Self-consistent integral equation theory for semiflexible chain polyelectrolyte solutions

A self-consistent integral equation theory is presented for the conformational behavior and static structure of polyelectrolyte solutions composed of semiflexible chain molecules. The free energy of the solution is expressed as the sum of an elastic, a Coulombic, and a medium-induced contribution, and is minimized with respect to the single chain structure factor. In the flexible limit, the theory is accurate for the chain conformations and static structure factor when compared to Monte Carlo simulations of flexible chains. For semiflexible chains near the flexible limit, the chain conformations are sensitive to the bare persistence length in dilute solutions but not in the semidilute regime. In contrast, the effect of the bare persistence length on the static structure factor is not as significant. The theory predicts that charged flexible chains exhibit more pronounced liquidlike order in solution than their rigid-rod counterparts, and the length scale of these liquidlike correlations is also shorter in flexible chains. (C) 2000 American Institute of Physics. [S0021-9606(00)51537-2].