Cholesteryl pelargonate를 이용한 고분자 안정화된 콜레스테릭 액정의 전기-광학적 특성 연구

Abstract

Polymer-stabilized cholesteric liquid crystals (PSCLCs) with various pitch length, which was controlled by using the chrial dopant concentration have been designed and fabricated. The effect of chrial dopant concentration on the morphology and the electro-optical properties such as the driving voltage, the contrast ratio, the hysteresis width, and the field-off response time were investigated. The scanning electron microscopy shows that the polymer networks become tighter with the increase of chiral dopant concentration. It was found that the driving voltage and the hysteresis width increase, which is ascribed to the increasing elastic force between the polymer network and the LC molecules. As the chiral dopant concentration is increased, the field-off response time decreases. Through the driving-mode switching, two bistable structures between transparent and non transparent states without holding voltages developed. Especially, PSCLC cell with 20 wt% of chiral dopant showed the best electro-optical properties.