2006 Fiscal Year Final Research Report Summary
Development of Highly Functional Ion-Transporting Materials : Introduction of Liquid-Crystalline Properties into Ionic Liquids and Alignment of the Molecular Assemblies.
| Project/Area Number |
17350065
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional materials chemistry
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KATO Takashi The University of Tokyo, Graduate School of Engineering, Professor, 大学院工学系研究科, 教授 (70214377)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIO Masafumi The University of Tokyo, Graduate School of Engineering, Research Associate, 大学院工学系研究科, 助手 (60345098)
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| Project Period (FY) |
2005 – 2006
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| Keywords | IONIC LIQUID / LIQUID CRYSTAL / SUPRAMOLECULE / SELF-ORGANIZATION / NANOPHASE SEGREGATION / ANISOTOPY / ION TRANSPORT / MASS TRANSPORT |
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| Research Abstract |
The use of molecular self-organization processes has attracted attention for the development of functional materials. Liquid crystals that spontaneously form dynamically ordered structures have great potentials to be used as anisotropic media for transportation of ions and electron. In the present study, we intended to produce functional ion-conductive materials by introducing liquid-crystalline properties into ionic molecules such as ionic liquids and by aligning their assemblies. Here, we report on a new family of one-dimensional ion-conductors : (1)ion-conductive polymer films based on columnar liquid-crystalline imidazolium ionic liquids and (2)columnar liquid-crystalline spiropyrans.
(1)One-Dimensional Ion-Conductive Polymer Films
We designed a fan-shaped imidazolium ionic liquid having polymerizable acrylate groups. This molecule formed a hexagonal columnar liquid-crystalline phase from 20 to 50 ℃. A uniform vertical alignment of the columnar structure on an amine-functionalized gl
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ass substrate was achieved. A parallel alignment of the columns on the normal glass substrate was also performed by mechanical shearing the sample in the columnar phase. Polymer films that retained the orientations of the columnar structures were obtained by UV irradiation into the aligned monomeric materials. The ionic conductivities parallel to the columnar axis for the polymer films were higher than those perpendicular to the columnar axis. The value of anisotropy of the ionic conductivities at 100 ℃ was 1500.
(2)Columnar Liquid-Crystalline Spiropyrans
Fan-shaped spiropyran derivatives were synthesized. Although these molecules were non-mesomorophic thereselves, the mixtures of spiropyrans and acidic molecules such as 4-methylbenzene sulfonic acid and methanesulfonic acid formed columnar liquid-crystalline phases through the structural isomerization from non-ionic spiropyrans to ionic merocyanines. These ionic columnar materials were aligned parallel on the surface of the glass substrate by mechanical shearing. The ionic conductivities of the aligned samples were measured by using a glass cell with comb-shaped gold electrodes. The materials in the columnar liquid-crystalline phases showed higher ionic conductivities along the direction parallel to the columnar axis than those across the columnar axis. Less
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