Influence of Liquid Crystal Concentration on the Electro-Optical Behavior of Polymer Dispersed Liquid Crystal Films Prepared by Electron Beam Processing

Abstract

Polymer dispersed liquid crystal (PDLC) films can be switched electrically from a light scattering off-state to a highly transparent on-state. Polymerization induced phase separation (PIPS) initiated by electron beam irradiation has been used as a powerful method to obtain defined PDLC films. Blends of an aromatic polyester acrylate in additional monomers were prepared as polymer matrix precursors. The eutectic nematic mixture E7 was used as liquid crystal material in this work. Mixtures including different amounts of these materials were exposed to the electron beam radiation. The optical transmission properties of the obtained PDLC films were investigated as a function of composition and amplitude of the applied AC voltage. The electro-optical curves strongly depend on the liquid crystal concentration and are highly reproducible.