Rubbing alignment is widely used in display industry, Rubbing cause anisotropy in rubbed polyimide thin film influence the alignment of Liquid Crystal.
The major part of this article is to analyze surface optical anisotropy of rubbed polyimide thin film. RAS signals and surface free energies of rubbed polyimide thin film with different rubbing strength are measured, and relationship between anisotropy of surface and rubbing strength is discussed. The mechanism of alignment can be understood by this work.
Reflection Anisotropy Spectroscopy (RAS) has been used in Semiconductor as a tool to monitor crystal growth for many years. RAS is a non-contact and non-destructive measurement method. It only measures the difference of two orthogonal complex reflection signals and optical anisotropy of surface. It¡¦s very sensitive to the anisotropy of surface. In the current studies, RAS has been used to detect surface anisotropy of rubbed polymer.
We measured the surface free energy of the rubbed polyimide thin films. It has been found that surface free energy is of anisotropy due to the application of mechanical rubbing to the polymer surface.
Pretilt angle influences the alignment of liquid crystals. The molecule orientation of PI surface and anisotropy of rubbed PI surface effect pretilt angle¡CPretilt angles measured by pretilt angle measurement system compare with RAS signals.
RAS signals, anisotropy of surface free energies, and pretilt angles are increasing with increasing rubbing strength.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0727107-160124 |
| Date | 27 July 2007 |
| Creators | Ye, Yi-Jhih |
| Contributors | Wen-yao Huang, Mei-ying Chang, Wen-jun Zheng, Shih-rong Bai |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0727107-160124 |
| Rights | off_campus_withheld, Copyright information available at source archive |
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