TEMPERATURE-DEPENDENCE OF LC-MOLECULAR ALIGNMENT ON RUBBED POLYMER LAYER

Liquid crystal molecules on a rubbed polymer alignment layer are orien ted at some polar angle away from the surface. This so-called pretilt angle is an important parameter which determines the electrooptical pr operties of liquid crystal devices. Therefore, there is a necessity to deeply study generation of pretilt angle and its stability. Several r esearchers study on this problem but the physical mechanism is not tho roughly understood. Therefore, we have investigated LC pretilt angle a nd polymer inclination angle and the effect of heat treatment about th ese angles. We have also studied the relation between LC materials and their pretilt angles as well as the effect of the heat treatment on t hem. From these results we discuss the mechanism of change in LC preti lt by the heat treatment.