Characterization of Vertical Alignment Film by X-Ray Reflectivity

摘要

Depth profile of mass density of vertical alignment film was investigated by X-ray reflectivity, in order to characterize side chains at film surface for vertical alignment of liquid crystals. Existence thin and low density top layer at surface of polyimide film, which was considered to be side chains, was clearly detected. Furthermore, existence of high density layer just below side chain layer was also found, and it is suggested that backbone chain ordering at film surface. Effect of rubbing on VA film was not detected. However, density growth by annealing just below side chain layer of rubbed VA film suggests more ordered backbone chain alignment induced by rubbing.