STRUCTURE OF POLYELECTROLYTE HYDROGELS STUDIED BY SANS

The structure of hydrogels based on sodium polyacrylate and crosslinke d by different low- and high-molecular-weight compounds is studied by small-angle neutron scattering (SANS). It is shown that the size of he terogeneities in the vicinity of crosslinking junctions does not depen d on the molecular weight of the polyfunctional crosslinking agents us ed. The dependence of heterogeneity dimensions on the gel concentratio n (or degree of swelling) was measured. It showed a maximum which was interpreted by analogy to the concentration behaviour of specific visc osity of polyelectrolyte solutions. Copyright (C) 1996 Elsevier Scienc e Ltd.