Phase Separations in Mixtures of a Flexible Polymer and a Cholesteric Liquid Crystal in the Presence of an External Field

Abstract

We present a mean field theory to describe phase behaviors in mixtures of a flexible polymer and a cholesteric liquid crystal under an external magnetic or electric field. Taking into account a chiral coupling between liquid crystals under the external field, we examine twist-untwist phase transitions and phase separations in the mixtures. Depending on the strength of the external field, we predict cholesteric-paranematic (Ch + N), nematic-paranematic (N + pN), cholesteric-nematic (Ch + N) phase separations on the temperature-concentration plane. We also calculate spinodal regions, which are important in phase separation kinetics inside binodal lines.

Phase diagrams of mixtures of a polymer and a cholesteric liquid crystal under an external field

“…5 and 6. 45 Field-induced cholesteric-nematic phase transitions have been observed in a mixtures of cholesterol chloride, nonanoate, and oleyl carbonate at a field of 3-5× 10 5 V/m. 5 It has been shown that CNT temperature decreases with increasing the applied field and a nematic phase appears for wide temperature ranges.…”