Liquid Crystal Photonics : Control of Light by Polymer-Dispersed Liquid Crystals Induced by Photoisomerization of Azobenzene Molecules

Abstract

We prepared polymer-dispersed liquid crystals containing azobenzene derivatives as a photoresponsive molecule and evaluated their optical response induced by photoirradiation. The optical property of the films was found to be affected by the compositional ratio of each component. The composite film with optimal compositional ratio showed a strong light scattering in an initial state. The reversible change between a light-scattering state and a transparent state was achieved by alternating irradiation with UV light and visible light. This phenomenon is ascribed to nematic ⟷ isotropic photochemical phase transition induced by trans ⟷ cis photoisomerization of the azobenzene molecules.