Multistable polymer stabilised cholesteric liquid crystal: exceeding reflection limit in visible region

Abstract

Cholesteric liquid crystal (CLC) with helically aligned molecules, demonstrates unique optical features. Conventionally, such structure reflects a maximum 50% of unpolarised light. Polymer-stabilised CLC was designed to exceed the limit by mixing liquid crystal (LC) and a photopolymerisable monomer of opposite chirality. The reflectance was carefully investigated and the result was 55.7% in the visible region at room temperature, where it exceeded the theoretical limit. Such phenomena were studied and theoretical model was discussed. Electro-optical test showed the driving voltage was of LC cell was slightly changed after polymerisation.

Keywords:

• reflection limit
• opposite chirality
• cholesteric liquid crystal
• polymer stabilised