3) Ion-Conductive Liquid Crystals: Functional Nanostructured Materials

Ion-conduction and ion-transportation are important in materials and in life systems. Our aim is to obtain new low-dimensional ion-conductive materials by using molecular self-assembly and by controlling nanophase segregation. We designed liquid-crystalline (LC) materials showing smectic phases, where ion-conducting and ion-insulating parts are phase-segregated on nanometer scale. These materials exhibit low-dimensional ionic conductivities. For example,
(1) Self-assembly of ionic liquid crystals showing one-dimensional ion conduction in columnar phases.
(2) Self-assembled LC materials consisting of lithium salts and low-molecular or polymeric mesogenic molecules containing oligo(ethylene oxide)s, showing two-dimensional ion conduction in smectic phases.

These studies are conducted by a collaboration with Prof. H. Ohno at Tokyo University of Agriculture and Technology.

3-1) 1D ion conduction in ionic liquid crystals

3-2) 3D ion conduction in bicontinuous cubic liquid crystals

3-3) Electric-Field-Responsive Propylenecarbonate-Based Columanr Liquid Crystals

3-4) 2D ion conduction in the polymeric materials containing oligo(ethyleneoxide)s

3-1) 1D ion conduction in ionic liquid crystals

1D 1????????????

Selected papers on this subject:

  1. Non-Covalent Approach to One-Dimensional Ion Conductors: Enhancement of Ionic Conductivities in Nanostructured Columnar Liquid Crystals
    Harutoki Shimura, Masafumi Yoshio, Koji Hoshino, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato
    J. Am. Chem. Soc., 130, 1759 (2008).
  2. Columnar Liquid-Crystalline Imidazolium Salts: Effects of Anions and Cations on Mesomorphic Properties and Ionic Conductivities
    Masafumi Yoshio, Takahiro Ichikawa, Harutoki Shimura, Takayoshi Kagata, Atsushi Hamasaki, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato
    Bull. Chem. Soc. Jpn., 80, 1836 (2007).
  3. One-Dimensional Ion-Conductive Polymer Films: Alignment and Fixation of Ionic Channels Formed by Self-Organization of Polymerizable Columnar Liquid Crystals
    Masafumi Yoshio, Takayoshi Kagata, Koji Hoshino, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato
    J. Am. Chem. Soc., 128, 5570 (2006).
  4. Spiropyran-Based Liquid Crystals: The Formation of Columnar Phases Via Acid-Induced Spiro-Merocyanine Isomerisation
    Boon Hooi Tan, Masafumi Yoshio, Takahiro Ichikawa, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato
    Chem. Commun., 2006, 4703.
  5. Self-Assembly of an Ionic Liquid and a Hydroxyl-Terminated Liquid Crystal: Anisotropic Ion Conduction in Layered Nanostructures
    Masafumi Yoshio, Takashi Kato, Tomohiro Mukai, Masahiro Yoshizawa, and Hiroyuki Ohno
    Mol. Cryst. Liq. Cryst., 413, 2235 (2004).
  6. One-Dimensional Ion Transport in Self-Organized Columnar Ionic Liquids
    Masafumi Yoshio, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato
    J. Am. Chem. Soc., 126, 994 (2004).

3-2) 3D ion conduction in bicontinuous cubic liquid crystals

3D

Selected papers on this subject:

  1. 3D Interconnected Ionic Nano-Channels Formed in Polymer Films: Self-Organization and Polymerization of Thermotropic Bicontinuous Cubic Liquid Crystals
    Takahiro Ichikawa, Masafumi Yoshio, Atsushi Hamasaki, Junko Kagimoto, Hiroyuki Ohno, and Takashi Kato
    J. Am. Chem. Soc., 133, 2163 (2011).
  2. Ion Conductive Behaviour in a Confined Nanostructure: NMR Observation of Self-Diffusion in a Liquid-Crystalline Bicontinuous Cubic Phase
    Anton E. Frise, Takahiro Ichikawa, Masafumi Yoshio, Hiroyuki Ohno, Sergey V. Dvinskikh, Takashi Kato, and Istvan Furo
    Chem. Commun., 46, 728 (2010)
  3. Self-Organization of Room-Temperature Ionic Liquids Exhibiting Liquid-Crystalline Bicontinuous Cubic Phases: Formation of Nano-Ion Channel Networks
    Takahiro Ichikawa, Masafumi Yoshio, Atsushi Hamasaki, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato
    J. Am. Chem. Soc., 129, 10662 (2007).

3-3) Electric-Field-Responsive Propylenecarbonate-Based Columanr Liquid Crystals

Selected papers on this subject:

  1. Electric-Field-Responsive Lithium-Ion Conductors of Propylenecarbonate-Based Columanr Liquid Crystals
    Harutoki Shimura, Masafumi Yoshio, Atsushi Hamasaki, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato
    Adv. Mater., 21, 1591 (2009).

3-4) 2D ion conduction in the polymeric materials containing oligo(ethyleneoxide)s

3D

Selected papers on this subject:

  1. A Columnar Liquid-Crystalline Shape-Persistent Macrocycle Having a Nanosegregated Structure
    Harutoki Shimura, Masafumi Yoshio, and Takashi Kato
    Org. Biomol. Chem., 7, 3205 (2009).
  2. Nano-Segregated Polymeric Film Exhibiting High Ionic Conductivities
    Kenji Kishimoto, Tomoyuki Suzawa, Tomoki Yokota, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato
    J. Am. Chem. Soc., 127, 15618 (2005).
  3. Nanostructured Anisotropic Ion-Conductive Films
    Kenji Kishimoto, Masafumi Yoshio, Tomohiro Mukai, Masahiro Yoshizawa, Hiroyuki Ohno, and Takashi Kato
    J. Am. Chem. Soc., 125, 3196 (2003).
  4. Liquid-Crystalline Complexes of Mesogenic Dimers Containing Oxyethylene Moieties with LiCF3SO3: Self-Organized Ion Conductive Materials
    Toshihiro Ohtake, Masumi Ogasawara, Kaori Ito-Akita, Naoko Nishina, Seiji Ujiie, Hiroyuki Ohno, and Takashi Kato
    Chem. Mater., 12, 782 (2000).
  5. Liquid-Crystalline Ion-Conductive Materials: Self-Organization Behavior and Ion-Transporting Properties of Mesogenic Dimers Containing Oxyethylene Moieties Complexed with Metal Salts
    Toshihiro Ohtake, Yasuyuki Takamitsu, Kaori Ito-Akita, Kiyoshi Kanie, Masahiro Yoshizawa, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato
    Macromolecules, 33, 8109 (2000).
  6. Liquid-Crystalline Complexes of a Lithium Salt with Twin Oligomers Containing Oxyethylene Spacers. An Approach to Anisotropic Ion Conduction
    Toshihiro Ohtake, Kaori Ito, Naoko Nishina, Hideyuki Kihara, Hiroyuki Ohno, and Takashi Kato
    Polym. J., 31, 1155 (1999).

Review Papers

  1. From Nanostructured Liquid Crystals to Polymer-Based Electrolytes
    Takashi Kato
    Angew. Chem. Int. Ed., 49, 7847 (2010)
  2. Self-Assembly of Functional Columnar Liquid Crystals
    Takashi Kato, Takuma Yasuda, Yuko Kamikawa, and Masafumi Yoshio
    Chem. Commun., 729 (2009)
  3. Functional Liquid-Crystalline Polymers for Ionic and Electronic Conduction
    Masahiro Funahashi, Harutoki Shimura, Masafumi Yoshio, and Takashi Kato
    Struct. Bond., 128, 151 (2008).
  4. Functional Liquid-Crystalline Assemblies: Self-Organized Soft Materials
    Takashi Kato, Norihiro Mizoshita, and Kenji Kishimoto
    Angew. Chem. Int. Ed., 45, 38 (2006).
  5. Self-Assembly of Phase-Segregated Liquid Crystal Structures
    Takashi Kato
    Science, 295, 2414 (2002).
  6. Liquid Crystalline Ionic Liquids
    Takashi Kato and Masafumi Yoshio
    Electrochemical Aspects of Ionic Liquids, H. Ohno Ed., John Wiley & Sons, Inc., p. 307 (2005).

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