Photochemical manipulation of colloidal structures in liquid-crystal colloids

T. Yamamoto*, Y. Tabe, H. Yokoyama

*この研究の対応する著者

研究成果: Conference contribution

抄録

We investigated photochemical manipulation of physical properties and colloidal structures of liquid-crystal (LC) colloids containing azobenzene compounds. In a LC suspension where polymeric particles were dispersed in a host LC, we achieved photochemical control of light-scattering properties of the suspension. In a nematic phase, when the suspension was sandwiched with two glass plates, the film became opaque. This would be attributable to an appearance of both multidomain structures of LC alignment and mismatches of refractive indices between the materials. The opaque state turned into a transparent one when a nematic-to-isotropic phase transition was induced by the trans-to-cis photoisomerization of the azo-dye. This will result from a disappearance of both the multidomain structures and the refractive-index mismatches in the isotropic phase. The transparent film went back into the initial opaque film when the nematic phase was obtained by the cis-to-trans photoisomerization. In a LC emulsion in which glycerol or water droplets were dispersed in liquid crystals, we examined photochemical change of defect structures and inter-droplet distances by the photochemical manner. At the initial state, Saturn ring and hedgehog defects were formed around the droplets. For the glycerol droplets, we observed structural transformations between Saturn ring and boojums on irradiation with ultra-violet and visible light. For the water droplets, the inter-droplet distances varied by changing defect size on the irradiation. These phenomena would result from modulation of anchoring conditions of the droplets by the photoisomerization of the azo-dyes.

本文言語English
ホスト出版物のタイトルLiquid Crystals and Applications in Optics
DOI
出版ステータスPublished - 2007 11 26
イベントLiquid Crystals and Applications in Optics - Prague, Czech Republic
継続期間: 2007 4 172007 4 18

出版物シリーズ

名前Proceedings of SPIE - The International Society for Optical Engineering
6587
ISSN(印刷版)0277-786X

Conference

ConferenceLiquid Crystals and Applications in Optics
国/地域Czech Republic
CityPrague
Period07/4/1707/4/18

ASJC Scopus subject areas

  • 電子材料、光学材料、および磁性材料
  • 凝縮系物理学
  • コンピュータ サイエンスの応用
  • 応用数学
  • 電子工学および電気工学

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