合成新型大傾斜角具廣溫度範圍之強誘電性液晶

Synthesis and Characterization of Novel Ferroelectric Liquid Crystalline with a Large Tilt Angle and Wide Temperature Range

吳念潔(Nien-Chieh Wu) ； 廖健同(Chien-Tung Liao) ； 李俊毅(Jiunn-Yih Lee)

《技術學刊》 26卷2期 (2011/06) Pp. 105-111

https://doi.org/10.29507/JT.201106.0003

摘要

本文在研究強誘電性行爲的低分子量有機矽氧烷液晶材料。設計並合成一末端基上含寡聚物矽氧烷，並且結構核心爲4-hydroxyphenyl 4'-hydroxybiphenyl-4-carboxylate與chiral octan-2-ol unit的液晶。此新型大傾斜角液晶具有廣泛旋光性C型層列(chiral smectic C, SmC(上標 *))的溫度範圍，並藉由實驗鑑定出SmC(上標 *)相。此SmC(上標 *)液晶相鑑定藉由正交偏光顯微鏡(polarizing optical microscope, POM)、示差掃描熱量分析儀(differential scanning calorimetry, DSC)和X光繞射分析儀(X-ray diffractometer, XRD)等光學儀器來測定液晶相特性，發現所設計液晶澄清點有下降的趨勢。

關鍵字

強誘電性行爲 ； 有機矽氧烷 ； 大傾斜角 ； 溫度範圍廣

並列摘要

The present paper is a study of the ferroelectric behavior in low molar mass organosiloxane liquid crystal materials. We have achieved the molecular design, synthesis and characterization of liquid crystals which have 4-hydroxyphenyl 4'-hydroxybiphenyl-4-carboxylate cores, chiral octan-2-ol units and oligomeric siloxane end-groups. A few novel compounds with large tilt angles and wide temperature ranges of SmC(superscript *) phase have been synthesized, and the mesophases have been compared.The characteristics of the liquid crystal phases under discussion were investigated by means of polarizing microscopy, differential scanning calorimetry, X-ray diffraction and electro-optical experiments. The influence of the molecular structure on the occurrence of the SmC(superscript *) phase was investigated. These substituents have a strong influence in reducing clearing temperatures and increasing temperature ranges.

並列關鍵字

ferroelectric behavior ； organosiloxane ； large tilt angle ； wide temperature range