Evaluating the surface alignment of homogeneous alignment and homeotropic alignment liquid crystal cell by retardation measurement of the surface layer

Abstract

It has been reported that the contact angle of isotropic phase droplet (or nematic phase droplet) on the rubbed polyimides (PIs) surface at the clearing temperature is strongly related to the rubbing strength. In this paper, we discuss detailed relationship between the surface order parameter and the contact angle of droplet using polarized IR absorption and birefringence measurement of LC surface layer of homogeneous cell. Based on the result, new model concerning formation of droplet contact angle was established. Additionally, surface layer of the homeotropic alignment LC cell was discussed.