Interfacial behavior in polyelectrolyte blends: Hybrid liquid-state integral equation and self-consistent field theory study

Polyelectrolytes and electrolyte solutions are known to demonstrate a rich array of phase behaviors due to the effects of long-ranged interactions inherent in Coulombic attractions and repulsions. While there is a wealth of literature examining these materials to provide some physical insight into their thermodynamics, all of these methods make strong approximations with regards to the nature of the ionic component. In this investigation we develop a hybrid liquid-state integral equation and self-consistent field theory numerical theory, and systematically demonstrate the ramifications on local ion structure on the overall thermodynamics of segregated polymer blends. We show effects on phase separation such as suppression due to hard sphere interactions and enhancement due to ion cohesion that are not described using traditional Poisson-Boltzmann mean-field theory.