Interaction of liquid crystal molecules with rubbed polyimide alignment films

Abstract

We have extensively studied the molecular orientation of liquid crystal(LC) molecules adsorbed on the surface of rubbed polyimide alignment films by the use of a high-sensitive FT-IR spectrometer. It has been confirmed that LC molecules are oriented parallel to the rubbing direction and the degree of orientation tends to deteriorate with increasing the rubbing density. It has been also found out that the tilt angle of LC molecules ranges from 19° to 21° which are in fair agreement with the tilt angle of the polyimide molecular chain.