藍相(Blue Phase)液晶材料之掌性摻雜體的合成與應用

Abstract

本實驗合成出具有掌性中心的液晶分子，單一小分子、棒狀及二聚體分子，除探討單獨分子的性質之外，還將液晶分子進行混摻，主要分為四部分分別是四大系列的掌性分子混摻液晶及單體，並且進行照光聚合，透過POM、DSC、XRD及光電量測來探討其液晶行為並觀察其藍相性質及溫度範圍。在所有系列當中僅兩大系列分子混摻具有藍相的性質，分別為將掌性中心放在結構中間的雙五環結構，我們將其作為兩大類，一類是單一分子一類是二聚體分子，混摻並照光聚合後的液晶藍相溫度範圍也變大。而其餘結構上之掌性中心在結構兩側的分子系列混摻物則不具有藍相，故無法在藍相之溫寬範圍進行照光聚合，無法進一步探討其藍相性質。

In this research, we synthesized several mesogens containing chiral centers such as single units, rod-like molecules and dimers. Except for examining the liquid crystalline behavior of these compounds, we also mixed them with a liquid crystalline molecule and a photocurable monomer, and then were photopolymerized under UV radiation. In order to investigate the liquid crystalline behavior of these mixtures, POM, DSC, powder XRD, electric-optical measurements in temperature range of blue phase were carried out. Of all this series of mixtures, only two mixtures in which the chiral dopants have isosorbide moiety situated at the center of the molecules show blue phase behavior, namely, mixtures of single units and dimers. Furthermore, the temperature ranges are expanded after photopolymerization. However, other mixtures have no obvious blue phase, so we did not perform the photopolymerization to investigate their blue phase behavior further.