Molecular mechanism of smectisation and regulation of polymorphism in nematic liquid crystal systems

Abstract

The study explores the application of catastrophe theory to describe the molecular mechanisms of smectisation and the regulation of polymorphism in nematic liquid crystal (NLC) systems. We propose a new approach for describing the stable and unstable states of NLC systems that induce the smectic (Sm) phase. A relation between the control variables of the cusp catastrophe and the Sm order parameter in NLC systems has been identified. The equilibrium states of the Sm phase are determined within the framework of catastrophe theory. By applying catastrophe theory to study the thermodynamic potential of an NLC system, we provide a detailed description of how the functional potential geometry changes depending on the control variables. The local geometry around the extremes of the functional thermodynamic potential allows for controllable catastrophes.