(524a) Conformations of Weak Polyelectrolytes in Confined Geometries

Recently designed charge-rejection and mosaic membranes hold exceptional promise for low-power water purification and material reclamation. The use of polyelectrolyte brushes and oligomeric grafts is key to controlling the behavior of these systems. Importantly, the surface charge on the interior of these membranes is controlled by the interplay between adhesive molecular interactions, pH, salt content, and polymer density. I will discuss the use of coarse-grained constant-pH molecular dynamics simulations for simulating the charging equilibrium and conformational changes in weak polyelectrolytes, with an explicit focus on confined polyelectrolyte chains and brushes. We demonstrate that the increased monomer densities and reduced chain entropy present in confinement can have significant effects on the apparent dissociation constant of a weak acid groups in a polymer chain.