ELASTICITY IN STRONGLY INTERACTING SOFT SOLIDS - A POLYELECTROLYTE NETWORK

This paper discusses the elastic behavior of a very long cross-linked polyelectrolyte chain (Debye-Huckel chain), which is weakly charged. T herefore the response of;the cross-linked chain (network)on an externa l constant force f acting on the ends of the chain is considered. A se lf-consistent variational computation of an effective field theory is employed. It is shown that the modulus of the polyelectrolyte network has two parts: the first term represents the usual entropy elasticity of connected flexible chains and the second term takes into account th e electrostatic interaction of the monomers. It is proportional to the squared cross-link density and the Debye-screening parameter.