Effect of Film Thickness on Photoinduced Bending Behavior of Crosslinked Azobenzene Liquid-Crystalline Polymers with Different Phase Structures.

Abstract

A ferroelectric liquid-crystalline monomer with an azobenzene moiety was used to prepare crosslinked liquid-crystalline polymer (CLP) films with a higher molecular order. CLP films with different molecular alignments were prepared by photopolymerization under various conditions: a smectic C* phase and a smectic A phase. Bending was induced by photoisomerization of azobenzene moieties causing a change in order parameter. Because of low glass transition temperature, this CLP films could bend and revert upon irradiation at 366 nm and >540 nm at room temperature. The contraction force of CLP films with different thichness was measured by thermomechanical analysis.