Optical characterization of lyotropic chromonic liquid crystals

We report the results of our studies on the optical and thermal properties of binary mixture of compounds, viz., Berberine (BBE) and Poly-ethylene glycol (PEG). The mixture shows very interesting coexistent biphasic regions N + I and N + C phases respectively at different concentrations of BBE sequentially when the specimen is cooled from its isotropic liquid phase. The temperature variations of optical anisotropy and optical textures have also been discussed. Formation of above molecular orientations has been confirmed by X-ray studies