含彎曲核心雙光軸向列相主體及旋光摻雜體藍相液晶材料之研究

Abstract

本實驗以實驗室自行合成具旋光性之香蕉型液晶混入同系列雙光軸向列相香蕉型液晶來穩定藍相 (BPIII) 並改善其光電特性。利用此新混摻方式，在混摻系統A、B實驗中均使藍相液晶獲得穩定與光電性質改善。系統A中所誘導出的藍相最寬可由39℃持續到室溫，應答時間也達到數毫秒，最大亮度及對比獲得提高。而驅動電壓過高的課題留待後續實驗改善。系統B於分子連結段加入極性官能基F離子來增強dipole，預期可以降低驅動電壓與增加亮度，但其藍相溫寬過窄 (<1.5℃) 而無法做光電量測。未來將於系列A香蕉型硬段增加dipole能力 (OMe→CN)來加強分子自身的側向極性，使之較易被電場誘導，並藉由混摻可以在不影響應答時間下再提高最大亮度與對比。

The liquid crystals synthesized which showed blue phase were mixed with compounds with similar structure and displayed nematic phase in order to stable mesophases, extend temperature ranges of liquid crystal (LC) range, increase the luminescence (L) and contrast ratio (CR) of our LC in in-plane switching cells. In our class A, BP was extend to 39 oC, as well, the L and CR were improved. The response times were all in millisecond class. However, the L was not saturated, and this issue needed to be resolved by synthesizing LC with functional groups with stronger dipole. For this purpose, class B containing fluorine and a chiral soft chain (OXD5B7*) and with blue phase about 0.2 oC were studied. The mixture of OXD5B7* and its derivatives displayed BPIII about 1.5 oC and O-E properties can not be done. In the future, class A will be modified by replacing functional (OMe→CN) to induce stronger dipole and with BP range in room temperature, furthermore, by mixture process, the L and CR could be further improved.