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The study of influence of anisotropy in rubbed polyimide thin films on liquid crystal alignment by means of reflection anisotropy spectroscopy

Rubbing alignment has been used popularly in display industry. However, the alignment mechanisms of rubbed polymer are still not well understood. The purpose of this study is to investigate the relationship between anisotropy of rubbed polyimide thin film and liquid crystal alignment. In this study, we discuss the effects of surface energy and RAS on the surface roughness and pretilt angle of liquid crystal molecules.
RAS is a non-contact optical probing technique developed originally for real-time, in situ monitoring of semiconductor growth . In this technique the normalized difference in reflectivity along two orthogonal directions is measured. Recently, the prospect of using RAS for process control in the fabrication of liquid crystal devices is investigated.
On the other hand, we have known that the magnitude of surface energy is related to the strength of molecular bond. We can obtain the variation of surface properties by measuring the difference of surface energy.
We found that the RA signal, pretilt angle and surface roughness are increasing with an increase in rubbing strength, but surface energy was decreased..

Identiferoai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0715108-162553
Date15 July 2008
CreatorsWang, Sin-ping
ContributorsMei-Ying Chang, Shin-Jung Bai, Wen-Jun Zheng, Tsung-Hsien Lin
PublisherNSYSU
Source SetsNSYSU Electronic Thesis and Dissertation Archive
LanguageCholon
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0715108-162553
Rightsunrestricted, Copyright information available at source archive

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