Monte Carlo study of the molecular organization in model nematic droplets. Field effects

The study of polymer dispersed liquid crystals (PDLC), formed of sub-micron or micron size liquid crystal droplets embedded in a polymer matrix is attracting increasing attention, both for their fundamental interest and for their applications in display technology [ l-6 1. PDLC possess an extremely large surface-to-volume ratio so that the aligning effect of surface boundary conditions, which has a profound effect on the orientation of molecules near the surface, has a possibility of propagating inside the droplet. In general there will be a competition between the molecular orientation induced by the surface boundary, the effects of ordering of the liquid crystal itself due to the molecules trying to arrange parallel to each other, and the disordering effect of temperature. The resulting molecular organization for a certain boundary condition will thus depend on a number of factors, including the strength of the surface interaction, the temperature, and so on. Even though these factors can to a good extent be controlled, it is not easy to predict the molecular orga-