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Title: Theory of polymer-dispersed cholesteric liquid crystals

Abstract

A mean field theory is presented to describe cholesteric phases in mixtures of a polymer and a cholesteric liquid crystal. Taking into account an anisotropic coupling between a polymer and a liquid crystal, we examine the helical pitch, twist elastic constant, and phase separations. Analytical expressions of the helical pitch of a cholesteric phase and the twist elastic constant are derived as a function of the orientational order parameters of a polymer and a liquid crystal and two intermolecular interaction parameters. We also find isotropic-cholesteric, cholesteric-cholesteric phase separations, and polymer-induced cholesteric phase on the temperature-concentration plane. We demonstrate that an anisotropic coupling between a polymer and a liquid crystal can stabilize a cholesteric phase in the mixtures. Our theory can also apply to mixtures of a nematic liquid crystal and a chiral dopant. We discuss the helical twisting power, which depends on temperature, concentration, and orientational order parameters. It is shown that our theory can qualitatively explain experimental observations.

Authors:
 [1]
  1. Department of Bioscience and Bioinformatics, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Kawazu 680-4, Iizuka, Fukuoka 820-8502 (Japan)
Publication Date:
OSTI Identifier:
22251532
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 139; Journal Issue: 17; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANISOTROPY; CHIRALITY; COUPLING; INTERACTIONS; LIQUID CRYSTALS; MEAN-FIELD THEORY; MIXTURES; POLYMERS

Citation Formats

Matsuyama, Akihiko. Theory of polymer-dispersed cholesteric liquid crystals. United States: N. p., 2013. Web. doi:10.1063/1.4828940.
Matsuyama, Akihiko. Theory of polymer-dispersed cholesteric liquid crystals. United States. https://doi.org/10.1063/1.4828940
Matsuyama, Akihiko. 2013. "Theory of polymer-dispersed cholesteric liquid crystals". United States. https://doi.org/10.1063/1.4828940.
@article{osti_22251532,
title = {Theory of polymer-dispersed cholesteric liquid crystals},
author = {Matsuyama, Akihiko},
abstractNote = {A mean field theory is presented to describe cholesteric phases in mixtures of a polymer and a cholesteric liquid crystal. Taking into account an anisotropic coupling between a polymer and a liquid crystal, we examine the helical pitch, twist elastic constant, and phase separations. Analytical expressions of the helical pitch of a cholesteric phase and the twist elastic constant are derived as a function of the orientational order parameters of a polymer and a liquid crystal and two intermolecular interaction parameters. We also find isotropic-cholesteric, cholesteric-cholesteric phase separations, and polymer-induced cholesteric phase on the temperature-concentration plane. We demonstrate that an anisotropic coupling between a polymer and a liquid crystal can stabilize a cholesteric phase in the mixtures. Our theory can also apply to mixtures of a nematic liquid crystal and a chiral dopant. We discuss the helical twisting power, which depends on temperature, concentration, and orientational order parameters. It is shown that our theory can qualitatively explain experimental observations.},
doi = {10.1063/1.4828940},
url = {https://www.osti.gov/biblio/22251532}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 17,
volume = 139,
place = {United States},
year = {Thu Nov 07 00:00:00 EST 2013},
month = {Thu Nov 07 00:00:00 EST 2013}
}