探討光學活性之(R)-1-丁氧基-2-丁醇衍生之 旋光性液晶材料之液晶相及其光電性質

Study on the Mesophases and Election Optical Properties of Chiral Liquid Crystals Derived From (R)-1-Butoxy-2-Butanol

陳建誌(Chien-Chih Chen)

指導教授 ： 吳勛隆

大同大學/工程學院/化學工程學系所/碩士(2008年)

摘要

本研究的主要目的為探討旋光部分的探討光學活性之(R)-1-丁氧基-2-丁醇衍生之旋光性液晶材料之液晶相及其光電性質中，對於生成誘電性液晶相的影響。合成二系列同樣以(S)-butylene oxide為起始物之旋光性液晶材料，以探討液晶相及物理光電特性的影響。
藉由偏光紋理圖及DSC的鑑定可分別得知液晶相及相轉移溫度的變化，經由電流轉換行為及介電性質的量測可進一步鑑定誘電性液晶相的存在。
實驗結果指出：旋光中心側邊取代基為甲烷基與乙烷基的相互比較，具有旋光中心側邊取代基為乙烷基的液晶材會降低誘電性液晶相的生成。硬核由單苯環延申為雙苯環時，結果顯示熔點，澄清點及液晶相的熱穩定性都增加，且改變誘電性液晶由單向性液晶轉變為雙向性液晶。
物理性質測量結果顯示：化合物I(=10, n=1)在室溫下的自發性極化值(Ps)最大值為5.49 nC/cm2。傾斜角(θ)的最大值為4.0°。化合物II(m=10, n=2) 的自發性極化值(Ps)最大值為12.96 nC/cm2。傾斜角(θ)的最大值為35°。

關鍵字

誘電性液晶

並列摘要

The purpose of this research was an attempt to explore the mesophases and election optical properties of chiral liquid crystals derived from (R)-1-butoxy-2-butanol. Two series of chiral liquid crystal materials derived from (S)-butylene oxide reacting, which were designed and synthesized to investigate the mesorphic and electro-optical properties.
The mesomorphic phases and their corresponding transition temperatures were primarily characterized by the microscopic textures and DSC thermograms, and the ferroelectric phases were further identified by the measurements of electric switching behavior and dielectric constant ε'.
The results show that comparing non-fluorinated liquid crystal materials possessing methyl substituent to that possessing ethyl substituent at the asymmetric carbon, the former reduces the formation of ferroelectric phase. Extending phenyl ring to biphenyl ring in the core of the molecules could result in increasing melting point, clear point and thermal stability of mesophases, and changing the formation of ferroelectric SmC* phase from monotropic to enantiontropic mesophase.
The physical measurement show that compound I(m=10, n=1) at room temperature of spontaneous polarization (Ps) of is 5.49 nC/cm2, and the optical tilt angle (θ) values is 4.0°. For Compound II(m=10, n=2), the maximum of Spontaneous polarization (Ps) values is 12.96 nC/cm2, and the maximum number of the optical tilt angle (θ) values is 35°.

並列關鍵字

ferroelectricity

參考文獻

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