含硫旋光尾鏈衍生之誘電性及反誘電性液晶材料的合成及其光電性質之研究

Synthesis and Properties of Ferroelectric and Antiferroelectric of Chiral Liquid Crystals Derived from (S)-[1-methyl-2-(2’-methylsulfanylethoxy)]ethanol

楊石城(Shih-cheng Yang)

指導教授 ： 吳勛隆

大同大學/工程學院/化學工程學系所/碩士(2006年)

摘要

本研究主要是在說明旋光性層列相液晶其結構與性質之間的關係，以 (S)- [1-methyl-2-(2’-methylsulfanylethoxy)] ethanol 為起始物合成一系列旋光性液晶材料，並探討非旋光末端烷鏈長度’m’對於液晶相及物理光電特性的影響，以建立分子結構與旋光液晶相的關係。
實驗結果顯示：第一系列液晶材料 I(m=8-12)只出現SmA*一種液晶相。在第二系列II(m=8-10)出現了SmA*,SmC* 和SmCA* 三種液晶相。在第二系列中增加非旋光烷鏈長度‘m’ 會降低澄清點相轉移溫度範圍、降低SmA*相轉移溫度範圍、提高SmC*液晶相轉移溫度範圍以及降低SmCA*液晶相範圍
第二系列液晶化合物在SmC*液晶相進行光電量測時顯示在改變溫度和頻率下可得到V型轉換行為，而在SmCA*液晶相中，則可得到雙遲滯轉換行為。電流轉換行為的量測結果則不會受到非旋光末端烷鏈長度’m’ 的改變而有太大的差異。第二系列的自發性極化值最大值介於9~33 nC/cm2 和傾斜角最大值介於31o~35o。

關鍵字

反誘電型液晶 ； 無閥v型光電轉換行為 ； 誘電型液晶

並列摘要

Research this prove optical rotation layer arrange looks relation between the his structure and nature of liquid crystal mainly, Israel (S) -[1-methyl-2-(2' -methylsulfanylethoxy) ]Ethanol formates a series of optical rotation liquid crystal materials for the initial thing, probe into and does not fasten all end length ' m ' of alkane chain it to the looks of the liquid crystal and influence of the photoelectric characteristic of physics, in order to establish molecular structure and relation of fastenning the looks of all liquid crystal.
The experimental result shows: The first serial of liquid crystal material I (m=8-12) only shows SmA* phase. In the second serial II (m=8-10) shows SmA*, SmC* and SmCA* three kinds of liquid crystal phases. Change and does not fasten all end length ' m ' of alkane chain, find it with not fastenning the increase of all end length ' m ' of alkane chain, the reducing thereupon of temperature range of the looks of the liquid crystal, namely clarify some temperature with rising with reducing, crystalline temperature temperature
The second serial liquid crystal chemical compound shows when SmC* liquid crystal carries on the photoelectricity amount to examine that can get the V type and change the behavior under changing the temperature and frequency, electric current change quantity of behavior examine result can is it fasten all end alkane chain length ' m ' is it have heavy difference too to change to receive. Second series of spontaneity polarization values maximum lie between 93 nC/cm2 and angle of inclination maximum lie between 31o- 35o.

並列關鍵字

Ferroelectric Liquid Crystal ； Chiral Liquid Crystal ； V-shaped switching

參考文獻

F. Reinitzer. Monatsh. Chem., 9, 421 (1888)

[8] N. A. Clark, S.T. Lagerwall, Appl. Phys. Lett., 36, 899.(1980)

[15] R. B. Meyer, Mol. Cryst. Liq. Cryst., 40, 74.(1976)

[18] H.S. Kitzerow , C. Bahr, Chirality in Liquid crystals,(Springer)Lett.,36,L69(1975)

[19] I. Nishiyama, J.W.Goodby, J.Mater. Chem.,2.1015(1992)