偶氮苯旋光性材料/向列型液晶複合系液晶之光電特性與光資訊讀寫研究

Electro-optical properties and optical storage of liquid crystal mixtures for chiral azobenzene component/nematic

張哲瑋(Che-Wei Chang)

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(2005年)

摘要

合成具有偶氮苯的旋光性材料與正、負型nematic液晶形成兩種複合系液晶而誘導出膽石醇相排列。藉著改變頻率與電場的方式來控制光學效果，達到光散亂與光透過的雙安定特性。當膽石醇複合系液晶添加偶氮苯旋光性材料時，可利用偶氮苯旋光物質的光異構化效果，使其旋光性降低，以達到控制UV曝光能量而呈現不同的選擇性反射光波波段功能。在紫外光照射下時，偶氮苯trans-cis光異構化行為使得膽石醇相與等方性相的相轉移改變，在光學現象上產生了光透過的狀態，且施加熱源或施加直流電場即可達到擦拭的效果，因具有可恢復特性，所以具有光讀寫與擦拭的功用。

關鍵字

偶氮苯旋光物質 ； 雙安定 ； 液晶複合系

並列摘要

A binary composite composed of a chiral azobenzene compound and a nematic liquid crystal was prepared to investigate its optical-electro behavior. The opaque-transparent change could be achieved by applying an electric field with different frequency or field strength.
The trans-cis photoisomerization by irradiating UV light would change the chirality and reflective wavelength of the composite in cholesteric phase. The Cholesteric-Isotropic (N*-I) phase transition was induced by this translation. The scattering-passing of the light would be observed during the phase transition. A reverse photoisomerization could be induced with heat and electric field. The optical storage application would be achieved by the change of the opaque-transparent states.

並列關鍵字

azobenzene ； bistable ； liquid crystalline composite