Twisted Molecular Reorientation by Axis-Selective Surface Photoreaction and Subsequent Self-Organization in Photocrosslinkable Polymer Liquid Crystals

Abstract

Highly functionalized birefringent films with a twisted nematic structure have been fabricated by axis-selective surface photoreaction and subsequent self-organization in photocrosslinkable polymer liquid crystals. The molecules at both film surfaces are selectively photoreacted owing to the strong absorption in the photoreactive material, and the resultant photocrosslinked mesogenic molecules induce the three-dimensional twisted structures in the film during the annealing process. Theoretical consideration was performed by assuming typical kinds of twisted structure, and we confirmed that the nematic directors are homogeneously twisted with fixed boundary conditions at the film surfaces.