新穎性彎曲型結構單一及混摻藍相液晶材料之合成與應用

Abstract

本論文主要是在合成出具有藍相液晶的香蕉型分子，我們首先合成具有掌性中心的香蕉型分子，在香蕉型分子的頂端含有 Nitrile 的官能基，有不含氟官能基的C5C7*的化合物，以及在硬段側邊導入氟的官能基，主要是為了得到低溫及高極性的香蕉型分子，並將其分別命名為 C3FC7* 、 C5FC7* 。在其分子中軟鏈段一邊為七個碳，含有一掌性中心，另一側的軟鍊段各分別為三、五碳，以討論碳數不同，對於產生藍相的關係。另外我們也合成了不含掌性中心的香蕉型分子，並將其分別命名為 C3FC7 、 C5FC7 。最後我們希望可以用混摻的方式，來得到藍相液晶，並拓寬藍相液晶的溫寬。香蕉型分子 C5FC7*得到單一分子即含有藍相，藍相溫寬約為 3°C，另外在介由混摻C5FC7 與 ISO-F，也可以得到藍相，且溫寬可到達 15°C。這些香蕉型分子，我們利用 DSC , FT-IR , POM , UV-Visible 及 X-ray 來進行驗證分析其物性。

In this thesis, we synthesized the banana-shaped liquid crystals with amorphous blue phase and investigated their properties. The banana‐shaped liquid crystals (LC) are based on chiral bent-core molecules containing Nitrile group and C5C7* moieties. The functional fluorine groups are incorporated into the main-chained segments, mainly in order to get low-temperature and high-polarity properties of the banana-shaped molecules, named C3FC7*, C5FC7*. Moreover, a series of molecules with chiral center bearing different alkyl chains (3 and 5 carbons, respectively) was compared to discuss the relationships between different carbon numbers and blue-phase properties. In addition, we also have synthesized a non-chiral center of the banana-shaped molecules, named C3FC7, C5FC7. Finally, we use those blended liquid crystal to obtain blue phase, and to increase range of the blue-phase temperature. Banana-shaped molecule C5FC7* has blue phase with temperature range to 3 °C, and also is blended C5FC7 and ISO-F to improve the range of amorphous blue-phase temperature to 15 °C. We used the DSC, FT-IR, POM, UV-Visible and X-ray measurement to verify the physical properties of those liquid crystals.