Abstract

Optical studies and order parameter of lyotropic chromonic liquid crystalline phase

Author(s): T.N.Govindaiah

We report the results of our studies on the optical and thermal properties of binary mixture of two compounds viz., abietic acid and poly ethylene glycol. The mixture shows a very interesting co-existent biphasic region of lyotropic nematic (N+I) and intermediate hexagonal M+I phases, sequentially when the specimen is cooled from its isotropic phase respectively at different concentrations of abietic acid in poly ethylene glycol molecule. The order parameter (S) of the co-existent biphasic region of lyotropic nematic (N+I) phase is estimated with the help of temperature dependence of optical anisotropy from the measured values refractive index and density data. The temperature variation of order parameter of the experimental curve is very well fitted with the Mayer–Saupe theoretical curve.