ALIGNMENT OF NEMATIC LIQUID CRYSTALS CONTROLLED BY THE PHOTOCHROMIC REACTION OF AGGREGATED SURFACE AZOBENZENES.

Abstract

The alignment and the texture of a nematic liquid crystalline phase were regulated by the surface photochromic reactions of azobenzene (Az) pendent polymer films. On the poly(4-n-hexyl-4′-(11-methacryloyloxy-n-undecyl)-oxyazobenzene) film, the nematic phase exhibited three characteristic textures: marbled, homeotropic and schlieren textures, and each one of which was alternatively obtained by controlling photoexposure. Disappearance of the parallel domains and appearance of the homeotropic phase along with UV exposure corresponded to deformation of an oriented structure of traps-Az in the polymer.