Optically isotropic chiral liquid crystals induced by polymer network and their electro-optical behavior

The optical and electro-optical properties of the optically isotropic liquid crystalline composites prepared by in-situ photo-polymerization of cross-linking monomers in the isotropic phase and the blue phase of the chiral liquid crystals were investigated. In the composites prepared in the isotropic phase, no typical platelet textures corresponding to blue phase I and blue phase II were seen, and no reflection peaks were observed around the wavelength where the polymer-stabilized blue phase should exhibit reflection. A large Kerr constant, being relatively insensitive to temperature, was obtained for composites even in a temperature range where a liquid crystal used exhibits chiral nematic phase. The response time of Kerr effect was on the order of tens to hundreds of microseconds.