Study of adjustable pretilt angle controlled with blending silanes coating on glass substrates of liquid crystal cells

• Main Authors: Tsung-Hung You, 游琮宏
• Other Authors: Chia-Rong Sheu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/83942174343806012245

碩士 === 國立成功大學 === 光電科學與工程研究所 === 95 === In this thesis, we study a suitable method possessing a capability of adjusting pretilt angle for liquid crystal alignment. In our experimental, two kinds of silane are used to blend with various concentration ratio for liquid crystal alignment, which are DMOAP (N,N-dimethyl-N-octadecyl-3- aminopropyltrimethoxysilyl chloride) for homeotropic alignment and MAP (N-methyl-3-aminopropyltrimethoxysilane) for homogeneous alignment, respectively. In order to align liquid crystals in cells, the composed glass substrates are dipped in blended silane solution to form the alignment thin film on glass surfaces before cell assembly. Pretilt angles are observed and measured in different blended silane conditions. The qualities of liquid crystal alignment in cells are observed with the polarized optical microscope (POM), and pretilt angles are measured with a setup based on the crystal rotation method. Experimental results show that adjustable pretilt angle about 16~19 degrees are achieved except homeotropic and homogeneous alignment in conditions of various blended silane solution. Meanwhile, we also find that the time after the fresh blended silane solution is an effective factor for pretilt angle variation.