Simple Theory for Persistent-Flexible Liquid Crystal Polymers Beyond the Second Virial Approximation

Abstract

ABSTRACTKhokhlov and Semenov (KS) have proposed a theory for long persistent chains that quite accurately describes the liquid crystalline behavior of dilute solutions of long homogeneous bend-elastic macromolecules. By replacing their second virial description of excluded volume effects with Lee's generalization of the Carnahan-Starling equation, results are obtained which are valid over a wider range of polymer concentrations. Comparison of the calculated order parameter and equation of state with experimental data for Poly(γ-benzyl-L-glutamate) yields good agreement for large polymer axial ratios, where rigid particle theories deviate strongly from experimental results. In addition, we show how this approach to persistent flexibility can be connected to a recent model for translational order in lyotropic liquid crystals.