Optical properties of colloid liquid crystal composites

Colloid-liquid crystal composites are a recently discovered class of soft s olid comprising a dense dispersion of spherical colloidal particles in a li quid crystalline host with unusual mechanical properties, We applied this c lass of system to a variety of liquid crystal device modes such as twist ne matic, homogenous aligned, White-Taylor GH and reflective cholesteric devic es. The observed electro-optical response suggests that the local viscosity (controlling molecular reorientation) is decoupled from the (much higher) bulk viscosity, Over a wide range of particle concentrations across the ful l temperature range of the nematic phase, strong electro-optical switching is observed for 5CB and several of the commercially available liquid crysta l mixtures. Contrast ratio, viewing angle characteristics, switching time a nd optical hysteresis exhibit a significant dependencies on particle densit y. We also demonstrate that how morphologies of the liquid crystal confined between the substrates affect the optical properties.