| Project/Area Number |
09450035
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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 |
Applied physics, general
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| Research Institution | The University of Tokyo |
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Principal Investigator |
SAKAI Keiji The University of Tokyo, Institute of Industrial Science, Associate Professor, 生産技術研究所, 助教授 (00215584)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAGI Kenshiro The University of Tokyo, Institute of Industrial Science, Professor, 生産技術研究所, 教授 (90013218)
SAKAMOTO Naoto The University of Tokyo, Institue of Industrial Science, Assistant Professor, 生産技術研究所, 助手 (10282592)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥13,000,000 (Direct Cost: ¥13,000,000)
Fiscal Year 1998: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1997: ¥10,600,000 (Direct Cost: ¥10,600,000)
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| Keywords | Molecular orientation / Liquid crystal / Isotropic phase / Orientational relaxation / Optical Kerr effect / Optical molecular control / Critical phenomena / 配向緩和 / スペクトロスコピー / 複屈折 / 相転移 |
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| Research Abstract |
Complex fluids such as gels, emulsions and bio-systems attract a great physical interest since they could be applied for various industries as new functional materials. The characteristic properties of the complex fluids can be attributed to their large degree of freedom, such as molecular conformation and association. The molecular orientation is one of the important orders, which plays a significant role in creating the liquid crystal phase. The purpose of the study is to develop a new experimental system for observing the orientational molecular dynamics of liquid materials in a wide frequency range.
We successfully developed the optical Kerr effect spectroscopy technique with a continuous wave laser. The anisotropic shape of the molecule necessarily accompanies the anistropic dielectricity. The electric field of the polarized laser beam induces the molecular orientation, which is measured by the optical ellipsometry as the Kerr effect. The critical phenomenon was observed for the nematogen near the nematic-isotropic phase transition temperature. The system was improved to observe the dynamic process of molecule rotation. The Pockels cell was driven with a wide band power supply for the high frequency control of the laser polarization. The complex response function was accurately measured, which gives us an important information on the phase transition and the molecular dynamics of liquid crystals. We observed the relaxation of the optical Kerr effect for the first time in the frequency domain in various kinds of liquid crystals. The laser induced molecular orientation technique would be a powerful tool for the investigation of the mechanism of phase transition of liquid crystals.
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