Abstract
The binary mixture of two non-mesogenic compounds, viz., cetyl-dimethyl-ethyl-ammonium bromide (CDEAB) and orthophosphoric acid (H3PO4) exhibits very interesting liquid crystalline smectic phases at large range of concentrations and temperature. The mixture with lower and higher concentrations of CDEAB exhibits SmA, SmE, and SmB phases, sequentially when the specimen is cooled from its isotropic phase. Different liquid crystalline phases observed in the mixture were studied using differential scanning calorimetry (DSC), X-ray, and optical microscopic techniques. The temperature variations of optical anisotropy and electrical conductivity have also been discussed. Helfrich potential and elastic moduli have been estimated in the smectic phase using Helfrich model.