Liquid Crystal Material Dependence on Rubbed PVCi Alignment Properties

Abstract

We report that the in-plane alignment direction changes by liquid crystal materials on a rubbed polyvinyl-cinnamate (PVCi) film surface. The alignment direction of almost LCs investigated in this study was perpendicular to the rubbing direction. However, a few LCs, for example, MBBA (N-p-methoxybenzylidene p-n-butylaniline) aligned parallel to the rubbing direction. On the other hand, all LCs investigated aligned perpendicular to the polarization direction of the UV light on the photo-alignment PVCi surface. Moreover, the alignment direction of MBBA changed perpendicular to parallel to the rubbing direction with the passage of time after MBBA was put on the irradiated with UV light and subsequently rubbed PVCi surface. These results suggest that the alignment surface is changed by wetting with the LC.

Keywords:

• Alignment direction
• nematic liquid crystal
• photoalignment
• polyvinyl-cinnamate
• rubbing