Transmittance of dispersed nematic/polymer systems of the NCAP type

A stationary effect of the electric-field-induced variation of the transmittance of thin-film disperse systems was studied theoretically. The systems consisting of a nematic liquid crystal (NLC) and a polymer (NCAP-type systems) represent flattened spheroid droplets with a bipolar NLC structure. These systems are characterized by a nonmonotonic dependence of the optical transmittance on the applied field strength for the normal incidence of light. This dependence is interpreted within the framework of a proposed phenomenological model based on the approximations of single scattering and anomalous diffraction. Experimental verification of the model is performed for dispersed systems with a poly(vinyl alcohol) matrix. A good agreement of the theoretical and experimental results is obtained. (C) 2000 MAIK "Nauka/Interperiodica".