On the Elastic Behavior of a Single Polyelectrolyte Chain

This paper discusses the elastic behavior of a single polyelectrolyte chain. A simple scaling analysis as in self avoiding walk chains are not possible, because three interplaying relevant length scales are involved, i.e., the Debye screening length and the Pincus blob size. Therefore a self-consistent computation of an effective variational propagator is employed. It is shown that the elastic force as a function f of the distance R behaves as f R for small f. For larger forces we find a new regime, characterized by deformations larger than a computed electrostatic blob size. These results are supported by simulations and intuitive physical arguments.