Anchoring effect of polymer films formed by liquid crystalline monomer

摘要

We have evaluated the polar anchoring strength of a thin molecule-aligned polymer film formed by a liquid crystalline monomer. The polymer film was obtained by photopolymerization of the monomer oriented by a rubbed polyimide alignment layer in a chamber filled with N{sub}2 gas. We fabricated a nematic liquid crystal cell using the thin aligned-polymer films as alignment layers, and then evaluated the polar anchoring strength of the polymer by measuring optical retardation curve of the cell driven by voltages. As the experimental result, the anchoring strength was one order of magnitude less than that of a conventional rubbed polyimide alignment layer. Besides the anchoring strength decreased with increasing a cure temperature of the monomer film. It is thought that this is because the alignment order of the polymer decreased with increasing the cure temperature. It was found that the anchoring strength of the molecule-aligned polymer surface can be controlled by the alignment order of the polymer.