Phase equilibria of a polymer–smectic-liquid-crystal mixture

Abstract

Phase diagrams of nematic--liquid-crystal mixtures have been extensively studied theoretically and experimentally to improve the basic understanding of miscibility and phase separation behavior of polymer-dispersed liquid crystals (PDLC's). To the best of our knowledge, the phase behavior of a PDLC composed of a polymer and a smectic liquid crystal is largely an unexplored area. We have developed a theoretical model for predicting phase diagrams of a polymer/smectic--liquid-crystal mixture by combining the Flory-Huggins (FH) theory for isotropic mixing and the Maier-Saupe-McMillan (MSM) theory for anisotropic ordering of liquid crystals (LC's). Our combined FH-MSM model is capable of predicting the phase diagrams of PDLC systems in which the LC component has either a smectic-A--nematic (Sm-A--N) transition and a nematic-isotropic (N-I) transition or a smectic-A--isotropic (Sm-A--I) transition. \textcopyright{} 1996 The American Physical Society.