Reentrant isotropic–discotic nematic lyotropic phase transition: a refractive index study

Abstract

In this work the temperature dependence of the extraordinary/ordinary refractive indices and the optical birefringence are determined near the reentrant isotropic–discotic nematic–isotropic phase transitions for a lyotropic mixture of potassium laurate, decanol and D₂O. These parameters are related to the extraordinary/ordinary molar refractivity through Vuks's equation and discussed in terms of structural changes in the micellar configuration at the transitions.