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
Selected papers on this subject:
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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).
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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).
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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).
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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.
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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).
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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