Eur. Phys. J. E 9, 79-87 (2002)
DOI: 10.1140/epje/i2002-10061-9

Non-uniformities in polymer/liquid crystal mixtures

I. Interfacial tension

A. Matsuyama¹, R.M.L. Evans² and M.E. Cates<sup>3

1</sup>  Department of Chemistry for Materials, Faculty of Engineering, Mie University, Tsu Mie 514-8507, Japan
²  Department of Physics and Astronomy, The University of Leeds, Leeds LS2 9JT, UK
³  Department of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ, UK

matuyama@chem.mie-u.ac.jp

(Received 9 August 2002 and Received in final form 16 October 2002 / Published online: 22 November 2002)

Abstract
We theoretically study interfacial properties between two coexisting phases in mixtures of a flexible polymer and a low-molecular-weight liquid crystal. By numerically solving Euler equations for compositional and orientational order parameter fields, we calculate the order parameter profiles and interfacial tensions for nematic-isotropic and isotropic-isotropic phase equilibria. We find that the order parameter profiles are non-monotonic at some temperatures. The nematic-isotropic interfacial tension increases with decreasing temperature and is approximately proportional to at temperatures below the nematic-isotropic transition temperature ( ) of the pure nematogen. The value of the exponent n is strongly affected by the existence of a triple point.

PACS
61.30.-v - Liquid crystals.
61.30.Hn - Surface phenomena: alignment, anchoring, anchoring transitions, surface-induced layering, surface-induced ordering, wetting, prewetting transitions, and wetting transitions.
61.30.St - Lyotropic phases.

© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2002