膽石醇液晶/誘導smectic/複合系液晶的電場變色效應與光資訊寫入與擦拭

Electro-Chromatism Effects and optical storage of liquid crystal mixtures for cholesterics / induced smectic

施創華(Chuang Hua Shin)

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

摘要
運用偶氮苯官能基的光應答性低分子液晶BMAB與BHMB光化學異構特性，於紫外光的照射下誘導出trans-cis的光異性化行為。其偶氮分子構造會從細長型的trans構造轉變成彎曲的cis構造，在光學現象上產生了光散亂的狀態。隨著軟鍵越長其相轉移溫度降低，可調配出不同溫度區間的光元件開關(optical switching)。因具有光及熱可恢復特性，所以應用於光資訊讀寫上時必須改善其穩定性，本實驗運用末端基強極性與末端基為弱極性的低分子nematic液晶與偶氮分子混合，試圖誘導出黏度較大的smectic相；此外添加10wt%具有chiral的R-811利用其光化學相轉移，使寫入的部份呈現cholesteric相。為了加強其寫入的解析度，採用PDLC的技術與原理進行研究與探討。

關鍵字

膽石醇液晶 ； 電場變色效應 ； 誘導smectic

並列摘要

Abstract
A low molecular weight liquid crystal doped with azobenzene liquid crystal molecular to induce smectic phase, then added a chiral compoment to induce cholesteric phase. By means of the photoisomeric property of Azobenzene liquid crystal molecular (BMAB、BHAB)，we induced trans-cis photoisomerization of the azobenzene molecular by alternating irradiation with UV light. The optical phenomenon is reversibly changeable and bistable between the light-scattering state and the transparent state. The longer the spacer is the lower the temperature of phase transition is. And we can find that the optical switching has different temperature conditions. We utilized the Polymer Disper Liquid Crystal technology to study the blend of liquid crystal.
The change of critical frequency of a transparent state and a light-scattering state by irradiation with UV light and visible light (heat or electric field of high frequency).

並列關鍵字

cholesterics ； Electro-Chromatism Effects ； induced smectic

參考文獻

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