THERMALLY INDUCED CHOLESTERIC ISOTROPIC TRANSITION IN LYOTROPIC POLYPEPTIDE LIQUID-CRYSTALS

In the reported experiments, the thermally induced cholesteric to isotropic transition of lyotropic polybenzylglutamate liquid crystals in six solvent combinations was examined optically. The solvents chosen for study support both low and high pitch values, positive and negative pitch temperature coefficients, and polypeptide denaturation. The biphasic zone below the clearing temperature is broad and solvent dependent. Unusual large-scale phase separations and solution morphologies occur in some solvents. No evidence was found for pretransitional chiral orientational ordering near the clearing point in the high-temperature isotropic phase.