Statistical Theory of Cholesteric Ordering in Hard-Rod Fluids and Liquid Crystalline Properties of Polypeptide Solutions

A statistical theory of lyotropic cholesteric phase in the system of long coiled rod molecules is presented. Effects of molecular exclusion and of attractive intermolecular force are both taken into consideration. On the basis of the theoretical results, experiments on the cholesteric solutions of polypeptide are investigated, where use is made of the scaled particle theory on the fluid of hard rod molecules. It is thus found that the experimental dependences of cholesteric twisting power on temperature, concentration and molecular weight of the polymer and also the experimental curvature elasticity are explained satisfactorily.