Novel Dynamical behaviors of charged Macromolecules in a crowded environment

The phenomenon of “ordinary-extraordinary” dynamical transition in salt-free polyelectrolyte solutions is well known. We report the emergence of additional dynamical mode at higher molecular weights of the polyelectrolyte. We find that the key variable Cp/Cs, which is normally used in describing the onset of the ordinary-extraordinary transition (fast and slow modes), is inadequate in describing the dynamics of polyelectrolyte solutions. For concentrated solutions of sodium polystyrene sulfonate of higher molecular weights, we observe a third intermediate mode. The emergence of the new mode depends crucially on the polymer molecular weight and the concentration of the added salt. We find that Cp/C* (where C* is overlap concentration) is a key variable in addition to Cp/Cs.