旋光性物質/向列型液晶複合系的調光閥效應研究

Light Modulated Effects in the Chiral Compound/Nematic Liquid Crystal

余穎(Yiing Ee)

指導教授 ： 黃振球

元智大學/工程學院/化學工程與材料科學學系/碩士(2001年)

摘要

利用Nematic低分子液晶與旋光性物質混合形成複合系液晶。研究此複合性液晶的光電效應及其相行為。
經由實驗發現複合系液晶在低比例時可誘導出Cholesteric相、Blue Phase、Smectic相。在高比例時誘導出Smectic相。本實驗在低比例時利用溫度變化達成光散亂及光透明，使液晶面板呈現明暗比。並利用應加電場改變分子排列形成雙安定效應。複合系液晶在Blue Phase時、在電場下形成電致變色效應、且具有安定性。利用可利用溫度快速變化調節液晶的透光度及電場切換所形成的透光度變化達到調光閥的功能
在7OCB/S811/R811混合系中，在Cholesteric相時，在電場下產生電場變色效應。隨著電場增加而呈現不同顏色的變化。

關鍵字

調光閥 ； 旋光性物質 ； 向列型 ； 液晶

並列摘要

The phase behavior and electro-optic properties of the mixture of chiral compound and nematic liquid crystal were studied. With low concentration of chiral compound, the cholesteric Phase,Blue Phase and Smectic Phase were induced. With large percent of chiral compound, we observed the only one phase－smectic phase.Without the electric field, the scattering and transparent states were achieved by thermal transition, and resulted in different contrasts of the liquid crystal panel with different temperatures.
Furthermore, it can also be achieved by bistable effect and electric switch.

並列關鍵字

Light Modulated ； Chiral ； Nematic ； Liquid Crystal

參考文獻

1.P Watson*, J. E. Anderson and V. Sergan, P. J. Bos “ The transition mechanism of the transient planar director configuration change in cholesteric liquid crystal displays,“ Liq. Cryst. 1999, 26, 9

2.P. Rudquist , L. Komitov and S. T. Lagerwall “ Volume-stabilized ULH structure for the flexoelectro-optic effect and the phase-shift effect in cholesterics,” Liq. Cryst. 1998, 24, 3

3.T. Geelhaar, “Liquid Crystals for display application,” Liq. Cryst. 1998, 24, 1

4.Klaus J. K. Semmler Theo J. Dingemans, Edward T. Samulski, “ Biaxial smectic phases in non-linear mesogens: optical properties and phase behavier of an oxadiazole liquid crystal,” Liq. Cryst. 1998, 24, 6

5.Jenn Chiu Hwang and Yu Chyi Tsai, “Bistable switching effects and thermal storage of polymer/induced smectic phase composite film,” Jpn. J. appl. Phys.. 1997, 36, 6A