Langmuir, 23 (24), 12350 -12355, 2007. 10.1021/la701557q S0743-7463(70)01557-3
Web Release Date: October 19, 2007

Copyright © 2007 American Chemical Society

Chromonic/Silica Nanohybrids: Synthesis and Macroscopic Alignment

Mitsuo Hara, Shusaku Nagano, Norihiro Mizoshita, and Takahiro Seki*

Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan

Received May 28, 2007

In Final Form: August 20, 2007

Abstract:

Some dye molecules self-aggregate to exhibit a lyotropic columnar liquid crystal state (chromonic liquid crystal) via stacking in relatively highly concentrated aqueous solutions. In this work, the chromonic liquid crystal structure was immobilized, for the first time, with silica networks by way of the sol-gel condensation process. The immobilization of the columnar structure was successfully attained in the presence of 2-(2-aminoethoxy)ethanol, which favorably mediates the interface between the anionic charge of the dye aggregates and the silica network. Without this molecule, the sol-gel process gave rise to a transformation from columnar to lamellar structure. Both spin-coating and dip-coating methods gave essentially the same results. In the dip-coated films, the dye molecules were aligned over a large area with orientation orthogonal to the lifting direction.


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