(523f) Dynamic Regimes in Entangled Asymmetric Coacervates with Added Salt

Mixtures of oppositely charged polyelectrolytes can phase separate to form a polymer rich phase called a coacervate, which has applications the consumer products and pharmaceutical industries, among others. In coacervates made from polyelectrolytes of high molecular weight, topological constraints known as entanglements alter the dynamic properties and can be due to either the polyanion, the polycation or both. In linear charge density asymmetric coacervates, the high lienar charge density and low linear charge density polymers have qualitatively different conformations resulting in several dynamic regimes that depend on which polymer is entangled. Adding salt to the coacervate modifies the coacervate concentration, which in turn alters entanglements and the coacervate dynamic regime. We develop a scaling theory to predict the dynamics of entangled liquid coacervates with added salt, finding that in strongly asymmetric coacervates addition of salt leads the high charge density polymer to transition from semiflexible to flexible entanglement regimes. We discuss how salt concentration modifies the dynamic regime of asymmetric coacervates and provide predictions for coacervate viscosity and other dynamic properties. The theory provides a method to design dynamic properties of asymmetric coacervates without ion binding.