Summary: | 碩士 === 國立成功大學 === 化學工程學系 === 89 === Three kinds of acrylic monomers of 6-(4-methoxy-4’-
oxy-azobenzene)propyl acrylate (Azo-3),6-(4-methoxy-4’-oxy-
azobenzene)hexyl acrylate (Azo-6), 6-(4-methoxy-4’-oxy-azobenzene)
undecyl acrylate (Azo-11) with various sidechain lengths of 3, 6, 11 carbons were synthesized. To investigate the electro-optical
properties of polymer stabilized cholesteric texture (PSCT) liquid crystal cell, the monomers were mixed with nematic liquid crystal E48, cholesteric liquid crystal CB15, and benzoin methyl ether (BME). The mixture was poured into an ITO cell and then irridiated by UV light for a certain period. The effects of the sidechain length of monomers and the crosslinking agents of 4,4’-bis〔6-(acryloyloxy)hexyloxy〕biphenyl (BAHB) and dipentaerythritol penta-/hexa-acrylate (DPPA) on the electro-optical properties of PSCT film were investigated. From the results of our investigation, it was found that the polymer matrix from azo-3 monomer could stabilize the electro-optical properties and decrease the threshold voltage of the PSCT cells. Adding of multifunctional DPPA could further stabilize the electro-optical properties of PSCT cells. The optimal conditions of feed monomer ratio of Azo-3/BAHB= 1:1, UV exposure time of 60 minutes were observed.
英文摘要---------------------------------------------------------------------------Ⅱ
目錄---------------------------------------------------------------------------------Ⅳ
表目錄------------------------------------------------------------------------------Ⅶ
圖目錄------------------------------------------------------------------------------Ⅷ
符號表---------------------------------------------------------------------------ⅩⅢ
第一章 緒論-----------------------------------------------------------------------1
1-1 液晶的簡介-------------------------------------------------------------------1
1-1-1 液晶的分類----------------------------------------------------------------3
1-1-2 液晶的特性---------------------------------------------------------------11
1-2 液晶聚合物概述-----------------------------------------------------------15
1-3 研究動機--------------------------------------------------------------------15
第二章 原理----------------------------------------------------------------------17
2-1 小分子液晶化合物的分子構造-----------------------------------------17
2-2 液晶的物理性質-----------------------------------------------------------18
2-2-1 液晶的光學異方性------------------------------------------------------18
2-2-2 外加電場對絕緣向列型液晶的影響---------------------------------20
2-2-3 液晶的撓曲電效應------------------------------------------------------24
2-2-4 向列型液晶流動對分子排列的影響---------------------------------25
2-3 膽固醇型液晶之光學性質-----------------------------------------------25
2-4 膽固醇-向列型相變化效應----------------------------------------------30
2-5 液晶-聚合物混合薄膜之介紹-------------------------------------------32
2-5-1 PDLC簡介----------------------------------------------------------------32
2-5-2 PSCT的簡介及工作原理----------------------------------------------34
2-6 光聚合反應-----------------------------------------------------------------40
第三章 實驗部分----------------------------------------------------------------44
3-1 藥品--------------------------------------------------------------------------44
3-2 儀器--------------------------------------------------------------------------45
3-3 實驗步驟-------------------------------------------------------------------- 46
3-3-1 含Azo之單體合成------------------------------------------------------46
3-3-2 合成4,4’-bis〔6-(acryloyloxy)hexyloxy〕biphenyl------------48
3-4 試樣的製作-----------------------------------------------------------------49
3-4-1 ITO玻璃的清洗及空cell的製作------------------------------------50
3-4-2 單體與液晶混合液之光聚合相分離測試--------------------------51
3-5 光電性質的測量-----------------------------------------------------------51
3-6 聚合物之SEM量測--------------------------------------------------------52
3-7 溶液配製成分表-----------------------------------------------------------52
第四章 結果與討論-------------------------------------------------------------57
4-1 單體的合成與鑑定--------------------------------------------------------- 57
4-1-1 含Azo中央基的液晶單體之合成------------------------------------57
4-1-2 不同烷基長度之單雙鍵單體合成------------------------------------57
4-1-3 4,4’-bis( 6-(acryloyloxy)hexyloxy)biphenyl (7)單體合成--------- 61
4-2 PSCT液晶顯示元件之光電特性探討----------------------------------------62
4-2-1 不同側鏈長度單體對光電特性之影響-----------------------------------63
4-2-2 加入不同雙鍵數單體對其光電性質影響--------------------------------66
第五章 結論----------------------------------------------------------------------93
參考文獻---------------------------------------------------------------------------94
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