Abstract
Polyvinyl-cinnamate (PVCi) is well known as a photo crosslinkable polymer to align liquid crystal (LC) molecules by a linearly polarized UV (LPUV) light exposure. In addition, it has been recognized that the easy axis is perpendicular to the rubbing direction, since sidechains of PVCi are oriented perpendicular to the main chains. However, we found that MBBA (N-p-methoxybenzylidene p-n-butylaniline) aligns parallel to the rubbing direction. In this study, the in-plane easy axis of LCs with different chemical structures has been investigated on the rubbed PVCi surface. We reported that LCs with and without polar groups aligned perpendicular and parallel to a rubbing direction on a rubbed PVCi surface, respectively. Easy axis control of the PVCi was realized by mixing LCs and an alignment patterning was successfully demonstrated on crosslinked and uncrosslinked surfaces by exposing with and without unpolarized UV light.
