Updated on 2026/01/17

写真a

 
OYAIZU, Kenichi
 
News & Topics
Affiliation
Faculty of Science and Engineering, School of Advanced Science and Engineering
Job title
Professor
Degree
博士(工学) ( 早稲田大学 )
PhD ( Waseda University )
Homepage URL
https://kenichioyaizu.myportfolio.com/

Research Experience

  • 2012.04
    -
    　

    Professor, Department of Applied Chemistry, Waseda University

  • 2007.04
    -
    2012.03

    Associate Professor, Department of Applied Chemistry, Waseda University

  • 2003.10
    -
    2007.03

    Associate Professor, Institute of Colloid and Interface Science, Tokyo University of Science

  • 1997.04
    -
    2003.09

    Lecturer, Advanced Research Institute for Science and Engineering, Waseda University

  • 1995.04
    -
    1997.03

    Research Assistant, Department of Applied Chemistry, Waseda University

  • 1992.04
    -
    1995.03

    JSPS Research Associate (DC1)

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Education Background

  • 1990.04
    -
    1995.03

    Waseda University   Graduate School, Division of Science and Engineering   Department of Applied Chemistry  

  • 1986.04
    -
    1990.03

    Waseda University   Faculty of Science and Engineering   Department of Applied Chemistry  

Committee Memberships

  • 2022.06
    -
    2024.05

    高分子学会国際交流委員会  第36期委員

  • 2022.04
    -
    2024.03

    高分子学会超分子研究会  第36期運営委員

  • 2022.04
    -
    2024.03

    高分子学会水素•燃料電池材料研究会  第36期運営委員

  • 2022.02
    -
    2023.02

    日本化学会第12回化学フェスタ実行委員会  実行委員

  • 2020.06
    -
    2022.05

    高分子学会国際交流委員会  第35期委員

  • 2020.06
    -
    2022.05

    高分子学会関東支部  第35期常任幹事

  • 2020.04
    -
    2022.03

    高分子学会水素•燃料電池材料研究会  第35期運営委員

  • 2020.04
    -
    2022.03

    高分子学会超分子研究会  第35期運営委員

  • 2021.01
    -
    2022.02

    日本化学会第11回化学フェスタ実行委員会  実行委員

  • 2018.08
    -
    2021.07

    MRS Communications  Advisory Board

  • 2019.05
    -
    2021.05

    日本化学会  理事

  • 2020.01
    -
    2021.02

    日本化学会第10回化学フェスタ実行委員会  実行委員

  • 2018.06
    -
    2020.05

    高分子学会  理事

  • 2018.06
    -
    2020.05

    高分子学会関東支部,  第34期常任幹事

  • 2018.04
    -
    2020.03

    高分子学会超分子研究会  第34期運営委員

  • 2018.04
    -
    2020.03

    高分子学会水素•燃料電池材料研究会  第34期運営委員

  • 2019.02
    -
    2020.01

    日本化学会第9回化学フェスタ実行委員会  実行委員

  • 2018.02
    -
    2019.01

    日本化学会第8回化学フェスタ実行委員会  実行委員

  • 2016.11
    -
    2018.05

    高分子学会関東支部23区懇話会  世話人

  • 2016.06
    -
    2018.05

    高分子学会関東支部  第33期常任幹事

  • 2016.04
    -
    2018.03

    高分子学会超分子研究会  運営委員長

  • 2016.04
    -
    2018.03

    高分子学会水素•燃料電池材料研究会  第33期運営委員

  • 2016.04
    -
    2018.03

    高分子学会超分子研究会  第33期運営委員長

  • 2017.03
    -
    2018.02

    日本化学会関東支部  支部長

  • 2017.03
    -
    2018.02

    日本化学会第7回化学フェスタ実行委員会  実行委員

  • 2015.03
    -
    2018.02

    日本化学会高分子ディビジョン  幹事

  • 2015.06
    -
    2017.05

    高分子学会  第32期 (後期) 行事委員

  • 2016.03
    -
    2017.02

    日本化学会関東支部  副支部長

  • 2016.03
    -
    2017.02

    日本化学会第6回化学フェスタ実行委員会  実行委員

  • 2014.08
    -
    2016.05

    日本化学連合企画委員会  企画委員

  • 2014.06
    -
    2016.05

    高分子学会関東支部  第32期常任幹事

  • 2014.04
    -
    2016.03

    高分子学会燃料電池材料研究会  第32期運営委員

  • 2014.04
    -
    2016.03

    高分子学会超分子研究会  第32期運営副委員長

  • 2015.03
    -
    2016.02

    日本化学会関東支部,  幹事・事業企画委員会委員長

  • 2015.02
    -
    2016.02

    日本化学会第5回化学フェスタ実行委員会  実行委員

  • 2014.03
    -
    2015.02

    日本化学会関東支部  幹事・事業企画委員会副委員長

  • 2014.02
    -
    2015.02

    日本化学会第4回化学フェスタ実行委員会  実行委員

  • 2012.06
    -
    2014.05

    高分子学会関東支部,  第31期常任幹事

  • 2012.04
    -
    2014.03

    高分子学会燃料電池材料研究会  第31期運営委員

  • 2012.04
    -
    2014.03

    高分子学会超分子研究会  第31期運営委員

  • 2013.02
    -
    2014.02

    日本化学会第3回化学フェスタ実行委員会  実行委員

  • 2010.04
    -
    2012.03

    高分子学会超分子研究会  第30期運営委員

  • 2009.04
    -
    2011.03

    高分子学会燃料電池材料研究会  第30期運営委員

  • 2007.04
    -
    2009.03

    高分子学会燃料電池材料研究会  第29期運営委員

  • 2006.06
    -
    2008.05

    高分子学会  第28期行事委員

  • 2006.04
    -
    2008.02

    電気化学会関東支部  幹事

  • 2005.04
    -
    2008.02

    日本化学会コロイドおよび界面化学部会  事業企画委員

  • 2005.02
    -
    2007.02

    Electrochemistry  Editorial Board Member

  • 2004.03
    -
    2005.02

    日本化学会コロイドおよび界面化学部会  幹事・事業企画委員

  • 2000.08
    　
    　

    Polymers for Advanced Technologies (John Wiley & Sons)  Editor, Special Issue for The 5th International Symposium on Polymers for Advanced Technologies

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Professional Memberships

  • 　
    　
    　

    Research Group on Materials for hydrogen and PEFC, SPSJ

  • 　
    　
    　

    Research Group on Supramolecular Chemistry, SPSJ

  • 　
    　
    　

    The Electrochemical Society of Japan

  • 　
    　
    　

    American Chemical Society

  • 　
    　
    　

    The Society of Polymer Science, Japan

  • 　
    　
    　

    Chemical Society of Japan

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Research Areas

  • Polymer chemistry

Research Interests

  • Polymer Synthesis, Functional Polymers

Awards

  • Yamazaki Sho

    2022.06   The Society of Materials Engineering for Resources of JAPAN   Polymers for Reversible Hydrogen Storage Inspired by Electrode-active Materials in Organic Batteries

  • The Award of the Society of Polymer Science, Japan

    2022.05   The Society of Polymer Science, Japan   Development of Functional Polymers for Energy Storage through Practical Materials Informatics

  • Prizes for Science and Technology, The Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology

    2013.04   Minister of Education, Culture, Sports, Science and Technology  

  • Oleo Science Award

    2007.06   Japan Oil Chemists' Society  

  • Chemical Society of Japan Award for Young Chemists

    2002.03   Chemical Society of Japan   Establishment of New Polymeric Material Synthesis Based on Multi-electron Transfer Process of Disproportionated μ-Oxo Complexes

  • Award for Encouragement of Research in Polymer Science; The Society of Polymer Science, Japan

    2001.05   The Society of Polymer Science, Japan   Development of Oxidative Polymerization Using Oxygen Splitting Reactions for Synthesis of Polyheteroacenes

  • Mizuno Award

    1995.03   Waseda University  

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Papers

  • Enhanced Lithium-Ion Transportability of Poly(ether-thioether)s and Their Oxidized Products under Polymer-in-Salt Conditions

    Akinari Chiba, Takuya Yokoo, Yuki Ogawa, Minhi Han, Sungnam Park, Kenichi Oyaizu

    ACS Applied Polymer Materials    2025.11

    DOI

    Scopus

  • Novel polyphenylene sulfide resin for high-frequency copper-clad laminates with low dielectric tangent and flame retardancy

    Daisuke Ito, Keizo Inoue, Yuichi Fujioka, Teruhiko Miki, Shinsuke Ishikawa, Akihiko Happoya, Seigo Watanabe, Tomohiro Miura, Kenichi Oyaizu

    Polymer    2025.11

    DOI

    Scopus

  • Deep learning prediction of ionic conductivity in polymer electrolytes using hierarchical polymer graphs

    Minhi Han, Takuya Yokoo, Jinyong Park, Kenichi Oyaizu, Sungnam Park

    Chemical Engineering Journal    2025.10

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Approach to Tuning the Dispersion Stability of TEMPO‐substituted Polymer Nanoparticles for Aqueous Organic Redox Flow Batteries

    Kohei Ishigami, Shinjiro Mori, Kenichi Oyaizu

    ChemSusChem    2025.09

    DOI

    Scopus

  • Poly(phenylene sulfide) derivatives as ultralow dielectric loss materials with stable frequency response

    Seigo Watanabe, Shuma Miura, Tomohiro Miura, Yoshino Tsunekawa, Daisuke Ito, Kenichi Oyaizu

    Communications Materials    2025.08

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • High Refractive Index Aromatic and Ether‐Containing Polythioureas: Improving Transparency and Mechanical Properties via Reciprocal Hydrogen Bonds

    Seigo Watanabe, Yoshino Tsunekawa, Kenichi Oyaizu

    Macromolecular Chemistry and Physics    2025.04

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Two-Electron Redox Chemistry of Nitroxide Radicals: Fundamental Mechanisms and Applications in Energy Storage

    Kai Zhang, Xiaoman Lin, Yanlin Shi, Kenichi Oyaizu, Zhongfan Jia

    ACS Electrochemistry    2025.02

    DOI

  • Bleaching effect of high refractive index xylylic poly(thiourea)s with “de-conjugated” polarizable hydrogen bonds

    Seigo Watanabe, Yoshino Tsunekawa, Kenichi Oyaizu

    Chemical Communications    2025

    DOI

  • Combining low viscosity and high volumetric redox density of organic polymers for energy-efficient catholytes in redox flow batteries: a redox-active polyelectrolyte approach

    Kohei Ishigami, Kenichi Oyaizu

    Journal of Materials Chemistry A    2025

    DOI

  • Poly(dibenzothiophenylene sulfide)s: Sulfur-rich Annulated Frameworks with Wide-Range Ultrahigh Refractive Index

    Seigo Watanabe, Zexin An, Hiromichi Nishio, Yoshino Tsunekawa, Kenichi Oyaizu

    Journal of Materials Chemistry C    2025

    　View Summary

    Poly(phenylene sulfide) (PPS) derivatives exhibit remarkable high-refractive properties due to their elevated sulfur content. However, their refractive indices (RI) have typically been limited in nD ~ 1.7-1.8, primarily due to...

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Enhanced Durability of Ca Metal Battery with Dual Salt: Synergistic Effect on Solid Electrolyte Interphase and Solvation Structure for Improved Electrodeposition

    Kazuaki Kisu, Arunkumar Dorai, Kan Hatakeyama-Sato, Tomoya Takano, Shigeyuki Takagi, Kenichi Oyaizu, Shin-ichi Orimo

    ACS Applied Materials & Interfaces    2024.12

    DOI

    Scopus

    7
    Citation
    (Scopus)

  • Aromatic Poly(dithioacetal)s: Spanning Degradability, Thermostability, and High Refractive Index Towards Eco‐friendly Optics

    Seigo Watanabe, Tomoya Yano, Zexin An, Kenichi Oyaizu

    ChemSusChem    2024.09

    　View Summary

    In the quest for eco‐friendly optics, high refractive index polymers (HRIPs) with degradability have been one of the desirable optical materials for realizing eco‐friendly and efficient lighting technologies. However, it has been challenging for HRIPs to simultaneously realize thermostability, high refractive index (RI), visible transparency, and efficient degradability, all of which are essential for their practical use. In this context, we herein focus on aromatic poly(dithioacetal)s, composed of visible‐transparent yet degradable dithioacetal moieties and rigid diphenyl disulfide spacers, exhibiting moderately high Tg (> 60 °C), high RI (> 1.7), and colorless film features. In addition, poly(dithioacetal)s can balance (1) high stability under the operating conditions even upon heating and (2) quantitative degradability that can selectively yield cyclic low‐molecular‐weight products that can be further repolymerized upon further addition of an acid catalyst. These results provide a key concept for high refractive index polymers that allow on‐demand degradability and recyclability without compromising their high potential thermal and optical properties.

    DOI

    Scopus

    7
    Citation
    (Scopus)

  • Sulfur-containing soft Lewis base polymers for improved lithium-ion conductivity under polymer-in-salt conditions

    Akinari Chiba, Kan Hatakeyama-Sato, Kenichi Oyaizu

    Bulletin of the Chemical Society of Japan   97 ( 5 )  2024.04

    　View Summary

    Abstract

    Solid polymer electrolytes have been intensively studied to improve the safety and energy density of lithium-ion batteries (LiBs). Although high-rate performance of LiBs has been reported in electrolytes under polymer-in-salt conditions with an excess of lithium salts and polymers, effective conditions for achieving high ionic conductivity remain unresolved. In this study, we elucidate the mechanism and high Li-ion transportability of poly(sulfone-thioether) under polymer-in-salt conditions. In particular, the composition of the polymer with an asymmetric Li salt, lithium(fluorosulfonyl)(trifluoromethane sulfonyl)imide (LiFTFSI), induced a high ionic conductivity above 10−5 S/cm, which is higher than that of the poly(ethylene oxide) (PEO)-Li salt system. Under polymer-in-salt conditions, the enhanced conductivity of poly(sulfone-thioether) contrasts with the conductivity drop observed in the conventional PEO system. These results show the superiority of polymers with soft Lewis bases, such as sulfur donor atoms, for Li-ion transport under polymer-in-salt conditions.

    DOI

    Scopus

    7
    Citation
    (Scopus)

  • Polarizable H‐Bond Concept in Aromatic Poly(thiourea)s: Unprecedented High Refractive Index, Transmittance, and Degradability at Force to Enhance Lighting Efficiency

    Seigo Watanabe, Luca M. Cavinato, Vladimir Calvi, Richard van Rijn, Rubén D. Costa, Kenichi Oyaizu

    Advanced Functional Materials    2024.04

    　View Summary

    Abstract

    Developing transparent and highly refractive environmentally friendly polymers has not been realized yet toward sustainable optoelectronics. This work describes poly(thiourea)s (PTUs) design following a new “polarizable group synergy” concept, combining highly polarizable hydrogen bonding groups and aromatic‐based spacers to form densely packed and high‐refractive‐index polymer networks. Specifically, PTUs containing m‐ and p‐phenylene spacers exhibit an easy synthesis, high thermostability (Tg = 159 °C), visible transparency (>92%T at 1 µm‐film), ultra‐high refractive index (nD = 1.81) based on the random H‐bonding arrays with a high packing constant (Kp = 0.738), and straightforward preparation of flexible films via solvent‐based techniques. Capitalizing on these assets, PTU‐films are integrated into benchmark graphene‐based lighting device architectures based on the light‐emitting electrochemical cells (LECs) concept. A joint optical modeling and experimental validation confirm the increase in external quantum efficiency expected by the enhanced light out‐coupling of PTU‐films. Finally, PTUs are efficiently depolymerized to low molecular weight compounds by simply adding diamines under heating, following the dynamic covalent bond exchange between thiourea moieties. Overall, this work highlights the PTU family as new promising materials with a unique polarizable H‐bond design to meet efficient and sustainable thin‐film lighting devices.

    DOI

    Scopus

    19
    Citation
    (Scopus)

  • Diverse Side-Chain Transformation of High Refractive Index Methylthio-Substituted Poly(phenylene sulfide)s

    Seigo Watanabe, Yoshino Tsunekawa, Teru Takayama, Kenichi Oyaizu

    Macromolecules   57 ( 6 ) 2897 - 2904  2024.03

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Reversible and high-density energy storage with polymers populated with bistable redox sites

    Kenichi Oyaizu

    Polymer Journal    2024.03

    DOI

    Scopus

    8
    Citation
    (Scopus)

  • Prediction of Photochromism of Salicylideneaniline Crystals Using a Data Mining Approach

    Shodai Hasebe, Kan Hatakeyama-Sato, Kenichi Oyaizu, Toru Asahi, Hideko Koshima

    ACS Omega    2023.12

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Precise Potential Tuning for Polymer-Mediated Aqueous Redox Flow Battery with Lithium Iron Phosphate as Target Cathode

    Yuto Igarashi, Kan Hatakeyama-Sato, Kan Kitagawa, Ryota Shinozaki, Kenichi Oyaizu

    ACS Applied Polymer Materials    2023.12

    DOI

    Scopus

    5
    Citation
    (Scopus)

  • Redox: Organic Robust Radicals and Their Polymers for Energy Conversion/Storage Devices

    Kan Hatakeyama-Sato, Kenichi Oyaizu

    Chemical Reviews    2023.09  [Refereed]  [Invited]

    DOI

    Scopus

    69
    Citation
    (Scopus)

  • Designing Strategy for High Refractive Index Polymers: From the Molecular Level to Bulk Structure Control

    Seigo Watanabe, Kenichi Oyaizu

    Bulletin of the Chemical Society of Japan    2023.08

    DOI

    Scopus

    34
    Citation
    (Scopus)

  • Combination of Poly(3-butylthiophene) Hole-Transporting Layer and Butylammonium Interface Passivation to Improve an Inorganic Perovskite Solar Cell

    Megumi Kojima, Lyufei Xue, Kenichi Oyaizu, Hiroyuki Nishide, Takeo Suga

    ACS Applied Polymer Materials    2023.06

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • All‐Solid‐State Rechargeable Air Batteries Using Dihydroxybenzoquinone and Its Polymer as the Negative Electrode

    Makoto Yonenaga, Yusuke Kaiwa, Kouki Oka, Kenichi Oyaizu, Kenji Miyatake

    Angewandte Chemie    2023.05  [Refereed]

    Authorship：Corresponding author

    DOI

  • All‐Solid‐State Rechargeable Air Batteries Using Dihydroxybenzoquinone and Its Polymer as the Negative Electrode

    Makoto Yonenaga, Yusuke Kaiwa, Kouki Oka, Kenichi Oyaizu, Kenji Miyatake

    Angewandte Chemie International Edition    2023.05  [Refereed]

    Authorship：Corresponding author

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Sandwich Configuration of Zinc Anode, Gel Electrolyte, and Radical Polymer Cathode for Fully Stretch‐Rechargeable Battery

    Jin‐Chieh Ho, Kan Hatakeyama‐Sato, Akinari Chiba, Masaki Hayashi, Yuto Igarashi, Kenichi Oyaizu, Wen‐Chang Chen

    Advanced Sustainable Systems    2023.04  [Refereed]

    Authorship：Corresponding author

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Thianthrene polymers as 4 V-class organic mediators for redox targeting reaction with LiMn2O4 in flow batteries

    Kan Hatakeyama-Sato, Karin Sadakuni, Kan Kitagawa, Kenichi Oyaizu

    Scientific Reports   13 ( 1 )  2023.04  [Refereed]

    Authorship：Last author, Corresponding author

    　View Summary

    Abstract

    Redox targeting reaction is an emerging idea for boosting the energy density of redox-flow batteries: mobile redox mediators transport electrical charges in the cells, whereas large-density electrode-active materials are fixed in tanks. This study reports 4 V-class organic polymer mediators using thianthrene derivatives as redox units. The higher potentials than conventional organic mediators (up to 3.8 V) enable charging LiMn2O4 as an inorganic cathode offering a large theoretical volumetric capacity of 500 Ah/L. Soluble or nanoparticle polymer design is beneficial for suppressing crossover reactions (ca. 3% after 300 h), simultaneously contributing to mediation reactions. The successful mediation cycles observed by repeated charging/discharging steps indicate the future capability of designing particle-based redox targeting systems with porous separators, benefiting from higher energy density and lower cost.

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • Supramolecular Cross-Linking of Thiophenylene Polymers via Multiple Hydrogen Bonds toward High Refractive Index

    Seigo Watanabe, Hiromichi Nishio, Teru Takayama, Kenichi Oyaizu

    ACS Applied Polymer Materials   5 ( 4 ) 2307 - 2311  2023.03

    DOI

    Scopus

    22
    Citation
    (Scopus)

  • Facile synthesis of telechelic poly(phenylene sulfide)s by means of electron-deficient aromatic sulfonium electrophiles

    Seigo Watanabe, Hiromichi Nishio, Kenichi Oyaizu

    RSC Advances   13 ( 46 ) 32363 - 32370  2023

    　View Summary

    This paper reports a facile synthesis of telechelic poly(phenylene sulfide)s through the Friedel–Crafts type electrophilic substitution of the poly(phenylene sulfide) precursors and the halogenated electron-deficient aromatic sulfonium cation.

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Using GPT-4 in Parameter Selection of Polymer Informatics: Improving Predictive Accuracy Amidst Data Scarcity and 'Ugly Duckling' Dilemma

    Kan Hatakeyama-Sato, Seigo Watanabe, Naoki Yamane, Yasuhiko Igarashi, Kenichi Oyaizu

    Digital Discovery    2023

    　View Summary

    Materials informatics and cheminformatics struggle with data scarcity, hindering the extraction of significant relationships between structures and properties. The "Ugly Duckling" theorem, suggesting the difficulty of data processing without assumptions...

    DOI

    Scopus

    9
    Citation
    (Scopus)

  • Extracting higher-conductivity designs for solid polymer electrolytes by quantum-inspired annealing

    Kan Hatakeyama-Sato, Yasuei Uchima, Takahiro Kashikawa, Koichi Kimura, Kenichi Oyaizu

    RSC Advances   13 ( 21 ) 14651 - 14659  2023  [Refereed]

    Authorship：Last author, Corresponding author

    　View Summary

    A quantum-inspired annealing system with a hybrid algorithm accelerates functional material discovery, shown by high-conductivity polymer electrolytes.

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Accelerating the Dehydrogenation Reaction of Alcohols by Introducing Them into Poly(allylamine)

    Kouki Oka, Yusuke Kaiwa, Kazuki Kobayashi, Yuka Tobita, Kenichi Oyaizu

    Polymer Chemistry    2023  [Refereed]

    Authorship：Last author, Corresponding author

    　View Summary

    A novel quaternized polymer was synthesized by introducing butanediol into poly(allylamine) and converting the remaining amino groups into quaternary ammonium cations. The polymer accelerated the dehydrogenation of butanediol due to...

    DOI

    Scopus

    5
    Citation
    (Scopus)

  • Charge-transport kinetics of dissolved redox-active polymers for rational design of flow batteries

    Kan Hatakeyama-Sato, Yuto Igarashi, Kenichi Oyaizu

    RSC Advances   13 ( 1 ) 547 - 557  2023  [Refereed]

    Authorship：Last author, Corresponding author

    　View Summary

    Electrochemical kinetics of dissolved redox-active polymers are formulated. The model can be used for the rational design of redox-flow cells.

    DOI

    Scopus

    14
    Citation
    (Scopus)

  • Accelerating charge/discharge of lithium iron phosphate by charge mediation reaction of poly(dimethylfluoflavin-substituted norbornene)

    Kan Hatakeyama-Sato, Choitsu Go, Takahiro Kaseyama, Takuji Yoshimoto, Kenichi Oyaizu

    Chemistry Letters   51 ( 11 ) 1040 - 1043  2022.09  [Refereed]

    Authorship：Last author, Corresponding author

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Transcending the Trade-off in Refractive Index and Abbe Number for Highly Refractive Polymers: Synergistic Effect of Polarizable Skeletons and Robust Hydrogen Bonds

    Seigo Watanabe, Teru Takayama, Kenichi Oyaizu

    ACS Polymers Au    2022.08  [Refereed]

    Authorship：Last author, Corresponding author

    DOI

  • Exploration of organic superionic glassy conductors by process and materials informatics with lossless graph database

    Kan Hatakeyama-Sato, Momoka Umeki, Hiroki Adachi, Naoaki Kuwata, Gen Hasegawa, Kenichi Oyaizu

    npj Computational Materials   8 ( 1 )  2022.08  [Refereed]

    Authorship：Last author, Corresponding author

    　View Summary

    Abstract

    Data-driven material exploration is a ground-breaking research style; however, daily experimental results are difficult to record, analyze, and share. We report a data platform that losslessly describes the relationships of structures, properties, and processes as graphs in electronic laboratory notebooks. As a model project, organic superionic glassy conductors were explored by recording over 500 different experiments. Automated data analysis revealed the essential factors for a remarkable room temperature ionic conductivity of 10−4–10−3 S cm−1 and a Li+ transference number of around 0.8. In contrast to previous materials research, everyone can access all the experimental results, including graphs, raw measurement data, and data processing systems, at a public repository. Direct data sharing will improve scientific communication and accelerate integration of material knowledge.

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Automated Design of Li + ‐Conducting Polymer by Quantum‐Inspired Annealing

    Kan Hatakeyama‐Sato, Hiroki Adachi, Momoka Umeki, Takahiro Kashikawa, Koichi Kimura, Kenichi Oyaizu

    Macromolecular Rapid Communications     2200385 - 2200385  2022.06  [Refereed]

    Authorship：Last author, Corresponding author

    　View Summary

    Automated molecule design by computers has been an essential topic in materials informatics. Still, generating practical structures is not easy because of the difficulty in treating material stability, synthetic difficulty, mechanical properties, and other miscellaneous parameters, often leading to the generation of junk molecules. We tackle the problem by introducing supervised/unsupervised machine learning and quantum-inspired annealing. Our autonomous molecular design system can help experimental researchers discover practical materials more efficiently. Like the human design process, new molecules are explored based on knowledge of existing compounds. A new solid-state polymer electrolyte for lithium-ion batteries is designed and synthesized, giving a promising room temperature conductivity of 10^-5 S/cm with reasonable thermal, chemical, and mechanical properties.

    DOI

    Scopus

    12
    Citation
    (Scopus)

  • Quadruply fused aromatic heterocycles toward 4 V‐class robust organic cathode‐active materials

    Kan Hatakeyama-Sato, Choitsu Go, Tomoki Akahane, Takahiro Kaseyama, Takuji Yoshimoto, Kenichi Oyaizu

    Batteries Supercaps   5 ( 8 )  2022.04  [Refereed]

    Authorship：Last author, Corresponding author

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Polymers for Reversible Hydrogen Storage Inspired by Electrode-active Materials in Organic Batteries

    Y. Kaiwa, K. Kobayashi, M. Kataoka, Y. Tobita, K. Oyaizu

    Int. J. Soc. Mater. Eng. Resour.   25   1 - 9  2022.04  [Refereed]

    Authorship：Last author, Corresponding author

  • Polymers for Safe Hydrogen Storage

    Kouki Oka, Yuka Tobita, Miho Kataoka, Kazuki Kobayashi, Yusuke Kaiwa, Hiroyuki Nishide, Kenichi Oyaizu

    Polymer International   71 ( 3 )  2022.03  [Refereed]

    DOI

  • Cover Image

    Kouki Oka, Yuka Tobita, Miho Kataoka, Kazuki Kobayashi, Yusuke Kaiwa, Hiroyuki Nishide, Kenichi Oyaizu

    Polymer International   71 ( 3 )  2022.03

    DOI

  • Poly(vinyl diphenylquinoxaline) as a hydrogen storage material toward rapid hydrogen evolution

    Kouki Oka, Miho Kataoka, Hiroyuki Nishide, Kenichi Oyaizu

    MRS Communications   12 ( 2 ) 213 - 216  2022.02  [Refereed]

    Authorship：Last author, Corresponding author

    DOI

    Scopus

    8
    Citation
    (Scopus)

  • Designing Ultrahigh-Refractive-Index Amorphous Poly(phenylene sulfide)s Based on Dense Intermolecular Hydrogen-Bond Networks

    Seigo Watanabe, Kenichi Oyaizu

    Macromolecules    2022.02  [Refereed]

    Authorship：Last author, Corresponding author

    DOI

    Scopus

    33
    Citation
    (Scopus)

  • Quantum circuit learning as a potential algorithm to predict experimental chemical properties

    Kan Hatakeyama-Sato, Yasuhiko Igarashi, Takahiro Kashikawa, Koichi Kimura, Kenichi Oyaizu

    Digital Discovery   2 ( 1 ) 165 - 176  2022  [Refereed]

    Authorship：Last author, Corresponding author

    　View Summary

    We introduce quantum circuit learning (QCL) as an emerging regression algorithm for chemo- and materials-informatics. The supervised model, functioning on the rule of quantum mechanics, can process linear and smooth...

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • Synthesis of colorless and high-refractive-index sulfoxide-containing polymers by the oxidation of poly(phenylene sulfide) derivatives

    Seigo Watanabe, Teru Takayama, Hiromichi Nishio, Kanta Matsushima, Yoko Tanaka, Seiya Saito, Yushun Sun, Kenichi Oyaizu

    Polymer Chemistry    2022  [Refereed]

    Authorship：Last author, Corresponding author

    　View Summary

    A series of poly(phenylene sulfide) (PPS) derivatives can be bleached while maintaining high refractive indices, by partially incorporating sulfoxide bonds through their mCPBA oxidation, owing to the loss of lone pairs around the sulfide atoms.

    DOI

    Scopus

    19
    Citation
    (Scopus)

  • Hydrophilic isopropanol/acetone‐substituted polymers for safe hydrogen storage

    Kouki Oka, Yuka Tobita, Miho Kataoka, Kazuki Kobayashi, Yusuke Kaiwa, Hiroyuki Nishide, Kenichi Oyaizu

    Polymer International   71 ( 3 ) 348 - 351  2021.12  [Refereed]

    Authorship：Last author, Corresponding author

    DOI

    Scopus

    9
    Citation
    (Scopus)

  • Alcohol-substituted Vinyl Polymers for Stockpiling Hydrogen

    Kouki Oka, Miho Kataoka, Yusuke Kaiwa, Kenichi Oyaizu

    Bulletin of the Chemical Society of Japan   94 ( 11 ) 2770 - 2773  2021.10  [Refereed]

    Authorship：Last author, Corresponding author

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • Synthesis of methylated phenylene sulfide polymers via bulk oxidative polymerization and their heat curing triggered by dynamic disulfide exchange

    Seigo Watanabe, Seiya Saito, Motoyasu Hirai, Kenichi Oyaizu

    Polymer Journal    2021.09  [Refereed]

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Catechol End-Capped Poly(arylene sulfide) as a High-Refractive-Index “TiO2/ZrO2-Nanodispersible” Polymer

    Seigo Watanabe, Kenichi Oyaizu

    ACS Applied Polymer Materials   3 ( 9 ) 4495 - 4503  2021.09  [Refereed]

    DOI

    Scopus

    21
    Citation
    (Scopus)

  • A PROXYL‐Type Norbornene Polymer for High‐Voltage Cathodes in Lithium Batteries

    Kan Hatakeyama‐Sato, Satoshi Matsumoto, Hirofumi Takami, Tomomi Nagatsuka, Kenichi Oyaizu

    Macromolecular Rapid Communications   42 ( 19 ) 2100374 - 2100374  2021.08  [Refereed]

    Authorship：Last author, Corresponding author

    DOI

    Scopus

    16
    Citation
    (Scopus)

  • Generative Models for Extrapolation Prediction in Materials Informatics

    Kan Hatakeyama-Sato, Kenichi Oyaizu

    ACS Omega   6 ( 22 ) 14566 - 14574  2021.06  [Refereed]

    DOI

    Scopus

    18
    Citation
    (Scopus)

  • Hydrophilic Anthraquinone-Substituted Polymer: Its Environmentally Friendly Preparation and Efficient Charge/Proton-Storage Capability for Polymer–Air Secondary Batteries

    Kouki Oka, Saki Murao, Miho Kataoka, Hiroyuki Nishide, Kenichi Oyaizu

    Macromolecules   54 ( 10 ) 4854 - 4859  2021.05  [Refereed]

    DOI

    Scopus

    25
    Citation
    (Scopus)

  • Anomalous potential shifts of redox-active molecules in highly concentrated electrolytes

    Kan Hatakeyama-Sato, Satoshi Matsumoto, Ikuma Aida, Kenichi Oyaizu

    Chemistry Letters   50 ( 7 ) 1375 - 1377  2021.04  [Refereed]

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • Tackling the Challenge of a Huge Materials Science Search Space with Quantum‐Inspired Annealing

    Kan Hatakeyama-Sato, Takahiro Kashikawa, Koichi Kimura, Kenichi Oyaizu

    Advanced Intelligent Systems   3 ( 4 ) 2000209 - 2000209  2021.04  [Refereed]

    DOI

  • Synthesis of vinyl polymers substituted with 2-propanol and acetone and investigation of their reversible hydrogen storage capabilities

    Kenichi Oyaizu

    Polymer Journal   53 ( 7 ) 799 - 804  2021.03  [Refereed]

    DOI

    Scopus

    12
    Citation
    (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 ( 1 ) 6 - 11  2021.03

  • Facile reversible hydrogenation of a poly(6‐vinyl‐2,3‐dimethyl‐1,2,3,4‐tetrahydroquinoxaline) gel‐like solid

    Yusuke Kaiwa, Kouki Oka, Hiroyuki Nishide, Kenichi Oyaizu

    Polymers for Advanced Technologies   32 ( 3 ) 1162 - 1167  2021.03  [Refereed]

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • Nitroxide radical polymers for emerging plastic energy storage and organic electronics: fundamentals, materials, and applications

    Kenichi Oyaizu

    Materials Horizons   8 ( 3 ) 803 - 829  2021.03  [Refereed]

    　View Summary

    <p>We review the electrochemical theory, material design, and device fabrication for nitroxide radical polymers in emerging plastic energy storage and organic electronics.</p>

    DOI

    Scopus

    97
    Citation
    (Scopus)

  • TEMPO‐Substituted Poly(ethylene sulfide) for Solid‐State Electro‐Chemical Charge Storage

    Kan Hatakeyama‐Sato, Hisato Wakamatsu, Satoshi Matsumoto, Karin Sadakuni, Koji Matsuoka, Tomomi Nagatsuka, Kenichi Oyaizu

    Macromolecular Rapid Communications   42 ( 4 ) 2000607 - 2000607  2021.02  [Refereed]

    DOI

    Scopus

    14
    Citation
    (Scopus)

  • Unravelling kinetic and mass transport effects on two-electron storage in radical polymer batteries

    Kai Zhang, Yuan Xie, Benjamin B. Noble, Michael J. Monteiro, Jodie L. Lutkenhaus, Kenichi Oyaizu, Zhongfan Jia

    Journal of Materials Chemistry A   9 ( 22 ) 13071 - 13079  2021  [Refereed]

    　View Summary

    <p>Electron transfer and mass transport kinetics between two redox couples in nitroxide radical polymers was investigated. Such impact on two-electron storage in radical polymer batteries was exemplified by two macromolecular structures.</p>

    DOI

    Scopus

    33
    Citation
    (Scopus)

  • Electrochemical characterization and thermodynamic analysis of TEMPO derivatives in ionic liquids

    Luke Wylie, Kan Hakatayama-Sato, Choitsu Go, Kenichi Oyaizu, Ekaterina I. Izgorodina

    Physical Chemistry Chemical Physics   23 ( 17 ) 10205 - 10217  2021  [Refereed]

    　View Summary

    <p>In this study we tailor the reversibility of the reduction process of three TEMPO derivatives – TEMPOL, 4-cyano-TEMPO, and 4-oxo-TEMPO – using ionic liquids.</p>

    DOI

    Scopus

    20
    Citation
    (Scopus)

  • Charge- and Proton-Storage Capability of Naphthoquinone-Substituted Poly(allylamine) as Electrode-Active Material for Polymer–Air Secondary Batteries

    Kouki Oka, Saki Murao, Kazuki Kobayashi, Hiroyuki Nishide, Kenichi Oyaizu

    ACS Applied Energy Materials   3 ( 12 ) 12019 - 12024  2020.12  [Refereed]

    DOI

    Scopus

    22
    Citation
    (Scopus)

  • Reversible Reduction of the TEMPO Radical: One Step Closer to an All-Organic Redox Flow Battery

    Kenichi Oyaizu

    ACS Sustainable Chemistry & Engineering   8 ( 49 ) 17988 - 17996  2020.12  [Refereed]

    DOI

    Scopus

    60
    Citation
    (Scopus)

  • Integrating multiple materials science projects in a single neural network

    Kan Hatakeyama-Sato, Kenichi Oyaizu

    Communications Materials   1 ( 1 )  2020.12  [Refereed]

    DOI

    Scopus

    19
    Citation
    (Scopus)

  • AIを活用した新規イオン伝導性高分子の探索と開発

    畠山歓, 小柳津研一

    機能材料   40   33 - 45  2020.11

    Authorship：Corresponding author

  • Charge-Transfer Complexes for Solid-State Li+ Conduction

    Kan Hatakeyama-Sato, Momoka Umeki, Toshiki Tezuka, Kenichi Oyaizu

    ACS Applied Electronic Materials   2 ( 7 ) 2211 - 2217  2020.07  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • 有機電極活物質を用いた二次電池･レドックスフロー電池

    小柳津研一

    電池技術   32   53 - 58  2020

  • 有機ポリマー電池の研究動向

    小柳津研一

    高分子   69   104 - 106  2020

  • “Progress in Organic Polymer Batteries”, Digest for English Readers

    K. Oyaizu

    Kobunshi   69   93  2020

  • AI-assisted Exploration of Superionic Glass-type Li+ Conductors with Aromatic Structures

    K. Hatakeyama-Sato, T. Tezuka, M. Umeki, K. Oyaizu

    J. Am. Chem. Soc.   142 ( 7 ) 3301 - 3305  2020  [Refereed]

    DOI

    Scopus

    90
    Citation
    (Scopus)

  • Poly(dihydroxybenzoquinone): Its High-density and Robust Charge Storage Capability in Rechargeable Acidic Polymer-air Batteries

    K. Oka, S. Furukawa, S. Murao, T. Oka, H. Nishide, K. Oyaizu

    Chem. Commun.   56 ( 29 ) 4055 - 4058  2020  [Refereed]

    DOI PubMed

  • Metal-free, Solid-state, and Paper-like Rechargeable Batteries Consisting of Redox-active Polyethers

    K. Hatakeyama-Sato, T. Tezuka, R. Ichinoi, S. Matsumono, K. Sadakuni, K. Oyaizu

    ChemSusChem   13 ( 9 ) 2443 - 2448  2020  [Refereed]

    DOI

    Scopus

    28
    Citation
    (Scopus)

  • Ultrafast Charge/discharge by a 99.9% Conventional Lithium Iron Phosphate Electrode Containing 0.1% Redox-active Fluoflavin Polymer

    K. Hatakeyama-Sato, T. Akahane, C. Go, T. Kaseyama, T. Yoshimoto, K. Oyaizu

    ACS Energy Lett.   5 ( 5 ) 1712 - 1717  2020  [Refereed]

    DOI

    Scopus

    29
    Citation
    (Scopus)

  • Conducting Redox Polymer as a Robust Organic Electrode-active Material in Acidic Aqueous Electrolyte towards Polymer-air Secondary Batteries

    K. Oka, C. Strietzel, R. Emanuelsson, H. Nishide, K. Oyaizu, M. Strømme, M. Sjödin

    ChemSusChem   13 ( 9 ) 2280 - 2285  2020  [Refereed]

    DOI PubMed

    Scopus

    32
    Citation
    (Scopus)

  • Phenolic Antioxidant-incorporated Durable Perovskite Layers and Their Application for a Solar Cell

    K. Suwa, T. Suga, K. Oyaizu, H. Segawa, H. Nishide

    MRS Commun.   10 ( 2 ) 312 - 316  2020  [Refereed]

    DOI

    Scopus

    11
    Citation
    (Scopus)

  • Reversible Hydrogen Fixation and Release under Mild Conditions by Poly(vinylquinoxaline)

    K. Oka, Y. Kaiwa, S. Furukawa, H. Nishide, K. Oyaizu

    ACS Appl. Polym. Mater.   2 ( 7 ) 2756 - 2760  2020  [Refereed]

    DOI

    Scopus

    17
    Citation
    (Scopus)

  • Allylic Hydrocarbon Polymers Complexed with Fe(II)(salen) as a Ultrahigh Oxygen-scavenging and Active Packaging Film

    Y. Wang, K. Oyaizu, H. Nishide

    Pure Appl. Chem.   92   871 - 882  2020  [Refereed]

    　View Summary

    <jats:title>Abstract</jats:title><jats:p>Macromolecular metal complexes provide a molecular-based synergy function of organic polymers and combined metal complexes. A new category of macromolecular complexes includes catalytically active metal complexes immobilized by organic polymers containing reactive substrate moieties in their repeating units. Here, we describe the extremely efficient oxidation of allylic hydrocarbon polymers with the attached iron complex catalyst, as well as the efficient oxygen-consumption or oxygen-scavenging function of the matrix polymer film. The less toxic <jats:italic>N</jats:italic>,<jats:italic>N</jats:italic>´-di(salicylaldehyde)ethylenediiminatoiron(II) complex was combined with or fixed onto a series of allylic hydrocarbon polymers as both the oxidative substrate and the film matrix, i.e. poly(1,2-butadiene), polynorbornene, poly(5-vinyl-2-norbornene), poly(2,5-norboenadiene), poly(dicyclopentadiene), and poly(5-ethylidene-2-norbornene). Ultra-high oxygen-scavenging capacity up to 300 mL (oxygen gas at STP)/g(film) was achieved, based on the oxidative consumption of the allylic bond (particularly of poly(5-ethylidene-2-norbornene)), which was more than three times that of the previously reported highest oxygen-scavenging polymers. These oxygen-scavenging films are based on the high reactivity of polymer-metal complexes that provides an innovative development in the area of active packaging polymer films that facilitate cost-effective performance, safety, and sustainability.</jats:p>

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • A Conducting Redox Polymer as Organic Anode Material for Polymer-manganese Secondary Batteries

    K. Oka, R. Löfgren, R. Emanuelsson, H. Nishide, K. Oyaizu, M. Strømme, M. Sjödin

    ChemElectroChem   7 ( 15 ) 3336 - 3340  2020  [Refereed]

    DOI

    Scopus

    21
    Citation
    (Scopus)

  • Polymer Sheet-based Hydrogen Carrier

    K. Oka, Y. Kaiwa, M. Kataoka, K. Fujita, K. Oyaizu

    Eur. J. Org. Chem.   2020 ( 36 ) 5876 - 5879  2020  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Methoxy-substituted Phenylenesulfide Polymer with Excellent Dispersivity of TiO2 Nanoparticles for Optical Application

    S. Watanabe, K. Oyaizu

    Bull. Chem. Soc. Jpn.   93 ( 11 ) 1287 - 1292  2020  [Refereed]

    DOI

  • 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

    Communn. Chem.   3 ( 1 ) 138  2020  [Refereed]

    DOI

    Scopus

    50
    Citation
    (Scopus)

  • A Highly Flexible Yet >300 mAh cm-3 Energy Density Lithium-ion Battery Assembled with the Cathode of a Redox-active Polyether Binder

    K. Hatakeyama-Sato, R. Mizukami, T. Serikawa, K. Oyaizu, H. Nishide

    Energy Technol.   8 ( 3 ) 1901159 - 1901159  2020  [Refereed]

    DOI

    Scopus

    5
    Citation
    (Scopus)

  • Ultrahigh oxygen-scavenging norbornene copolymers bearing imidazolyl iron complexes for fabricating active and sustainable packaging films

    Kenichi Oyaizu

    Chemical Communications   56   964 - 967  2020  [Refereed]

    　View Summary

    <p>A tough and transparent polynorbornene film affixing an iron–salen catalyst exhibited an ultra-high oxygen-scavenging capacity up to 300 mL g−1.</p>

    DOI

    Scopus

    5
    Citation
    (Scopus)

  • Facile Synthesis of Isotactic Polyacrylonitrile via Template Polymerization in Interlayer Space for Dielectric Energy Storage

    Y. Wang, R. Nakamura, T. Suga, S. Li, Y. Ohki, H. Nishide, K. Oyaizu

    ACS Appl. Polym. Mater.   2 ( 2 ) 775 - 781  2020  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • 有機系蓄電池の電荷貯蔵機構と将来性

    小柳津研一

    応用物理学会有機分子･バイオエレクトロニクス分科会誌   31   5 - 8  2020

  • Facile Synthesis of Poly(glycidyl ether)s with Ionic Pendant Groups by Thiol-ene Reactions

    K. Hatakeyama-Sato, S. Kimura, S. Matsumoto, K. Oyaizu

    Macromol. Rapid Commun.   41   1900399  2020  [Refereed]

    DOI

    Scopus

    9
    Citation
    (Scopus)

  • Redox-Active Polymers as an Organic Energy Storage Material

    Kenichi Oyaizu

    Conjugated Polymers    2019.03

    DOI

    Scopus

    12
    Citation
    (Scopus)

  • Toward Improved Performance of All-Organic Nitroxide Radical Batteries with Ionic Liquids: A Theoretical Perspective

    Kenichi Oyaizu

    ACS Sustainable Chem. Eng.   7   5367 - 5375  2019.03  [Refereed]

    DOI

    Scopus

    29
    Citation
    (Scopus)

  • Anti-oxidizing Radical Polymer-incorporated Perovskite Layers and Their Photovoltaic Characteristics in Solar Cells

    K. Suwa, K. Oyaizu, H. Segawa, H. Nishide

    ChemSusChem   12   5207 - 5212  2019  [Refereed]

    DOI

    Scopus

    26
    Citation
    (Scopus)

  • Hole-transporting diketopyrrolopyrrole-thiophene polymers and their additive-free application for a perovskite-type solar cell with an efficiency of 16.3%

    Maruo, Hirofumi, Sasaki, Yusuke, Harada, Kohei, Suwa, Koki, Oyaizu, Kenichi, Segawa, Hiroshi, Carter, Kenneth, Nishide, Hiroyuki

    Polymer Journal   51 ( 1 ) 91 - 96  2019  [Refereed]

    DOI

    Scopus

    24
    Citation
    (Scopus)

  • Synthesis of Lithium-ion Conducting Polymers Designed by Machine Learning-based Prediction and Screening

    K. Hatakeyama-Sato, T. Tezuka, Y. Nishikitani, H. Nishide, K. Oyaizu

    Chem. Lett.   48 ( 2 ) 130 - 132  2019  [Refereed]

    DOI

    Scopus

    43
    Citation
    (Scopus)

  • Hydrophilic Organic Redox-active Polymer Nanoparticles for Higher Energy Density Flow Batteries

    K. Hatakeyama-Sato, T. Nagano, S. Noguchi, Y. Sugai, J. Du, H. Nishide, K. Oyaizu

    ACS Applied Polym. Mater.   1 ( 2 ) 188 - 196  2019  [Refereed]

    DOI

    Scopus

    52
    Citation
    (Scopus)

  • Ultra-thin and Stretchable Rechargeable Devices with Organic Polymer Nanosheets Conformable to Skin Surface

    K. Hatakeyama-Sato, H. Wakamatsu, K. Yamagishi, T. Fujie, S. Takeoka, K. Oyaizu, H. Nishide

    Small   2019 ( 13 ) 1805296 - 1805296  2019  [Refereed]

    DOI

    Scopus

    38
    Citation
    (Scopus)

  • Full Organic Aqueous Battery Based on TEMPO Small Molecule with Millimeter-thick Electrodes

    S. Perticarari, E. Grange, T. Doizy, E. Quarez, K. Oyaizu, D. Guyomard, P. Poizot, F. Odobel, J. Gaubicher

    Chem. Mater.   31   1869 - 1880  2019  [Refereed]

    DOI

    Scopus

    45
    Citation
    (Scopus)

  • Perovskite/TiO2 Interface Passivation Using Poly(vinylcarbazole) and Fullerene for the Photovoltaic Conversion Efficiency of 21%

    W. Okada, T. Suga, K. Oyaizu, H. Segawa, H. Nishide

    ACS Appl. Energy Mater.   2 ( 4 ) 2848 - 2853  2019  [Refereed]

    DOI

    Scopus

    32
    Citation
    (Scopus)

  • n-Type Redox-active Benzoylpyridinium-substituted Supramolecular Gel for an Organogel-based Rechargeable Device

    K. Hatakeyama-Sato, R. Ichinoi, Y. Sasada, Y. Sasaki, K. Oyaizu, H. Nishide

    Chem. Lett.   48 ( 6 ) 555 - 557  2019  [Refereed]

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Reversible Hydrogen Releasing and Fixing with Poly(vinylfluorenol) through a Mild Ir-Catalyzed Dehydrogenation and Electrochemical Hydrogenation

    R. Kato, K. Oka, K. Yoshimasa, M. Nakajima, H. Nishide, K. Oyaizu

    Macromol. Rapid Commun.   2019 ( 16 ) 1900139  2019  [Refereed]

    DOI PubMed

    Scopus

    23
    Citation
    (Scopus)

  • Characterization of PEDOT-quinone Conducting Redox Polymers in Water-in-salt Electrolytes for Safe and High-Energy Li-Ion Batteries

    K. Oka, C. Strietzel, R. Emanuelsson, H. Nishide, K. Oyaizu, M. Strømme, M. Sjödin

    Electrochem. Commun.   105   106489  2019  [Refereed]

    DOI

    Scopus

    33
    Citation
    (Scopus)

  • Oxygen Scavenging and Oxygen Barrier Poly(1,2-butadiene) Films Containing an Iron-complex Catalyst

    Y. Wang, M. Shoda, A. Hisama, K. Oyaizu, H. Nishide

    Macromol. Chem. Phys.   2019   1900294  2019  [Refereed]

    DOI

    Scopus

    8
    Citation
    (Scopus)

  • Non-conjugated Redox-active Polymer Mediators for Rapid Electrocatalytic Charging of Lithium Metal Oxides

    K. Hatakeyama-Sato, T. Masui, T. Serikawa, Y. Sasaki, W. Choi, S. -G. Doo, H. Nishide, K. Oyaizu

    ACS Appl. Energy Mater.   2 ( 9 ) 6375 - 6382  2019  [Refereed]

    DOI

    Scopus

    27
    Citation
    (Scopus)

  • An Ultrahigh Output Rechargeable Electrode of a Hydrophilic Radical Polymer/Nanocarbon Hybrid with an Exceptionally Large Current Density beyond 1 A cm−2

    Kan Hatakeyama-Sato, Hisato Wakamatsu, Ryu Katagiri, Kenichi Oyaizu, Hiroyuki Nishide

    Advanced Materials   30 ( 26 ) 1800900  2018.06  [Refereed]

    DOI

    Scopus

    91
    Citation
    (Scopus)

  • Arylamine polymers prepared via facile paraldehyde addition condensation: an effective hole-transporting material for perovskite solar cells

    Koki Suwa, Suguru Tanaka, Kenichi Oyaizu, Hiroyuki Nishide

    Polymer International   67 ( 6 ) 670 - 674  2018.06  [Refereed]

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • Polymer-Based White-Light-Emitting Electrochemical Cells with Very High Color-Rendering Index Based on Blue-Green Fluorescent Polyfluorenes and Red-Phosphorescent Iridium Complexes

    Yoshinori Nishikitani, Tetsuyuki Cho, Soichi Uchida, Suzushi Nishimura, Kenichi Oyaizu, Hiroyuki Nishide

    ChemPlusChem   83 ( 5 ) 463 - 469  2018.05  [Refereed]

    DOI

    Scopus

    23
    Citation
    (Scopus)

  • Oxoammonium cation of 2,2,6,6-tetramethylpiperidin-1-oxyl: A very efficient dopant for hole-transporting triaryl amines in a perovskite solar cell

    H. Maruo, S. Tanaka, M. Takamura, K. Oyaizu, H. Segawa, H. Nishide

    MRS Communications   8 ( 1 ) 122 - 126  2018.03  [Refereed]

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • Diffusion-Cooperative Model for Charge Transport by Redox-Active Nonconjugated Polymers

    Kan Sato, Rieka Ichinoi, Ryusuke Mizukami, Takuma Serikawa, Yusuke Sasaki, Jodie Lutkenhaus, Hiroyuki Nishide, Kenichi Oyaizu

    Journal of the American Chemical Society   140 ( 3 ) 1049 - 1056  2018.01  [Refereed]

    DOI

    Scopus

    149
    Citation
    (Scopus)

  • Poly(diphenanthrenequinone-substituted norbornene) for long life and efficient lithium battery cathodes

    Takuma Kawai, Satoshi Nakao, Hiroyuki Nishide, Kenichi Oyaizu

    Bulletin of the Chemical Society of Japan   91 ( 5 ) 721 - 727  2018  [Refereed]

    DOI

    Scopus

    16
    Citation
    (Scopus)

  • 酸化還元活性な高分子による集合組織の動的制御

    佐藤歓, 小柳津研一

    化学   73   70 - 71  2018

  • 有機材料でいかに電荷を貯蔵するか: 単一分子のレドックス反応から有機蓄電材料への展開

    小柳津研一, 西出宏之

    化学と工業   71   462 - 464  2018

  • Poly(vinyldibenzothiophenesulfone): Its Redox Capability at Very Negative Potential Toward an All-organic Rechargeable Device with High-energy Density

    K. Oka, R. Kato, K. Oyaizu, H. Nishide

    Adv. Funct. Mater.   28 ( 50 ) 1805858  2018  [Refereed]

    DOI

    Scopus

    49
    Citation
    (Scopus)

  • High-color-rendering-index white polymer light-emitting electrochemical cells based on ionic host-guest systems: Utilization of blend films of blue-fluorescent cationic polyfluorenes and red-phosphorescent cationic iridium complexes

    Yoshinori Nishikitani, Kotaro Suga, Soichi Uchida, Suzushi Nishimura, Kenichi Oyaizu, Hiroyuki Nishide

    ORGANIC ELECTRONICS   51   168 - 172  2017.12  [Refereed]

    DOI

    Scopus

    17
    Citation
    (Scopus)

  • Ag nanocluster-based color converters for white organic light-emitting devices

    Yoshinori Nishikitani, Daisuke Takizawa, Soichi Uchida, Yue Lu, Suzushi Nishimura, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF APPLIED PHYSICS   122 ( 18 ) 184302  2017.11  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Grafted radical polymer brush for surface-driven switching of chiral nematic liquid crystals

    Kan Sato, Takaaki Yamasaki, Hiroyuki Nishide, Kenichi Oyaizu

    POLYMER JOURNAL   49 ( 10 ) 691 - 693  2017.10  [Refereed]

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • Command Surface of Self-Organizing Structures by Radical Polymers with Cooperative Redox Reactivity

    Kan Sato, Takahiro Mizuma, Hiroyuki Nishide, Kenichi Oyaizu

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   139 ( 39 ) 13600 - 13603  2017.10  [Refereed]

    DOI

    Scopus

    17
    Citation
    (Scopus)

  • Synthesis of Highly Crystallized Poly(1,4-phenylene sulfide) via Oxygen-Oxidative Polymerization of Diphenyl Disulfide

    Fuyuki Aida, Naoto Takasu, Yohei Takatori, Hiroyuki Nishide, Kenichi Oyaizu

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   90 ( 7 ) 843 - 846  2017.07  [Refereed]

    DOI

    Scopus

    5
    Citation
    (Scopus)

  • Supramolecular Organic Radical Gels Formed with 2,2,6,6-Tetramethylpiperidin-1-oxyl-Substituted Cyclohexanediamines: A Very Efficient Charge-Transporting and -Storable Soft Material

    Yoshito Sasada, Rieka Ichinoi, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY OF MATERIALS   29 ( 14 ) 5942 - 5947  2017.07  [Refereed]

    DOI

    Scopus

    31
    Citation
    (Scopus)

  • Redox Mediation through TEMPO-substituted Polymer with Nanogap Electrodes for Electrochemical Amplification

    Hiroshi Tokue, Keita Kakitani, Hiroyuki Nishide, Kenichi Oyaizu

    CHEMISTRY LETTERS   46 ( 5 ) 647 - 650  2017.05  [Refereed]

    DOI

    Scopus

    11
    Citation
    (Scopus)

  • Totally Organic-based Bendable Rechargeable Devices Composed of Hydrophilic Redox Polymers and Aqueous Electrolyte

    Kan Sato, Ryu Katagiri, Natsuru Chikushi, Subin Lee, Kenichi Oyaizu, Jae-Suk Lee, Hiroyuki Nishide

    CHEMISTRY LETTERS   46 ( 5 ) 693 - 694  2017.05  [Refereed]

    DOI

    Scopus

    14
    Citation
    (Scopus)

  • Low-Cost, Organic Light-Emitting Electrochemical Cells with Mass-Producible Nanoimprinted Substrates Made Using Roll-to-Roll Methods

    Kan Sato, Soichi Uchida, Shigetaka Toriyama, Suzushi Nishimura, Kenichi Oyaizu, Hiroyuki Nishide, Yoshinori Nishikitani

    ADVANCED MATERIALS TECHNOLOGIES   2 ( 5 ) 1600293  2017.05  [Refereed]

    DOI

    Scopus

    41
    Citation
    (Scopus)

  • A hydrogen-storing quinaldine polymer: nickel-electrodeposition-assisted hydrogenation and subsequent hydrogen evolution

    Ryo Kato, Takahiro Oya, Yuma Shimazaki, Kenichi Oyaizu, Hiroyuki Nishide

    POLYMER INTERNATIONAL   66 ( 5 ) 647 - 652  2017.05  [Refereed]

    DOI

    Scopus

    11
    Citation
    (Scopus)

  • Charge Discharge with Rocking-Chair-Type Li+ Migration Characteristics in a Zwitterionic Radical Copolymer Composed of TEMPO and Trifluoromethanesulfonylimide with Carbonate Electrolytes for a High-Rate Li-Ion Battery

    Hiroshi Tokue, Tomoaki Murata, Haruka Agatsuma, Hiroyuki Nishide, Kenichi Oyaizu

    MACROMOLECULES   50 ( 5 ) 1950 - 1958  2017.03  [Refereed]

    DOI

  • Synthesis of Dimethyl-Substituted Polyviologen and Control of Charge Transport in Electrodes for High-Resolution Electrochromic Displays

    Kan Sato, Ryusuke Mizukami, Takahiro Mizuma, Hiroyuki Nishide, Kenichi Oyaizu

    POLYMERS   9 ( 3 ) 86  2017.03  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • 高純度ポリフェニレンスルフィドの合成化学

    小柳津研一

    ENEOS Technical Review   59 ( 1 ) 11 - 14  2017

    CiNii

  • A ketone/alcohol polymer for cycle of electrolytic hydrogen-fixing with water and releasing under mild conditions

    Ryo Kato, Keisuke Yoshimasa, Tatsuya Egashira, Takahiro Oya, Kenichi Oyaizu, Hiroyuki Nishide

    NATURE COMMUNICATIONS   7   13032  2016.09  [Refereed]

    DOI

    Scopus

    32
    Citation
    (Scopus)

  • Metallopolyyne polymers with ferrocenyl pendant ligands as cathode active materials for organic battery application

    Zhengong Meng, Kan Sato, Takashi Sukegawa, Kenichi Oyaizu, Cheuk-Lam Ho, Jing Xiang, Ying-Hsuan Feng, Yih Hsing Lo, Hiroyuki Nishide, Wai-Yeung Wong

    JOURNAL OF ORGANOMETALLIC CHEMISTRY   812   51 - 55  2016.06  [Refereed]

    DOI

    Scopus

    31
    Citation
    (Scopus)

  • A Quasi-Solid State DSSC with 10.1% Efficiency through Molecular Design of the Charge-Separation and -Transport

    Michio Suzuka, Naoki Hayashi, Takashi Sekiguchi, Kouichi Sumioka, Masakazu Takata, Noriko Hayo, Hiroki Ikeda, Kenichi Oyaizu, Hiroyuki Nishide

    SCIENTIFIC REPORTS   6   28022  2016.06  [Refereed]

    DOI

    Scopus

    74
    Citation
    (Scopus)

  • Synthesis and Charge-Discharge Properties of Organometallic Copolymers of Ferrocene and Triphenylamine as Cathode Active Materials for Organic-Battery Applications

    Jing Xiang, Kan Sato, Hiroshi Tokue, Kenichi Oyaizu, Cheuk-Lam Ho, Hiroyuki Nishide, Wai-Yeung Wong, Mingdeng Wei

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY   ( 7 ) 1030 - 1035  2016.03  [Refereed]

    DOI

    Scopus

    35
    Citation
    (Scopus)

  • Emerging Organosulfonium Electrophiles as Unique Reagents for Carbon Sulfur Bond Formation: Prospects in Synthetic Chemistry of Organosulfur Compounds

    Fuyuki Aida, Kenichi Oyaizu

    CHEMISTRY LETTERS   45 ( 2 ) 102 - 109  2016.02  [Refereed]

    DOI

    Scopus

    23
    Citation
    (Scopus)

  • Dynamic switching of ionic conductivity by cooperative interaction of polyviologen and liquid crystals for efficient charge storage

    Kan Sato, Takaaki Yamasaki, Takahiro Mizuma, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF MATERIALS CHEMISTRY A   4 ( 9 ) 3249 - 3252  2016  [Refereed]

    DOI

    Scopus

    19
    Citation
    (Scopus)

  • Enhanced catalytic activity of oxovanadium complexes in oxidative polymerization of diphenyl disulfide

    Fuyuki Aida, Yohei Takatori, Daichi Kiyokawa, Kentaro Nagamatsu, Kenichi Oyaizu, Hiroyuki Nishide

    POLYMER CHEMISTRY   7 ( 11 ) 2087 - 2091  2016  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Poly(norbornyl-NDIs) as a potential cathode-active material in rechargeable charge storage devices

    Y. Sasada, S. J. Langford, K. Oyaizu, H. Nishide

    RSC ADVANCES   6 ( 49 ) 42911 - 42916  2016  [Refereed]

    DOI

    Scopus

    15
    Citation
    (Scopus)

  • Electrochemical current rectification with cross reaction at a TEMPO/viologen-substituted polymer thin-layer heterojunction

    H. Tokue, K. Kakitani, H. Nishide, K. Oyaizu

    RSC ADVANCES   6 ( 101 ) 99195 - 99201  2016  [Refereed]

    DOI

    Scopus

    11
    Citation
    (Scopus)

  • Vanadyl-TrBR4-Catalyzed Oxidative Polymerization of Diphenyl Disulfide

    Fuyuki Aida, Souske Yamaguchi, Yohei Takatori, Kentaro Nagamatsu, Daichi Kiyokawa, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULAR CHEMISTRY AND PHYSICS   216 ( 18 ) 1850 - 1855  2015.09  [Refereed]

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Poly(1,4-phenylene sulfide) (PPS) Synthesis via Oxidative Polymerization of Diphenyl Disulfide: Mechanistic Insight into the Selective Formation of 1,4-Thiophenylene Chain

    Fuyuki Aida, Yohei Takatori, Daichi Kiyokawa, Kentaro Nagamatsu, Hiroyuki Nishide, Kenichi Oyaizu

    CHEMISTRY LETTERS   44 ( 6 ) 767 - 769  2015.06  [Refereed]

    DOI

    Scopus

    11
    Citation
    (Scopus)

  • Facile grafting-onto-preparation of block copolymers of TEMPO and glycidyl methacrylates on an oxide substrate as an electrode-active layer

    Katsuyuki Takahashi, Konstantine Korolev, Kazumasa Tsuji, Kenichi Oyaizu, Hiroyuki Nishide, Evgeny Bryuzgin, Alexander Navrotskiy, Ivan Novakov

    POLYMER   68   310 - 314  2015.06  [Refereed]

    DOI

    Scopus

    29
    Citation
    (Scopus)

  • Polyviologen as the charge-storage electrode of an aqueous electrolyte- and organic-based dye-sensitized solar cell

    Michio Suzuka, Shu Hara, Takashi Sekiguchi, Kenichi Oyaizu, Hiroyuki Nishide

    POLYMER   68   353 - 357  2015.06  [Refereed]

    DOI

    Scopus

    17
    Citation
    (Scopus)

  • Synthesis of Poly(TEMPO-Substituted Glycidyl Ether) by Utilizing t-BuOK/18-Crown-6 for an Organic Cathode-Active Material

    Kan Sato, Takashi Sukegawa, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULAR SYMPOSIA   351 ( 1 ) 90 - 96  2015.05  [Refereed]

    DOI

    Scopus

    22
    Citation
    (Scopus)

  • High-Density and Robust Charge Storage with Poly(anthraquinone-substituted norbornene) for Organic Electrode-Active Materials in Polymer-Air Secondary Batteries

    Takuma Kawai, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULES   48 ( 8 ) 2429 - 2434  2015.04  [Refereed]

    DOI

    Scopus

    87
    Citation
    (Scopus)

  • Electrochemical Formation of a Polyviologen-ZnO Composite with an Efficient Charging Capability

    Hirofumi Maruo, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   44 ( 3 ) 393 - 395  2015.03  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Facile charge transport and storage by a TEMPO-populated redox mediating polymer integrated with polyaniline as electrical conducting path

    Kenichi Oyaizu, Hanae Tatsuhira, Hiroyuki Nishide

    POLYMER JOURNAL   47 ( 2 ) 212 - 219  2015.02  [Refereed]

    DOI

    Scopus

    31
    Citation
    (Scopus)

  • Kinetic Control of Electron Transfer at Doped Zinc Oxide/Redox-active Molecule Interface for Photocurrent Rectification

    Michio Suzuka, Shu Hara, Takashi Sekiguchi, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   44 ( 1 ) 41 - 43  2015.01  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Efficient charge transport of a radical polyether/SWCNT composite electrode for an organic radical battery with high charge-storage density

    Takashi Sukegawa, Kan Sato, Kenichi Oyaizu, Hiroyuki Nishide

    RSC ADVANCES   5 ( 20 ) 15448 - 15452  2015  [Refereed]

    DOI

    Scopus

    59
    Citation
    (Scopus)

  • Oxygen-enriched electrolytes based on perfluorochemicals for high-capacity lithium-oxygen batteries

    Yuki Nishikami, Toshihiro Konishi, Ryo Omoda, Yuichi Aihara, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF MATERIALS CHEMISTRY A   3 ( 20 ) 10845 - 10850  2015  [Refereed]

    DOI

    Scopus

    33
    Citation
    (Scopus)

  • 導電性高分子, ポリアニリンをつくる

    小柳津研一

    高分子   64 ( 7 ) 445 - 447  2015

    CiNii

  • Expanding the Dimensionality of Polymers Populated with Organic Robust Radicals toward Flow Cell Application: Synthesis of TEMPO-Crowded Bottlebrush Polymers Using Anionic Polymerization and ROMP

    Takashi Sukegawa, Issei Masuko, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULES   47 ( 24 ) 8611 - 8617  2014.12  [Refereed]

    DOI

    Scopus

    95
    Citation
    (Scopus)

  • Ionic Liquid-inspired Redox Shuttles: Properties of a Ferrocenylimidazolium Salt as an Efficient Mediator for Dye-sensitized Solar Cells

    Kenichi Oyaizu, Hiroki Ikeda, Noriko Hayo, Fumiaki Kato, Hiroyuki Nishide

    CHEMISTRY LETTERS   43 ( 7 ) 1134 - 1136  2014.07  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Redox-active Hydroxy-TEMPO Radical Immobilized in Nafion Layer for an Aqueous Electrolyte-based and Dye-sensitized Solar Cell

    Ryo Kato, Fumiaki Kato, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   43 ( 4 ) 480 - 482  2014.04  [Refereed]

    DOI

    Scopus

    23
    Citation
    (Scopus)

  • Anionic Polymerization of 4-Methacryloyloxy-TEMPO Using an MMA-Capped Initiator

    Takashi Sukegawa, Hajime Omata, Issei Masuko, Kenichi Oyaizu, Hiroyuki Nishide

    ACS MACRO LETTERS   3 ( 3 ) 240 - 243  2014.03  [Refereed]

    DOI

    Scopus

    60
    Citation
    (Scopus)

  • TEMPO/Viologen Electrochemical Heterojunction for Diffusion-Controlled Redox Mediation: A Highly Rectifying Bilayer-Sandwiched Device Based on Cross-Reaction at the Interface between Dissimilar Redox Polymers

    Hiroshi Tokue, Kenichi Oyaizu, Takashi Sukegawa, Hiroyuki Nishide

    ACS APPLIED MATERIALS & INTERFACES   6 ( 6 ) 4043 - 4049  2014.03  [Refereed]

    DOI

    Scopus

    29
    Citation
    (Scopus)

  • In-situ Polymerization of Thiophene Derivatives Using a Gas-phase Oxidant to Form a Hole-transporting Layer in Dye-sensitized Solar Cell

    Yoshito Sasada, Fumiaki Kato, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   27 ( 3 ) 347 - 350  2014  [Refereed]

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • 高密度レドックス分子を用いた有機電池

    小柳津研一

    応用物理学会有機分子･バイオエレクトロニクス分科会誌   25   281 - 287  2014

  • Polyviologen Hydrogel with High-Rate Capability for Anodes toward an Aqueous Electrolyte-Type and Organic-Based Rechargeable Device

    Naoki Sano, Wataru Tomita, Shu Hara, Cheong-Min Min, Jae-Suk Lee, Kenichi Oyaizu, Hiroyuki Nishide

    ACS APPLIED MATERIALS & INTERFACES   5 ( 4 ) 1355 - 1361  2013.02  [Refereed]

    DOI

    Scopus

    106
    Citation
    (Scopus)

  • Synthesis of Pendant Nitronyl Nitroxide Radical-Containing Poly(norbornene)s as Ambipolar Electrode-Active Materials

    Takashi Sukegawa, Ayumi Kai, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULES   46 ( 4 ) 1361 - 1367  2013.02  [Refereed]

    DOI

    Scopus

    85
    Citation
    (Scopus)

  • Self-doping inspired zwitterionic pendant design of radical polymers toward a rocking-chair-type organic cathode-active material

    Il Seok Chae, Masafumi Koyano, Kenichi Oyaizu, Hiroyuki Nishide

    Journal of Materials Chemistry A   1 ( 4 ) 1326 - 1333  2013.01  [Refereed]

    DOI

    Scopus

    43
    Citation
    (Scopus)

  • Air Battery: Design of Organic Anode-Active Polymer Layers

    Kenichi Oyaizu

    MEMBRANE    2013

    DOI

  • BODIPY-Sensitized Photocharging of Anthraquinone-Populated Polymer Layers for Organic Photorechargeable Air Battery

    Kenichi Oyaizu, Yukina Niibori, Akinari Takahashi, Hiroyuki Nishide

    Journal of Inorganic and Organometallic Polymers and Materials   23 ( 1 ) 243 - 250  2013  [Refereed]

    DOI

    Scopus

    18
    Citation
    (Scopus)

  • Robust and efficient charge storage by uniform grafting of TEMPO radical polymer around multi-walled carbon nanotubes

    Wonsung Choi, Shogo Endo, Kenichi Oyaizu, Hiroyuki Nishide, Kurt E. Geckeler

    JOURNAL OF MATERIALS CHEMISTRY A   1 ( 9 ) 2999 - 3003  2013  [Refereed]

    DOI

    Scopus

    44
    Citation
    (Scopus)

  • Redox equilibrium of a zwitterionic radical polymer in a non-aqueous electrolyte as a novel Li+ host material in a Li-ion battery

    Il Seok Chae, Masafumi Koyano, Takashi Sukegawa, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF MATERIALS CHEMISTRY A   1 ( 34 ) 9608 - 9611  2013  [Refereed]

    DOI

    Scopus

    36
    Citation
    (Scopus)

  • Enhanced bimolecular exchange reaction through programmed coordination of a five-coordinate oxovanadium complex for efficient redox mediation in dye-sensitized solar cells

    Kenichi Oyaizu, Noriko Hayo, Yoshito Sasada, Fumiaki Kato, Hiroyuki Nishide

    DALTON TRANSACTIONS   42 ( 45 ) 16090 - 16095  2013  [Refereed]

    DOI

    Scopus

    20
    Citation
    (Scopus)

  • 空気電池: 有機負極を目指したポリマー膜の設計

    小柳津研一, 西出宏之

    膜   38   131 - 136  2013

  • Indoline dye-coupled polyviologen: Its electrochemical property and electropolymerization

    Naoki Sano, Miu Suzuki, Wataru Tomita, Kenichi Oyaizu, Hiroyuki Nishide

    Japanese Journal of Applied Physics   51 ( 10 ) 10NE17  2012.10  [Refereed]

    　View Summary

    An indoline dye-coupled polyviologen was designed as a possible photoanode material for organic photovoltaic cells. A new donor-acceptor (D- A) coupled molecule (CVD131) was immobilized on a current collector by the reductive electropolymerization of its two cyanopyridinium moieties. The formed polyviologen could efficiently accept an excited electron from the indoline dye moiety. © 2012 The Japan Society of Applied Physics.

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Indoline Dye-Coupled Polyviologen: Its Electrochemical Property and Electropolymerization

    Naoki Sano, Miu Suzuki, Wataru Tomita, Kenichi Oyaizu, Hiroyuki Nishide

    JAPANESE JOURNAL OF APPLIED PHYSICS   51 ( 10 ) 10NE17  2012.10  [Refereed]

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Macromolecular Complexes Leading to High-Performance Energy Devices

    Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULAR SYMPOSIA   317 ( 1 ) 248 - 258  2012.08  [Refereed]

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • TEMPO-substituted polyacrylamide for an aqueous electrolyte-typed and organic-based rechargeable device

    Natsuru Chikushi, Hiroshi Yamada, Kenichi Oyaizu, Hiroyuki Nishide

    SCIENCE CHINA-CHEMISTRY   55 ( 5 ) 822 - 829  2012.05  [Refereed]

    DOI

    Scopus

    46
    Citation
    (Scopus)

  • Nitroxide Radicals as Highly Reactive Redox Mediators in Dye-Sensitized Solar Cells

    Fumiaki Kato, Akitomo Kikuchi, Takumi Okuyama, Kenichi Oyaizu, Hiroyuki Nishide

    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION   51 ( 40 ) 10177 - 10180  2012  [Refereed]

    DOI

    Scopus

    90
    Citation
    (Scopus)

  • Electrolyte anion-assisted charge transportation in poly(oxoammonium cation/nitroxyl radical) redox gels

    Kentaro Nakahara, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF MATERIALS CHEMISTRY   22 ( 27 ) 13669 - 13673  2012  [Refereed]

    DOI

    Scopus

    42
    Citation
    (Scopus)

  • Nitroxide Radical Molecules as Highly Reactive Redox Mediators in Dye-sensitized Solar Cells

    F. Kato, A. Kikuchi, T. Okuyama, K. Oyaizu, H. Nishide

    Angew. Chem. Int. Ed.   124   10324 - 10327  2012  [Refereed]

    DOI

  • Aqueous Electrochemistry of Poly(vinylanthraquinone) for Anode-Active Materials in High-Density and Rechargeable Polymer/Air Batteries

    Wonsung Choi, Daisuke Harada, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   133 ( 49 ) 19839 - 19843  2011.12  [Refereed]

    DOI

    Scopus

    227
    Citation
    (Scopus)

  • Radical Polymer-Wrapped SWNTs at a Molecular Level: High-Rate Redox Mediation Through a Percolation Network for a Transparent Charge-Storage Material

    Wonsung Choi, Shota Ohtani, Kenichi Oyaizu, Hiroyuki Nishide, Kurt E. Geckeler

    ADVANCED MATERIALS   23 ( 38 ) 4440 - +  2011.10  [Refereed]

    DOI

    Scopus

    106
    Citation
    (Scopus)

  • Designing current collector/composite electrode interfacial structure of organic radical battery

    Sunao Yoshihara, Haruhiko Katsuta, Hiroshi Isozumi, Masanori Kasai, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF POWER SOURCES   196 ( 18 ) 7806 - 7811  2011.09  [Refereed]

    DOI

    Scopus

    36
    Citation
    (Scopus)

  • Functionalization of poly(4-chloromethylstyrene) with anthraquinone pendants for organic anode-active materials

    Kenichi Oyaizu, Wonsung Choi, Hiroyuki Nishide

    POLYMERS FOR ADVANCED TECHNOLOGIES   22 ( 8 ) 1242 - 1247  2011.08  [Refereed]

    DOI

    Scopus

    66
    Citation
    (Scopus)

  • Organic Radical Battery Approaching Practical Use

    Kentaro Nakahara, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   40 ( 3 ) 222 - 227  2011.03  [Refereed]

    DOI

    Scopus

    249
    Citation
    (Scopus)

  • Dual Dopable Poly(phenylacetylene) with Nitronyl Nitroxide Pendants for Reversible Ambipolar Charging and Discharging

    Kenichi Oyaizu, Takashi Sukegawa, Hiroyuki Nishide

    CHEMISTRY LETTERS   40 ( 2 ) 184 - 185  2011.02  [Refereed]

    DOI

    Scopus

    46
    Citation
    (Scopus)

  • p- and n-Type Bipolar Redox-Active Radical Polymer: Toward Totally Organic Polymer-Based Rechargeable Devices with Variable Configuration

    Takeo Suga, Shuhei Sugita, Hiroki Ohshiro, Kenichi Oyaizu, Hiroyuki Nishide

    ADVANCED MATERIALS   23 ( 6 ) 751 - +  2011.02  [Refereed]

    DOI

    Scopus

    230
    Citation
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  • POLYMERIZATION OF LACTIC O-CARBOXYLIC ANHYDRIDE USING ORGANOMETALLIC CATALYSTS

    Xiu-li Zhuang, Hai-yang Yu, Zhao-hui Tang, Kenichi Oyaizu, Hiroyuki Nishide, Xue-si Chen

    CHINESE JOURNAL OF POLYMER SCIENCE   29 ( 2 ) 197 - 202  2011.01  [Refereed]

    DOI

    Scopus

    24
    Citation
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  • Synthesis of Amphiphilic Block Copolymers Bearing Stable Nitroxyl Radicals

    Xiuli Zhuang, Chunsheng Xiao, Kenichi Oyaizu, Natsuru Chikushi, Xuesi Chen, Hiroyuki Nishide

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   48 ( 23 ) 5404 - 5410  2010.12  [Refereed]

    DOI

    Scopus

    36
    Citation
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  • Synthesis and Charge Transport Properties of Redox-Active Nitroxide Polyethers with Large Site Density

    Kenichi Oyaizu, Takeshi Kawamoto, Takeo Suga, Hiroyuki Nishide

    MACROMOLECULES   43 ( 24 ) 10382 - 10389  2010.12  [Refereed]

    DOI

    Scopus

    129
    Citation
    (Scopus)

  • Biodegradable and Electroactive TEMPO-Substituted Acrylamide/Lactide Copolymers

    Xiuli Zhuang, Han Zhang, Natsuru Chikushi, Changwen Zhao, Kenichi Oyaizu, Xuesi Chen, Hiroyuki Nishide

    MACROMOLECULAR BIOSCIENCE   10 ( 10 ) 1203 - 1209  2010.10  [Refereed]

    DOI

    Scopus

    25
    Citation
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  • Improving Charge/Discharge Properties of Radical Polymer Electrodes Influenced Strongly by Current Collector/Carbon Fiber Interface

    Sunao Yoshihara, Hiroshi Isozumi, Masanori Kasai, Hisatomo Yonehara, Yuko Ando, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   114 ( 25 ) 8335 - 8340  2010.07  [Refereed]

    DOI

    Scopus

    58
    Citation
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  • Nitroxide Radicals for Highly Efficient Redox Mediation in Dye-sensitized Solar Cells

    Fumiaki Kato, Naoki Hayashi, Takaya Murakami, Chie Okumura, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   39 ( 5 ) 464 - 465  2010.05  [Refereed]

    DOI

  • Electronic Communication in the Formation of a Quartet Molecule 2,6,10-Tris[bis(p-methoxyphenyl)aminium]triphenylene

    Takeshi Ibe, Shu Kaiho, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   39 ( 4 ) 356 - 357  2010.04  [Refereed]

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • Synthesis and Electrochemistry of Schiff Base Cobalt(III) Complexes and Their Catalytic Activity for Copolymerization of Epoxide and Carbon Dioxide

    Xiuli Zhuang, Kenichi Oyaizu, Yongsheng Niu, Kenichiroh Koshika, Xuesi Chen, Hiroyuki Nishide

    MACROMOLECULAR CHEMISTRY AND PHYSICS   211 ( 6 ) 669 - 676  2010.03  [Refereed]

    DOI

    Scopus

    21
    Citation
    (Scopus)

  • Mesoscale Radical Polymers: Bottom-Up Fabrication of Electrodes in Organic Polymer Batteries

    Kenichi Oyaizu, Hiroyuki Nishide

    Advanced Nanomaterials   1   319 - 332  2010.01  [Refereed]

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • Radical Polymers with Ultimate Population of Unpaired Electrons

    K. Oyaizu

    高分子   59   390 - 390  2010

  • Redox-active polyimide/carbon nanocomposite electrodes for reversible charge storage at negative potentials: expanding the functional horizon of polyimides

    Kenichi Oyaizu, Akihiko Hatemata, Wonsung Choi, Hiroyuki Nishide

    JOURNAL OF MATERIALS CHEMISTRY   20 ( 26 ) 5404 - 5410  2010  [Refereed]

    DOI

    Scopus

    86
    Citation
    (Scopus)

  • A TEMPO-substituted polyacrylamide as a new cathode material: an organic rechargeable device composed of polymer electrodes and aqueous electrolyte

    Kenichiroh Koshika, Natsuru Chikushi, Naoki Sano, Kenichi Oyaizu, Hiroyuki Nishide

    GREEN CHEMISTRY   12 ( 9 ) 1573 - 1575  2010  [Refereed]

    DOI

    Scopus

    154
    Citation
    (Scopus)

  • Porphyrin-Dye Sensitized Solar Cell Utilizing Nitroxide Radical Mediator

    Takaya Murakami, Fumiaki Kato, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   23 ( 3 ) 353 - 355  2010  [Refereed]

  • Nanolithographic patterning via electrochemical oxidation of stable poly(nitroxide radical)s to poly(oxoammonium salt)s

    Tsuyoshi Hyakutake, Jin Young Park, Yasunori Yonekuta, Kenichi Oyaizu, Hiroyuki Nishide, Rigoberto Advincula

    JOURNAL OF MATERIALS CHEMISTRY   20 ( 43 ) 9616 - 9618  2010  [Refereed]

    DOI

    Scopus

    27
    Citation
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  • Synthesis of Poly(oxoammonium salt)s and Their Electrical Properties in the Organic Thin Film Device

    Takeo Suga, Shunya Takeuchi, Takanori Ozaki, Miki Sakata, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   38 ( 12 ) 1160 - 1161  2009.12  [Refereed]

    DOI

    Scopus

    26
    Citation
    (Scopus)

  • Environmentally benign batteries based on organic radical polymers

    Hiroyuki Nishide, Kenichiroh Koshika, Kenichi Oyaizu

    PURE AND APPLIED CHEMISTRY   81 ( 11 ) 1961 - 1970  2009.11  [Refereed]

    DOI

    Scopus

    80
    Citation
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  • An Aqueous, Electrolyte-Type, Rechargeable Device Utilizing a Hydrophilic Radical Polymer-Cathode

    Kenichiroh Koshika, Naoki Sano, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULAR CHEMISTRY AND PHYSICS   210 ( 22 ) 1989 - 1995  2009.11  [Refereed]

    DOI

    Scopus

    136
    Citation
    (Scopus)

  • Radical Polymers for Organic Electronic Devices: A Radical Departure from Conjugated Polymers?

    Kenichi Oyaizu, Hiroyuki Nishide

    ADVANCED MATERIALS   21 ( 22 ) 2339 - 2344  2009.06  [Refereed]

    DOI

    Scopus

    427
    Citation
    (Scopus)

  • Chiral alkylated poly(m-phenylene)s: Optical activity and thermal stability of helical structures

    Risa Sone, Ichiro Takemura, Kenichi Oyaizu, Hiroyuki Nishide

    SYNTHETIC METALS   159 ( 9-10 ) 925 - 930  2009.05  [Refereed]

    DOI

    Scopus

    5
    Citation
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  • Emerging N-Type Redox-Active Radical Polymer for a Totally Organic Polymer-Based Rechargeable Battery

    Takeo Suga, Hiroki Ohshiro, Shuhei Sugita, Kenichi Oyaizu, Hiroyuki Nishide

    ADVANCED MATERIALS   21 ( 16 ) 1627 - +  2009.04  [Refereed]

    DOI

    Scopus

    373
    Citation
    (Scopus)

  • Macrocycles for Fuel Cell Cathodes

    K. Oyaizu, H. Murata, Makoto Yuasa

    Springer Series in Materials Science   111   139 - 162  2009

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • An ultrafast chargeable polymer electrode based on the combination of nitroxide radical and aqueous electrolyte

    Kenichiroh Koshika, Naoki Sano, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMICAL COMMUNICATIONS   ( 7 ) 836 - 838  2009  [Refereed]

    DOI

    Scopus

    185
    Citation
    (Scopus)

  • A rechargeable battery based on hydrophilic radical polymer electrode and its green assessment

    K. Koshika, M. Kitajima, K. Oyaizu, H. Nishide

    GREEN CHEMISTRY LETTERS AND REVIEWS   2 ( 3 ) 169 - 174  2009  [Refereed]

    DOI

    Scopus

    15
    Citation
    (Scopus)

  • Facilitated oxygen transport through a Nafion membrane containing cobaltporphyrin as a fixed oxygen carrier

    Masami Shoji, Kenichi Oyaizu, Hiroyuki Nishide

    POLYMER   49 ( 26 ) 5659 - 5664  2008.12  [Refereed]

    DOI

    Scopus

    32
    Citation
    (Scopus)

  • Preparation of pH-sensitive liposomes retaining SOD mimic and their anticancer effect

    Kazue Hiraka, Mayuko Kanehisa, Miho Tamai, Shoichiro Asayama, Shoji Nagaoka, Kenichi Oyaizu, Makoto Yuasa, Hiroyoshi Kawakami

    COLLOIDS AND SURFACES B-BIOINTERFACES   67 ( 1 ) 54 - 58  2008.11  [Refereed]

    DOI

    Scopus

    35
    Citation
    (Scopus)

  • Nernstian Adsorbate-like Bulk Layer of Organic Radical Polymers for High-Density Charge Storage Purposes

    Kenichi Oyaizu, Yuko Ando, Hiroaki Konishi, Hiroyuki Nishide

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   130 ( 44 ) 14459 - +  2008.11  [Refereed]

    DOI

    Scopus

    208
    Citation
    (Scopus)

  • Synthesis and characterization of radical-bearing polyethers as an electrode-active material for organic secondary batteries

    Kenichi Oyaizu, Takeo Suga, Kentaro Yoshimura, Hiroyuki Nishide

    MACROMOLECULES   41 ( 18 ) 6646 - 6652  2008.09  [Refereed]

    DOI

    Scopus

    144
    Citation
    (Scopus)

  • Reduction of 2,3,5-triphenyl-2H-tetrazolium chloride in the presence of polyelectrolytes containing 4-styrenesulfonate moieties

    Ignacio Moreno-Villoslada, Marcos Soto, Felipe Gonzalez, Francisco Montero-Silva, Susan Hess, Ichiro Takemura, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   112 ( 17 ) 5350 - 5354  2008.05  [Refereed]

    DOI

    Scopus

    21
    Citation
    (Scopus)

  • Materials science - Toward flexible batteries

    Hiroyuki Nishide, Kenichi Oyaizu

    SCIENCE   319 ( 5864 ) 737 - 738  2008.02  [Refereed]

    DOI

    Scopus

    1073
    Citation
    (Scopus)

  • ラジカル電池: 有機ラジカルポリマーの電極反応に基づく二次電池

    小柳津研一

    化学と教育   56 ( 3 ) 118 - 119  2008

    DOI CiNii

  • Synthesis and Properties of Poly(phenylene ether) Diblock Copolymers Bearing Acid Substituents

    Kenichi Oyaizu, Hidenori Murata, Daisuke Yoshi, Takehiro Ishikawa, Makoto Yuasa

    KOBUNSHI RONBUNSHU   65 ( 2 ) 145 - 149  2008  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Preparation of Novel Gold Nanoparticles Modofoed with Thiol-substituted Porphyrin and Their Derivatives

    H. Murata, K. Oyaizu, M. Komuro, R. Awa, H. Tsukioka, T. Saotome, M. Yuasa

    J. Jpn. Soc. Colour Mater.   81 ( 2 ) 37 - 42  2008  [Refereed]

    　View Summary

    Recently, there has been an increasing number of reports on cancer therapies such as photodynamic therapy and hyperthermia. However, there is a problem that the therapies can only be used for superficial thin tumor cells. In this study, we synthesized novel porphyrin having thiol group which can be adsorbed onto gold surface in order to obtain porphyrin-modified gold nanoparticles. We think that heat is generated around tumor cells in a deep part of a human body by the irradiation of electromagnetic wave to the gold nanoparticles. Gold nanoparticles are more stable than other nanoparticles, because of superior stability against oxidation and less toxicity. Porphyrin takes a role as a protective agent of gold nanoparticles, and is expected to promote the selective attachment of gold nanoparticles to tumor cells. The nanosize of the gold nanoparticles was accomplished by the sodium borohydride reduction method and citrate reduction method. The combination of thiol and gold nanoparticles was confirmed by the quenching of porphyrin in the fluorescence spectrum and shift of the Soret peak in the UV-vis spectrum. We evaluated the characteristics of porphyrin-modified gold nanoparticles by the measurement of the residence time in blood, permittivity, and cytotoxicity test.

    DOI CiNii

  • Totally Organic Polymer-Based Electrochromic Cell Using TEMPO-Substituted Polynorbornene as a Counter Electrode-Active Material

    Yusuke Takahashi, Naoki Hayashi, Kenichi Oyaizu, Kenji Honda, Hiroyuki Nishide

    POLYMER JOURNAL   40 ( 8 ) 763 - 767  2008  [Refereed]

    DOI

    Scopus

    77
    Citation
    (Scopus)

  • Construction of Manganese Porphyrin Modified Hemoglobin Complex and Its Antioxidant Activities

    Hidenori Murata, Yuji Ito, Tomoyuki Shimpo, Kenichi Oyaizu, Makoto Yuasa

    KOBUNSHI RONBUNSHU   65 ( 4 ) 277 - 282  2008  [Refereed]

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Synthesis of Six-coordination Proximal Base Conjugation Iron(III) porphyrin Complexes and Evaluation as a Superoxide Sensor

    Makoto Yuasa, Kenichi Oyaizu, Hidenori Murata, Yujiro Toyoda, Masahiro Namba, Masaki Shitara

    KOBUNSHI RONBUNSHU   65 ( 5 ) 349 - 354  2008  [Refereed]

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • Synthesis of Poly(2,6-dimethyl-1,4-phenylene oxide) by Double-Step Polymerization in Supercritical Carbon Dioxide

    Hidenori Murata, Takuro Sato, Kenichi Oyaizu, Takeshi Furuya, Yoshihiro Takebayashi, Satoshi Yodai, Katsuto Otake, Makoto Yuasa

    KOBUNSHI RONBUNSHU   65 ( 11 ) 688 - 694  2008  [Refereed]

    DOI

    Scopus

  • Synthesis of cobalt complex using pyrrole derivative with basic ligand and application to cathodic catalyst for oxygen reduction

    Hidenori Murata, Yuichi Iai, Takahisa Otake, Kenichi Oyaizu, Kozo Kozawa, Makoto Yuasa

    ELECTROCHEMISTRY   75 ( 12 ) 964 - 968  2007.12  [Refereed]

  • Battery-inspired, nonvolatile, and rewritable memory architecture: a radical polymer-based organic device

    Yasunori Yonekuta, Kentaro Susuki, Kenichi Oyaizu, Kenji Honda, Hiroyuki Nishide

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   129 ( 46 ) 14128 - +  2007.11  [Refereed]

    DOI

    Scopus

    161
    Citation
    (Scopus)

  • Electrocatalytic activities for the reduction of oxygen of carbon particles modified with polypyrrole including various metal ions as electrocatalytic sites

    Makoto Yuasa, Kenichi Oyaizu, Hidenori Murata, Ken Tanaka, Masakuni Yamamoto, Shinichi Sasaki

    ELECTROCHEMISTRY   75 ( 10 ) 800 - 806  2007.10  [Refereed]

  • Structural implication of oxoammonium cations for reversible organic one-electron redox reaction to nitroxide radicals

    Yasunori Yonekuta, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   36 ( 7 ) 866 - 867  2007.07  [Refereed]

    DOI

    Scopus

    93
    Citation
    (Scopus)

  • 金属錯体を用いた新しいカソード触媒の開発

    小柳津研一, 湯浅真

    ケミカルエンジニヤリング   52 ( 3 ) 175 - 180  2007

    CiNii

  • 非貴金属とポリピロールのコンポジットからなる燃料電池触媒

    小柳津研一, 湯浅真

    高分子   56   153 - 153  2007

  • Fabrication of Sensor for Reactive Oxygen Species Using Gold Electrodes Modified with Electropolymerized Porphyrins and Application for Detection of Stress of Plants

    M. Yuasa, K. Oyaizu, H. Murata, T. Kobayashi, C. Kobayashi

    J. Oleo Sci.   56 ( 2 ) 81 - 86  2007  [Refereed]

    　View Summary

    Reactive Oxygen Spiecies (ROS) such as superoxide anion radical (·O2-) act as signals for the activation of stress-response and defense pathways. However, excess ROS generated by perturbing ·O2- homeostasis stimulated many environmental stress, including intense light, drought, temperature stress, herbicides, induce high radical toxicity. Consequently, quantitative analysis of ·O2- is a subject of intense research, since most of ROS are derived from ·O2-. Iron meso-tetrakis(3-thienyl)porphyrin complexes were electropolymerized onto a Au wire electrode. The modified Au electrode were applied to ·O2- sensor to detect catalytic oxidation current of ·O2- which was generated as an intermediate during the oxidation of xanthine by catalystic XOD. It was revealed that the sensor was quantitative to measure ·O2-. The modified Au electrode were applied to measure oxidation current of ·O2- in mung beans under environmental stress condition. Plants were grown in atmosphere, 25°C and in black darkness. The other plants were exposed to oxygen excess. The oxidation current of ·O2- were increased plants were grown by high-oxygen environment compared to plants were grown at atmosphere. This experiment was indicated that environmental stress such as hyperoxia induced excess ·O2- and Au wire sensor using iron porphyrin complexes is capable of ·O2- detection in plants under environmental stresses.<br>

    DOI CiNii

    Scopus

    4
    Citation
    (Scopus)

  • Antioxidant and Anticancer Properties of Metalloporphyrins Embedded in Liposomes

    M. Yuasa, K. Oyaizu, H. Murata, Y. Sahara, T. Hatsugai, A. Ogata

    J. Oleo Sci.   56 ( 2 ) 87 - 93  2007  [Refereed]

    　View Summary

    Reactive oxygen species (ROS) are implicated in many disease such as inflammation, arteriosclerosis, cancer. Therefore, a water-soluble cationic metalloporphyrins with SOD activity are studied widely as antioxidant drugs. Further, liposomes are applied to drug delivery system (DDS) as drug carriers and investigated for example disposition and stability. We designed PEG modified liposomes for avoiding reticuloendothelial system (RES) and embedded cationic metalloporphyrins for DDS, evaluated antioxidant and anticancer property.<br>    Preservation of these particle size measured DLS in an in vitro system, in order to simulate in vivo conditions of flow. Result of this measurement, we found Pluronic F-68/ liposomes have a long circulation property, and avoid fusion with plasma protein. SOD activity was determined by the stopped-flow analysis and cytochrome c assay, which allowed the evaluation of kcat and IC50 for the reaction with a superoxide anion radical (·O2-). Anti cancer property was measured by cell viability test. We found that F-68/ liposomes were the most effective catalyst as antioxidant and anticancer. These results revealed that porphyrin-embedded PEG-liposomes had the property of long circulation in blood and that this compound was effective as a SOD model compound with a drug carrier capacity.<br>

    DOI CiNii

    Scopus

    7
    Citation
    (Scopus)

  • Synthesis of Cationic Manganese Porphyrin Bearing Alkylsulfonio Groups and Evaluation of Their Antioxidant Activities

    M. Yuasa, K. Oyaizu, H. Murata, M. Komuro, R. Awa, A. Ohkubo

    J. Oleo Sci.   56 ( 2 ) 95 - 101  2007  [Refereed]

    　View Summary

    A water-soluble cationic 5, 10, 15, 20-tetrakis(2-dimethylsulfoniophenyl)-porphinatomanganese(III) ion (MnT2M2SuP) and a 5, 10, 15, 20-tetrakis(4-dimethylsulfoniophenyl)porphinatomanganese(III) ion (MnT4M2SuP) were synthesized as superoxide dismutase (SOD) mimics which were introduced into PEG-liposome composed of dimyristoylphosphatidylcholine (DMPC) and Pluronic F-68 to examine the effect of the liposome on the capacity for use as drug delivery system (DDS) to maintain and perpetuate blood circulation. Fluorescence spectra in pseudo blood circulation experiments indicated that MnT4M2SuP continued to be bundled in PEG-liposome, while fluorescence from cross-section of cell observed by confocal laser scanning microscope indicated that PEG-liposome was ingested into a cell. SOD activity was determined by stopped-flow analysis, which allowed the determination of kcat values for the reaction of the metalloporphyrins with superoxide anion radical (&middot;O2-). Solution of PEG-liposome loaded with MnT2M2SuP or MnT4M2SuP were the most effective catalyst as a SOD mimic to decompose &middot;O2- at second-order rate constants of 3.5-4.5&times;107 M-1s-1.<br>

    DOI CiNii

    Scopus

    3
    Citation
    (Scopus)

  • Quantitative analysis of active oxygen species by potentiometry

    Makoto Yuasa, Kenichi Oyaizu, Hidenori Murata, Katsuya Eguchi, Yujiro Toyoda

    KOBUNSHI RONBUNSHU   64 ( 2 ) 90 - 95  2007  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • pH-sensitive liposome retaining Fe-porphyrin as SOD mimic for novel anticancer drug delivery system

    Hiroyoshi Kawakami, Kazue Hiraka, Miho Tamai, Aiko Horiuchi, Akihiko Ogata, Tomomi Hatsugai, Aritomo Yamaguchi, Kenichi Oyaizu, Makoto Yuasa

    POLYMERS FOR ADVANCED TECHNOLOGIES   18 ( 1 ) 82 - 87  2007.01  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Low-energy driven electrochromic devices using radical polymer as transparent counter electroactive material

    Yusuke Takahashi, Kenichi Oyaizu, Kenji Honda, Hiroyuki Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   20 ( 1 ) 29 - 34  2007  [Refereed]

    DOI

    Scopus

    18
    Citation
    (Scopus)

  • Evaluation of O2-・ Scavenging Activities of Antioxidant Compounds Using an Electrochemical Superoxide Sensor

    M. Yuasa, K. Oyaizu, H. Murata, S. Ohseki, T. Aoki

    Mater. Technol.   25 ( 4 ) 175 - 181  2007  [Refereed]

    CiNii

  • Electrochemical synthesis of polyaniline film in supercritical carbon dioxide as a solvent

    Hidenori Murata, Kenichi Oyaizu, Manabu Hoshino, Yasuhiro Yokota, Makoto Yuasa

    KOBUNSHI RONBUNSHU   64 ( 11 ) 812 - 816  2007  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Preparation of Cathodic Catalyst for Fuel Cell Using Cobalt-polypyrrole Complex Containing Basic Compound and Their Catalytic Activities for Oxygen Reduction

    M. Yuasa, K. Oyaizu, H. Murata, K. Ikkanda, K. Tanaka, T. Imai

    Mater. Technol.   25 ( 6 ) 313 - 319  2007  [Refereed]

    CiNii

  • Synthesis and characterization of a pi-conjugated hybrid of oligothiophene and porphyrin

    Kenichi Oyaizu, Mainabu Hoshino, Masuhide Ishikawa, Takuya Imai, Makoto Yuasa

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   44 ( 18 ) 5403 - 5412  2006.09  [Refereed]

    DOI

    Scopus

    7
    Citation
    (Scopus)

  • Surface-modified mesoporous silicas as recyclable adsorbents of an endocrine disrupter, bisphenol A

    Aritomo Yamaguchi, Terumasa Awano, Kenichi Oyaizu, Makoto Yuasa

    Journal of Nanoscience and Nanotechnology   6 ( 6 ) 1689 - 1694  2006.06  [Refereed]

    　View Summary

    Surface-modified mesoporous silicas (MSs) were investigated for recyclable adsorption of an endocrine disrupter, bisphenol A (BPA). Surface-modified MSs were prepared by (i) post-synthesis surface modification of MSs using surface hydroxyl groups and organosilanes (m-MS) and by (ii) co-condensation of tetraethoxysilane and the corresponding organosilanes (d-MS). Infrared measurements indicated that organic groups mainly existed on the surface of m-MS, which resulted in a surface characterized by high hydrophobicity. Both organic groups and isolated hydroxyl groups existed on the surface of d-MS, resulting in both hydrophobicity and hydrophilicity on the surface. The amount of BPA adsorbed on surface-modified MSs per organic group was similar for m-MS and d-MS, however, the d-MS established equilibrium for BPA adsorption faster than m-MS, as measured by UV-vis spectra. A larger amount of BPA per surface area could be adsorbed on carbon materials than on the surface-modified MSs, however, the regeneration of carbon materials by washing could not be done easily. The surface-modified MSs retain adsorption capacity for BPA after several regeneration cycles, demonstrating that the surface-modified MSs are effective recyclable adsorbents of the endocrine disrupter, bisphenol A. Copyright © 2006 American Scientific Publishers All rights reserved.

    DOI PubMed

    Scopus

    13
    Citation
    (Scopus)

  • Surface-modified mesoporous silicas as recyclable adsorbents of an endocrine disrupter, bisphenol A

    Aritomo Yamaguchi, Terumasa Awano, Kenichi Oyaizu, Makoto Yuasa

    JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY   6 ( 6 ) 1689 - 1694  2006.06  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Highly stable polymerizable vesicles in anionic surfactant/ammonium salt mixtures in the presence of cross-linking monomers for convenient preparation of hollow nanospheres

    K Oyaizu, Y Shiba, Y Nakamura, M Yuasa

    LANGMUIR   22 ( 12 ) 5261 - 5265  2006.06  [Refereed]

    DOI

    Scopus

    7
    Citation
    (Scopus)

  • Stepwise direct synthesis of alumino-silicate mesoporous materials with high ion-exchange capacity

    A. Yamaguchi, R. Sano, K. Oyaizu, M. Yuasa

    Journal of the Japan Society of Colour Material (Shikizaki)   79 ( 2 ) 47 - 54  2006.02  [Refereed]

  • Superoxide Dismutase Mimics

    Kenichi Oyaizu

    Oleoscience    2006

    DOI

  • Catalytic oxygen reduction activities of cobalt porphyrin substituted polythiophene membrane

    Takuya Imai, Hidenori Murata, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   55 ( 2 ) 4025  2006

    　View Summary

    Finding nonnoble metal catalysts for electrodes in fuel cells is an important subject of recent study. In this study, a new polythiophene derivative bearing the porphyrin, cobalt 5-(3-thienyl)-10,15,20-triethyl-21H, 23H-porphine, was synthesized by electropolymerization onto the surface of carbon particles. The modified carbon particles were suspended in an alcoholic solution of Nafion, and a pseudo-MEA was prepared on an electrode by casting the solution. The catalyst showed highly efficient catalytic activity for the selective four electron reduction of oxygen at E1/2 = 0.57 V vs SCE by rotating ring-disk voltammetry.

  • Electropolymerization of thiophene having porphyrin group and its application to superoxide sensor

    Manabu Hoshino, Hidenori Murata, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   55 ( 2 ) 2972  2006

    　View Summary

    Iron 5-(3-thienyl)-10,15,20-triethylporphyrin was electropolymerized in supercritical carbon dioxide (scCO2) to yield the corresponding conductive polymer film. The film was analyzed by scanning electron microscopy, laser microscopy and AFM. It was revealed that the thiophene-porphyrin film synthesized in scCO2 was more dense and smoother than those synthesized in dichloromethane. The electrocatalyst was applied to a superoxide anion radical sensor, and its detection sensitivity was drastically increased.

  • Synthesis of structure-defined conjugated polymers directly bound to porphyrins

    Kenichi Oyaizu, Manabu Hoshino, Takuya Imai, Hidenori Murata, Makoto Yuasa

    Polymer Preprints, Japan   55 ( 2 ) 3030 - 3031  2006

    　View Summary

    5-(3-Thienyl)-10,15,20-triethyl-21H,23H-porphine was prepared by the ring closure of pyrrole and a 3:1 mixture of propionaldehyde and 3- thiophenecarbaldehyde. Oxidative polymerization of the porphyrin with typical oxidants such as FeCl3 gave a polythiophene derivative bearing porphyrins directly bound to the β-position of the main chain. The very bulky β-substituents allowed the polymerization to proceed regioselectively even at room temperature, resulting in the formation of the β-substituted polythiophene with an HT-HT content of more than 90%. The porphyrin substituents aligned cofacially along the main chain, which served as the catalytic site for the four-electron reduction of O2 to H2O (O2 + 4e- + 4H+ = 2H2O) when cobalt ions were introduced into the porphyrins. A novel platinum-free catalyst for the reduction of O2 for fuel cell cathodes, 1/CB (M = CoII), was thus prepared by the electropolymerization of the porphyrin at the surface of carbon black (CB), which reduced O2 with four electrons at more poritive potentials than the standard two-electron reduction potential of O2 to H2O2.

  • Synthesis and polymerization mechanism of poly(phenylene ether) diblock copolymers

    Daisuke Yoshii, Hidenori Murata, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   55 ( 2 ) 2973  2006

    　View Summary

    Oxidative polymerization of 2,6-dimethylphenol catalyzed by copper-amine complexes provides a convenient method to synthesize poly(2,6-dimethyl-1,4- phenylene ether) (PPE). Based on the mechanism of polymerization and depolymerization of PPE, it was anticipated that PPE block copolymers should be obtained. In this work, the behavior of polymerization, and the structure of the resulting copolymers were investigated. The depolymerization of PPE with oligo(2,6-difluoro-1,4-phenylene ether) using a CuCl2/N,N,N′, N′-tetramethylethylenediamine catalyst was accomplished to produce the corresponding copolymer. Structural analyses using NMR, DSC, and XRD revealed that the polymer was a block copolymer. During the depolymerization reaction, an intermediate phenoxyl radical was observed by ESR. The depolymerization with other oligomeric PPE will be discussed.

  • Synthesis and properties of novel antioxidant using reconstituted and polymerized hemoglobin

    Yuji Ito, Tamami Takeda, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   55 ( 1 ) 1882  2006

    　View Summary

    Degradation of cellular metabolism leads to serious tissue damage through generation of excessive reactive oxygen species (ROS). It is necessary to make protective mechanisms to eliminate ROS. Mn porphyrin complex has an antioxidation activity. Novel antioxidant was prepared using Mn porphyrin and polymerized hemoglobin having long-term circulation property without being removed by an excretion process.

  • Synthesis of pluronic F88/poly(L-lactic acid) block copolymers and preparation of vesicles

    Yukiaki Nakamura, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   55 ( 1 ) 1124  2006

    　View Summary

    Ring-opening polymerization of L-lactide using tin(II) 2-ethylhexanoate as a catalyst in the presence of polyethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer (pluronic F88) was used to synthesize an amphiphilic block copolymer. The obtained block copolymer was applied to prepare vesicles for drug carrier applications.

  • Preparation of electropolymerized film of metalloporphyrins and application to electrocatalysts

    Manabu Hoshino, Daisuke Komago, Kenichi Oyaizu, Katsuto Otake, Makoto Yuasa

    Polymer Preprints, Japan   55 ( 1 ) 428  2006

    　View Summary

    Processing of conductive polymers generally employ organic solvents such as acetonitrile. This work report electrochemical synthesis of a conductive polymer thin film in surpercritical carbon dioxide (scCO2). Iron 5-(3-thienyl)-10,15,20-triethylporphyrin film synthesized in scCO2 was analyzed by scanning electron microscopy and laser microscopy. It was revealed that the thickness and smoothness of the porphyrin film synthesized in scCO2 was 1/10 of those of the film synthesized in dichloromethane.

  • Synthesis and structure of poly(phenylene ether) copolymers based on polymerization-depolymerization mechanism

    Daisuke Yoshii, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   55 ( 1 ) 378  2006

    　View Summary

    Oxidative polymerization of 2,6-dimethylphenol catalyzed by copper-amine complexes provides a convenient method to synthesize poly(2,6-dimethyl-1,4- phenylene ether) (PPE). Based on the mechanism of polymerization and depolymerization of PPE, it was anticipated that structure-defined PPE copolymers should be obtained, such as alternating copolymers or block copolymers. In this work, the behavior of polymerization, structure and composition of the resulting copolymers were investigated. The depolymerization of PPE with 2,6-difluorophenol using a CuCl2/N,N,N′N′- tetramethylethylenediamine catalyst was accomplished to produce the corresponding copolymer. Structural analyses using 1H-NMR, 13C-NMR, and 19F-NMR revealed that the polymer consisted of both oxy-2,6-dimethyl-l,4-phenylene units and oxy-2,6-difluoro-l,4-phenylene units. Attempts to control the composition of the comonomers will be discussed.

  • Synthesis of polymeric cobalt complex using pyrrole derivatives and application to cathodic catalyst for fuel cells

    Yuichi Iai, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   55 ( 1 ) 353  2006

    　View Summary

    In order to further increase the active site of oxygen reduction, polymerizable ligand with a strong coordinating ability was synthesized. The compound is a pyrrole derivative that strongly coordinates to cobalt(II) ions. It was revealed that the metal complex could be used as the cathode catalyst in fuel cells. The potential for oxygen reduction was very positive (Ep = 0.41 V vs SCE) for the catalyst prepared by refluxing the corresponding compound, cobalt acetate, and the carbon particles.

  • 対流ボルタンメトリー(2) (回転リング-ディスク電極系)

    小柳津研一, 湯浅真

    Electrochemistry   74   81 - 83  2006

  • スーパーオキシドジスムターゼミミックス: その分子設計とナノバイオ応用

    湯浅真, 小柳津研一, 村田英則

    オレオサイエンス   6   307 - 317  2006

  • 燃料電池開発の現状と将来

    小柳津研一, 湯浅真

    理大科学フォーラム   263 ( 5 ) 32 - 38  2006

    CiNii

  • 電子・スピン機能材料としてのπ共役系縮合環ポリマー

    小柳津研一

    日本化学会コロイドおよび界面化学部会ニュースレター   31 ( 2 ) 2 - 5  2006

  • 高分子錯体ナノ薄膜を活用した固体高分子形燃料電池系カソード触媒

    湯浅真, 小柳津研一, 村田英則

    ケミカルエンジニヤリング   51 ( 5 ) 353 - 356  2006

    CiNii

  • ポリチオフェニレンの新規合成法

    小柳津研一

    高分子   55   888 - 888  2006

  • Non-cyanide electroless gold plating using polyphenols as reducing agents

    Y Ohtani, A Horiuchi, A Yamaguchi, K Oyaizu, M Yuasa

    JOURNAL OF THE ELECTROCHEMICAL SOCIETY   153 ( 1 ) C63 - C66  2006  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Development of Method for Rapid Measurement of Blood Reactive Oxygen Species in Calves

    H. Takahashi, T. Miyamoto, Y. Takahashi, R. Horino, M. Fujino, K. Nakamura, M. Yamada, Y. Yamamoto, T. Oohashi, S. Tsutsui, M. Nanba, K. Oyaizu, M. Yuasa

    Bull. Natl. Inst. Anim. Health   112 ( 112 ) 25 - 31  2006  [Refereed]

    　View Summary

    An electrochemical sensor for reactive oxygen species like the superoxide anion radical using polymeric iron porphyrin complexes was developed by Yuasa et al. of the Tokyo University of Science. The present experiment was designed to develop a method for rapid measurement of reactive oxygen species in calf blood by employing this technique. The needle-type sensor, including an integrated microelectrode, was dipped into calf blood in a test tube. After xanthine oxidase (O_2^- ・ -generating enzmyme), superoxide dismutase (O_2^- ・ -scavenging enzyme) and opsonized zymosan (phagocyte stimulant) were successively administered in the blood, the current value detected by the sensor in the blood was recorded. The current value increased, decreased and reincreased after the successive administrations of xanthine oxidase, superoxide dismutase and opsonized zymosan, respectively. The sensor was proven to detect the reactive oxygen species of blood. Change in the reactive oxygen species concentration of calf blood following castration was investigated, by dipping the needle-type sensor in the calf blood just after sampling. The reactive oxygen species concentration increased to a maximum at 3 hr, decreasing gradually thereafter following the castration. The fluctuation was almost linked to those of the blood chemiluminescence activity and leukocyte count. Thus, we succeeded in perfoming a rapid measurement of the reactive oxygen species concentration in the peripheral blood of calves.

    DOI CiNii

  • Controlled oxidation of dextran for evolution of polyether segment bearing pendant carboxyl groups for corrosion inhibition applications

    K Oyaizu, A Yamaguchi, T Hayashi, Y Nakamura, D Yoshii, Y Ito, M Yuasa

    POLYMER JOURNAL   38 ( 4 ) 343 - 348  2006  [Refereed]

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • Stepwise Direct Synthesis of Aluminosilicate Mesoporous Materials for Catalyst Supports

    A. Yamaguchi, R. Sano, K. Oyaizu, M. Yuasa

    J. Jpn. Soc. Colour Mater.   2   47 - 54  2006  [Refereed]

  • Investigations of Bath Compositions and Operating Conditions of Gold Plating Using Hydantoin-gold Complex

    Y. Ohtani, K. Sugawara, K. Nemoto, A. Shiozawa, A. Yamaguchi, K. Oyaizu, M. Yuasa

    J. Sur. Finish. Soc. Jpn.   57   167 - 171  2006  [Refereed]

    DOI

  • Novel electrocatalysts for oxygen reduction using cobaltporphyrins that undergo facile electropolymerization

    M Yuasa, K Oyaizu, A Yamaguchi, T Imai, M Kitao

    KOBUNSHI RONBUNSHU   63 ( 3 ) 182 - 188  2006  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Preparation of novel conductive polymer ligand-coated carbon particles by electropolymerization of pyridylthiophene and application as metal complex catalysts for oxygen reduction

    K Oyaizu, A Yamaguchi, Y Iai, K Tanaka, M Yuasa

    KOBUNSHI RONBUNSHU   63 ( 3 ) 189 - 195  2006  [Refereed]

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Preparation of Hollow Fine Particles by Polymerization of Vesicles and Their Application to Functional Materials

    Y. Shiba, Y. Nakamura, K. Oyaizu, M. Yuasa

    J. Jpn. Soc. Colour Mater.   79   237 - 242  2006  [Refereed]

  • Improved activity of cathode catalysts for fuel cells by optimizing the conditions for preparation of carbon particles modified with cobalt-polypyrrole complex

    Makoto Yuasa, Kenichi Oyaizu, Hidenori Murata, Ken Tanaka, Masakuni Yamamoto

    KOBUNSHI RONBUNSHU   63 ( 9 ) 601 - 606  2006  [Refereed]

    DOI

    Scopus

    5
    Citation
    (Scopus)

  • Fabrication of electrodes for highly sensitive detection of a superoxide anion radical by electropolymerization of thienylporphyrins in the prescence of thiophene and application to active oxygen sensors

    M Yuasa, K Oyaizu, H Murata, M Ishikawa, S Tsutsui, M Namba

    KOBUNSHI RONBUNSHU   63 ( 6 ) 427 - 431  2006  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Investigation of carbon materials as supports for metalloporphyrins used for cathode catalyst in fuel cells

    Makoto Yuasa, Kenichi Oyaizu, Hidenori Murata, Mizuki Kitao, Kenji Fujita

    KOBUNSHI RONBUNSHU   63 ( 9 ) 607 - 612  2006  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Methods for Prediction of Gold Plating Characteristics by Numerical Analysis

    M. Yuasa, N. Momozawa, K. Oyaizu, Y. Ohtani, K. Sugawara

    J. Sur. Finish. Soc. Jpn.   57   789 - 792  2006  [Refereed]

    DOI

  • Electrochemical synthesis of conducting polypyrrole film in a homogeneous supercritical CO2/acetonitrile system

    H. Yan, T. Sato, D. Komago, A. Yamaguchi, K. Oyaizu, M. Yuasa, K. Otake

    LANGMUIR   21 ( 26 ) 12303 - 12308  2005.12  [Refereed]

  • Electrochemical synthesis of a polypyrrole thin film with supercritical carbon dioxide as a solvent

    H Yan, T Sato, D Komago, A Yamaguchi, K Oyaizu, M Yuasa, K Otake

    LANGMUIR   21 ( 26 ) 12303 - 12308  2005.12  [Refereed]

    DOI

    Scopus

    31
    Citation
    (Scopus)

  • Electrochemical detection and sensing of reactive oxygen species

    M Yuasa, K Oyaizu

    CURRENT ORGANIC CHEMISTRY   9 ( 16 ) 1685 - 1697  2005.11  [Refereed]

    DOI

    Scopus

    41
    Citation
    (Scopus)

  • A water-soluble gold(III) comprex with a hydantoin ligand for gold plating

    K. Oyaizu, Y. Ohtani, A. Shiozawa, K. Sugawara, T. Saito, M. Yuasa

    INORGANIC CHEMISTRY   44 ( 20 ) 6915 - 6917  2005.10  [Refereed]

  • Highly stable Gold(III) complex with a hydantoin ligand in alkaline media

    K Oyaizu, Y Ohtani, A Shiozawa, K Sugawara, T Saito, M Yuasa

    INORGANIC CHEMISTRY   44 ( 20 ) 6915 - 6917  2005.10  [Refereed]

    DOI

    Scopus

    35
    Citation
    (Scopus)

  • Cobaltporphyrin-adsorbed carbon black: highly efficient electrocatalysts for oxygen reduction

    M Yuasa, A Yamaguchi, K Oyaizu, Y Fujito, M Kitao, T Sato

    POLYMERS FOR ADVANCED TECHNOLOGIES   16 ( 9 ) 702 - 705  2005.09  [Refereed]

    DOI

    Scopus

    17
    Citation
    (Scopus)

  • Structure and redox properties of electropolymerized film obtained from iron meso-tetrakis(3-thienyl)porphyrin

    M Yuasa, K Oyaizu, A Yamaguchi, M Ishikawa, K Eguchi, T Kobayashi, Y Toyoda, S Tsutsui

    POLYMERS FOR ADVANCED TECHNOLOGIES   16 ( 8 ) 616 - 621  2005.08  [Refereed]

    DOI

    Scopus

    34
    Citation
    (Scopus)

  • Modifying carbon particles with polypyrrole for adsorption of cobalt ions as electrocatatytic site for oxygen reduction

    M Yuasa, A Yamaguchi, H Itsuki, K Tanaka, M Yamamoto, K Oyaizu

    CHEMISTRY OF MATERIALS   17 ( 17 ) 4278 - 4281  2005.08  [Refereed]

    DOI

    Scopus

    240
    Citation
    (Scopus)

  • Electrochemical sensor for superoxide anion radical using polymeric iron porphyrin complexes containing axial 1-methylimidazole ligand as cytochrome c mimics

    M Yuasa, K Oyaizu, A Yamaguchi, M Ishikawa, K Eguchi, T Kobayashi, Y Toyoda, S Tsutsui

    POLYMERS FOR ADVANCED TECHNOLOGIES   16 ( 4 ) 287 - 292  2005.04  [Refereed]

    DOI

    Scopus

    46
    Citation
    (Scopus)

  • Novel approach for the preparation of metal containing mesoporous silica using solubilization of fatty acid salt

    A Yamaguchi, M Yokoyama, T Ogura, K Oyaizu, M Yuasa, T Ohkubo, H Sakai, M Abe

    CHEMISTRY LETTERS   34 ( 3 ) 346 - 347  2005.03  [Refereed]

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Investigation of support materials for metalloporphyrins as oxygen reduction catalyst

    Mizuki Kitao, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 2 ) 4610 - 4611  2005

    　View Summary

    Cobalt meso-tetraethylporphyrin was adsorbed onto the surface of a carbon particle.The resulting particle efficiently catalyzed the reduction of oxygen. Several types of carbon particles were investigated as the support material for the catalyst. It was revealed that carbon particles with a large surface area provide effective catalysts, which were applicable as the cathode catalysts for fuel cells.

  • Synthesis of alkylsulfonio-porphyrin complexes and its anti-cancer and anti-oxidant properties

    Masayasu Komuro, Ryota Awa, Yuji Ito, Aritomo Yamaguchi, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 1 ) 2288  2005

    　View Summary

    In living body, oxygen (O2) generates reactives oxygen species (ROS) such as superoxide anion radical (O2- ·). Living body has superoxide dismutase (SOD) enzyme for elimination of ROS. However, decrese of activity of SOD causes inflammation, cancer, and other deseases. In this study, we synthesized metalloporphyrins as anti-oxidant and anti-cancer drug. Novel alkylsulfonioporphyrin complexes were synthesized. It was revealed that they were effective as anti-oxidant and as anti-cancer agents, by stopped-flow method and cell viability tests, respectively.

  • In vivo measurement of superoxide anion radical by means of electrode modified with electropolymerized iron porphyrin

    Satoshi Tsutsui, Masahiro Namba, Masuhide Ishikawa, Katsuya Eguchi, Aritomo Yamaguchi, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 1 ) 1383  2005

    　View Summary

    Iron meso-tettakis(3-thiofuryl)porphyrin (FeT3ThP) complexes were synthesized and electropolymerized onto a carbon microelectrode. Heparin/polypyrrole membrane, which can be expected for antithrombogenicity and conductivity, was electropolymerized on the porphyrin-modified electrodes. The obtained modified electrodes were applied to a Superoxide anion (O 2-̇) sensor to detect the catalytic oxidation current of O2-̇. Chronoamperometory revealed that quantitative O2-̇ sensing could be performed using the polymerized FeT3 ThP covered with heparin/polypyrrole film with antithrombogenicity.

  • Synthesis of conductive polymers having nitrogen atoms as donor atoms and analysis of complexation process for metal irons

    Yuichi Iai, Koji Ikkanda, Ken Tanaka, Aritomo Yamaguchi, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 1 ) 1734  2005

    　View Summary

    It was found that 3-pyridylthiophen formed a conductive thin film by electropolymerization. The polymer, which had nitrogen atoms as donor atoms, coordinated to cobalt(II) ion. It was demonstrated that the metal-polymer complex could be used as a cathode catalyst for fuel cells. The potential of oxygen reduction was very high (Ep ∼ 0.4 V vs SCE) for the catalyst prepared by refluxing pyrrole, cobalt, and carbon particles which were modified by polymerization of 3-pyridylthiophen and pyrrole.

  • Analysis of four-electron reduction of oxygen catalyzed by polypyrrole-coated carbon particles containing various metal ions

    Ken Tanaka, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 2 ) 4076  2005

    　View Summary

    Polypyrrole-coated carbon particles containing various metal ions as active sites were prepared and evaluated as an electrocatalyst for the reduction of oxygen at a rotating disk electrode. Catalytic activity of the particle was precisely determined by electroanalytical methods. Possibility of the Co-Pd catalyst as cathode materials for fuel cells was investigated.

  • Synthesis of iron /meso-tetrakis(2-thiofuryl)porphyrin complexes and evaluation of the superoxide sensor

    Masahiro Namba, Satoshi Tsutsui, Masuhide Ishikawa, Katsuya Eguchi, Aritomo Yamaguchi, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 1 ) 1732  2005

    　View Summary

    Iron /meso-tetrakis(2-thiofuryl)porphyrin complex was synthesized as the electrocatalyst of a superoxide sensor. An electrode was modified with the electropolymerized porphyrin film for evaluation of superoxide anion radical. When superoxide anion radical was generated by xanthine oxidase-catalyzed oxidation of xanthin, the current increased drastically in chronoamperometory. The relationship between the steady-state current for the oxidation and its concentration calculated from each XOD activity in the presence of 0.1 M xanthin-containing phosphate buffer solution at a potential of 0.5 V. The porphyrin-modified electrode were quantitative to measure superoxide anion radical.

  • Studies on polyphenylene ethers as coating binder

    Yuichi Shiba, Daisuke Yoshii, Aritomo Yamaguchi, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 1 ) 1915  2005

    　View Summary

    We studied poly(phenylene ether)s that were yielded by oxidative polymerization of 3- or 5-methylsalicylic acid under aqueous conditions as water-soluble binder for coating. The coating material composed of the polymer and pigment microparticles such as CaCO3 showed good characteristics for coating process, because it had significantly low viscosity at high shear rate compared to the conventional coating materials based on poly (vinyl alcohol) as the binder.

  • Preparation of size-controlled polymerizable vesicles and their application to hollow organic white pigments

    Yukiaki Nakamura, Yuichi Shiba, Aritomo Yamaguchi, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 1 ) 1065  2005

    　View Summary

    Polymerizable vesicles composed of vinylbenzyltrimethylammonium chloride as polymerizable cation surfactant, sodium dodecylsulfate as anion surfactant, and divinylbenzene as cross-linker were prepared. It was found that the hollow polymer particle, which was provided by the polymerization of the vesicles, could be applied to hollow organic white pigment.

  • Preparation of nanocarriers containing SOD mimics and their anticancer mechanism

    Miho Tamai, Ryouta Araki, Kazue Hiraka, Shoichiro Asayama, Shoji Nagaoka, Tomomi Hatsugai, Akihiko Ogata, Kenichi Oyaizu, Makoto Yuasa, Hiroyoshi Kawakami

    Polymer Preprints, Japan   54 ( 1 ) 2151  2005

    　View Summary

    We have reported the anticancers effect by metalloporphyrins as SOD mimics on the cancer cells. Metalloporphyrins as SOD mimics convert intracellular O2- · to H2O2 and it reacts on iron porphyrins to form OH · by Fenton reaction. Finally H 2O2 and OH- generated by the metalloporphyrin are expected to cause cell death. We have prepared novel liposomes containing metallporphyrins showing SOD activity. The liposomes were composed of DMPC and their size was less than 100nm. The liposomes showed a significant cytotoxicty for cancer cells when compared with cisplatin and metalloporphyrins.

  • Synthesis of new cobalt complex-modified carbon particles by electropolymerization and their catalytic oxygen reduction activities

    Takuya Imai, Mizuki Kitao, Aritomo Yamaguchi, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 1 ) 1733  2005

    　View Summary

    It has been reported that cobalt porphyrin complexes show oxygen reduction activity. In this study, [meso-tetra(thiophen-3-yl)porphinato]cobalt(II) (CoT3ThP) complex was synthesized and electropolymerized onto carbon particles. The electropolymerization condition was investigated using a glassy carbon electrode. The catalyst prepared from CoT3ThP by a suitable process showed relatively high catalytic activity for the reduction of oxygen.

  • Design and evaluation of electrochemical ROS sensor using electropolymerized film of iron porphyrin with 6-coordination stabilized structure

    Yujiro Toyoda, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 2 ) 3351 - 3352  2005

    　View Summary

    A novel electropolymerizable iron porphyrin having a stabilized 6-coordination structure was designed and synthesized, which was applied to electrochemical detection of superoxiede anion radical. Selection of suitable imidazole ligand led to highly efficient detection of superoxide by the ROS sensor.

  • Disposition control of metalloporphyrins as SOD mimics

    Miho Tamai, Shoichiro Asayama, Shoji Nagaoka, Kenichi Oyaizu, Makoto Yuasa, Hiroyoshi Kawakami

    Polymer Preprints, Japan   54 ( 2 ) 5195 - 5196  2005

    　View Summary

    We have reported the effects of metalloporphyrins as SOD mimics on the anticancer and antioxidation. Fe-porphyrins as SOD mimics convert intracellular O2- · to H2O2 and it reacts on iron porphyrins to form OH · by Fenton reaction. Finally, H 2O2 and OH · generated by the Fe-porphyrin are expected to cause cell death. In this study, we have synthesized liposomes with water-soluble cationic metalloporphyrins as SOD mimic and have investigated the effect of the liposomes on cancer cell death. Liposomes were prepared using a sonication method. Cell viabilities of cell lines treated with Fe-porphyrins, liposomes containing Fe-porphyrins, and cisplatin were estimated by a Alamar Blue Assay. Liposomes containing Fe-porphyrins showed a significant cytotoxicity for cancer cell as compared with cisplatin.

  • Optimization of carbon-supported polypyrrole complex as cathode catalyst for fuel cells

    Kenichi Oyaizu, Ken Tanaka, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 2 ) 4547 - 4548  2005

    　View Summary

    Carbon particles coated with metal complexes were prepared as cathode catalyst for fuel cells. The metal complex composed of metal ions such as cobalt(II), iron(II), and nickel(II) ions, and nitrogen-containing conductive polymers such as polypyrrole as polymeric ligands. The catalysts were prepared by electropolymerization of corresponding monomers onto the surface of carbon particles such as carbon black which was dispersed in the electrolyte solution containing the monomers, followed by complexation using metal acetates and related salts. Rotating ring-disk voltammetry experiments revealed that the complex composed of a mixture of cobalt and palladium ions as central ions and polypyrrole as the ligand served as a highly efficient electrocatalyst for the selective four-electron reduction of oxygen at E1/2 ≈ 0.5 V vs SCE, without the formation of partially reduced oxygen species such as H 2O2.

  • Synthesis and properties of water-soluble poly(phenylene ether)s

    Daisuke Yoshii, Yuichi Shiba, Aritomo Yamaguchi, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 1 ) 292  2005

    　View Summary

    Poly(phenylene ether)s are known as a high-performance engineering plastic having high thermal stability and chemical resistance. The polymer is depolymerizable under oxidative conditions. Water-soluble poly(phenylene ether)s were examined as novel paper binder materials having a variety of properties. Novel water-soluble poly(phenylene ether)s bearing ionic substituents were synthesized by oxidative polymerization of phenol derivatives. Characterization of the polymer revealed that it could be applied as re-usable paper binder materials.

  • Properties of electropolymerized thiophene film 3-substituted with imidazolyl group

    Tomohiro Kobayashi, Kenichi Oyaizu, Makoto Yuasa

    Polymer Preprints, Japan   54 ( 2 ) 3353 - 3354  2005

    　View Summary

    Electropolymerizable iron porphyrins have been found to be effective as an electrocatalyst for the detection of a superoxide anion radical. Thiophene 3-substituted with an imidazolyl group was synthesized and electropolymerized. Coordination of the imidazolyl group to various iron complexes provided a novel electrocatalyst for the detection of superoxide. Properties of the electrochemical sensors were evaluated.

  • 金属ポルフィリンの分子集合系および多核錯体系を用いた酸素還元触媒

    小柳津研一, 湯浅真

    高分子加工   54 ( 2 ) 88 - 93  2005

    CiNii

  • In vivo活性酸素種センサーの研究開発

    湯浅真, 小柳津研一

    化学と教育   53 ( 3 ) 128 - 131  2005

    DOI CiNii

  • サイクリックボルタンメトリー(4) (電極吸着系および電極触媒系の特徴と観測例)

    小柳津研一, 湯浅真

    Electrochemistry   73 ( 6 ) 460 - 463  2005

    CiNii

  • 高分子錯体を用いた燃料電池用酸素還元触媒

    小柳津研一, 湯浅真

    膜   30   254 - 259  2005

  • 電解重合性ポルフィリン錯体の設計と活性酸素センサーへの応用

    小柳津研一, 湯浅真

    表面   43 ( 5 ) 1 - 6  2005

    CiNii

  • 対流ボルタンメトリー(1) (概要および回転ディスク電極系)

    小柳津研一, 湯浅真

    Electrochemistry   73 ( 12 ) 1060 - 1063  2005

    CiNii

  • Surface Modification of Reconstituted Hemoglobins Containing SOD-active Metalloporphyrins

    M. Yuasa, K.Oyaizu, A. Yamaguchi, T. Hayashi, U. Midorikawa

    J. Oleo Sci.   54   115 - 123  2005  [Refereed]

    DOI

  • Formation of active sites for the NO plus CO reaction over palladium catalysts supported on mesoporous silica

    A Yamaguchi, T Hayashi, K Oyaizu, M Yuasa

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   78 ( 1 ) 192 - 194  2005.01  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Preparation of Liposomes Surface-Loaded with Cationic Manganese Porphyrins as SOD Mimics

    Makoto Yuasa, Kenichi Oyaizu, Akihiko Ogata, Noriyoshi Matsukura, Aritomo Yamaguchi

    Journal of Oleo Science   54 ( 4 ) 233 - 239  2005  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Synthesis of Polymeric Reconstituted Hemoglobins as Superoxide Dismutase Mimics Designed for Long-term Circulation Maintenance

    Makoto Yuasa, Kenichi Oyaizu, Takamitsu Hayashi, Aritomo Yamaguchi

    Journal of Oleo Science   54 ( 7 ) 413 - 418  2005  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Novel Functional Nano-size Nonionic Surfactant Particles on Which Cationic Metalloporphyrins are Absorbed; Preparation, Characterization, and Anti-oxidant Properties

    Makoto Yuasa, Kenichi Oyaizu, Yukihiro Hanyuu, Kazunori Kasahara, Aritomo Yamaguchi

    Journal of Oleo Science   54 ( 8 ) 465 - 471  2005  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Synthesis of Hexameric Manganese Porphyrin as an SOD Mimic and SOD Activity

    Makoto Yuasa, Kenichi Oyaizu, Yukihiro Hanyuu, Takamitsu Hayashi, Aritomo Yamaguchi

    Journal of Oleo Science   54 ( 9 ) 513 - 518  2005  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Coordination Equilibria of Hydantoin Derivatives with Gold Ions

    Y. Ohtani, T. Saito, K. Sugawara, A. Shiozawa, A. Yamaguchi, K. Oyaizu, M. Yuasa

    J. Sur. Finish. Soc. Jpn.   56   479 - 480  2005  [Refereed]

    DOI

  • Preparation, Characterization, and Catalytic Properties of Pd Metal Particles Supported on Mesoporous Silicas

    A. Yamaguchi, K. Iwaoka, K. Oyaizu, M. Yuasa

    Mater. Technol.   23   272 - 278  2005  [Refereed]

  • Water-soluble poly(phenylene ether) derivatives as environmentally benign and heat-resistant coating materials for paper

    Y Shiba, D Yoshii, K Oyaizu, M Yuasa

    KOBUNSHI RONBUNSHU   62 ( 12 ) 591 - 597  2005  [Refereed]

  • Electron-transfer kinetics of nitroxide radicals as an electrode-active material

    T Suga, YJ Pu, K Oyaizu, H Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   77 ( 12 ) 2203 - 2204  2004.12  [Refereed]

    DOI

    Scopus

    174
    Citation
    (Scopus)

  • Liposomal surface-loading of water-soluble cationic iron(III) porphyrins as anticancer drugs

    Makoto Yuasa, Kenichi Oyaizu, Aiko Horiuchi, Akihiko Ogata, Tomomi Hatsugai, Aritomo Yamaguchi, Hiroyoshi Kawakami

    MOLECULAR PHARMACEUTICS   1 ( 5 ) 387 - 389  2004.09  [Refereed]

    DOI

    Scopus

    31
    Citation
    (Scopus)

  • Micellar cobaltporphyrin nanorods in alcohols

    M Yuasa, K Oyaizu, A Yamaguchi, M Kuwakado

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   126 ( 36 ) 11128 - 11129  2004.09  [Refereed]

    DOI

    Scopus

    76
    Citation
    (Scopus)

  • Electrocatalysis for dioxygen reduction by a mu-oxo decavanadium complex in alkaline medium and its application to a cathode catalyst in air batteries

    EL Dewi, K Oyaizu, H Nishide, E Tsuchida

    JOURNAL OF POWER SOURCES   130 ( 1-2 ) 286 - 290  2004.05  [Refereed]

    DOI

    Scopus

    22
    Citation
    (Scopus)

  • New pi-conjugated polyelectrolyte composed of alkylphenoxathiinium-type repeating units

    K Oyaizu, T Mikami, E Tsuchida

    MACROMOLECULES   37 ( 6 ) 2325 - 2327  2004.03  [Refereed]

    DOI

    Scopus

    8
    Citation
    (Scopus)

  • Electroreduction of oxygen at a Pt/C-modified electrode with a cobaltporphyrin complex

    B Shentu, K Oyaizu, H Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   77 ( 2 ) 401 - 405  2004.02  [Refereed]

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Linear ladder-type pi-conjugated polymers composed of fused thiophene ring systems

    K Oyaizu, T Iwasaki, Y Tsukahara, E Tsuchida

    MACROMOLECULES   37 ( 4 ) 1257 - 1270  2004.02  [Refereed]

    DOI

    Scopus

    105
    Citation
    (Scopus)

  • Paints Containing Polyaniline as Corrosion Protective Paints of Iron Materials

    Kenichi Oyaizu

    Journal of the Japan Society of Colour Material    2004

    DOI

  • 協奏的多電子移動系の構築とその機能開拓

    小柳津研一, 湯浅真

    表面   41   22 - 33  2004

  • 鉄系材料の防食塗料としてのポリアニリン含有塗料

    湯浅真, 小柳津研一

    色材協会誌   77   26 - 33  2004

  • Preparation of a tetraphenylporphyrinatocobalt(II)-poly(3,4azopyridylene) complex and its oxygen enrichment effect at an oxygen electrode

    B Shentu, K Oyaizu, H Nishide

    JOURNAL OF MATERIALS CHEMISTRY   14 ( 22 ) 3308 - 3311  2004  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Investigation of Hydantoin Derivatives as Complexing Agent for Gold Plating

    Y. Ohtani, K. Sugawara, K. Nemoto, A. Shiozawa, A. Yamaguchi, K. Oyaizu, M. Yuasa

    J. Sur. Finish. Soc. Jpn.   55   933 - 936  2004  [Refereed]

    DOI

  • Crystal structure and reactivity of a five-coordinate chloroiron(III) complex with a bulky tetradentate Schiff base ligand

    K Oyaizu, E Tsuchida

    INORGANICA CHIMICA ACTA   355   414 - 419  2003.11  [Refereed]

    DOI

    Scopus

    26
    Citation
    (Scopus)

  • Polythiophenylene synthesis through multi-electron transfer process

    K Oyaizu, E Tsuchida

    MACROMOLECULAR SYMPOSIA   204   19 - 25  2003.11  [Refereed]

    DOI

    Scopus

  • Depolymerization of poly(2,6-dimethyl-1,4-phenylene oxide) under oxidative conditions

    K Saito, T Masuyama, K Oyaizu, H Nishide

    CHEMISTRY-A EUROPEAN JOURNAL   9 ( 17 ) 4240 - 4246  2003.09  [Refereed]

    DOI

    Scopus

    32
    Citation
    (Scopus)

  • Oxovanadium(V) hydroxide with a tetradentate Schiff base ligand resulting from oxidation of oxovanadium(IV) with O-2

    K Oyaizu, E Tsuchida

    INORGANICA CHIMICA ACTA   353   332 - 335  2003.09  [Refereed]

    DOI

    Scopus

    7
    Citation
    (Scopus)

  • The first oxovanadium ring in [{O=V(salen)}(2)(mu-F)][VO(salen)][BF4]center dot(CH2Cl2)(x) crystals

    K Oyaizu, E Tsuchida

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   125 ( 19 ) 5630 - 5631  2003.05  [Refereed]

    DOI

    Scopus

    18
    Citation
    (Scopus)

  • Cationic polysulfonium membrane as separator in zinc-air cell

    EL Dewi, K Oyaizu, H Nishide, E Tsuchida

    JOURNAL OF POWER SOURCES   115 ( 1 ) 149 - 152  2003.03  [Refereed]

    DOI

    Scopus

    76
    Citation
    (Scopus)

  • Oxovanadium(III-V) mononuclear complexes and their linear assemblies bearing tetradentate Schiff base ligands: structure and reactivity as multielectron redox catalysts

    E Tsuchida, K Oyaizu

    COORDINATION CHEMISTRY REVIEWS   237 ( 1-2 ) 213 - 228  2003.02  [Refereed]

    DOI

    Scopus

    119
    Citation
    (Scopus)

  • Coordination of BF4- to oxovanadium(V) complexes, evidenced by the redox potential of oxovanadium(IV/V) couples in CH2Cl2

    K Oyaizu, EL Dewi, E Tsuchida

    INORGANIC CHEMISTRY   42 ( 4 ) 1070 - 1075  2003.02  [Refereed]

    DOI

    Scopus

    24
    Citation
    (Scopus)

  • Alkylsulfonioarylene and thioarylene polymers derived from sulfonium electrophiles

    E Tsuchida, K Oyaizu

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   76 ( 1 ) 15 - 47  2003.01  [Refereed]

    DOI

    Scopus

    28
    Citation
    (Scopus)

  • Four-electron reduction of dioxygen catalyzed by a decavanadium complex

    EL Dewi, K Oyaizu, E Tsuchida

    INORGANICA CHIMICA ACTA   342   316 - 318  2003.01  [Refereed]

    DOI

    Scopus

    9
    Citation
    (Scopus)

  • Ion-exchange and apparent diffusion coefficients within cationic polysulfonium coatings containing ferricyanide

    EL Dewi, H Nakano, K Oyaizu, H Nishide, E Tsuchida

    JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY   A40 ( 1 ) 37 - 47  2003  [Refereed]

    DOI

    Scopus

    7
    Citation
    (Scopus)

  • Convenient syntheses of methylsulfonioarylene and thioarylene polymers from 1,4-bis(methylsulfinyl)benzene

    K Oyaizu, H Yonemaru, T Iwasaki, R Matsubara, E Tsuchida

    JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY   A40 ( 4 ) 415 - 423  2003  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Heteropolyacene with thianthrenimn ring systems proving pi electron delocalization over S atoms

    K Oyaizu, R Matsubara, T Iwasaki, E Tsuchida

    JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY   A40 ( 7 ) 655 - 670  2003  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Palladium-catalyzed synthesis of oligo(methylthio)aniline and conversion to polyacene-type electrolytes bearing phenothiazinium repeating units

    K Oyaizu, F Mitsuhashi, E Tsuchida

    MACROMOLECULAR CHEMISTRY AND PHYSICS   203 ( 10-11 ) 1328 - 1336  2002.07  [Refereed]

    DOI

  • Reduction of oxygen at an electrode modified by cobaltporphyrin liquid membrane

    BQ Shentu, K Oyaizu, H Nishide

    CHEMISTRY LETTERS   ( 7 ) 712 - 713  2002.07  [Refereed]

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • 磁極で操る電極反応—界面電子移動における磁気効果

    小柳津研一

    化学   57   56 - 57  2002

  • ヘテロポリアセンの合成と機能

    小柳津研一

    高分子加工   51 ( 12 ) 548 - 553  2002

    CiNii

  • Synthetic routes to polyheteroacenes: Characterization of a heterocyclic ladder polymer containing phenoxathiinium-type building blocks

    K Oyaizu, T Mikami, F Mitsuhashi, E Tsuchida

    MACROMOLECULES   35 ( 1 ) 67 - 78  2002.01  [Refereed]

    DOI

    Scopus

    42
    Citation
    (Scopus)

  • Electroreduction of oxygen enriched in a [poly(ethyleneiminato)]cobalt(II) layer

    K Oyaizu, H Nakano, B Shentu, H Nishide

    JOURNAL OF MATERIALS CHEMISTRY   12 ( 10 ) 3162 - 3166  2002  [Refereed]

    DOI

    Scopus

    7
    Citation
    (Scopus)

  • Erratum: Copper(II) complexes resulting from the oxygenation of (2,9-dimethyl-1,10-phenanthroline)copper(I) chloride in the presence of dimethylformamide (Bulletin of the Chemical Society of Japan (2001) 74 (869))

    Kenichi Oyaizu, Masayoshi Ueno, Hong Li, Eishun Tsuchida

    Bulletin of the Chemical Society of Japan   74 ( 12 ) 2463  2001.12

  • A mu-oxo diiron(III) complex with a short Fe-Fe distance: crystal structure of (mu-oxo)bis[N,N '-o -phenylenebis(salicylideneiminato)iron(III)]

    K Oyaizu, EL Dewi, E Tsuchida

    INORGANICA CHIMICA ACTA   321 ( 1-2 ) 205 - 208  2001.09  [Refereed]

    DOI

  • Oxidative polymerization of pyrrole promoted by four-electron transfer to O-2: Catalysis of O-2-oxidation by mu-oxo dinuclear complexes with macrocyclic ligands

    K Oyaizu, A Haryono, H Shinoda, E Tsuchida

    MACROMOLECULAR CHEMISTRY AND PHYSICS   202 ( 7 ) 1273 - 1279  2001.05  [Refereed]

    DOI

  • Copper(II) complexes resulting from the oxygenation of (2,9-dimethyl-1,10-phenanthroline)copper(I) chloride in the presence of dimethylformamide

    K Oyaizu, M Ueno, H Li, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   74 ( 5 ) 869 - 870  2001.05  [Refereed]

    Authorship：Lead author

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Electrochemical and ferromagnetic couplings in 4,4 ',4 ''-( 1,3,5-benzenetriyl)tris(phenoxyl) radical formation

    H Nishide, R Doi, K Oyaizu, E Tsuchida

    JOURNAL OF ORGANIC CHEMISTRY   66 ( 5 ) 1680 - 1685  2001.03  [Refereed]

    DOI

    Scopus

    24
    Citation
    (Scopus)

  • Synthesis and properties of novel sulfonated arylene ether/fluorinated alkane copolymers

    K Miyatake, K Oyaizu, E Tsuchida, AS Hay

    MACROMOLECULES   34 ( 7 ) 2065 - 2071  2001.03  [Refereed]

    DOI

    Scopus

    177
    Citation
    (Scopus)

  • Structure and redox properties of a novel decavanadium cluster [(V=O)(10)(mu(2)-O)(9)(mu(3)-O)(3)(C5H7O2)(6)] in dichloromethane

    K Oyaizu, EL Dewi, E Tsuchida

    JOURNAL OF ELECTROANALYTICAL CHEMISTRY   498 ( 1-2 ) 136 - 141  2001.02  [Refereed]

    DOI

    Scopus

    18
    Citation
    (Scopus)

  • Polysulfonium as a new electrode-modifying polyelectrolyte

    K Oyaizu, H Nakano, J Natori, E Tsuchida

    JOURNAL OF ELECTROANALYTICAL CHEMISTRY   498 ( 1-2 ) 232 - 236  2001.02  [Refereed]

    DOI

    Scopus

    12
    Citation
    (Scopus)

  • Polymerization of methyl phenyl sulfoxide under acidic conditions: Synthesis and X-ray structure analysis of a phenylene sulfonium polymer

    K Miyatake, K Oyaizu, Y Nishimura, E Tsuchida

    MACROMOLECULES   34 ( 5 ) 1172 - 1179  2001.02  [Refereed]

    DOI

    Scopus

    17
    Citation
    (Scopus)

  • Synthesis and thermal properties of a polysulfonium salt with a comb-like structure

    K Miyatake, A Haryono, K Oyaizu, E Tsuchida

    JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY   38 ( 8 ) 851 - 859  2001  [Refereed]

    DOI

    Scopus

    11
    Citation
    (Scopus)

  • A new synthetic route to poly(seleno-1,4-phenylene) from selenoanisole

    K Oyaizu, Y Ikai, E Tsuchida

    JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY   38 ( 10 ) 1049 - 1057  2001  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Copper-catalyzed oxidative coupling of 2,4,6-trimethylphenol with oxygen

    K Oyaizu, K Saito, E Tsuchida

    CHEMISTRY LETTERS   ( 11 ) 1318 - 1319  2000.11  [Refereed]

    DOI

    Scopus

    16
    Citation
    (Scopus)

  • First synthesis of high molecular weight poly(2,6-difluoro-1,4-phenylene oxide) by oxidative polymerization

    K Oyaizu, Y Kumaki, K Saito, E Tsuchida

    MACROMOLECULES   33 ( 16 ) 5766 - 5769  2000.08  [Refereed]

    DOI

    Scopus

    39
    Citation
    (Scopus)

  • Crystal structures of dimeric manganese(III) complexes of tetradentate Schiff-base ligands with ancillary axial donors

    K Oyaizu, T Nakagawa, E Tsuchida

    INORGANICA CHIMICA ACTA   305 ( 2 ) 184 - 188  2000.07  [Refereed]

    DOI

    Scopus

    16
    Citation
    (Scopus)

  • Electroreduction of mu-oxo iron(III) porphyrins adsorbed on an electrode leading to a cofacial geometry for the iron(II) complex: Unexpected active site for the catalytic reduction of O-2 to H2O

    K Oyaizu, A Haryono, J Natori, H Shinoda, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   73 ( 5 ) 1153 - 1163  2000.05  [Refereed]

    DOI

    Scopus

    25
    Citation
    (Scopus)

  • Papers presented at PAT '99 - Tokyo - Editorial

    Ohno, H., Takeoka, S., Oyaizu, K.

    Polymers For Advanced Technologies   11 ( 8-12 ) 369 - 369  2000

    DOI

  • Synthesis and characterization of nickel dithiocarbamate complexes bearing ferrocenyl subunits

    K Oyaizu, K Yamamoto, Y Ishii, E Tsuchida

    CHEMISTRY-A EUROPEAN JOURNAL   5 ( 11 ) 3193 - 3201  1999.11  [Refereed]

    DOI

  • High-spin polyphenoxyl based on poly(1,4-phenyleneethynylene)

    H Nishide, T Maeda, K Oyaizu, E Tsuchida

    JOURNAL OF ORGANIC CHEMISTRY   64 ( 19 ) 7129 - 7134  1999.09  [Refereed]

    DOI

    Scopus

    39
    Citation
    (Scopus)

  • Catalysis of the electroreduction of O-2 to H2O by vanadium-salen complexes in acidified dichloromethane

    E Tsuchida, K Oyaizu, EL Dewi, T Imai, FC Anson

    INORGANIC CHEMISTRY   38 ( 16 ) 3704 - 3708  1999.08  [Refereed]

    DOI

    Scopus

    59
    Citation
    (Scopus)

  • Molecular structure of a mu-oxo chromium-iron complex: Rare example of a crystallographically characterized mu-oxo heterometallic porphyrin

    K Oyaizu, A Haryono, Y Nishimura, K Yamamoto, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   72 ( 8 ) 1781 - 1784  1999.08  [Refereed]

    DOI

    Scopus

    14
    Citation
    (Scopus)

  • (mu-peroxo)bis[pyridine(phthalocyaninato)iron(III)] as a convenient catalyst for the four-electron reduction of dioxygen

    K Oyaizu, A Haryono, J Natori, E Tsuchida

    JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS   94 ( 24 ) 3737 - 3742  1998.12  [Refereed]

    DOI

    Scopus

    21
    Citation
    (Scopus)

  • Catalytic behavior of a mu-oxo dimanganese(III) octaethylporphyrin in O-2 reduction

    K Oyaizu, A Haryono, H Yonemaru, E Tsuchida

    JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS   94 ( 22 ) 3393 - 3399  1998.11  [Refereed]

    DOI

    Scopus

    24
    Citation
    (Scopus)

  • A novel decavanadium(V) cluster with a chiral framework: [(O = V)(10)(mu(2)-O)9(mu(3)-O)(3)(C5H7O2)(6)] having an approximate C-3 symmetry

    K Oyaizu, E Tsuchida

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   120 ( 1 ) 237 - 238  1998.01  [Refereed]

    DOI

    Scopus

    32
    Citation
    (Scopus)

  • Electrocatalytic reduction of dioxygen to water by a carbon electrode coated with (eta-oxo)bis[(meso-tetraphenylporphyrinato)iron(III)]: a convenient template for cofacially oriented iron(II) porphyrins

    A Haryono, K Oyaizu, K Yamamoto, J Natori, E Tsuchida

    CHEMISTRY LETTERS   ( 3 ) 233 - 234  1998  [Refereed]

  • Oxidative polymerization of pyrrole with a vanadium dinuclear complex as a two-electron redox catalyst

    E Tsuchida, K Yamamoto, K Oyaizu

    JOURNAL OF ELECTROANALYTICAL CHEMISTRY   438 ( 1-2 ) 167 - 171  1997.11  [Refereed]

    DOI

    Scopus

    23
    Citation
    (Scopus)

  • Highly selective oxygen transport through a cobalt porphyrin liquid membrane

    XS Chen, H Nishide, K Oyaizu, E Tsuchida

    JOURNAL OF PHYSICAL CHEMISTRY B   101 ( 29 ) 5725 - 5729  1997.07  [Refereed]

    DOI

    Scopus

    13
    Citation
    (Scopus)

  • Oxidation of disulfides by 4-electron transfer to O2: A Ru(bpy)32+-catalyzed photo-oxidation system for selective formation of polythioethers

    Kimihisa Yamamoto, Kenichi Oyaizu, Shintaro Kobayashi, Eishun Tsuchida

    Phosphorus, Sulfur and Silicon and Related Elements   120-121   407 - 408  1997

    　View Summary

    Tris(2,2′-bipyridine)ruthenium(II) chloride catalyzed the photo-oxidative polymerization of diaryl disulfides by O2, by which poly(thioarylene)s were efficiently produced. The polymerization proceeded through the electrophilic reaction of the sulfonium cation which was produced selectively by the photo-redox system.

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Oxidation of disulfides by 4-electron transfer to O-2: A Ru(bpy)(3)(2+)-catalyzed photo-oxidation system for selective formation of polythioethers

    K Yamamoto, K Oyaizu, S Kobayashi, E Tsuchida

    PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS   120   407 - 408  1997  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Role of Multinuclear Complexes in Coordination and 4-Electron Reduction of Dioxygen

    K. Yamamoto, K. Oyaizu, E. Tsuchida

    J. Inorg. Biochem.   67   390 - 390  1997  [Refereed]

    DOI

  • Catalytic cycle of a divanadium complex with salen ligands in O-2 reduction: Two-electron redox process of the dinuclear center (salen equals N,N'-ethylenebis(salicylideneamine))

    K Yamamoto, K Oyaizu, E Tsuchida

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   118 ( 50 ) 12665 - 12672  1996.12  [Refereed]

    DOI

    Scopus

    96
    Citation
    (Scopus)

  • Multielectron redox process of vanadium complexes in oxidation of low-coordinate vanadium(III) to oxovanadium(V) with dioxygen

    K Oyaizu, K Yamamoto, K Yoneda, E Tsuchida

    INORGANIC CHEMISTRY   35 ( 23 ) 6634 - &  1996.11  [Refereed]

    DOI

    Scopus

    55
    Citation
    (Scopus)

  • Multi-electron transfer process of a vanadium dinuclear complex for molecular conversions

    E Tsuchida, K Yamamoto, K Oyaizu

    METAL-CONTAINING POLYMERIC MATERIALS     139 - 149  1996  [Refereed]

  • SYNTHESIS OF REACTIVE FUNCTIONALIZED OLIGO(P-PHENYLENE SULFIDE)S

    E TSUCHIDA, K YAMAMOTO, K OYAIZU, F SUZUKI, AS HAY, ZY WANG

    MACROMOLECULES   28 ( 2 ) 409 - 416  1995.01  [Refereed]

    DOI

    Scopus

    39
    Citation
    (Scopus)

  • Multi‐electron transfer process of vanadyl complexes for oxidative polymerization of diphenyl disulfide

    Kimihisa Yamamoto, Kenichi Oyaizu, Eishun Tsuchida

    Polymers for Advanced Technologies   6 ( 3 ) 155 - 158  1995  [Refereed]

    　View Summary

    Oligo(p‐phenylene sulfide) is synthesized by oxidative polymerization of diphenyl disulfide with oxygen catalyzed by vanadyl acetylacetonate under strongly acidic conditions. The mechanistic studies reveal that the redox cycles of the vanadyl complexes give rise to catalysis through a two‐electron transfer between diphenyl disulfide and molecular oxygen. The VO catalysts act as an excellent electron mediator to bridge a 1.0 V potential gap between the oxidation potential of disulfides and the reduction potential of oxygen. The VO‐catalyzed oxygen‐oxidative polymerization provides pure oligo(pphenylene sulfide)s containing an S–S bond. The polymeric product is of low molecular weight due to the insolubility under these conditions. (N,N′‐ethylenebis(salicylideneaminato))oxovanadium‐(IV), VO(salen), was used as an inert model compound to elucidate the redox chemistry of the vanadium complex. VO(salen) reacts with trifluoromethanesulfonic acid (CF3SO3H) or triphenylmethyl tetrafluoroborate (ϕ3C(BF4)) to form a deoxygenated complex, VIV(salen)2+, and a μ‐oxodinuclear complex, [(salen)VOV(salen)]X2, (X = CF3SO3− or BF4−). The dimerization of VO(salen) is initiated by deoxygenation to produce V(salen)2+ which enters into an equilibrium with a second VO(salen) complex to produce the μ‐oxo dimer. The two‐electron transfer of the μ‐oxo dinuclear vanadium complex is elucidated. Copyright © 1995 John Wiley &amp
    Sons, Ltd.

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Preparation of poly(1,4‐phenylene)s by electro‐oxidative polymerization

    Kenichi Oyaizu, Kimihisa Yamamoto, Toshio Asada, Hiroyuki Nishide, Eishun Tsuchida

    Polymers for Advanced Technologies   6 ( 4 ) 254 - 257  1995  [Refereed]

    　View Summary

    The effect of substituents on the electropolymerization of benzene derivatives and the redox properrties of the corresponding polymers were determined using Brown's substituent constants (σ+). Electron‐donating groups lower the oxidation potential by which increase in the current efficiency was observed. However, stabilization of the produced cation radicals by the electron‐donating groups resulted in a decrease in the polymerization efficiency. The appropriate values of σ+ for the efficient polymerization ranged near −1.5. Copyright © 1995 John Wiley &amp
    Sons, Ltd.

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • SYNTHESIS OF POLY(2,6-DIMETHYLPHENYLENE SULFIDE) BY PHOTOOXIDATIVE POLYMERIZATION

    K YAMAMOTO, K OYAIZU, E TSUCHIDA

    MACROMOLECULAR CHEMISTRY AND PHYSICS   195 ( 9 ) 3087 - 3094  1994.09  [Refereed]

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • ACID-PROMOTED ELECTRON-TRANSFER TO FACILITATE OXIDATIVE POLYMERIZATION OF DIARYL DISULFIDES

    K OYAIZU, N IWASAKI, K YAMAMOTO, H NISHIDE, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   67 ( 5 ) 1456 - 1461  1994.05  [Refereed]

    DOI

  • ELECTROCHEMICAL INVESTIGATIONS OF THE COMPLEXES RESULTING FROM THE ACID-PROMOTED DEOXYGENATION AND DIMERIZATION OF (N,N'-ETHYLENEBIS(SALICYLIDENEAMINATO))OXOVANADIUM(IV)

    E TSUCHIDA, K YAMAMOTO, K OYAIZU, N IWASAKI, FC ANSON

    INORGANIC CHEMISTRY   33 ( 6 ) 1056 - 1063  1994.03  [Refereed]

    DOI

    Scopus

    78
    Citation
    (Scopus)

  • PREPARATION OF POLY(1,4-PHENYLENE) BY OXIDATIVE POLYMERIZATION OF BENZENE WITH 2,3-DICHLORO-5,6-DICYANO-P-BENZOQUINONE

    K YAMAMOTO, K OYAIZU, T ASADA, H NISHIDE, E TSUCHIDA

    CHEMISTRY LETTERS   ( 2 ) 363 - 366  1994.02  [Refereed]

    DOI

  • Multielectron Transfer Process and Molecular Conversion

    E. Tsuchida, K. Yamamoto, K. Oyaizu

    Kagaku   49 ( 4 ) 74 - 75  1994

    CiNii

  • PREPARATION OF POLY(THIO-1,4-PHENYLENE)S BY OXYGEN-OXIDATIVE POLYMERIZATION OF DIARYL DISULFIDES

    K YAMAMOTO, M JIKEI, K OYAIZU, F SUZUKI, H NISHIDE, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   67 ( 1 ) 251 - 256  1994.01  [Refereed]

    DOI

  • PHOTOOXIDATIVE POLYMERIZATION OF BIS(3,5-DIMETHYLPHENYL) DISULFIDE FOR SYNTHESIS OF POLY(THIOARYLENE)

    K YAMAMOTO, K OYAIZU, E TSUCHIDA

    CHEMISTRY LETTERS   ( 7 ) 1101 - 1104  1993.07  [Refereed]

    DOI

  • ELECTROCHEMICAL CONFIRMATION OF DISPROPORTIONATION OF MU-OXO-BIS[(N,N'-ETHYLENEBIS(SALICYLIDENEAMINATO))VANADIUM(IV)] TETRAFLUOROBORATE

    K YAMAMOTO, K OYAIZU, N IWASAKI, E TSUCHIDA

    CHEMISTRY LETTERS   ( 7 ) 1223 - 1226  1993.07  [Refereed]

    DOI

  • OXOVANADIUM-CATALYZED OXIDATIVE POLYMERIZATION OF DIPHENYL DISULFIDES WITH OXYGEN

    K YAMAMOTO, E TSUCHIDA, H NISHIDE, M JIKEI, K OYAIZU

    MACROMOLECULES   26 ( 13 ) 3432 - 3437  1993.06  [Refereed]

    DOI

    Scopus

    66
    Citation
    (Scopus)

  • Thermolysis of reactive oligo(p‐phenylene sulfide) containing disulfide bond

    Kenichi Oyaizu, Junya Katoh, Fumiaki Suzuki, Mitsutoshi Jikei, Kimihisa Yamamoto, Hiroyuki Nishide, Eishun Tsuchida

    Polymers for Advanced Technologies   2 ( 3 ) 155 - 159  1991  [Refereed]

    DOI

    Scopus

    7
    Citation
    (Scopus)

▼display all

Books and Other Publications

  • ハイドロジェノミクス : “水素"を使いこなすためのサイエンス

    折茂, 慎一, 福谷, 克之, 藤田, 健一( Part： Contributor, リチャージャブル燃料電池)

    共立出版  2022.01 ISBN: 9784320044982

  • “Redox-active Polymers as an Organic Energy Storage Material”, Handbook of Conducting Polymers

    K. Oyaizu, H. Nishide

    CRC Press/Taylor & Francis  2019

  • “レドックスポリマー微粒子を活物質として用いたレドックスフロー電池” 『レドックスフロー電池の開発動向』

    小柳津研一

    シーエムシー出版  2017 ISBN: 9784781312620

  • “高分子ラジカル電池”, 『スピン化学が拓く分子磁性の新展開』, CSJカレントレビュー

    西出宏之, 小柳津研一

    化学同人  2014 ISBN: 9784759813760

  • “Organic Batteries”, Encyclopedia of Sustainable Science and Technology, ed by R. A. Meyers

    H. Nishide, K. Oyaizu

    Springer  2012 ISBN: 9780387894690

  • “Polyradicals in Batteries”, Encyclopedia of Radicals in Chemistry, Biology and Materials, ed by C. Chatgilialoglu, A. Studer

    K. Oyaizu, H. Nishide

    Wiley  2012 ISBN: 9780470971253

  • “有機ラジカル電池” 『最先端電池と材料』, 最先端材料システムワンポイントシリーズ

    小柳津研一, 西出宏之

    共立出版  2012 ISBN: 9784320044296

  • “Molecular Catalysis for Fuel Cells”, Energy Production and Storage: Inorganic Chemical Strategies for a Warming World, ed by R. H. Crabtree

    K. Oyaizu

    Wiley  2011 ISBN: 9780470749869

  • “Mesoscale Radical Polymers: Bottom-up Fabrication of Electrodes in Organic Polymer Batteries”, Advanced Nanomaterials, ed by K. Geckeler, H. Nishide

    K. Oyaizu, H. Nishide

    Wiley  2010 ISBN: 9783527317943

  • “芳香族化合物の酸化的ラジカル重合”, 『ラジカル重合ハンドブック』

    西出宏之, 小柳津研一

    エヌ・ティー・エス  2010 ISBN: 9784860432744

  • “Macrocycles for Fuel Cell Cathodes”, Molecular Catalysis for Energy Conversion, ed by T. Okada

    K. Oyaizu, H. Murata, M. Yuasa

    Springer  2009 ISBN: 9783540707301

  • “チエニルポルフィリン類を用いた共役ポリマーの拡張と新機能の開拓” 『次世代共役ポリマーの超階層制御と革新機能』, 赤木和夫監修

    小柳津研一

    シーエムシー  2009 ISBN: 9784781300733

  • “有機ラジカル電池の展望” 『高性能蓄電池』

    小柳津研一, 西出宏之

    エヌ・ティー・エス  2009 ISBN: 9784860432638

  • “フレキシブルラジカルポリマー電池” 『次世代二次電池材料の開発』

    小柳津研一, 西出宏之

    シーエムシー  2009 ISBN: 9784781301792

  • “Heteroacenes and Heterohelicenes: Bottom-up Strategies for Syntheses of Molecular Solenoids and Springs”, Bottom-up Nanofabrication: Supramolecules, Self-assemblies, and Organized Films, ed by K. Ariga, H. S. Nalwa

    K. Oyaizu, M. Yuasa

    American Scientific Publishers  2007 ISBN: 1588830799

  • “錯体系電極触媒”『燃料電池と高分子』, 先端高分子材料ワンポイントシリーズ, 高分子学会燃料電池材料研究会編

    小柳津研一, 西出宏之

    共立出版  2005 ISBN: 4320043693

  • “Multi-electron Transfer and Catalytic Mechanisms in Oxidative Polymerization”, Bioinorganic Catalysis Second Edition, Revised and Expanded, ed by J. Reedijk E. Bouwman

    E. Tsuchida, K. Yamamoto, K. Oyaizu

    Marcel Dekker  1999 ISBN: 0824702417

  • “Multi-electron Transfer Process of a Vanadium Dinuclear Complex for Molecular Conversions”, Metal Containing Polymeric Materials, ed by C. U. Pittman, C. E. Carraher, B. M. Culberston, M. Zeldin, J. E. Sheets

    E. Tsuchida, K. Yamamoto, K. Oyaizu

    Plenum Press  1996 ISBN: 9780306452956

  • “Molecular Conversion Based on Multi-electron Transfer System”, Novel Trends in Electroorganic Synthesis

    E. Tsuchida, K. Yamamoto, K. Oyaizu

    Kodansha, VCH  1995 ISBN: 9784062075039

▼display all

Presentations

  • 有機ラジカル型色素増感太陽電池の高機能化

    日本化学会第94春季年会 

    Presentation date： 2014.03

  • 創電・エネルギー貯蔵分野における高分子未来技術

    ゴム技術フォーラム, ゴム・エラストマーと資源・エネルギー, 第3回調査委員会 

    Presentation date： 2014.02

  • ラジカルイオン電池の最新動向

    高分子学会第22回ポリマー材料フォーラム 

    Presentation date： 2013.11

  • 有機ラジカル型色素増感太陽電池-電荷輸送の基礎と応用

    光化学協会370-01光化学応用講座, 次世代光電変換技術への応用 

    Presentation date： 2013.10

  • 創電・エネルギー貯蔵分野における高分子未来材料

    第58回高分子夏季大学 

    Presentation date： 2013.07

  • ラジカルメディエータを用いた有機太陽電池

    光機能材料研究会第43回講演会 

    Presentation date： 2013.04

  • 有機ラジカル型色素増感太陽電池

    日本化学会第93春季年会 

    Presentation date： 2013.03

  • Polymers for Energy Storage

    POLYCHAR 21, World Forum on Advanced Materials 

    Presentation date： 2013.03

  • 有機空気二次電池: 蓄電・導電ポリマーとデバイス設計

    平成24年度化学系学協会東北大会, 高分子コロキウム 

    Presentation date： 2012.09

  • 蓄電ポリマーの設計と有機ラジカル電池・空気二次電池への応用

    高分子学会12-3ポリマーフロンティア21 

    Presentation date： 2012.09

  • Radical Molecules as Highly Reactive Mediators for Dye-Sensitized Solar Cell

    The Third International Organic Excitonic Solar Cell Conference (IOESC2012) 

    Presentation date： 2012.09

  • Polymers for Energy Storage Ecomaterials

    The 1st International Symposium on Polymer Ecomaterials (PEM 2012) 

    Presentation date： 2012.08

  • 有機蓄電・創電ポリマーとデバイス設計

    日本化学会第92春季年会 

    Presentation date： 2012.03

  • Polymers for Energy Storage Materials

    HPI-APA International Conference on Innovation in Polymer Science and Technology (IPST 2011) 

    Presentation date： 2011.11

  • 有機空気二次電池: 電気を貯める高分子の設計

    第77回高分子若手研究会 [関西] 

    Presentation date： 2011.11

  • 光空気電池: エネルギーを貯める有機分子の設計

    日本化学会第1回CSJ化学フェスタ (2011世界化学年記念大会) 

    Presentation date： 2011.11

  • High-Density Redox Polymers for Energy Conversion and Storage

    XIX Mendeleev Congress on General and Applied Chemistry 

    Presentation date： 2011.09

  • Radical Block Copolymers for Application to Electro-active Biomaterials

    The 10th China-Japan-Korea Foresight Joint Symposium on Gene Delivery and International Symposium on Biomaterials 

    Presentation date： 2011.05

  • 高密度レドックスポリマーによるエネルギー変換: 有機ラジカル電池と太陽電池

    静岡大学薄膜基板研究懇話会第14回研究発表会 

    Presentation date： 2011.01

  • 有機ラジカル電池

    第41回繊維学会夏季セミナー 

    Presentation date： 2010.08

  • Redox Polymers with Ultimate Site Densities: Soft Electronic Interfaces for Flexible Rechargeable Devices

    Presentation date： 2010.02

  • ラジカルポリマー電池

    第18回ポリマー材料フォーラム 

    Presentation date： 2009.11

  • 有機ラジカル電池: ラジカルポリマーによる電荷の輸送と貯蔵

    第71回武蔵野地区高分子懇話会 

    Presentation date： 2009.11

  • New Material Development in Fuel Cell Technology

    International Conference on Fuel Cell &amp; Hydrogen Technology (CFCHT 2009) 

    Presentation date： 2009.10

  • 有機ラジカル電池：フレキシブルでプリンタブルな有機二次電池

    2008年度印刷・情報記録・表示研究会講座 

    Presentation date： 2009.02

  • Vanadyl Complex Catalysts for New Polymer Syntheses

    Polymer Science Lecture Series, State Key Laboratory of Polymer Physics and Chemistry, Chinese Academy of Sciences 

    Presentation date： 2008.01

  • Organic Radical Batteries with High Power Density

    3rd Global Plastic Electronics Conference and Showcase 

    Presentation date： 2007.10

  • Novel Functionalization of Polythiophene Derivatives

    The Second International Symposium on Polymer Chemistry (PC2006) 

    Presentation date： 2006.06

  • 高分子錯体を用いた燃料電池用酸素還元触媒

    日本膜学会第27年会 

    Presentation date： 2005.05

  • Polythiophenylene Synthesis through Multi-electron Transfer Processes

    IUPAC 10th International Symposium on Macromolecule-metal Complexes (MMC X) 

    Presentation date： 2003.05

  • Polythiophenylene Synthesis through Multi-electron Transfer Processes

    International Symposium on Biotechnology, Metal Complexes and Catalysis (BMC) 

    Presentation date： 2002.11

  • ポリヘテロアセンの合成と機能

    第51回高分子年次大会 

    Presentation date： 2002.05

  • μ-オキソ不均化錯体系の多電子過程を利用した新機能物質合成法の確立

    日本化学会第81春季年会 

    Presentation date： 2002.03

  • Electroreduction of mu-Oxo Dinuclear Porphyrins Adsorbed on an Electrode Leading to a Cofacial Geometry: Active Site for the Reduction of O2

    Materials Science &amp; Technology Cooperation Workshop (MATEC Bremen) 

    Presentation date： 2000.06

▼display all

Research Seeds

Research Projects

  • Multiple Integration of Soft Polarized Structures for Development of Photo- and Electric Field-Functional Polymers

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2022.06
    -
    2027.03
     

  • Development of Organic Energy Materials Chemistry

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2021.04
    -
    2026.03
     

  • 高速移動水素による次世代創蓄電デバイスの設計

    Project Year :

    2018.06
    -
    2023.03
     

    　View Summary

    プラスチックフィルム中でプロトンを高速移動させるための構造要件を検討した、スルホフェニレンを側鎖に複数連結してスルホン酸基を高密度導入することにより、バルクのイオン交換容量がほぼ同じであるプラスチックフィルムに比べて親水性が1.4倍、プロトン導電率が4.5倍増大することを見出した。コンパクトな分子構造で密度高いポリビニルフルオレノンを設計・合成し、その電荷および水素の交換反応と水素発生を明らかにした。数wt%の高質量水素密度を期待し、水素付加・脱離体をフルオレノンから窒素複素環式化合物へと拡張したポリビニルキノキサリンを設計・合成し、常圧、80～120℃の温和な条件下で可逆的に水素化・水素発生が起こることを確認した。酸性水溶液を用いたリチャージャブル燃料電池のモデルデバイスとして、電子/プロトン交換反応に基づく有機レドックスポリマーを負極に用いた有機空気二次電池を作製し、予備的な検討ではあるものの500回を超える高いサイクル特性を実証した。界面から移動するプロトンの移動速度をその場で計測する新手法として、遠紫外域の界面選択的分光(Far-UV-ATR)法の確立に取り組み、水素の貯蔵・放出する高分子膜を第一の対象として計測を進めた。水素を付加・脱離した化学状態の違いにより250nm付近に顕著な吸収違いが見られ、この電子遷移を時間依存密度汎関数法で帰属した。さらにIr錯体共存下での加熱による水素発生過程（酸化）、電極からの電子移動と水の付加によるアルコールへの還元過程の観測に成功した。親水性ポリビニルフルオレノンを水素貯蔵性高分子シートとしてアノード側に内蔵することにより、発電と充電を繰り返して行うことができるリチャージャブル燃料電池の原理を計画を前倒して実証した。水素高速移動機能の高度化を推進し、プラスチックフィルム中におけるプロトンの挙動を制御する分子設計および高次構造形成技術を確立し、従来の有機材料に比べて著しく高いプロトン導電率を示す薄膜を達成した。また、これらの成果を他計画研究と融合させることにより発展させ、リチャージャブル燃料電池の原理を計画を前倒して実証することができた。本計画研究では５年間の間に、水素高速移動機能の高度化（ステージⅠ）、学問分野の枠を超えた水素機能の融合（ステージⅡ）、領域全体での多彩な高次水素機能の誘起（ステージⅢ）に順次取り組む。2020年度はステージIIでの研究を進めながら、他計画研究との連携を一層深めながらステージIIIへ移行していく。プラスチック薄膜中におけるプロトン高密度化と高速移動：スルホン酸化ポリフェニレン系高分子において、フェニレン環の置換位置や配列規則性がプラスチックフィルムとしての物性に及ぼす効果を明らかにする。A05-1と連携しながらフィルム中における水の分布を詳細に解析し、高プロトン導電性を示す構造要件を整理する。高分子双安定性を利用した水素の貯蔵・放出の高速・高密度化：水素供与体と受容体が同程度に安定である「双安定性(を有する)高分子」を利用して、水素の貯蔵と放出を高速化・高密度化させることを目指す。A04と連携しながら、例えば二級アルコールとこれから2プロトンが脱離したジアニオンが共に安定構造となるような有機化合物を高分子化して、プロトンの交換反応速度を著しく増加させることを目指す。新規深紫外界面分光(Far-UV-ATR)法による水素貯蔵高分子の構造解析：分担者が開発したFar-UV-ATR法を用いて、電位や雰囲気を厳密に制御した条件下でポリビニルフルオレノンなどの水素貯蔵高分子の構造変化を解明する。電極界面から深さ方向の官能基を定量的に解析し、水素貯蔵・放出過程のその場観察を行う。これらの課題に関して、公募研究との連携も開始して、多様な高次水素機能の発現を加速する

  • HYDROGENOMICS: Creation of Innovative Materials, Devices, and Reaction Processes using Higher-Order Hydrogen Functions

    Project Year :

    2018
    -
    2023
     

  • Development of Energy Conversion Materials Based on Bistability of Polymers

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2017.04
    -
    2022.03
     

    Oyaizu Kenichi

    　View Summary

    The present study was performed with the aim of fundamental understanding of the charge transport and storage processes in amorphous polymers with densely substituted charge-transfer sites that exhibit electrochemical reversibility. The research also aimed at deriving a generalized concept of redox bistability of polymers.
    Specifically, we have organized chemical structures applicable as charge transfer sites and synthesized polymers with small equivalent weights (i.e. high density in monomer units). We also showed that the charge transport efficiency is enhanced by using molecular-level composite electrodes incorporating π-conjugated systems. Based on these findings, we have developed various examples of redox-bistable polymers such as potential-driven mediators that enable high-density charge storage and fast charging, and established them as a group of functional polymers characterized by redox bistability.

  • Development of High-density Redox Fluid for Charge Storage

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2018.06
    -
    2021.03
     

    Oyaizu Kenichi

    　View Summary

    Polymer nanoparticles capable of giving high density redox fluids were developed, in pursuit of the challenge to unravel the limit of charge storage density anticipated for redox-active colloidal fluid. Mechanisms of charge transport and storage based on the exchange reaction of nanoparticles were determined, which led to the design principle of organic materials for fast and large capacity energy storage.
    In particular, amorphous polymers bearing organic robust radicals per repeating unit to undergo the exchange reaction were developed, which demonstrated the fast charge transport properties. The polymers were employed as the electrode-active materials in organic radical batteries, especially in organic redox-flow batteries in which the aqueous electrolyte dispersion of the nanoparticular polymers allowed high density and reversible charge storage.

  • Synthesis of Pure and High Molecular-weight Poly(phenylene sulfide) Derivatives and Development of Their Functionality

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2016.04
    -
    2018.03
     

    Oyaizu Kenichi

    　View Summary

    Polymerization of diphenyl disulfide (PhSSPh) proceeded in the presence of vanadyl complexes to catalyze the oxidation of PhSSPh with oxygen. Because water decomposed the active form of the catalyst, pricy strong acid anhydrides have been regarded as essential. We solved this problem using molten PhSSPh as the monomer, where the eliminated water was removed by evaporation. This led to the establishment of the process to yield highly pure and high molecular-weight PPS. Calculation results suggested the terminal disulfide functionality, based on the comparison of the HOMO levels and the shapes of their lobes. The reaction was expanded to those with many kinds of diaryl disulfides to yield poly(1,4-arylene sulfide)s (PAS), typically for those containing methyl groups at the phenyl ring. The PAS, derived from bis(3,5-dimethylphenyl) disulfide, showed a high glass transition temperature with the capability of wet processing by virtue of the enhanced solubility in common organic solvents

  • Aromatic Ketone Polymers for A Hydrogen Career

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2015.04
    -
    2017.03
     

    Nishide Hiroyuki

    　View Summary

    We have proposed aromatic ketone polymers as a new class of hydrogen careers and elucidated their hydrogen storage property. The fluorenone polymers were synthesized, and highly efficient hydrogenation of the polymers was examined through the electrolytic reduction and successive protonation with water. Quantitative hydrogen evolution from the hydrogenated polymers was measured by heating in the solution containing catalyst, to characterize the aromatic ketone polymers as a hydrogen career

  • Development of Organic Gel Junction Devices for Electrochemical Transistors

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2014.04
    -
    2016.03
     

    OYAIZU Kenichi

    　View Summary

    High-density redox polymers with excellent charge-transport properties, based on electron self-exchange reactions in polymer layers, were employed to develop characteristic electrochemical devices for large flux charge transport and rectification at interfaces of dissimilar polymers. Capability of modulating the charge-transport properties as a function of equilibrated potentials gave rise to redox conduction properties determined by applied voltage of a gate electrode, which allowed fabrication of redox transistors. AC current amplification was accomplished with electrochemical circuits containing the redox transistor, by tuning diffusion currents based on rate constants for the exchange reaction and thickness of diffusion layers, potential gaps that dominated cross reaction at polymer/polymer heterojunctions, and molecular design of the electrochemical interfaces

  • Development of Organic Anode-active Polymers for High-density Energy Storage

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2013.04
    -
    2016.03
     

    OYAIZU Kenichi

    　View Summary

    Electron-transfer processes of quinones characterized by their electrochemical reversibility and rapid reaction rates were employed to develop organic anode-active materials for energy storage, based on electron self-exchange reactions in the polymer layer. Polymers bearing anthraquinones as pendant group per repeating unit gave rise to highly efficient charge transport properties to allow fabrication of organic rechargeable air battery, giving insight into the nature of n-type charge storage with the polymers. The polymers were developed according to (i) design of novel n-type redox-active groups, (ii) analyses of electron- and ion-transport processes, (iii) precise control of these processes for rectification at heterojunctions, and (iv) establishment of charge storage with polymers characterized by rocking-chair-type migration of electroneutralizing ions and bipolar charging capabilities, which led to (v) rational design of a series of high-density energy-storable polymers

  • 有機ラジカルのＳＯＭＯ制御による新しい光・電子機能性ポリマーの開拓

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(S))

    Project Year :

    2012
    -
    2016
     

    　View Summary

    本研究は、当初計画に基づき、有機安定ラジカル種の可逆的かつ速い電子授受に着目し世界に先駆け合成してきたラジカルポリマーによる高速電荷輸送と高密度電荷貯蔵の発見とその解釈を起点とした、π共役物性に支配される従来の導電性ポリマーから脱却した電子交換反応に基く導電・蓄電物質の基礎科学確立を目指して推進した。計画書記載の研究方針である ①大流束電荷輸送系の創出と ②ヘテロ接合を用いた流束制御 を基軸とした現象の普遍化による学問的深化と、③有機ラジカル種の拡充による超高速化やpnバイポーラ性など新規物性も活用した ④SOMO (Singly Occupied MO)π共役複合系へと一般化する道筋での有機物性化学の新領域開拓を着実に推進した。新型太陽電池や次世代蓄電池など実デバイスに波及する、実践的学術として確立しつつある。本年度の成果を以下に記す。
    1. 電子交換に基づく導電現象の物理化学 (1) 非共役系での導電現象の確立と深化：薄層化（界面積増大）により膜厚を精密制御する方法を、高い交換反応性を有するラジカル種とも組合せ、電荷・イオン伝播の大流束輸送系を構築した。(2) 大流束輸送系の解析：大流束輸送の非平衡熱力学を解明するため、電荷輸送の素過程を様々な解析法により定量的に捉えた。
    ２. ラジカルポリマーの合成有機化学 (1) ラジカルポリマーを与える反応有機化学の確立：これまでに確立した重合法を駆使して、分子量、分散度に加え不対電子密度を制御したポリマーを精密合成した。(2) ラジカル不対電子の合成化学による特性制御：従来明らかにして来た安定ラジカル種に加え、pnバイポーラ性を有するフェルダジルやニトロニルニトロキシド、不均一電子移動速度定数が極めて大きいアダマンタン骨格などに拡張し、レドックス電位、電解質膨潤度、対イオンや溶媒の物質移動量と速度の実測より電荷輸送特性を解明した。

  • π共役レドックス融合型エネルギー貯蔵マテリアルの創出

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(新学術領域研究(研究領域提案型))

    Project Year :

    2013.04
    -
    2015.03
     

    　View Summary

    (1) 律速過程と充放電性能の相関解明：複合電極における電荷の移動抵抗への寄与が推測される素過程として、ポリマー内の自己電子交換、ポリマー／π共役界面での交差電子交換、π共役固体ネットワークの電子移動、π共役固体集電体間の電子移動に分類し、各過程の寄与について電極組成・構造を変えたπ共役／凝縮レドックス融合物質の電気化学応答をもとに解明した。π共役固体の組成を調整した電極の電荷移動抵抗と固体／ポリマー間の接触面積の相関、膜厚の異なる電極における電荷移動抵抗を明らかにした。材質の異なる集電体上に形成された複合電極における電荷移動抵抗の支配因子を明確にした。電荷移動抵抗が充放電特性と直接相関をもつことを実証し、充放電特性向上に向けた活物質の設計指針の一つを導出した。(2) 律速段階における電荷移動の効率向上と高密度エネルギー貯蔵物質としての実証：π共役／凝縮レドックス融合物質に電荷補償系を共存させ、電荷保持力を確かめた。予備知見として明らかにしている高密度レドックスポリマー単独による可逆的エネルギー貯蔵能を、π共役系との分子レベルでの融合により向上させ、従来性能を超えた有機電池を実現した。具体的には、定電流下での平衡電位を参照電極基準で測定し、ポリマーに蓄積される電荷密度を求めた。また、減衰挙動から電荷保持力を含めた速度パラメータを見積もり、電荷貯蔵効率を把握した。電解質中での平衡膨潤度、対イオンや溶媒の物質移動量と速度を実測し、対イオン種や溶媒因子との相関を明確にすることにより、レドックス凝縮系としての特性を解明した。レドックス席の速い外圏的電子移動が、膨潤ゲル中でも大きな速度定数を与えることを実証し、高速電荷輸送可能な機能性界面を分子レベルで創出した。以上を総合し、π共役／凝縮レドックス融合物質を斬新なエネルギー貯蔵材料の一つとして確立した。26年度が最終年度であるため、記入しない。26年度が最終年度であるため、記入しない

  • π共役レドックス融合型エネルギー貯蔵マテリアルの創出

    Project Year :

    2013.04
    -
    2015.03
     

    　View Summary

    (1) 律速過程と充放電性能の相関解明：複合電極における電荷の移動抵抗への寄与が推測される素過程として、ポリマー内の自己電子交換、ポリマー／π共役界面での交差電子交換、π共役固体ネットワークの電子移動、π共役固体集電体間の電子移動に分類し、各過程の寄与について電極組成・構造を変えたπ共役／凝縮レドックス融合物質の電気化学応答をもとに解明した。π共役固体の組成を調整した電極の電荷移動抵抗と固体／ポリマー間の接触面積の相関、膜厚の異なる電極における電荷移動抵抗を明らかにした。材質の異なる集電体上に形成された複合電極における電荷移動抵抗の支配因子を明確にした。電荷移動抵抗が充放電特性と直接相関をもつことを実証し、充放電特性向上に向けた活物質の設計指針の一つを導出した。(2) 律速段階における電荷移動の効率向上と高密度エネルギー貯蔵物質としての実証：π共役／凝縮レドックス融合物質に電荷補償系を共存させ、電荷保持力を確かめた。予備知見として明らかにしている高密度レドックスポリマー単独による可逆的エネルギー貯蔵能を、π共役系との分子レベルでの融合により向上させ、従来性能を超えた有機電池を実現した。具体的には、定電流下での平衡電位を参照電極基準で測定し、ポリマーに蓄積される電荷密度を求めた。また、減衰挙動から電荷保持力を含めた速度パラメータを見積もり、電荷貯蔵効率を把握した。電解質中での平衡膨潤度、対イオンや溶媒の物質移動量と速度を実測し、対イオン種や溶媒因子との相関を明確にすることにより、レドックス凝縮系としての特性を解明した。レドックス席の速い外圏的電子移動が、膨潤ゲル中でも大きな速度定数を与えることを実証し、高速電荷輸送可能な機能性界面を分子レベルで創出した。以上を総合し、π共役／凝縮レドックス融合物質を斬新なエネルギー貯蔵材料の一つとして確立した。26年度が最終年度であるため、記入しない。26年度が最終年度であるため、記入しない

  • 非晶質凝縮相を形成する高分子錯体の創出とエネルギー変換・貯蔵素子への応用

    Project Year :

    2012.04
    -
    2014.03
     

    　View Summary

    前年度の研究成果に基づき、高密度レドックスポリマー複合膜における電子移動と、それに伴うイオン輸送の全容解明により、有機光電変換に不可欠な革新的ポリマー・金属錯体複合素子を創出するとともに、金属錯体の光誘起電子・エネルギー移動を組み込んだ電荷分離・輸送系へ拡張し、光電変換能を引き出すことを目的として研究展開した。本年度の成果内容は以下の通りである。(1) n型レドックス席への拡張：n型酸化還元電位と電極反応の速度定数を把握し、酸化チタンのフェルミレベルに近い準位で可逆的な1電子移動を示すn型レドックス席を絞り込んだ。次いでこれらをペンダント置換基として導入した高密度レドックスポリマーを分子量高く合成し、電極修飾膜でn型容量を実測した。(2) n型電荷輸送の確立：酸化チタンのフェルミレベル近傍で可逆的1電子レドックス席を高密度に含有するレドックスポリマーは、励起色素から受け渡された電子を高エネルギー準位を保ったまま輸送でき、自己電子交換により電荷分離距離が顕著に増加するため、逆電子移動による電荷再結合を抑制できることを明らかにした。光電荷分離による起電力発生を実証し、従来にない全有機湿式太陽電池の実現に向けたn型輸送材料として確立した。初年度に得られたn型ポリマー膜に色素として働く金属錯体と電荷補償系を共存させ、光起電力の発生を確かめた。(3) n型ポリマーを用いた光電変換系の確立：透明電極上に形成させたn型ポリマー膜に、金属錯体（色素）を擬不均一系での高密度担持や、それをペンダント基とする高分子錯体の積層により複合した。光照射下での開回路電圧を測定し、蓄積される電荷密度を求めた。また、減衰挙動から逆電子移動を含めた速度パラメータを見積もった。選定されたn型電荷輸送層とp型電荷補償系を共存させたセルを構成し、開放電圧、短絡電流、フィルファクター、光電変換効率を把握し、高い開放電圧を引出した。25年度が最終年度であるため、記入しない。25年度が最終年度であるため、記入しない

  • π共役レドックス融合型エネルギー貯蔵マテリアルの創出

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(新学術領域研究(研究領域提案型))

    Project Year :

    2013
    -
    2014
     

    　View Summary

    本研究は、レドックス活性基を含有する有機ポリマーを活物質とした有機二次電池に関する研究において、物質移動の促進が効率高い電荷拡散に繋がることに基づき、伝導性と蓄電特性を両立しうる斬新な融合物質を創出することを目的とする。一般に蓄電能を有するポリマーは電子伝導性が乏しく、単独で電池容量を確保することは困難であり、有機二次電池を実用可能なレベルに到達させるには、導電助剤の添加による活物質の電気抵抗低減が必要となっている。従来の研究ではポリマー設計に力点が置かれ、分散状態や界面構造、集電体との相互作用など、本質的な構造因子は十分に研究されていなかった。これに対し本研究は、導電助剤であるπ共役有機固体とレドックスポリマーの融合による新材料創製を目指して、界面構造や分散状態などスケールを俯瞰した構造設計によりポリマーの性質を最大限引き出すことを目的とした。電気伝導と電荷輸送を融合させ、材料設計のスケール性を分子レベルからナノ寸法へ拡張し、斬新なエネルギー貯蔵マテリアルを創出するのが狙いである。本年度の具体的な成果を以下に記す。
    (1) 斬新なπ共役／凝縮レドックス融合物質の創出：π-πスタックによりバンドル形成するSWNTを、高密度レドックスポリマーの一つであるポリ（ニトロキシド置換メタクリレート）（PTMA）により分子ラッピングし、導電性を維持しながら高分散体を得た。PTMA被覆したSWNTをPTMA中に均一配置することにより、微量な炭素含有量で導電性ポリマー電極を形成させた。得られた電極が透明性と高速な充放電特性を示すことを明確にし、光電極としての可能性も含め応用範囲を拡大した。(2) π共役／凝縮レドックス融合物質における律速過程の解明：電子授受効率を高める導電助剤として炭素繊維との複合系を含め、集電体上に形成した多様な組成・膜厚のπ共役／凝縮レドックス融合物質における電荷移動を解析した。

  • Development of n-type redox polymers and their application to organic anode-active materials

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2009
    -
    2012
     

    OYAIZU Kenichi, NISHIDE Hiroyuki

    　View Summary

    Polyimides were found to exhibit excellent redox capability per repeating unit when they were made into a carbon nanocomposite layer at a molecular level. The reversible redox reaction obtained by placing the polyimide/carbon composite layer on a current collector was applied to the charge-storage process of anodes in organic batteries. A variety of polymers with an ultimate density of organic redox-active sites were synthesized, and their basic properties as the anode-active materials were determined. Enhanced charge transfer process accomplished by the precise control of mass-transfer process led to rapid and large-capacity charge storage with the polymers. A design strategy of electrode-active materials with excellent ionic migration processes was proposed, which allowed significant reduction of the amount of electrolytes in batteries.

  • Development of Organic Memory Devices Using Radical Polymers

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2009
    -
    2011
     

    NISHIDE Hiroyuki, OYAIZU Kenichi

    　View Summary

    Organic aliphatic polymers bearing a redox-active robust radical pendant per repeating unit have been applied as key materials for organic polymer memo-ries that are viewed as next-generation memory devices. Synthesis of the so-called radical polymers with designed SOMO levels and elucidation of charge injection mechanisms at polymer/metal interfaces allowed fabrication of nonvolatile memories with ON/OFF ratio of more than 10^5, high cycle durability, and excellent bistability. Factors that dominate the electric bistability in response to the applied voltage have been determined, which offered insight into the design principles of entirely organic organic memories. Thin devices made of the radical polymer layers sandwiched by two metal electrodes demonstrated the mem-ory properties at low applied voltages, which were based on the characteristic charge in-jection and transport behaviors found for the radical polymers.

  • SOMO Design of Radical Polymers for Development of Fully Organic Rechargeable Batteries

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2007
    -
    2011
     

    NISHIDE Hiroyuki, OYAIZU Kenichi, SUGA Takeo

    　View Summary

    We have been developing "organic radical batteries" by fabricating the prototypes using organic radical polymers as electode-active materials. The radical batteries are characterized by the unprecedented battery performances that accomplish both a high energy density and an excellent power rate capability, taking advantage of the designable polymer chain and the fast electron transpfer kinetics found for the radical pendants. The present research aims at establishing novel organic electrodes by unraveling the the electron-and mass-transfer processes of the radical polymers, in pursuit of basic principles that dominate the organic redox reactions through singly occupied molecular orbitals(SOMO). Rational molecular design and synthesis of radical polymers have been attempted with a view to further improve the energy and power densities to provide next-generation and sustainable organic rechargeable batteirs.

  • ラジカルポリマーゲルを用いた超高速電荷輸送ソフト界面の構築

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(新学術領域研究(研究領域提案型))

    Project Year :

    2009
    -
    2010
     

    　View Summary

    本研究は、有機安定ラジカル種がモノマー単位当たり置換した非共役系ポリマーである「ラジカルポリマー」を用いて、高速かつ高密度の電荷輸送・貯蔵機能をもつ電解質膨潤ゲル膜を創出し、膜の内部における電子移動とそれにともなうイオン輸送現象の全容解明により、革新的電極活物質を創出することを目的とする。特に、これらの支配因子と考えられる膜/電解液界面における物質移動を、ポリマーゲル表面への規則的・階層的構造の導入を手段として効率化する切り口から、大容量の電荷貯蔵に関わるソフト界面の化学を確立する。酸化還元活性なラジカル席が密集した電解液膨潤ゲルを、外部からの電気刺激により酸化状態やDonnan平衡が素早くダイナミックに変化する機能性ソフト界面と捉え、エネルギー分野を志向した材料開拓の切り口から、ソフト界面の分子科学創出の一例として貢献する。
    (1)界面構造制御による炭素フリーの活物質設計
    メソスコピックレベルの規則・階層的構造をポリマーゲル/電解液界面に形成させ、電極面積当たりのレドックス容量と充放電のレート特性を両立させた斬新な機能性ゲルを創出した。光架橋ラジカル膜へのパターニングや相分離を利用したイオン移動チャンネルの導入により、電荷や対イオンの正味の拡散距離を低減させた構造を構築し、ポリマー膜への電荷注入が対イオンによる電荷補償に律速されず、あたかも溶存レドックス種のように素早く応答するソフト界面として確立した。
    (2)電子・イオン輸送現象の解明と制御
    ポリマーのキャスト膜における低次元イオン輸送チャンネルを形成するイオノフォア機能を期待して、ラジカル置換ポリエーテル類へと展開、ラジカル部位の電荷補償カチオン種について、ポリエーテル相互作用に基づく拡散経路を形成させた。有効レドックス層として働くポリマー膜厚を把握し、対イオンの拡散性向上が不活性層低減に繋がることを実証した。

  • ラジカルポリマーゲルを用いた超高速電荷輸送ソフト界面の構築

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(新学術領域研究(研究領域提案型))

    Project Year :

    2009
    -
    2010
     

    　View Summary

    本研究は、有機安定ラジカル種がモノマー単位当たり置換した非共役系ポリマーである「ラジカルポリマー」を用いて、高速かつ高密度の電荷輸送・貯蔵機能をもつ電解質膨潤ゲル膜を創出し、膜の内部における電子移動とそれにともなうイオン輸送現象の全容解明により、革新的電極活物質を創出することを目的とする。特に、これらの支配因子と考えられる膜/電解液界面における物質移動を、ポリマーゲル表面への規則的・階層的構造の導入を手段として効率化する切り口から、大容量の電荷貯蔵に関わるソフト界面の化学を確立する。酸化還元活性なラジカル席が密集した電解液膨潤ゲルを、外部からの電気刺激により酸化状態やDonnan平衡が素早くダイナミックに変化する機能性ソフト界面と捉え、エネルギー分野を志向した材料開拓の切り口から、ソフト界面の分子科学創出の一例として貢献する。(1)界面構造制御による炭素フリーの活物質設計メソスコピックレベルの規則・階層的構造をポリマーゲル/電解液界面に形成させ、電極面積当たりのレドックス容量と充放電のレート特性を両立させた斬新な機能性ゲルを創出した。光架橋ラジカル膜へのパターニングや相分離を利用したイオン移動チャンネルの導入により、電荷や対イオンの正味の拡散距離を低減させた構造を構築し、ポリマー膜への電荷注入が対イオンによる電荷補償に律速されず、あたかも溶存レドックス種のように素早く応答するソフト界面として確立した。(2)電子・イオン輸送現象の解明と制御ポリマーのキャスト膜における低次元イオン輸送チャンネルを形成するイオノフォア機能を期待して、ラジカル置換ポリエーテル類へと展開、ラジカル部位の電荷補償カチオン種について、ポリエーテル相互作用に基づく拡散経路を形成させた。有効レドックス層として働くポリマー膜厚を把握し、対イオンの拡散性向上が不活性層低減に繋がることを実証した

  • エネルギーデバイスを目指した高密度電子輸送材料の創製

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(萌芽研究)

    Project Year :

    2007
    -
    2008
     

    　View Summary

    本研究では、負極活物質として電極反応速度が大きく、還元ドープにより高容量が期待できる新規なn型活性ポリマーを設計・合成することを目的とする。具体的には、還元電位と電子移動速度を制御して、n型活性なポリマーを探索した。n型ドープ状態の安定化に働く各種因子を解明し、卑な電位で安定度高く電子貯蔵できるポリマーを合成した。さらに、安定ラジカル種に関する申請者の従来知見を活用し、ニトロニルニトロキシド、フェノキシル、ガルビノキシルおよびセミキノンラジカルへと拡張し、斬新なn型活性物質群として確立した。
    (1)n型ポリマーの合成
    前年度に選定されたn型活性なレドックス席を有するメタ(ア)クリレード、スチレン誘導体などを合成し、対応するポリマーを得た。カルボニル基が隣接位に置換したアシルニトロキシドモノマーは、対応するヒドロキシルアミンを出発物として、酸クロ法により保護基、ビニル基を導入して得た。重合後、ベンゾイル基の脱保護、酸化を経てニトロキシドポリマーを得た。
    (2)n型ラジカルポリマーの拡張
    ガルビノキシルおよびフェノキシルとの関連から、キノン/セミキノンラジカルをレドックス席に有するポリマーを合成した。セミキノンラジカルの安定度の向上と、キンヒドロン生成の抑制が期待できる主鎖型および剛直なペンダント構造を有するポリマーを合成した。
    (3)全有機二次電池の試作
    ポリマー膜内の電子・イオンの拡散過程を解析し、負極活物質と導電性部材との複合化について検討した。

  • Development of Functional Liposomes Modified with Hydrophilic Porphyrins Based on Electrostatic Force

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2005
    -
    2007
     

    OYAIZU Kenichi

    　View Summary

    The present study aimed at development of functionality of liposomes by surface modification with metal complexes using electrostatic interaction, thereby employing the functional liposomes to a variety of catalytic reactions that proceed at the surface of the liposome surface. Hydrophilic metal complexes such as cationic porphyrins substituted with pyridinium, sulfonium, and thophenium groups were synthesized. The metal complexes of these porphyrins with Fe and Mn were immobilized at the surface of the anionic liposomes by electrostatic interaction. The porphyrin complexes were exposed at the surface of the liposomes, in contrast to those reported for many types of porphyrin-bearing liposomes which typically employed hydrophobic complexes to accommodate the porphyrins in the lipid bilayers. The proposed porphyrin-modified liposomes proved to be a new type of functional nanoparticles. For example, the Fe-porphyrin modified liposome underwent catalytic disproportionation reaction of superoide anion radical according to 2O_2+2H^+→H_2O_2+O_2, and also catalyzed the Fenton reation of hydrogen peroxide according to H_2O_2→2OH・. The liposome was sufficientluy small in diameter to be delivered to cells, where it underwent the catalytic reaction related to the active oxygen species, producing the hydroxyl radical HO・to effectively induce apoptosis of the targeted cell. The porphyrin-modified liposome based on the electrostatic effect was shown to be an effective antitumor agent with high tumor cell selectivity

  • Synthesis of Novel Functional Conductive Polymers in Supercritical Carbon Dioxide and their Properties

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2004
    -
    2006
     

    YUASA Makoto, OYAIZU Kenichi, MURATA Hidenori

    　View Summary

    In this work, we have investigated the electrochemical synthesis of conductive polymers in homogenous supercritical condition. The effects of several factors such as pressure, phase behavior and mass transfer process for the obtained polymer film were examined.
    Thiophene was chosen as a model monomer to electropolymerize in supercritical carbon dioxide (scCO_2). The homogeneous supercritical state was confirmed by the observation of the phase behavior through a high-pressure cell with a viewing window. The conductive polymer film of thiophene synthesized in scCO_2 was characterized with cyclic voltammetry, SEM, Laser microscopy, AFM and four-point probe conductivity. The roughness of the film in that system was decreased with the further addition of CO_2. This result suggested that the low viscosity of scCO_2 play an important role in improving the transfer rate of solvent. The roughness of the film prepared in the homogeneous scCO_2/ acetonitrile (AN) system was reduced compared with that prepared in dichloromethane. The slow growth of the film and the high diffusion rate of the monomer seemed to account for the smooth and flat film formation. Other conductive polymers, polyaniline and polypyrrole, were successfully synthesized in a homogeneous scCO_2/ AN system.
    This electropolymerization system was extended to the polymerization of thienylporphyrin (H23ThTEtP) for the application as a superoxide sensor. The resulting film of H23ThTEtP was characterized using SEM, laser microscopy and AFM. It was revealed that the electropolymerized film in scCO_2 provided flatter, smoother and higher densified active sites than the one electropolymerized in organic solvent.
    The polymerized film as an electrocatalyst was applied to a superoxide sensor. The catalyst displayed selectivity and activity for the oxidation of 02・and showed a linear relationship between current and 02・concentration, which revealed the possibility of quantitative analysis of 02・in vivo. The catalyst showed higher sensitivity than the one electropolymerized in organic solvent.

  • Synthesis of Novel Functional Conductive Polymers in Supercritical Carbon Dioxide and their Properties

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2004
    -
    2006
     

    YUASA Makoto, OYAIZU Kenichi, MURATA Hidenori

    　View Summary

    In this work, we have investigated the electrochemical synthesis of conductive polymers in homogenous supercritical condition. The effects of several factors such as pressure, phase behavior and mass transfer process for the obtained polymer film were examined.
    Thiophene was chosen as a model monomer to electropolymerize in supercritical carbon dioxide (scCO_2). The homogeneous supercritical state was confirmed by the observation of the phase behavior through a high-pressure cell with a viewing window. The conductive polymer film of thiophene synthesized in scCO_2 was characterized with cyclic voltammetry, SEM, Laser microscopy, AFM and four-point probe conductivity. The roughness of the film in that system was decreased with the further addition of CO_2. This result suggested that the low viscosity of scCO_2 play an important role in improving the transfer rate of solvent. The roughness of the film prepared in the homogeneous scCO_2/ acetonitrile (AN) system was reduced compared with that prepared in dichloromethane. The slow growth of the film and the high diffusion rate of the monomer seemed to account for the smooth and flat film formation. Other conductive polymers, polyaniline and polypyrrole, were successfully synthesized in a homogeneous scCO_2/ AN system.
    This electropolymerization system was extended to the polymerization of thienylporphyrin (H23ThTEtP) for the application as a superoxide sensor. The resulting film of H23ThTEtP was characterized using SEM, laser microscopy and AFM. It was revealed that the electropolymerized film in scCO_2 provided flatter, smoother and higher densified active sites than the one electropolymerized in organic solvent.
    The polymerized film as an electrocatalyst was applied to a superoxide sensor. The catalyst displayed selectivity and activity for the oxidation of 02・and showed a linear relationship between current and 02・concentration, which revealed the possibility of quantitative analysis of 02・in vivo. The catalyst showed higher sensitivity than the one electropolymerized in organic solvent.

  • π共役系剛直鎖ポリヘテロアセン類におけるナノ構造制御と量子秩序

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(若手研究(A))

    Project Year :

    2002
    -
    2003
     

    　View Summary

    本研究は、芳香族スルホニウム塩類の親電子置換反応を擬二次元型π共役系高分子の新合成法として確立すると共に、その電子・光電子物性を詳細に解明することを目的とする。特に、歪みの無いπ共役系構造におけるドーピング構造の安定化を、計算と実験の両面から明らかにする。本年度の研究実績は以下の通りである。1.擬二次元π共役系連鎖の基礎物性解析合成されたヘテロポリアセン類(フェノチアジニウム型、チアントレニウム型、フェノキサチイニウム型およびチオフェンラダー型)の吸収スペクトルにおけるπ-π^*遷移吸収波長、吸光係数、薄膜の屈折率、CVにおける酸化還元電位、熱安定度(Tg,Tm,Td)などの基礎物性を正確に測定、これらを構造と相関させて整理した。酸化還元電位は置換基の導入や対アニオンにより調節可能であった。分子軌道計算を援用して、3d-2p共鳴効果、励起エネルギーおよびドーピング構造などを算出、実験結果を反映させながら高伝導体を実現させる有効な分子骨格を決定した。併せて構造明確な低重合度閉環体の性質を計算予測し、ポリマーと共に合成した。2.電子・光電子機能の解明溶液キャスト法により上記4種類のポリスルホニオアセンの成膜試料を作成、4端子法によりバルク電子伝導度を測定、酸化ドーピングによる伝導度向上を実証すると共に、還元ドーピングも可能であることを酸化還元電位から実証した。紫外可視およびESRスペクトルからポーラロン、バイポーラロン生成を確認すると共に、ラジカル濃度の定量からポーラロン状態の安定度を正確に把握した。伝導度の温度依存性から伝導機構を明らかにすると共に、対イオンを変化させて配向試料を作成、YAGレーザを用いて二次非線形感受率を予備的に測定することにより、偏光方向や波長依存性を明らかにした。以上を総合して、新しい物質系である長鎖共役型ポリスルホニオアセンについて、光電子機能に関する基礎的な性質を解明した

  • π共役系剛直鎖ポリヘテロアセン類におけるナノ構造制御と量子秩序

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(若手研究(A))

    Project Year :

    2002
    -
    2003
     

    　View Summary

    本研究は、芳香族スルホニウム塩類の親電子置換反応を擬二次元型π共役系高分子の新合成法として確立すると共に、その電子・光電子物性を詳細に解明することを目的とする。特に、歪みの無いπ共役系構造におけるドーピング構造の安定化を、計算と実験の両面から明らかにする。本年度の研究実績は以下の通りである。1.擬二次元π共役系連鎖の基礎物性解析合成されたヘテロポリアセン類(フェノチアジニウム型、チアントレニウム型、フェノキサチイニウム型およびチオフェンラダー型)の吸収スペクトルにおけるπ-π^*遷移吸収波長、吸光係数、薄膜の屈折率、CVにおける酸化還元電位、熱安定度(Tg,Tm,Td)などの基礎物性を正確に測定、これらを構造と相関させて整理した。酸化還元電位は置換基の導入や対アニオンにより調節可能であった。分子軌道計算を援用して、3d-2p共鳴効果、励起エネルギーおよびドーピング構造などを算出、実験結果を反映させながら高伝導体を実現させる有効な分子骨格を決定した。併せて構造明確な低重合度閉環体の性質を計算予測し、ポリマーと共に合成した。2.電子・光電子機能の解明溶液キャスト法により上記4種類のポリスルホニオアセンの成膜試料を作成、4端子法によりバルク電子伝導度を測定、酸化ドーピングによる伝導度向上を実証すると共に、還元ドーピングも可能であることを酸化還元電位から実証した。紫外可視およびESRスペクトルからポーラロン、バイポーラロン生成を確認すると共に、ラジカル濃度の定量からポーラロン状態の安定度を正確に把握した。伝導度の温度依存性から伝導機構を明らかにすると共に、対イオンを変化させて配向試料を作成、YAGレーザを用いて二次非線形感受率を予備的に測定することにより、偏光方向や波長依存性を明らかにした。以上を総合して、新しい物質系である長鎖共役型ポリスルホニオアセンについて、光電子機能に関する基礎的な性質を解明した

  • Precision Synthesis of Poly(thiophene)s by oxidative polymerization

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2001
    -
    2002
     

    NISHIDE Hideyuki, OYAIZU Kenichi

    　View Summary

    Alkyl-sulfinyl substituted poly(l,2-phenyleneoxide) and poly(1,3-phenylene) are prepared by oxidative polymerization under air to lead them the double-stranded structure via oxidation and superacid-induced intraraolecular condensation. The extended π-conjugation system of the result polymers is also discussed. Additionally, a depolymerization of the polymers consisted of alkylsulfinyl phenols are revealed and applied to the control of molecular weight.
    (1) Synthesis of the helical polymer consisted of condensed thiophene rings. A oxidative polymerization of 4-methoxy-2-methylsulfinylphenol afforded the precursor poly(1,2-phenyleneoxide) with pendant methylsulfinyl groips. The following intramolecular condensation gave the phenoxathiinium-type helical ladder polymer. The absorption maximum and tail in the UV-vis spectrum of the ladder polymer showed bathochromicalfy shift comprable with those of the precursor polymer to suggest the extended π-conjugated planarity even in the helical structure. A Pd catalyzed polymerization of 1,3-benzene bis(boronate) and methylthio substituted 1,3-dibromobenzene provided the corresponding poly(1,3-phenylene). The oxidation and the intramolecular condensation of the pendant groups were carried out to yield the helical ladder polymer. The stricture was characterized by NMR, IR and Elemental analysis, the absorption spectrun revealed the delocalization of the π-electron.
    (2) Study of the polymerization and depolymerization kinetics. In order to control the nolecular weight of the poly (alkylsulfinyl-phenyleneoxide), the condition of depolymerization of poly (2,6-dimethyl-1,4-phenyleneoxide) (PPO) was studied. An addition of 2,6-dimethylphenol and evaluated phenoxy-radicals in the oxidative condition shifted the equilibrium to the depolymerization of the polymer. The molecular weight after the depolymerization depended on the concentration of the terminal OH groups and agreed with the theoretical calculated molecular weight. A presence of the intermediate phenoxy-radical in the ESR and the rate constants from UV-vis spetra indicated the depolymerization of polyfphenyleneoxide) was occurred by the repetitive redistribution.

  • Synthesis of Nitrogen-containing Polymers Using Dinitrogen Splitting

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    1999
    -
    2000
     

    OYAIZU Kenichi, TSUCHIDA Eishun

    　View Summary

    The present research aims at making a catalytic system to allow molecular splitting of nitrogen for molecular conversion of organic molecules. One-step multi-electron transfer complexes were applied for the multi-electron reduction of nitrogen via a μ-dinitrido type complex.
    The four-electron reduction of oxygen catalyzed by a μ-oxo divanadium complex were expanded to the μ-dinitrido complex for the reduction of nitrogen. An effective complex, Nb diethyldithiocarbamate complex was found which formed the desired μ-dinitrido complex upon the reaction with nitrogen. Electrocatalytic reduction of nitrogen was established using the complex.
    The N-N bond splitting reaction was investigated using MO calculations and in-situ electrochemical Raman spectroscopy, which revealed that the multi-electron transfer is fostered by the catalytic system.

  • One-Step Multi-electron Transfer for Molecular Conversion

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    1996
    -
    1998
     

    TSUCHIDA Eishun, OYAIZU Kenichi, KOMATSU Teruyuki, NISHIDA Hiroyuki, ANSON Fred C, MIYATAKE Kenji

    　View Summary

    The research project aims at elucidating the multi-electron transfer process of oxygen molecules incorporated into the macromolecule-metal complexes, in order to establish novel molecular conversion processes which are promoted by the four-electron reduction of oxygen.
    Followings have been established : Detailed analysis of the oxygen splitting reaction by one-step four-electron transfer, establishment of oxidative polymerization facilitated by multi-electron transfer process, elucidation of multi-electron transfer process in molecular assemblies. Based on these results, a general strategy to allow molecular conversions to proceed efficiently by multi-electron transfer process has been provided.
    1. Multi-nuclear metal complexes that show one-step multi-electron transfer processes were synthesized and their structure was determined. A general method to provide a one-step multi-electron transfer was provided.
    2. Oxygen splitting reaction by way of a μ-dioxo intermediate MOM-OO-MOM was established.
    3. Synthesis of novel compounds, polysulfoniums and polythioethers, were established, and their properties were determined in detail.
    4. Structure and properties of molecular assembly systems were elucidated, in terms of photoelectron transfer process.
    5. Synthesis of high molecular-weight polyheteroacenes were established, and their physicochemical properties were determined.

  • d-pπ超共役高分子ポリスルホニウムの合成と光電子特性

    日本学術振興会  科学研究費助成事業

    Project Year :

    1996
    　
    　
     

    小柳津 研一, 土田 英俊

    　View Summary

    スルホニオ基と1,4-フェニレン基が交互に連結した新規構造ポリスルホニウムの生成反応を見出した。メタンスルフィン酸ナトリウムとベンゼンを強酸中で反応させると、ジヒドロキシメチルスルホニウムカチオンが活性種となって重合が進行し、ポリ(メチルスルホニオ-1,4-フェニレン)が生成する。本重合反応をキシレン、ジフェニルエーテル、ジフェニルスルフィドなどの芳香族モノマーに適用、ポリスルホニウム化合物の幅広い合成法として確立した。さらに従来重合不活性とされていたメチルフェニルスルホキシドがアミンの存在下では重合し、同様にポリ(メチルスルホニオ-1,4-フェニレン)を生成することを明らかにした。特に、当量のジフェニルアミンを添加した系では定量的に重合体が得られる。ジフェニルメチルスルホニウムを用いたモデル解析から、スルホニウム-アミンの電荷移動錯体形成を経由して重合が生起する機構を解明した。
    得られた新物質ポリスルホニウムは水や極性有機溶媒に可溶な白色粉末であり、安定に単離が可能である。電子スペクトルよりλmaxは251nm(ε=2.15×10^4)であり、二量体(λmax=231nm)、三量体(λmax=242nm)に較べ長波長側にシフトしていることから、スルホニウム硫黄原子の3d空軌道を介したπ共役系が広がっていることが示された。またメチルスルホニオ基に変えパ-フルオロアルキルスルホニオ基を導入すると、共役系はさらに拡大することを確認した。これらの実験結果は分子軌道法(PM3)による電子構造計算からも裏付けられており、一連の芳香族ポリスルホニウム化合物の構造と光学特性の相関を解明できた。さらに電子供与置換基としてフェノキシ基を有するパ-フルオロアルキルスルホニウム化合物は大きな分子超分極率(β=1860au)を持っていることから、ニトロアニリン(β=769au)よりも優れた二次非線形光学特性を示すことが期待される。

  • Molecular Conversion Using One-Step Multi-electron Transfer Complex

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    1995
    -
    1996
     

    YAMAMOTO Kimihisa, OYAIZU Kenichi, TSUCHIDA Eishun

    　View Summary

    Vanadyl (salen) multi-nuclear complexes act as electron mediators to allow catalytic multi-electron electroeduction of oxygen. By adjusting redox potentials to the value close to the thermodynamic potential for the 4-electron reduction of oxygen using a variety of ligands, the objective of the present study is to establish multi-electron reduction systems of molecular oxygen by the use of these complexes as electron mediators. It is also intended to elucidate novel molecular conversion systems by the use of these complexes as oxidation systems for organic substrates.
    It the first year, vanadium complexes with inert ligands were prepared and the redox potentials were determined. Also, the corresponding dinuclear complexes were prepared. X-ray studies of these complexes revealed the structure of the oxygen-binding sites in these complexes. By near-infrared spectrum, the redox state of the complexes were determined. Kinetic analysis for the oxygenation of the catalyst revealed the presence of mu-dioxo intermediate.
    In the second year, the selected vanadium complexes were used as electron mediators, and the reduction of oxygen was examined. Koutecky-Levich Plots obtained by the rotating ring-disk voltammetry revealed the 4-electron process and the production of water. The turn-over number of the catalyst was determined to exceed 10. It was concluded that selective 4-electron reduction system of oxygen was established.

  • チエニルポルフィリン類を用いた共役ポリマーの合成と機能開拓

    　View Summary

    本研究は、メソ位3-チエニル基置換されたポルフィリンを用いてポルフィリンとポリチオフェンからなる全共役系の高分子錯体を合成し、連鎖に沿ったポルフィリン環の配向が無秩序から共面配列まで階層的に制御された一連のp共役連鎖を創出することを目的とする。物質移動が顕著に促進される超臨界二酸化炭素中での電解重合により、精密な積層膜を構築する。これを用いて、ポリチオフェン鎖がポルフィリン部位の酸化還元における電子移動経路を提供することを実証し、高効率な電子移動触媒およびエネルギー変換系としての可能性を明らかにする。本研究の結果、類例のない全共役系ポルフィリンーポリチオフェン複合体を提供することに成功し、ポリチオフェンに沿ったポルフィリン環の配列制御や人工格子の構築に展開すると共に、ポリチオフェンを電子伝達経路に用いてポルフィリンのレドックス活性を向上させた。具体的成果を以下に述べる。(1)チエニルポルフィリン類の設計と合成 ポルフィリンーポリチオフェン複合体の単量体としてチエニルポルフィリンを合成し、中心金属を導入した。チエニル基の置換位置の違いに基く生成ポリマーの高次構造の多様性により薄膜物性に差異が生じることを明らかにした。(2)化学酸化重合によるポリマー合成 チエニルポルフィリン類を化学酸化重合し、ポルフィリン配向度の高いHT-HT型ポリマーを得た。ポルフィリン環の立体障害が緩和された共重合体を合成し、立体規則性を保ちながらポルフィリン環の配向度が制御された一連の誘導体に展開した。各種スペクトルからポルフィリンの整列度を解析し、成膜性と導電性を有する配向ポルフィリン集積体として確立した。(3)電解重合による薄膜化 常温常圧下におけるチエニルポルフィリン類の電解重合を経て、超臨界二酸化炭素環境下における電解重合へ展開し、膜厚や配向度が精密制御された高密度ポルフィリン集積膜を作製した。ナノレベルの超構造薄膜を形成しうる材料としての性質を、構造と相関させてまとめた。(4)多重積層膜の構築と機能開拓 超臨界二酸化炭素中で得られる平滑・高密度の導電性薄膜を用いて、膜厚がナノメータレベルで制御された積層構造を構築した。ポルフィリン環に局在するHOMOの高いエネルギーレベルにより極めて高いエネルギーレベルにより極めてp-ドーブ容易なポルフィリン-ポリチオフェン複合体として確立した

  • チエニルポルフィリン類を用いた共役ポリマーの拡張と新機能の開拓

    　View Summary

    本研究は、ポリマーのレドックス特性とバルク構造の相関を明らかにし、高効率な電荷貯蔵材料として確立することを目的とする。具体的には、ポルフィリンをレドックスサイトに有する共役系高分子錯体に関する従来知見を拡張し、迅速・可逆なレドックス反応を特徴とする有機レドックス中心に着目、主鎖にペンダント結合させたレドックスポリマーを合成する。機能ユニットの配向が無秩序から規則配列まで階層的に制御された一連の高分子を創出し、高次構造がレドックス部位の活性における電荷補償を支配していることを明確にし、高効率な電荷貯蔵材料として確立する。(1) チエニルポルフィリン類の拡張チエニルポルフィリン類の合成を縦続し、種々の中心金属を導入した。立体規制されたポリマーを得る反応条件を把握し、ポルフィリン配向度を決定した。(2) レドックスポリマーのキャラクタリゼーション可逆な-電子還元を示す有機置換基を探索した。縮合環のレドックスにより可逆な電極反応が期待できるポリマーを創出し、これらの成膜性、導電性等の基礎物性を把握した。(3) 超構造構築と新機能の開拓平滑で高密度の導電性ポリマー薄膜を用いて、膜厚制御された薄膜を基板電極上に形成させ、膜を介した電位・電流応答を解明した。膜内電子移動に由来する触媒機能についても明らかにした。(4) レドックス機能の拡張と電子貯蔵材料への応用レドックス活性が、導電経路に働く主鎖共役系により顕著に向上するとの知見を基に、電極触媒へと応用した。鉄ポルフィリンがスーパーオキシドの酸化触媒となりうることに着目し、不安定ラジカル種の高感度検出について検討した。これらを電子貯蔵部位として用い、電荷貯蔵材料としての性質を解明した。ユニット当り可逆的に1電子移動し、安定度高く高レベルドープ可能であることを実証した

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Misc

  • PMSE 433-Radical polymers for organic-based rechargeable device

    Hiroyuki Nishide, Kenichi Oyaizu

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   236  2008.08

    Research paper, summary (international conference)  

  • Involvement of reactive oxygen species in ovulation

    NARIAI Koichi, TSUBOTA Akihito, NAMIKI Yoshihisa, FUJISE Kiyotaka, MURATA Hidenori, OYAIZU Kenichi, YUASA Makoto

      25 ( 2 ) S22  2008.04

    CiNii

  • 排卵卵胞における酸化ストレスマーカーの免疫組織化学的検出 (第36回成医会柏支部例会一般演題)

    成相 孝一, 坪田 昭人, 保科 定賴, 藤瀬 清隆, 金山 喜一, 石川 満寿英, 江口 勝哉, 豊田 裕次郎, 設楽 正樹, 小柳津 研一, 湯浅 真

    東京慈恵会医科大学雑誌   122 ( 4 ) 172 - 172  2007.07

    CiNii

  • Microelectrode Studies of Electrochemical Reaction using Supercritical Carbon Dioxide as the Solvent

    D. Komago, H. Yan, T. Sato, A. Yamaguchi, K. Oyaizu, M. Yuasa

    Proceedings of 7th International Symposium on Supercritical Fluids (ISSF2005)    2005.05

  • 協奏的多電子移動系の構築とその機能開拓

    小柳津 研一, 湯浅 真

    表面   41 ( 3 ) 96 - 107  2003.03

    CiNii

  • Synthesis and Properties of Polyheteroacenes

    OYAIZU Kenichi

      51 ( 1 ) 22 - 24  2002.05

    CiNii

  • Copper(II) complexes resulting from the oxygenation of (2,9-dimethyl-1,10-phenanthroline)copper(I) chloride in the presence of dimethylformamide (vol 74, pg 869, 2001)

    K Oyaizu, M Ueno, H Li, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   74 ( 12 ) 2463 - 2463  2001.12

  • Multielectron transfer of a decanuclear oxovanadium cluster and application to oxygen batteries.

    K Oyaizu, EL Dewi, E Tsuchida

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   220   U467 - U467  2000.08

    Research paper, summary (international conference)  

  • Electroreduction of oxygen to water by vanadium complexes.

    K Oyaizu, EL Dewi, FC Anson, E Tsuchida

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   217   U970 - U971  1999.03

    Research paper, summary (international conference)  

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    小柳津 研一, 西出 宏之, 畠山 歓, 鈴木 美結, 赤羽 智紀

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    5649716

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    6069787

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    5947688

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    小柳津 研一, 佐野 直樹, 西出 宏之

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    6052631

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Syllabus

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Sub-affiliation

  • Faculty of Science and Engineering   Graduate School of Advanced Science and Engineering

Research Institute

  • 2024
    -
    2026

    Waseda Research Institute for Science and Engineering   Concurrent Researcher

  • 2024
    -
    2026

    Waseda Center for a Carbon Neutral Society   Concurrent Researcher

Internal Special Research Projects

  • 高耐熱・結晶性エンプラの精密3D造形を目指した革新的相溶化法の開拓

    2019  

    　View Summary

    本研究は，ポリフェニレンスルフィド（PPS）の機能展開を目指し， PPSの三次元（3D）プリンティング造形の鍵になりうる新しい高分子物質を開拓することを目的とした。モノマーであるジフェニルジスルフィドにメチル基，エチル基，メトキシ基，アルケニル基を導入し，対応するポリマーを直鎖かつ成形加工可能な高分子量体として得た。2,6-位にアルキル基を有する場合，PPSは完全非晶質になりポリスチレンとの相溶性を獲得することを明らかにしている。今回得られたPPS誘導体も同様の相溶性を示した。アルケニル基の反応性により無機酸化物との親和性が向上し，コンポジット材料として展開できることも明確にした。

  • 低環境負荷型合成プロセスによる超高屈折率ポリマーの創出

    2018  

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    本研究は，申請者らが見出した芳香族ジスルフィド類の酸化重合をさらに追究し，ポリフェニレンスルフィド誘導体をはじめとしたポリチオエーテル高分子の革新的合成法として幅広く確立するとともに，低環境負荷かつ省エネプロセスでの芳香族系耐熱性高分子材料の合成法として定着させることを目的として展開した。特に，従来にない透明かつ高屈折率の機能性光学樹脂を創出することを目指した。この結果，従来の芳香族求核置換反応機構に基づく重縮合では困難とされたアルキル置換基を有する新規PPS誘導体が酸化重合で簡単に合成できることを確立した。これらが完全非晶質の耐熱性固体を与えることを明らかにし，熱特性を兼ね備えた透明光学樹脂としての展開と合わせ，関連する無定形高分子固体における電荷・イオン輸送の解明にも役立つ知見を得た。

  • 電極活物質に用いる高度機能性バインダーの研究開発

    2016  

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    　本申請は、ラジカルポリマーに関するこれまでの研究で見出された有機系活物質の酸化還元に伴う制御可能な膨潤・収縮過程を、全く新しいバインダー材料として応用する着想で、活物質の充放電に伴う体積変化を補償する高度機能性バインダーを創出することを目的とした。特に、酸化・還元と膨潤・収縮の両状態を自在かつ可逆的にコントロールできる新規バインダー材料として、スルホン酸基を含有させたニトロキシドラジカルポリマーが従来のp型とは異なる電解質カチオンによる電荷補償過程（n型過程）を示すことの発見に基づき、その具体例を展開した。 &nbsp; &nbsp;

  • 電荷分離・輸送分子の組織化による新しい光電変換系の構築

    2015  

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    本研究は、有機二次電池の具体化に不可欠な高特性の電極活物質を創出するとともに、色素分子の複合化により、光電変換能を引き出すことを目的とした。特に、これらの支配因子と考えられる膜／電解液界面における物質移動を、レドックス基と化学結合させた色素分子を用いて効率化する切り口から、光電荷分離に関わる基本的な性質を引き出すことを試みた。その結果、これらと電解質の界面に配置させた色素部位の増感反応を活用し、効率高い有機太陽電池を試作・動作実証することが可能となった。さらに、光電荷分離・輸送性を高めた新しいポリマーの設計 (例えば色素準位とマッチさせたポテンシャル勾配の形成など) により、光電変換系としての変換効率を向上させた。これら基礎的追究から得られる知見を総合し、有機太陽電池を構成しうる斬新な光電荷分離・輸送材料としての可能性を明確にした。

  • 電荷分離・輸送制御による人工光合成システムの構築

    2015  

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    本研究は、可逆的な酸化還元を示すレドックス席を密度高く有するレドックスポリマー、すなわち高密度レドックスポリマーが形成する膜における電子移動と、それに伴うイオン輸送の解明により、水の光分解に資する電荷輸送物質を創出するとともに、レドックス／色素複合分子による光電荷分離系へ拡張し、人工光合成モデルとしての可能性を明確にすることを目的とした。このような分子組織体を電荷輸送層に利用したセルを予備的に試作した。さらに、光電荷分離・輸送性を高めた新しい高密度ポリマーの設計により、光反応系としての効率を向上させる因子を明確にした。これらの知見を総合し、人工光合成モデルを構成する光電荷分離・輸送材料としての具体化の可能性を明らかにした。

  • 電荷分離・輸送分子の組織化による新しい光電変換系の構築

    2014  

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    本研究は、有機二次電池の具体化に不可欠な革新的電極活物質を創出するとともに、色素複合分子の組織化による効率高い光電変換能を引き出すことを目的として研究展開した。具体的には、これらの支配因子と考えられる膜／電解液界面における物質移動を、規則的・階層的な集合組織の構築を手段として効率化する切り口から、光電荷分離に関わる協働機能を引き出した。次いで、この複合組織体と電解質の界面に配置させた色素部位の増感反応を活用し、有機太陽電池を試作して動作実証した。さらに、光電荷分離・輸送性を高めた新しいポリマーの設計により、光電変換系としての変換効率を向上させた。

  • 光蓄電デバイスの遍在性向上に資する大流束電荷輸送レドックス系の創発

    2014  

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    本研究は、高密度レドックスポリマーによる電荷輸送の概念を拡張し、新たに有機色素を組み込んだ複合系を対象として、遍在型電源の例示である有機光･空気二次電池の実現に必須となる革新的電荷分離・輸送・貯蔵ポリマーを創出することを目的とした。光反応の支配因子と考えられる界面における電荷分離効率を、分子レベルでの色素複合体形成を手段として高める切り口から、有効な光化学系の構築に関する基礎知見を集積した。高密度レドックスポリマー内の電子移動機構に立脚した分子設計により、高い電荷分離・輸送効率で蓄電にも対応できる色素複合レドックスポリマーの実例を拡張し、斬新な光機能負極を有機系新物質として確立した。

  • キノイド系有機負極を用いた超高密度エネルギー変換系の創発

    2012  

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    キノン類の速い電子授受に着目し、アントラキノン置換ポリマーによるn型電荷輸送の実現とこれを負極とする有機空気二次電池の実証を起点として、卑な電位での電子交換反応に立脚した導電・蓄電現象に関わる基礎科学を確立することを目的とする。具体的には、有機負極として働くポリマーの拡充を斬新なn型レドックス席の創出と電荷輸送・貯蔵過程における電子・イオン輸送の解明を基軸とした普遍化により計り、ヘテロ接合面のボトムアップ集積に立脚した高速輸送性および界面での交差反応に基く整流性発現を、ロッキングチェア型電荷補償やpnバイポーラ性を持たせた多様な電荷貯蔵形態の実証を経て超高密度蓄電物質の創出へと繋げ、化学・電気エネルギー変換に関連した有機物性化学の新領域を開拓することを目指して研究展開した。この結果、負電荷の高密度蓄積すなわちn型ヘビードーピングが可能な斬新なn型レドックス席と主鎖構造を絞り込み、形成されるレドックス勾配から電荷輸送の駆動力を引き出すための方法論を導出できた。また、レドックス席間の電荷・物質移動過程を解析し、電子交換をポリマー内で連続的に生起させ、可逆的・高速かつ高密度な電荷貯蔵の要件を明確にした。さらに、レドックス凝縮相による電荷輸送の概念を拡張し、分子細線としての共役鎖を組込んだ複合系に踏み込むための手掛かりを明確にした。以上を組み合わせて、n型ポリマーをLi負極と組合せたロッキングチェア型電荷補償による高エネルギー密度化、pnバイポーラ性に基づく極性フリーの電荷貯蔵形式、酸素極と組合せた空気二次電池、光負極を導入した光空気二次電池など、多様な蓄積形態が可能な電荷貯蔵物質としてのアイデアを確立した。このような非共役キノイドポリマーを活物質とする概念自体は新規性が高く、有機空気電池の実証を成功例として展開し成果集積の道筋をつけた。電極反応や光反応の多くが一電子移動に基づき不安定なラジカル種を経由する点に着目し、電荷保持力や化学安定度を高める観点から2電子反応に焦点を絞る発想に学術的意義を期待している。有機ポリマー合成を手段とすることにより、無機材料にない光・電気応答の実現、高密度・高速化を具体化するとともに、ポリマー内の迅速かつ可逆的な電荷・物質移動を制御し、高密度エネルギー変換をソフトマテリアルの応用の一つとして位置づけることが可能となってきている。

  • ラジカルポリマーを用いた電荷分離・輸送ソフト界面の構造制御と光電変換系の構築

    2011  

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    ニトロキシド、ニトロニルニトロキシド、ガルビノキシル、フェルダジル、トリアリールアミニウム、2,6-ジ-tert-ブチルフェノキシルラジカルなどの有機安定ラジカル種を繰返し構造単位当たりにペンダント置換基として有する非共役ポリマーであるラジカルポリマーを、電荷輸送および貯蔵材料に利用し、色素と組合せた分子レベルの光電荷分離界面を構築することによって、効率高い光電変換系の構築に取り組んだ。ラジカルポリマー膜における電子移動と、それに伴うイオン輸送現象の全容解明により、有機二次電池の具体化に不可欠な革新的電極活物質を創出するとともに、色素を組み込んだ光電荷分離・輸送系へ拡張し、光電変換能に基づく新型有機太陽電池を試作、動作実証することにより、その効果を明らかにした。特に、これらの支配因子と考えられる膜／電解液界面における物質移動を、ラジカルポリマーゲル表面への規則的・階層的構造の導入を手段として極限まで効率化する切り口から、光電荷分離に関わるソフト界面の化学として一般性高い知見を確立した。研究期間内に、安定ラジカル種の電気化学・磁気的性質、ラジカルポリマーでの蓄電に関わる諸現象の解明、ラジカルポリマーゲル／電解質界面に配置させた色素の増感反応の実証に焦点を絞り、新規ポリマー合成を中心とした具体的成果を集積した。この結果、インドリン系有機色素、ルテニウム錯体色素を単一分子レベルで制御しながらポリマー界面に配置させた電荷分離界面で、吸収波長と吸光度、内部変換効率、太陽電池セルでの開放電圧、短絡電流密度、フィルファクターとの相関を詳細に解明し、色素の励起電子受容とメディエータ分子による連続的再生が全体の光電変換効率を支配していることを明らかにすると共に、密集したラジカル分子が光電荷分離の頻度因子を増加させ、効率高い光電変換系を可能とすることを明らかにした。メディエータ分子およびラジカルポリマーのエネルギー準位は化学構造により自在設計可能であり、従来の湿式太陽電池と比べて一層の効率向上を可能とする有機分子ならではの自由度を有することを、これら全有機太陽電池の優位性の一つとして確立した。

  • 高密度電荷分離・輸送ポリマーの創製

    2009  

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    レドックス活性なポリマー膜への電荷注入は、濃度勾配に基づく拡散による電荷輸送と、電荷補償する対イオンの注入･放出を伴う。膜内輸送現象の包括的な制御により、固体膜本来のレドックス活性を引き出すことが、界面での電荷分離とバルク相への輸送を可能とするための課題となっている。本研究は、レドックス席を高密度で含有するポリマーのメソスコピックレベルの超構造構築とその分子レベルでの精密制御を手段とする輸送現象の全容解明により、斬新なエネルギー変換･貯蔵材料としての具体化を目指している。ポリマー膜の電荷輸送性を向上させるには、対イオンの構造制御や膨潤性の調節によりその拡散性を高めると同時に、レドックス席当りの当重量を抑え、レドックス席間の二次反応である自己電子交換を速くする必要がある。この指針に沿って、ニトロキシラジカル/オキソアンモニウムカチオンのレドックス対が、安定な高速レドックス応答を示すと共に当重量を極限まで小さくできることを明らかにした。以下に具体的に述べる。(1) ニトロキシラジカルポリマーをはじめとするレドックスポリマー内の輸送現象を解明した。有限厚み層への電荷注入、拡散による電荷輸送、低振動数域での電荷飽和 (レドックスキャパシタンスの発生) を解析し、構造や基礎物性との相関を明らかにした。(2) イオン種の溶媒和半径、ポリマー/溶液界面における (脱) 溶媒和とDonnan平衡に関する検討から迅速応答する電荷補償イオン種を選定し、電荷輸送の見かけの拡散定数を用いて移動度を定量的に把握した。(3) 有機レドックス席を高密度に導入したポリマーを合成し、溶媒和状態の制御によりイオン輸送チャンネルを形成できることを見出した。これを元に、ポリマー膜への電荷注入が対イオンによる電荷補償に律速されず、あたかも溶存レドックス種のように応答する物質系として確立した。(4) 膜内レドックス席の高密度化と自己電子交換の高速化により輸送性が顕著に向上することを実証した。

  • 電子濃縮キノイドポリマーの創製と電極活物質への応用

    2008  

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    n型レドックス活性な酸化還元席であるイミドやアントラキノンから誘導されるアニオンラジカルの化学安定度を増加させ、斬新なレドックス活性種として確立することにより、卑な電位で電気化学的に可逆応答を示す新しいレドックスポリマーを創出した。イミド類は、-1 V vs. Ag/AgCl 付近で一電子還元され、アニオンラジカルの後続反応抑制に効く非プロトン性条件下において、可逆性高いレドックス応答が電気化学計測により実証された。一方、キノン類の二電子移動は、同条件下-0.8～-1.2 Vにおいて段階的に (異なる酸化還元電位で二段階にて) 生起し、セミキノンラジカルQ-･への第一還元波 (Q + e- = Q-･)に続きジアニオンを与える第二波 (Q-･ + e- = Q2-) が観測された。これらの有機電極反応を可逆性高く生起させるには、キノン酸素原子との水素結合形成が有効な手段であることを一般性高い知見として確立した。電荷貯蔵材料すなわち二次電池の電極活物質として長期使用に耐えうる化学安定性を具えた骨格として、イミド骨格に加えキノン類の中で突出した化学安定度を示すアントラキノン骨格に着目し、水素結合を安定度高く分子内で形成させるため、酸素原子の隣接位にアシルアミノ基などのプロトンドナー性置換基を導入したモデル化合物を合成した。分子内水素結合を構造データ (各種NMR、単結晶X線構造解析など) から実証すると共に、アニオンラジカルの安定化に寄与していることを結合次数の解析から実証した。電極反応速度に相当する不均一系電子移動速度を幅広く実測し、溶媒因子などとの相関を明確にした。電子移動速度は、サイクリックボルタンメトリーを用いたNicolson法、Tafelプロットによる交換電流密度i0, ACインピーダンス測定によるナイキストプロットなどから定量し、電極表面の微細構造、吸着種の有無も含め詳細に解明した。

  • レドックスポリマーの相分離制御に基づく高速・大容量エネルギー貯蔵材料の創製

    2007  

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    ポリビニルフェロセン膜やレドックス活性な対イオンを導入したNafion膜などにおいて、膜内電荷輸送はイオン移動に律速されることが知られている。Ansonらは拡散輸送の高速化に取り組み、親水・疎水型ブロックコポリマーをマトリクスとするナノ相分離系で、拡散係数の3桁上昇を達成している。低次元イオン伝導を可能とする規則的なイオンチャンネルの構築など、ポリマーの特性向上につながる方法論が進歩している一方、導電性ポリマーはエネルギー容量が小さく、レドックス反応の遅いジスルフィド類はレート特性に劣るため、電極活物質としての高速・大容量化に向けて新しい設計コンセプトが待望されている。代表者らは、ニトロキシラジカル/オキソアンモニウムカチオンのレドックス対が、安定な高速レドックス応答を示すと共に当重量を小さくできる点に着目し、イオン拡散チャンネルを精密設計することによって、レドックス容量を極限まで引き出せると着想した。本研究は、ニトロキシラジカルポリマーをはじめレドックスポリマー内の輸送現象を詳細解明すること、有限厚み層への電荷注入、拡散による電荷輸送、低振動数域での電荷飽和現象を分離して解析し、構造や基礎物性との相関を明確にすること、イオン種の溶媒和半径、ポリマー/溶液界面における溶媒和に関する検討から迅速応答する電荷補償イオン種を選定、電荷輸送の見かけの拡散定数を用いて移動度を定量的に把握することを目的として推進した。以下に成果概要を記す。(1) 膜内輸送現象の解明レドックスポリマー膜内の電荷の拡散輸送過程を交流インピーダンス法により解析し、電荷移動に支配される高振動数域、膜の有限厚みによるレドックス容量が観測される低振動数域と分けて定量化した。等価回路を用いた解析から電荷移動抵抗を求め、様々な材質の電極基板を用いて表面構造がポリマーとの接触界面に与える影響を明らかにした。ポリマー膜中の電荷移動を支配する抵抗成分を、高振動数域の複素インピーダンスから求め、ポリマーの一次構造や膨潤度との相関を解明した。等重量が小さく電極反応の可逆性が高いポリマーを代表例として、物質移動パラメータを電極界面における平衡状態の関数として求め、高速パルスアンペロメトリーの解析とあわせ、膜内輸送現象の全容を解明した。次に、膜内を拡散するイオン種の溶媒和半径、溶液との界面における溶媒和エネルギーに関する基礎的検討から、対イオンの拡散が電荷輸送と直接関連していることを実証した。セルフドープ型ポリマーの設計と合成も含め、幅広いイオン種の拡散挙動を電荷輸送の見かけの拡散定数を用いて定量的に把握した。(2) イオン拡散過程の制御法の確立さまざまな主鎖構造のポリマーを合成し、一次構造と膨潤度の相関を追究し、レドックスサイト間距離を考慮して膜内における効率高い自己電子交換反応の存在を明確にした。イオンの拡散性を十分高めることにより、ニトロキシラジカルなどのレドックス席への電荷注入が対イオンの追随にほとんど律速されず、自己電子交換による電荷の拡散輸送が溶液中と同様に効率よく進行する物質系として確立した。

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