The isotropic–nematic phase transition and other properties of a solution of semiflexible polyelectrolytes

We extend previous work [G. J. Vroege and T. Odijk, Macromolecules 21, 2848 (1988)] on the formation of nematic liquid crystals from uncharged semiflexible polymers to the charged case. The polyelectrolytes are modeled as long slender worm-like cylinders interacting via both hard-core and electrostatic repulsions in the second virial approximation. Analogously to rod-like polyelectrolytes it is possible to describe the result of charge by introducing an effective diameter and a twisting effect. We then calculate numerically the orientational distribution function as a function of concentration. We determine the effect of charge on the phase transition and—in the nematic phase—its influence on the order parameter and the global persistence length (directly connected to the splay elastic modulus). Although the phase transition concentrations are clearly dependent on charge, the properties of the nematic phase at the transition are not—in contrast to the result for rod-like polyelectrolytes.