Study on the mechanism of controlling the pretilt angle of liquid crystals on the plasma-treated polyimide film surface and the magnetic nanoparticles

• Main Authors: Meng Chiou Huang, 黃孟秋
• Other Authors: Ru-Pin Pan
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/4b6zk9

碩士 === 國立交通大學 === 電子物理系所 === 96 === The widely-used mechanical rubbing method in the liquid crystal display industries has some drawbacks such as leaving the dust, static charges, and scratches on the treated surfaces. Besides, it is also difficult to satisfy the demands for multi-domain pattern and high pretilt angle. To overcome these limitations, a non-contact surface treatment on the polyimide film by using a diode type plasma system has been studied. A capability of inducing high pretilt angle is found in this work. The influences of treating time and plasma energy on the alignment effect are discussed. A significant amount of maghemite nanoparticles are deposited on the polyimide surfaces treated by the plasma beam at the same time. To find out the mechanism of surface alignment with high pretilt angle, the relation between the surface roughness and the size of coated nanoparticles has been characterized by using scanning electron microscope (SEM) and atomic force microscope (AFM). Further investigations on the change of chemical bonds on the treated surfaces have also been carried out by using x-ray photoelectron spectroscopy (XPS).