Alignment control of particle chains formed in liquid-crystal colloids by an azo-dye layer

Abstract

By means of an azo-dye layer consists of Brilliant Yellow (BY), we successfully achieved an alignment control of chain-like structures formed with colloidal particles dispersed in liquid-crystals. On diagonal irradiation of the layer with unpolarized ultra-violet light, the chain-like structures exhibited an in-plane rotation toward the irradiated light. At the same time, we observed alignment change of bulk liquid crystal in a polarized optical microscope. Therefore, the photoinduced rotation of the colloidal structures will be responsible to the photoinduced alignment change of the liquid crystal molecules on the azo-dye aligning layer.