Photo-Crosslinkable Polymers for Photostimulated Alignment of Liquid-Crystalline Materials

Abstract

Alignment of a liquid-crystalline monomer by layers of photo-crosslinkable polymers with methacrylate backbones and photo-dimerizable side groups is experimentally investigated. The studied polymers demonstrate photostimulated alignment after rubbing with a cloth, like benzaldehyde polymers. However, the exposure dose of 365-nm radiation required for them is smaller by two orders of magnitude owing to long-wavelength shifts of the absorption spectra. The availability of high-power LEDs emitting at this wavelength could potentially increase several times the productivity of the layer-alignment process for liquid-crystalline materials based on polymers exhibiting photostimulated alignment. Also, lasers emitting at 355 nm can now be used effectively for aligning hologram recording.