凝膠玻璃分散液晶薄膜及其光電特性之研究

Abstract

本論文的主要目的是藉矽氧烷系列為凝膠(sol-gel)主要原料, 藉其不同烷氧基水解縮合形成sol-gel,並在非反應基甲基, 苯基存在不同比例下觀察其sol-gel速度快慢, 並根據sol-gel 後形成之gel-glass特性,取透明度高且折射率合於E7之gel-glass成份以毛細原理, 旋轉塗佈方式及塗佈製成cell 測其光電特性, 為提升對比度加入Ti(OC2H5)4 得較佳對比度, 並觀察cell內部gel-glass組成 。 研究後發現, 在成份的選擇上,(C6H5)2Si(OH)2因立體效應及反 應基少gel-glass成膜時間耗時(>72hrs)性質不佳。在取三甲氧基矽丙胺,1-甲基-1,1-二乙氧基矽丙胺, 三甲氧基矽苯適當的比例混合gel-glass 性質良好, 以毛細原理型形成cell液晶分佈少液晶無法吸入, 旋轉塗佈方式液晶分佈不均光電特性不佳。 而在非反應基C6H5- 有使膜硬化時間縮短, 電阻值提升的現象, 而同樣非反應基CH3-之量多時, 使導電度提升。 -CH2CH2CH2NH2 量多時有使gel-glass性質軟化導電度提升作用, 在不加Ti(OC2H5)4 製成cell 對比度可到 4.8(off 18%,on 86%),threshold Voltage 8V, cell 內部組成網狀結構均勻, 特性良好。 加入Ti(OC2H5)4 之cell 因Ti(OC2H5)4 會提高折射率, 硬度提升, 導電度下降, 而在選擇直鏈基1-甲基-1,1-二乙氧基矽丙胺量比例增加,以配合Ti(OC2H5)4 加入形成之影響, 將成份選擇加入Ti(OC2H5)4 後折射率之量合於E7 製成 之cell, 即可得對比度升至22.5左右, 電壓為13V, 而cell內部gel-glass網狀結構緻密, 這將直接與 GDLC 之特性有關。

This thesis is focus on gel-glass liquid crystal dispersed (GDLC) by amino-silicon materials sol-gel process. Following silicon alkoxides have different function groups after their hydrolysis, condensation will have different gelation time, refractive index, resistivity. Owing to refractive index induces contrast ratio that gel-glass materials need to match E7 refractive index for enhance electro-optical performance. The non-active function groups CH3-, C6H5- quantities will impact gelations time, gel-glass structure and response voltage. Cells were made by spin coating, capillary principle, droplets dispersed. Showing spin coating, capillary principle have poor electro-optical performance. 3-(Diethoxymethoxysilyl) propylamine composition offered the gel-glass matrix better flexibility & lower resistivity. Ttanium ethoxide was used successfully to adjust the refractive index and improve the contrast ratio (GDLC-17 C.R.=22.5) . From cell optical microscope structure: the stronger, uniformer structure relative better electro-optical performance (Fig 4-4-1 c). GDLC system matrix are controlled by raw materials compositions, active groups, non-active groups, temperature, humidity…etc.. Here focus materials and active, non-active groups composition that high-line excellent cell gel-glass structure and excellent electro-optical performance.