Origins of remarkable light scattering induced from a phase separated structure for polymer/ (liquid crystal(LC)) composite film were discussed. It was proposed that the main origins of light scattering might be associated with 1) spatial distortion of nematic directors, 2) discon-tinouous change of nematic directors among LC channels, and 3) optical boundary (mismatching of refractive indices) between LC phase and matrix polymer. The phase separated structure of the composite film was formed through a spinodal decomposition. The faster the solvent evaporated, the smaller the domain size in the composite film was. With an increase in channel size of liquid crystal, the rise and decay times decreased and increased, respectively, and the threshold voltage of light switching decreased. A dielectic model expression was introduced to evaluate a magnitude of electric field applied to the liquid crystalline phases when an external electric field was applied to a composite film. It was suggested from the dielectric model calculation and also, was demonstrated experimentally that the larger electric field is effectively applied to the liquid crystalline phases by using the matrix polymer with the greater magnitude of dielectric constant and electric conductivity. Reversible and bistable electrooptic effects bing driven by dual frequencies were recognized for a smectic phase of the composite composed of liquid crystalline polymer (LCP) and LC. The response speed of bistable light switching can be remarkably enhanced by reducing the LCP fraction with keeping a stable smectic layer structure for the ternary induced smectic composite system. A rewritable optical storage effect induced by photoirradiation to a LCP/LC/ (photoresponsive molecule) ternary composite system was also demonstrated.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)