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 n ot possible, because three interplaying relevant length scales are inv olved, i.e., the Debye screening length and the Pincus blob size. Ther efore a self-consistent computation of an effective variational propag ator is employed. It is shown that the elastic force as a function f o f the distance R behaves as f proportional to R for small f. For large r forces we find a new regime, characterized by deformations larger th an a computed electrostatic ''blob size''. These results are supported by simulations and intuitive physical arguments.