Deswelling Dynamics of Chemically-Active Polyelectrolyte Gels.

Ion-induced volume phase transitions in polyelectrolyte gels play an important role in physiological processes such as mucus storage and secretion in the gut, nerve excitation, and DNA packaging. Experiments have shown that changes in ionic composition can trigger rapid swelling and deswelling of these gels. Based on a previously developed computational model, we carry out 2D simulations of gel deswelling within an ionic bath. The dynamics of the volume phase transition are governed by the balance of chemical and mechanical forces on components of the gel. Our simulation results highlight the close connections between the patterns of deswelling, the ionic composition, and the relative magnitude of particle-particle interaction energies.