Novel photoalignment materials for liquid crystals based on modified polysiloxane

Novel photosensitive alignment materials based on allyl-cinnamate-grafted m ethyl hydrogen polysiloxane fluid (MHPF) were used in fabricating liquid cr ystal (LC) cells by sandwiching nematic LC molecules between two indium-tin -oxide (ITO) patterned substrates. The LC aligning ability of this kind of alignment layer, fabricated by linearly polarized UV-induced polymerization (LPP), was characterized based on polarizing microscopic and conoscopic ob servations. The influences of the thickness of LPP films, LC materials, dif ferent end groups, baking conditions and exposure conditions on the alignme nt and thermal stability are discussed in detail. The results confirmed tha t the photoalignment films exhibited not only good aligning ability but als o excellent thermal stability.