A STUDY ON THE MORPHOLOGY AND ELECTROOPTIC PROPERTIES OF LIQUID CRYSTAL-POLYMER COMPOSITE FILMS

We have studied the relationship between the morphology and the electr o-optic properties of liquid crystal-polymer composite (LCPC) material s. The materials consist of the liquid crystal (80% by weight) and the polymerizable mixture (20% by weight) composed of the monofunctional monomer, the oligomer, and the multifunctional acryl monomer. The resu lts show that the electro-optic properties such as the driving voltage and the transmittance depend strongly on the polymer species used. Wh en the solubility between the liquid crystal and the growing polymers formed during the polymerization process is low and the speed of phase separation is fast, the morphology shows a 'Network' type, the liquid crystal exhibits a continuous phase through the sample, and such a fi lm scatters light strongly in the off state. The maximum transmittance in the on state depends primarily on the polymer morphology and secon dly on the solubility between the polymers and the liquid crystal in t he 'Network' type LCPC film. The morphology of the optimum sample chos en from the experimental results shows an intermediate morphology betw een the 'Swiss Cheese' and the 'Network' types.