The effect of added salt on polyelectrolyte structure

We present results of molecular dynamics simulations of strong, flexible polyelectrolyte chains in solution with added salt. The effect of added salt on the polyelectrolyte chain structure is fully treated for the first time as a function of polymer density. Systems above and below the Manning condensation limit are studied. The chain structure is intimately tied to the ion density near the chain even for chains in the counterion condensation (CC) regime. The end-to-end distance is demonstrated to be a function of the inverse Debye screening length and the Bjerrum length. The ion density near the polymer chain depends on the amount of added salt, and above the condensation limit the chains significantly contract due to added salt.