Pressure-driven reentrance phenomena in a binary mixture of achiral liquid crystals: role of inverse layer spacing

Abstract

The occurrence of pressure-driven reentrant phenomena in a binary mixture of liquid crystals exhibiting the phase sequence on cooling is observed in high-pressure experimental studies has been explained within the framework of Landau de Gennes theory. In this phenomenological theory, the free energy density is written as an expansion series containing terms involving powers of nematic and smectic () order parameters and the () and () coupling terms. The most important feature of the work is that the role of inverse layer spacing , which mimics an order parameter, couples with the order parameters. The influence of concentration on reentrant behaviour is also discussed by varying the coupling between the concentration variable and the order parameters. We found that the order parameters coupling terms and inverse of layer spacing play an important role and that the present analysis is in good qualitative agreement with the available experimental results.