Charging Behavior of Associating Weak Polyelectrolytes

Weak polyelectrolytes are useful in the creation of “smart” materials for separations and drug delivery. The charges on weak polyelectrolytes are dynamic and sensitive to the surroundings, causing polymer chains to behave differently depending on the acidity and salinity of their environment. In this study, we utilize a hybrid Monte Carlo/Molecular Dynamics formalism to elucidate a novel interplay between weak polyelectrolyte charging and polyion complexation, where associative effects can induce larger than expected charging to weak polyelectrolyte systems. We discuss the implications of these results for materials formed by oppositely charged polymers such as layer-by-layer films and complex coacervates, and how this might affect the performance of these materials.