Cholesteric/誘導smectic複合系液晶的感溫光閥應用

Apply of thermal light-valve of liquid crystal mixtures for cholesterics/ induced smectic

徐暐宬(Wei-Cheng Shu)

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(2000年)

摘要

利用兩種Nematic低分子液晶混合誘導出Smectic相；然後再混合一種具有具有光學旋光性chiral成份-cholesteric液晶(CB15)的低分子液晶，我們利用上述的三成份液晶複合系研究其相行為與光學性質。經由實驗發現-藉著誘發Smectic相與Ch相的熱轉移來產生光學效果。本實驗未加電場及偏光板，只利用熱轉移來達成光散亂與光透明的現象，使液晶面板會隨著溫度的不同而呈現明暗的變化。而在CB15高濃度下在未加入偏光板及電場情況下會發現在室溫會出現炫麗的色彩-具有可見光的選擇性吸收波長。這實驗是對三種低分子液晶複合系的熱光學特性研究，並討論CB15的含量對複合系液晶相和熱光學特性的影響。期望應用於熱控制的光閘或窗簾等。

關鍵字

液晶 ； 膽固醇液晶 ； 雙安定 ； 層列型 ； 誘導層列型

並列摘要

The phase behavior and electro-optic properties of three-component composite：in which a chiral cholesteric liquid crystal (CB15) was mixed with mixtures of two low molecular weight nematic liquid crystals with induced smectic phase－were studied. Experiments showed that optical effect can be generated by thermal transition of induced smectic and cholesteric phases. Without electric field and polarizer，scattering and transparent states were achieved by thermal transition，resulted in different contrasts of liquid crystal panel with different temperatures. Furthermore，high concentration of CB15 showed brilliant colors at room temperature without polarizer and electric field.－selective absorption wavelength of visible light. Main purpose was study thermal-optical properties of three low M.W. liquid crystal composites and effects of the concentration of CB15 on thermal optics LC composite and properties. It is values are expected on application on thermal-controlled light-valves or shutters.

並列關鍵字

LC ； cholesteric ； bistable ； smectic ； induce smectic

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