（向列型/圓盤型）和(向列型/旋光性物質)液晶複合系的相行為與光電特性的研究

The research on the phase behavior and optical-electro properties in the (nematic/discotic) and (nematic/chiral dopant) liquid-crystalline composite system

陳文仁(Wen-Ren Chen)

指導教授 ： 黃振球

元智大學/工程學院/化學工程與材料科學學系/博士(2004年)

摘要

本論文研究以圓盤型液晶混合向列型液晶，和向列型液晶混合旋光性物質形成雙成份液晶複合系，探討兩複合系的相行為與光電特性，(圓盤型/向列型)液晶複合系在80/20~30/70 wt%下會產生誘導層列相，此誘導層列相可用特殊分子排列和堆疊方式解釋，而(向列型/旋光性物質)液晶複合系，則在低旋光比例(20%以下)誘導出N*相，中旋光比例(25~30%)誘導出包含BP和TGBA*等frustrated液晶相，高旋光比例(40~80%)則形成SmA*相，複合系分子排列的整齊性，隨旋光性物質含量增加和溫度的降低而逐漸提高，此複合系受電場大小和頻率變化的影響亦為研究課題。

關鍵字

液晶複合系 ； 誘導層列相 ； 螺旋截距 ； TGB相 ； 光電性質

並列摘要

Two binary liquid-crystalline composite systems were composed of (a nematogen and a discotic mesogen) and (a nematogen and a chiral dopant). The phase behaviour and optical-electro properties of two binary composites have been investigated. The former system yielded an induced SmA phase in the range of 80/20~30/70 wt.%. The layer-stacking structure of binary composite was proposed in the SmA phase. The latter system formed N* phase in the S811 content under 20 wt.%. The frusted phases, BP and TGBA*, and the SmA* phases were formed in the range 25~30% and 40~80%. The orientational ordering of the binary composites increased with increasing the chiral dopant content and decreasing sample temperature. The optical-electro properties were also investigated under the external electric field.

並列關鍵字

liquid crystalline composite system ； induced smectic phase ； helical pitch ； TGB phases ； optical-electro properties

參考文獻

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