Web Release Date: October 19,
Chromonic/Silica Nanohybrids: Synthesis and Macroscopic Alignment
and
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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