(475e) Effect of Salt on Diffusion of Polyelectrolyte in Polyelectrolyte Coacervates

The dynamics of polyelectrolyte chains in polyelectrolyte complexes and coacervates is of interest for many applications ranging from health to personal care. The dynamics and phase behavior of polyelectrolyte complexes is influenced by salt. Previously, time-salt superposition has been applied to show equivalency between salt and temperature. Additionally, previous works have shown that the diffusion coefficient of polyelectrolyte in polyelectrolyte multilayers (PEMs) increases with increase in salt concentration. However, information is lacking on how the polyelectrolyte relaxes in polyelectrolyte coacervates and how the diffusion of polyelectrolyte is related to the diffusion of counterions. Here, we study the effect of salt (2.5 – 4.0 M NaBr) on individual diffusion coefficient of poly[sodium 4-styrene sulphonate] (PSS) and poly[(vinylbenzyl) trimethylammonium chloride] (PVBTMA) in PSS-PVBTMA coacervates using fluorescence recovery after photobleaching (FRAP). The mean diffusion coefficient of counterions within the coacervates was measured by performing time-dependent conductivity measurements. Due to the high water content, the diffusion of counterions within the coacervate phase remains constant. The diffusion of polyelectrolyte is related to the polymer and water content within the coacervate phase.