2019年

    J-GLOBAL

  • Ammonium-functionalized poly(arylene ether)s as anion-exchange membranes

    Junpei Miyake, Masahiro Watanabe, Kenji Miyatake

    POLYMER JOURNAL   46 ( 10 ) 656 - 663  2014年10月

    書評論文,書評,文献紹介等  

     概要を見る

    The recent progress of our research on anion-exchange membranes (AEMs) for alkaline fuel cell applications is reviewed. The anion conductivity and the mechanical, thermal and chemical stability of AEMs are insufficient. To address these issues, we have designed and synthesized a novel series of poly(arylene ether)-based AEMs with quaternized ammonium groups. First, the effect of the sequence of the polymer main chain (random or block) on the AEM properties, especially the anion conductivity, is discussed. We emphasize that fluorenyl groups serve effectively as scaffolds for the ammonium groups. We then discuss the alkaline stability of both the polymer backbone and the quaternized ammonium groups. Partial fluorination improves the alkaline stability of the polymer main chains. Among the several ammonium groups investigated, we propose that pyridinium groups are seemingly more stable than the typical aliphatic ammonium (for example, trimethylammonium) groups. The results imply that aromatic AEMs are potentially applicable to alkaline fuel cells that use hydrogen or hydrazine as a fuel.

    DOI

  • 固体高分子形燃料電池の高性能化のための要素材料研究開発の進展

    内田裕之, 宮武健治, 野原愼士, 矢野啓, 脇坂暢, BAE Byungchan, 出来成人, 渡辺政廣

    科学と工業   85 ( 8 ) 321 - 327  2011年08月

    J-GLOBAL

  • Fluorene-containing cardo polymers as ion conductive membranes for fuel cells

    Kenji Miyatake, Byungchan Bae, Masahiro Watanabe

    POLYMER CHEMISTRY   2 ( 9 ) 1919 - 1929  2011年

    書評論文,書評,文献紹介等  

     概要を見る

    For polymer electrolyte fuel cells, proton conducting electrolyte membranes are key materials. This review highlights aromatic polymers containing cardo groups and ionic functions as emerging electrolyte materials. First, the role of biphenyl fluorene groups on sulfonated polyimides is discussed. Discussion then focuses on how to balance proton conductivity and membrane stability with sulfonated poly(arylene ether)s making the most of the bulky cardo groups. Block copolymer structure containing fully sulfonated biphenyl fluorene groups in its hydrophilic component and compact hydrophobic component is proposed. Effect of superacid groups onto the properties of fluorene-containing polymers is discussed. Replacing sulfonic acid groups with ammonio groups afforded the cardo polymers highly anion conducting properties, which make them potentially applicable to alkaline fuel cells.

    DOI

  • 固体高分子形燃料電池用電極触媒および高分子電解質膜の研究開発

    内田裕之, 宮武健治, 野原愼士, 矢野啓, 脇坂暢, BAE Byungchan, 渡辺政廣

    溶融塩および高温化学   53 ( 3 ) 103 - 109  2010年11月

    CiNii J-GLOBAL

  • Oxygen Reduction at the Pt/Carbon Black-Polyimide Ionomer Interface (vol 113C, pg 7772, 2009)

    Kenji Miyatake, Takuya Omata, Donald A. Tryk, Hiroyuki Uchida, Masahiro Watanabe

    JOURNAL OF PHYSICAL CHEMISTRY C   113 ( 50 ) 21264 - 21264  2009年12月

    その他  

    DOI

  • Effects of the decomposition products of sulfonated polyimide and Nafion membranes on the degradation and recovery of electrode performance in PEFCs

    Akihiro Kabasawa, Jurnpei Saito, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    ELECTROCHIMICA ACTA   54 ( 10 ) 2754 - 2760  2009年04月

     概要を見る

    Degradation and recovery of electrode performance during the operation of polymer electrolyte fuel cells (PEFCs) with sulfonated polyimide (SPI-8) and Nafion (R) membranes were evaluated by changes in cell voltage (E(cell)), mass activity (MA), Tafel slope (TS), and electrochemical surface area (ECA) of the Pt catalyst. During continuous cell operation, values of E(cell), MA and ECA decreased, but TS increased. It was found by ion chromatography combined with mass spectrometry (IC/MS) that the drain water contained, as decomposition products, bisulfate and several other ionic compounds derived from the side chain of SPI-8. These ionic compounds were found to adsorb on the surface of the Pt cathode catalyst and to suppress oxygen adsorption, resulting in increases in the overpotential for the oxygen reduction reaction (ORR). The cathode performance was able to recover by potential cycling under high humidity conditions, as the ionic compounds were removed from the Pt surface. (C) 2008 Elsevier Ltd. All rights reserved.

    DOI CiNii

  • Durability of a novel sulfonated polyimide membrane in polymer electrolyte fuel cell operation

    Akihiro Kabasawa, Jumpei Saito, Hiroshi Yano, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    ELECTROCHIMICA ACTA   54 ( 3 ) 1076 - 1082  2009年01月

     概要を見る

    A novel sulfonated polyimide membrane containing triazole groups (SPI-8) was subjected to long-term fuel cell operation. Excellent durability of the SPI-8 membrane was confirmed by single cell operation for 5000 h at 80 degrees C. Open circuit voltage and hydrogen crossover through the membrane showed only minor changes during cell operation, indicating a lack of catastrophic damage for the SPI-8 membrane. It was found by post-test analyses of the membrane that the ion exchange capacity (IEC) decreased only slightly, but the molecular weight decreased to 1/10, resulting in a loss of mechanical strength. It was concluded that the major degradation mode of the sulfonated polyimide membrane involves the ring-opening of the imide linkages via hydrolysis, while a certain degree of side chain degradation occurs as a result of oxidative attack by radical species. (c) 2008 Elsevier Ltd. All rights reserved.

    DOI CiNii

  • Gas diffusion electrodes containing sulfonated polyether ionomers for PEFCs

    Alexis B. Beleke, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    ELECTROCHIMICA ACTA   53 ( 4 ) 1972 - 1978  2007年12月

     概要を見る

    Gas diffusion electrodes (GDEs) containing sulfonated polyether (SPE) ionomers as proton conducting binder have been prepared and evaluated in H-2/O-2 polymer electrolyte fuel cells. An autoclave treatment has been applied for the first time to a hydrocarbon ionomer for the preparation of GDEs. The GDEs worked well as anode without practical overpotential up to 800 mA/cm(2) of the current density. As cathode, the GDEs showed significant dependence on the SPE content and its ion exchange capacity (IEC). Higher catalyst utilization was achieved for the GDEs with higher SPE content due to enhanced proton conduction. Cyclic voltammetry implied higher catalyst utilization of the SPE-based GDEs than that of the conventional Nation (R)-based GDEs. Scanning transmission electron microscopy (STEM) revealed that the SPE ionomer coated uniformly on the surface of Pt/carbon black catalysts. Humidification conditions affect proton conductivity and swelling of the SPE ionomer and thus were crucial for the cathode performance. SPE ionomer with medium IEC (2.17 meq/g) served best in GDEs in terms of catalyst utilization. (c) 2007 Elsevier Ltd. All rights reserved.

    DOI

  • Distribution profile of water and suppression of methanol crossover in sulfonated polyimide electrolyte membrane for direct methanol fuel cells

    Eiji Higuchi, Naoki Asano, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    ELECTROCHIMICA ACTA   52 ( 16 ) 5272 - 5280  2007年04月

     概要を見る

    We have developed novel cross-linked sulfonated polyimide (c-SPI) membrane as an electrolyte for direct methanol fuel cells (DMFCs). When the DMFC using the c-SPI membrane (thickness = 155 mu m), Pt-Ru dispersed on carbon black (Pt-Ru/CB) anode and Pt/CB cathode with a Nafion (R) ionomer was operated at 80 degrees C and 0.1 A cm(-2) with 1 M CH3OH and oxygen (oxidant), the methanol crossover rate, j(CH3OH), was suppressed to about 1/2 compared with that of the Nafion (R) 117 membrane (thickness = 180 mu m) with the same electrodes. It was found for both cells that the j(CH3OH) was not so small as expected from the membrane thickness. In order to obtain a clue for the suppression of j(CH3OH), the distribution profiles of water (containing CH3OH) in thickness direction were investigated by measuring the specific resistances (rho) between Pt probes inserted into the electrolyte membrane. Values of rho p at the anode side were low irrespective of the discharge current density, because such a part of the membrane was humidified thoroughly by liquid water (I M CH3OH) allowing free penetration of CH3OH into the swollen polymer. In contrast, the values of p at the cathode side were high at the low current density due to drying of the membrane contacting with oxidant gas (O-2 or air) in low humidity. We have succeeded to suppress the j(CH3OH) further (about 1/2 at 0.2 A cm(-2)) by using bilayer c-SPI, having a low ion exchanging (low swelling) barrier layer at the anode side without increasing the ohmic resistance, compared with that of the single c-SPI. (c) 2007 Elsevier Ltd. All rights reserved.

    DOI CiNii

  • Enhanced proton conduction in polymer electrolyte membranes with acid-functionalized polysilsesquioxane

    Kenji Miyatake, Takahiro Tombe, Yohei Chikashige, Hiroyuki Uchida, Masahiro Watanabe

    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION   46 ( 35 ) 6646 - 6649  2007年

    DOI PubMed CiNii

  • Durability of novel sulfonated poly(arylene ether) membrane in PEFC operation

    Makoto Aoki, Yohei Chikashige, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    ELECTROCHEMISTRY COMMUNICATIONS   8 ( 9 ) 1412 - 1416  2006年09月

     概要を見る

    A novel proton conducting polymer electrolyte membrane, poly(arylene ether) ionomer containing sulfofluorenyl groups (SPE-1), was subjected to long term fuel cell operation. High durability of the SPE-1 membrane was confirmed by single cell test at 80 degrees C and at a constant current density of 0.2 A/cm(2). Under 90% RH operation, superior hydrolytic stability of the SPE-1 membrane was demonstrated even after 5000 h with no noticeable degradations with respect to cell performances, ion exchange capacity, thickness, and molecular weight. Under 60% RH operation, some change in the molecular weight was observed after 2350 h presumably due to the oxidative degradation caused by the increased cross-over of reactant gases through the membrane. (c) 2006 Elsevier B.V. All rights reserved.

    DOI CiNii

  • Aliphatic/aromatic polyimide lonomers as a proton conductive membrane for fuel cell applications

    N Asano, M Aoki, S Suzuki, K Miyatake, H Uchida, M Watanabe

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   128 ( 5 ) 1762 - 1769  2006年02月

     概要を見る

    To produce a proton conductive and durable polymer electrolyte membrane for fuel cell applications, a series of sulfonated polyimide ionomers containing aliphatic groups both in the main and in the side chains have been synthesized. The title polyimide ionomers 1 with the ion exchange capacity of 1.78-2.33 mequiv/g were obtained by a typical polycondensation reaction as transparent, ductile, and flexible membranes. The proton conductivity of 1 was slightly lower than that of the perfluorinated ionomer (Nafion) below 100 degrees C, but comparable at higher temperature and 100% RH. The highest conductivity of 0.18 S cm(-1) was obtained for 1 at 140 degrees C. lonomer 1 with high IEC and branched chemical structure exhibited improved proton conducting behavior without sacrificing membrane stability. Microscopic analyses revealed that smaller (< 5 nm) and well-dispersed hydrophilic domains contribute to better proton conducting properties. Hydrogen and oxygen permeability of 1 was 1-2 orders of magnitude lower than that of Nafion under both dry and wet conditions. Fuel cell was fabricated with 1 membrane and operated at 80 degrees C and 0.2 A/cm(2) supplying H-2 and air both at 60% or 90% RH. lonomer 1 membrane showed comparable performance to Nafion and was durable for 5000 h without distinct degradation.

    DOI PubMed CiNii

  • Gas diffusion electrodes for polymer electrolyte fuel cell using sulfonated polyimide

    Eiji Higuchi, Kenichi Okamoto, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    RESEARCH ON CHEMICAL INTERMEDIATES   32 ( 5-6 ) 533 - 542  2006年

    書評論文,書評,文献紹介等  

     概要を見る

    Gas diffusion electrodes for high temperature polymer electrolyte fuel cells (PEFCs) have been prepared by using a novel proton conductive sulfonated polyimide (SPI) electrolyte. The catalyst layer was composed of Pt-loaded carbon black (Pt-CB) and SPI ionomer. The polarization properties and the microstructure of the catalyst layer were investigated as a function of the SPI/CB weight ratio. The anodic polarization was found to be negligibly small for all the compositions examined. The highest cathode performance was obtained at SPI/CB = 0.5 (by weight), where the best balance of high catalyst utilization and oxygen gas diffusion rate through the ionomer was obtained.

  • Durability of Sulfonated Polyimide Membrane Evaluated by Long Term PEFC Operation

    Makoto Aoki, Naoki Asano, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    Journal of the Electrochemical Society   153 ( 6 ) A1154 - A1158  2006年

    DOI CiNii

  • Application of sulfonated polyimide membranes to direct methanol fuel cells

    JM Song, N Asano, K Miyatake, H Uchida, M Watanabe

    CHEMISTRY LETTERS   34 ( 7 ) 996 - 997  2005年07月

     概要を見る

    Sulfonated polyimide (SPI) membrane has been evaluated as an electrolyte membrane for direct methanol fuel cells (DMFCs) in comparison with Nation((R)) 112. The membrane-electrolyte assemblies (MEAs) were made by hot-pressing each membrane, an anode of Pt-Ru dispersed on carbon black (PtRu/CB) and a cathode of Pt/CB with Nafion((R)) ionomer. The cell prepared with SPI membrane exhibited a suppressed methanol crossover to a half of Nation((R)) 112, resulting in the improved cell performance.

    DOI CiNii

  • Gas diffusion electrodes for polymer electrolyte fuel cells using novel organic/inorganic hybrid electrolytes: effect of carbon black addition in the catalyst layer

    O Nishikawa, K Doyama, K Miyatake, H Uchida, M Watanabe

    ELECTROCHIMICA ACTA   50 ( 13 ) 2719 - 2723  2005年04月

     概要を見る

    We have prepared novel gas diffusion electrodes for polymer electrolyte fuel cells (PEFC) using new organic/inorganic hybrid electrolytes. The catalyst layers were prepared by mixing 3-(trihydroxysilyl)-1-propanesulfonic acid [(THS)Pro-SO3H], 1,8-bis(triethoxysilyl) octane (TES-Oct), Pt loaded carbon black (Pt-CB) and water, followed by a sol-gel reaction. It was found that addition of uncatalyzed carbon black (u-CB) into the cathode catalyst layer enhanced the performance at high current density region, due to an increase in the gas diffusion rate. The optimum volume ratio of u-CB/Pt-CB was found to be 0.1, at which the gas diffusivity and the catalyst utilization are well balanced. (c) 2004 Elsevier Ltd. All rights reserved.

    DOI CiNii

  • Recent progress in proton conducting membranes for PEFCs

    K Miyatake, M Watanabe

    ELECTROCHEMISTRY   73 ( 1 ) 12 - 19  2005年01月

    書評論文,書評,文献紹介等  

     概要を見る

    Recent progress in proton conducting membrane materials for high temperature polymer electrolyte fuel cells (PEFCs) is reviewed. Perfluorinated ionomers, hydrocarbon ionomers, and other miscellaneous materials are included. As a state,of-the-art material, perfluorinated ionomers have been mostly studied. The current research has focused on reinforcement (with porous support, fibril, fiber, or fabric) and chemical modification (by copolymerization or cross-linking). Considerable improvement has been achieved in the thermal, chemical and mechanical stability as well as the proton conductivity. The perfluorinated ionomer dispersed with nanoparticles of metal oxides and platinum has proved its potential availability as an electrolyte membrane for non-humidified operating PEFCs. As alternative membranes, non-fluorinated hydrocarbon materials have been a great challenge. Aromatic ionomers such as sulfonated polyimides and polyethers, or acid-doped polybenzimidazoles have been developed. Ionic liquids, organic/inorganic hybrids, and fullerene derivatives have also been described as a novel class of anhydrous proton conducting materials.

  • Preparation of the electrode for high temperature PEFCs using novel polymer electrolytes based on organic/inorganic nanohybrids

    Osamu Nishikawa, Toshiya Sugimoto, Shigeki Nomura, Kazuo Doyama, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    Electrochimica Acta   50 ( 2-3 ) 667 - 672  2004年11月

     概要を見る

    Novel organic/inorganic hybrid electrolytes have been designed for high temperature polymer electrolyte fuel cells (PEFCs). The hybrid electrolyte membranes were synthesized from 1,8-bis(triethoxysilyl)octane (TES-Oct) and 3-(trihydroxysilyl)-1-propanesulfonic acid ((THS)Pro-SO3H) via sol-gel process. The membranes with sulfonic acid groups covalently bonded to the silica show higher proton conductivity of 5 × 10-2 S/cm at 160°C than that of previously reported homologous materials containing phosphotungstic acid as acid function. A series of electrodes with different composition of the organic/inorganic nanohybrid materials to the platinum loaded carbon has been prepared in order to elucidate the availability of the electrolytes in the catalyst layer. By optimizing the composition of the nanohybrids, high electrode performance comparable to that using Nafion® ionomer has been obtained. The novel organic/inorganic hybrid materials have proved to be a promising material as the ionomer in the electrodes and the electrolyte membranes for high temperature PEFCs. © 2004 Elsevier Ltd. All rights reserved.

    DOI

  • Gas Diffusion Electrodes for Polymer Electrolyte Fuel Cells Using Novel Organic/Inorganic Hybrid Electrolytes

    Osamu Nishikawa, Kazuo Doyama, Kenji Miyatake, Hiroyuki Uchida, Masahiro Watanabe

    Electrochemistry   72 ( 4 ) 232 - 237  2004年

    CiNii

  • Highly proton conductive polyimide electrolytes containing fluorenyl groups

    Kenji Miyatake, Hua Zhou, Hiroyuki Uchida, Masahiro Watanabe

    Chemical Communications   3 ( 3 ) 368 - 369  2003年

     概要を見る

    Novel sulfonated polyimides containing fluorenyl groups show good thermal and oxidative stability as well as a high proton conductivity of 1.67 S cm−1 at 120 °C and 100% RH. © 2003 The Royal Society of Chemistry.

    DOI PubMed CiNii

▼全件表示

産業財産権

  • CO2電解装置、およびCO2電解生成物の製造方法

    宮武 健治, 横田 尚樹, 永瀬 勝也, 兼古 寛之, 岡本 裕二, ジア チンシン

    特許権

  • リバーシブル燃料電池

    宮武 健治, 小柳津 研一

    特許権

  • 陰イオン交換樹脂および電解質膜

    宮武 健治, 小澤 佳弘, 横田 尚樹, 高橋 優子, 永瀬 勝也

    特許権

受賞

  • BCSJ Award Article

    2022年05月   日本化学会   Sulfonated and Fluorinated Aromatic Terpolymers as Proton Conductive Membranes: Synthesis, Structure, and Properties  

    受賞者: Ren Kumao, Kenji Miyatake

  • FCDIC学術賞

    2021年05月   燃料電池開発情報センター   高性能・高耐久性炭化水素系電解質膜の創製  

    受賞者: 宮武健治

  • 文部科学大臣表彰科学技術賞(研究部門)

    2021年04月   文部科学省   次世代燃料電池への応用を目指した革新的高分子薄膜の研究  

    受賞者: 宮武健治, 犬飼潤治, 内田誠

  • 第25回山梨科学アカデミー賞

    2020年11月   山梨科学アカデミー   高性能イオン導電性高分子の開発とエネルギーデバイスへの応用  

    受賞者: 宮武健治

  • 平成25年度科研費審査委員表彰

    2013年10月   日本学術振興会  

    受賞者: 宮武健治

  • ドイツ・イノベーション・アワード ゴットフリード・ワグネル賞

    2013年06月   ドイツ 科学・イノベーション フォーラム東京、在日ドイツ商工会議所  

    受賞者: 宮武健治

     概要を見る

    燃料電池への応用を目指したイオン導電性高分子の開発

  • 平成24年度高分子学会日立化成賞

    2012年09月   高分子学会  

    受賞者: 宮武健治

     概要を見る

    イオン伝導性高分子の合成と燃料電池への展開

  • 第12回山梨科学アカデミー奨励賞

    2007年05月   山梨科学アカデミー  

    受賞者: 宮武健治

     概要を見る

    固体高分子形燃料電池の高性能化を目指した新型電解質膜に関する研究

  • 平成17年度科学技術分野の文部科学大臣表彰若手科学者賞

    2005年04月   文部科学省  

    受賞者: 宮武健治

     概要を見る

    燃料電池分野における高分子電解質膜の研究

  • 高分子研究奨励賞

    2003年05月   高分子学会  

    受賞者: 宮武健治

     概要を見る

    芳香族高分子電解質膜の合成とプロトン伝導特性に関する研究

▼全件表示

共同研究・競争的資金等の研究課題

  • 再生可能エネルギー最大導入に向けた電気化学材料研究拠点

    研究期間:

    2022年09月
    -
    2031年03月
     

    杉山正和

  • アニオン導電性高分子:エネルギーデバイスのための新展開

    日本学術振興会 

    研究期間:

    2022年09月
    -
    2025年03月
     

    宮武健治

  • 高性能イオン導電性薄膜の開発と水素製造デバイスへの応用

    公益財団法人JKA  研究補助事業

    研究期間:

    2022年04月
    -
    2024年03月
     

    宮武健治

  • アニオン導電性薄膜の導電率・安定性の両立と高性能アルカリ形燃料電池への挑戦

    岩谷直治記念財団 

    研究期間:

    2022年04月
    -
    2023年03月
     

  • 高性能アニオン膜型アルカリ水電解のための材料開発と膜電極接合体に関する研究開発

    NEDO  水素利用等先導研究開発事業

    研究期間:

    2021年07月
    -
    2023年03月
     

    宮武健治

  • 高速移動水素による次世代創蓄電デバイスの設計

    研究期間:

    2018年07月
    -
    2023年03月
     

  • 新型アニオン導電性薄膜を用いた高性能アルカリ型燃料電池の開発

    公益財団法人JKA  研究補助事業

    研究期間:

    2020年04月
    -
    2022年03月
     

    宮武健治

  • 燃料電池の高性能化を目指した高耐久性イオン伝導膜の設計と開発

    科学技術振興機構 

    研究期間:

    2019年04月
    -
    2022年03月
     

  • 高性能アニオン交換膜を用いた水電解水素製造技術の開発

    NEDO 

    研究期間:

    2019年07月
    -
    2021年07月
     

  • 多機能性高分子イオニクス材料の創製とエネルギーデバイスへの応用

    研究期間:

    2018年04月
    -
    2021年03月
     

  • ポリフェニレンイオノマーへの挑戦

    研究期間:

    2018年06月
    -
    2020年03月
     

  • 革新的アニオン導電性高分子を用いた三相界面の創製とアルカリ形燃料電池への展開

    JST  CREST

    研究期間:

    2012年10月
    -
    2019年03月
     

▼全件表示

講演・口頭発表等

  • 高プロトン導電性薄膜の創製とリチャージャブル燃料電池への挑戦

    宮武健治  [招待有り]

    令和4年電気学会全国大会  

    発表年月: 2022年03月

  • アニオン交換膜の設計とアルカリ型エネルギーデバイスへの応用

    宮武健治  [招待有り]

    FC EXPO2022  

    発表年月: 2022年03月

  • 新規高分子電解質膜の開発:耐久性向上のための設計指針

    宮武健治  [招待有り]

    高分子学会2021東海シンポジウム  

    発表年月: 2022年01月

  • Partially Fluorinated Proton Conductuve Polyphenylene Ionomers for Fuel Cells

    K. Miyatake, Z. Long  [招待有り]

    Materials Research Meeting 2021 (MRM2021)  

    発表年月: 2021年12月

  • Polyphenylene ionomer membranes: effect of reinforcement

    K. Miyatake  [招待有り]

    Solid State Proton Conductors (SSPC-20)  

    発表年月: 2021年09月

  • Alkaline stable and highly conductive anion exchange membranes containing perfluoroalkyl groups

    K. Miyatake  [招待有り]

    The 3rd Japan-China Clean Energy Forum-Hydrogen Energy and Carbon Capture  

    発表年月: 2021年09月

  • Partially fluorinated anion exchange membranes for alkaline fuel cells and electrolyzers

    K. Miyatake, K. Otsuji, K. Kakainuma, M. Uchida  [招待有り]

    European Electrolyzer & Fuel Cell Forum 2021  

    発表年月: 2021年06月

  • Partially Fluorinated Anion Exchange Membranes for Alkaline Fuel Cells and Electrolyzers

    K. Miyatake, K. Otsuji, K. Kakainuma, M. Uchida  [招待有り]

    Workshop on Ion Exchange Membrane for Energy Applications  

    発表年月: 2021年06月

  • 炭化水素系電解質:今後何をすべきか、何ができるか

    宮武健治  [招待有り]

    20-1水素・燃料電池材料研究会   高分子学会  

    発表年月: 2021年01月

  • Polyphenylene Ionomers: Design, Synthesis, and Properties

    K. Miyatake  [招待有り]

    3rd G'L'owing Polymer Symposium in KANTO (GPS-K 2020)   The Society of Polymer Science, Japan  

    発表年月: 2020年11月

  • Alkaline stable and highly conductive anion exchange membranes containing perfluoroalkyl groups"

    K. Miyatake  [招待有り]

    The 2nd Japan-China Forum on Power Batteries for New Energy Vehicles   JST  

    発表年月: 2020年10月

  • 高分子膜の設計次第で燃料電池はどう変わる?

    宮武健治  [招待有り]

    第10回日本化学会化学フェスタ2020   日本化学会  

    発表年月: 2020年10月

  • Partially fluorinated anion exchange membranes for electrochemical applications

    K. Miyatake, T. Kimura, J. Inukai, M. Uchida  [招待有り]

    Pacific Rim Meeting on Electrochemical and Solid-State Science 2020 (PRiME 2020),   Electrochemical Society  

    発表年月: 2020年10月

  • 高プロトン導電性高分子薄膜:分子設計とエネルギーデバイスへの応用

    宮武健治  [招待有り]

    日本物理学会第75回年次大会   (名古屋大学)  日本物理学会  

    発表年月: 2020年03月

  • Anion Exchange Membranes Containing Quinquephenylene Groups

    Kenji Miyatake  [招待有り]

    Workshop on Ion Exchange Membrane for Energy Application   (Bad Zwischenahn, Germany) 

    発表年月: 2019年06月

  • パネルディスカッション「エネルギー大変革時代を切り拓く博士人材」

     [招待有り]

    早稲田大学パワー・エネルギー・プロフェッショナル育成プログラム キックオフシンポジウム  

    発表年月: 2019年03月

  • 燃料電池の高性能化を目指したイオン伝導性薄膜の開発:山梨大学における産学官連携と大学院教育

    宮武 健治  [招待有り]

    秋田大学新素材・機能性材料開発セミナー  

    発表年月: 2019年03月

  • イオン伝導性芳香族高分子の設計と燃料電池への応用

    宮武 健治  [招待有り]

    高分子学会18-2有機エレクトロニクス研究会   (大阪)  高分子学会有機エレクトロニクス研究会  

    発表年月: 2018年12月

  • Polyphenylene Ionomers as Fuel Cell Membranes

    K. Miyatake  [招待有り]

    The 12th SPSJ International Polymer Conference   (Hirosima)  SPSJ  

    発表年月: 2018年12月

  • 次世代燃料電池を目指した高分子薄膜への挑戦

    宮武 健治  [招待有り]

    第50回有機合成セミナー  

    発表年月: 2018年10月

  • Research and Development of Electrocatalysts and Polymer Electrolytes for Superlative, Stable, and Scalable Performance Fuel Cell

    A. Iiyama, K. Kakinuma, M. Uchida, J. Miyake, K. Miyatake, H. Yano, J. Inukai, H. Uchida  [招待有り]

    International Fuel Cell Workshop 2018  

    発表年月: 2018年08月

  • Partially Fluorinated Aromatic Anion Exchange Membranes: Effect of Ammonium Structure

    K. Miyatake  [招待有り]

    Workshop on Ion Exchange Membrane for Energy Applications   (Germany) 

    発表年月: 2018年06月

  • Development of Innovative Ion Conductive Membranes for Next Generation Fuel Cells

    K. Miyatake  [招待有り]

    The 2nd International Symposium on Hydrogen Energy‒based Society  

    発表年月: 2017年11月

  • エネルギーデバイスへの応用を指向した高性能イオン伝導性薄膜

    宮武健治  [招待有り]

    第66回高分子討論会  

    発表年月: 2017年09月

  • Aromatic Polymer Based Anion Conductive Membranes for Alkaline Fuel Cells

    K. Miyatake  [招待有り]

    IUPAC 17th International Symposium on Macromolecular Complexes  

    発表年月: 2017年08月

  • Anion Exchange Membranes Composed of Perfluoroalkyl Main Chain and Pendant Ammonium Groups

    K. Miyatake  [招待有り]

    Workshop on Ion Exchange Membrane for Energy Applications  

    発表年月: 2017年06月

  • Chemically Stable Aromatic Ionomers as Proton Exchange Membranes

    K. Miyatake, J. Miyake, R. Taki, R. Akiyama, R. Shimizu

    The 11th SPSJ International Polymer Conference   (Fukuoka, Japan) 

    発表年月: 2016年12月

  • Anion Exchange Membranes Composed of Fluoroalkyl and Ammonium-Functionalized Fluorenyl groups: Effect of the Hydrophilic Component

    M. Ozawa, J. Miyake, Miyatake

    The 11th SPSJ International Polymer Conference   (Fukuoka, Japan) 

    発表年月: 2016年12月

  • Sulfonated Aromatic Polymers Containing Phosphine Oxide Groups as Chemically Stable Proton Exchange Membranes

    I. Hosaka, R. Akiiyama, J. Miyake, Miyatake

    The 11th SPSJ International Polymer Conference   (Fukuoka, Japan) 

    発表年月: 2016年12月

  • Molecular Consideration of Aromatic Proton Conducting Copolymers: Effect of Hydrophilic and Hydrophobic Components

    R. Oida, R. Akiyama, J. Miyake, K. Miyatake

    The 11th SPSJ International Polymer Conference   (Fukuoka, Japan) 

    発表年月: 2016年12月

  • 中性子準弾性散乱による固体高分子電解質膜におけるプロトンダイナミクスの湿度依存性の解析

    岩井良樹, 茂木昌都, 松本匡史, 伊藤孝憲, 犬飼潤冶, 青木誠, 木村太郎, 宮武健治, 三宅純平, 富永大輝, 福嶋喜章, 柴田薫, 日下部正人, 今井英人

    第57回電池討論会   (幕張メッセ国際会議場) 

    発表年月: 2016年11月

  • 炭化水素系電解質膜を用いた固体高分子形燃料電池の加速耐久評価と劣化機構解析

    清水瞭, 辻淳一, 佐藤信之, 伊丹俊輔, 高野純, 日下部正人, 宮武健治, 飯山明裕, 内田誠

    第57回電池討論会   (幕張メッセ国際会議場) 

    発表年月: 2016年11月

  • Ionomer Layer Design of the Electrode Using PGM-Free Electrocatalysts for Anion Exchange Membrane Fuel Cells

    K. Asazawa, A. Takano, E. Nishino, S. Yamagucha, J. Miyake, M. Uchida, K. Miyatake

    PRiME2016   (Hawaii, U.S.A) 

    発表年月: 2016年10月

  • Aromatic Ionomers As Alternative Fuel Cell Membranes: Issues and Possibilities

    K. Miyatake

    PRiME2016   (Hawaii, U.S.A) 

    発表年月: 2016年10月

  • Oxygen Reduction Reaction Activity and Durability of Platinum/Cobalt Alloy Nanoparticle Catalysts in Alkaline Media

    Y. Shimizu, M. Uchida, K. Miyatake

    PRiME2016   (Hawaii, U.S.A) 

    発表年月: 2016年10月

  • Systematic Studies on the Phase Separations at Bulks and Surfaces of the Anion Exchange Membranes with Different Polymer Structures

    T. Kimura, R. Akiyama, K. Miyatake, J. Inukai

    PRiME2016   (Hawaii, U.S.A) 

    発表年月: 2016年10月

  • Synthesis and Properties of Partially Fluorinated Anion Exchange Membranes Containing Ammonium-Functionalized Fluorenyl Groups

    M. Ozawa, J. Miyake, K. Miyatake

    PRiME2016   (Hawaii, U.S.A) 

    発表年月: 2016年10月

  • Stability of Perfluoroalkylene Based Anion Exchange Membranes for Alkaline Fuel Cell Applications : Impact of Varying Ammonium Structure

    A. M. A. Mahmoud, K. Miyatake

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Synthesis and Characterization of Tricomponent Aromatic Copolymers as Proton Exchange Membranes

    Y. Zhang, J. Miyake, R. Akiyama, K. Miyatake

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Synthesis and Characterization of Sulfonated Aromatic Copolymers Containing Phosphine Oxide Groups as Chemically Stable Proton Exchange Membranes

    I. Hosaka, R. Akiyama, J. Miyake, K. Miyatake

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Oxygen Reduction Reaction Activity and Durability of Platinum/Cobalt Alloy Nanoparticles for Orr in Alkaline Media

    Y. Shimizu, K. Miyatake

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Synthesis of an Aromatic Copolymer Membrane Having High Density Sulfonic Groups

    A. Ozaki, J. Miyake, R. Akiyama, K. Miyatake

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Synthesis of Properties of Novel Anion Exchange Membranes Containig Flouoroalky1 and Ammonium-Functionalized-Functionalized Fluorenyl Groups

    M. Ozawa, J. Miyake, K. Miyatake

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Durability of Sulfonated Aromatic Copolymer Membranes in Accelerated Stress Evaluation

    R. Shimizu, Y. Sakiyama, J. Tanaka, A. Itami, K. Miyatake, A. Iiyama, M. Uchida

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Effect of Aliphatic Groups in the Anion Conductive Polymer Main Chains on the Alkaline Stability and Properties

    H. Ono, J. Miyaka, K. Miyatake

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Systematic Study on Structures and Ion Conductions at Bulks and Surfaces of Anion Exchange Membranes for Fuel Cells

    T. Kimura, R. Akiyama, K. Miyatake, J. Inukai

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Synthesis and Properties of New Alkylene Containing Polymer Backbone for Anion Conductive Polymer

    S. Shimada, R. Akiyama, H. Ono, J. Miyake, K. Miyatake

    The 5th International Seminar for Special Doctoral Program‘Green Energy Conversion Science and Technology’   (Nagano, Japan) 

    発表年月: 2016年08月

  • Durability and Degradation Analysis of Novel Hydrocarbon Ionomer Membranes in PEFC Accelerated Stress Evaluation

    R. Shimizu, Y. Sakiyama, J. Takano, S. Itami, M. Kusakabe, K. Miyatake, A. Iiyama, M. Uchida

    67th Annual Meeting of the International Society of Electrochemistry (ISE)   (The Hague, The Netherlands) 

    発表年月: 2016年08月

  • Anion Exchange Membranes Containing Perfluoroalkyl Groups

    K. Miyatake, H. Ono, J. Miyatake

    Workshop on Ion Exchange Membranes for Energy Applications-EMEA2016   (Bad Zwischenahn. Germany) 

    発表年月: 2016年06月

  • フッ化アルキルとオリゴフェニレン骨格からなる新規アニオン交換膜の合成と物性

    小野英明, 三宅純平, 島田盛史, 内田誠, 宮武健治

    平成28年度繊維学会年次大会   (タワーホール船堀) 

    発表年月: 2016年06月

  • キンケフェニレン構造を有する芳香族系プロトン導電性高分子の合成と物性評価

    三宅純平, 滝隆之介, 秋山良, 望月崇史, 宮武健治

    第65回高分子学会年次大会   (神戸国際会議場・展示場) 

    発表年月: 2016年05月

  • 親水部にオリゴフェニレン構造を有するアニオン導電性高分子の合成と物性評価

    横田尚樹, 秋山良, 三宅純平, 宮武健治

    第65回高分子学会年次大会   (神戸国際会議場・展示場) 

    発表年月: 2016年05月

  • 新規アニオン交換膜を用いたダイレクトヒドラジン燃料電池

    西野英理子, 山田純子, 朝澤浩一郎, 横田尚樹, 秋山良, 三宅純平, 宮武健治

    第65回高分子学会年次大会   (神戸国際会議場・展示場) 

    発表年月: 2016年05月

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