Non-uniformities in polymer/liquid crystal mixtures

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 (T - T _NI)ⁿ at temperatures below the nematic-isotropic transition temperature ( T _NI) of the pure nematogen. The value of the exponent n is strongly affected by the existence of a triple point.