Phase diagrams of mixtures of a polymer and a cholesteric liquid crystal under an external field.
We present a mean field theory to describe phase behaviors in mixtures of a polymer and a cholesteric liquid crystal under an external magnetic or electric field. Taking into account a chiral coupling between a polymer and a liquid crystal under the external field, we examine twist-untwist phase transitions and phase separations in the mixtures. It is found that a cholesteric-nematic phase transition can be induced by not only the external field but also concentration and temperature. Depending on the strength of the external field, we predict cholesteric-paranematic (Ch+pN), nematic-paranematic (N+pN), cholesteric-nematic (Ch+N) phase separations, etc., on the temperature-concentration plane. We also discuss mixtures of a non-chiral nematic liquid crystal and a chiral dopant.
Department of Bioscience and Bioinformatics, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Kawazu 680-4, Iizuka, Fukuoka 820-8502, Japan.
Akihiko
A
Matsuyama
D055590:Electromagnetic Phenomena; D050866:Liquid Crystals / Q000737:chemistry*; D060526:Magnetic Fields; D008962:Models, Theoretical; D044367:Phase Transition; D011108:Polymers / Q000737:chemistry*; D013696:Temperature
D011108:Polymers