Influence of the cross-linker reactivity on the formation of inhomogeneities in hydrogels

Polyacrylamide hydrogels cross-linked with different types and concentrations of crosslinkers were prepared and characterized by means of static light scattering and elasticity measurements. Big differences in the excess light scattering revealed different tendencies of the networks to form polymer agglomerations and inhomogeneities. Furthermore, the efficiency of the cross-linking reaction changed with the type of cross-linker chosen. A correlation between these two properties has been observed and attributed to the different reactivities of the cross-linker molecules.