On-line study of polyelectrolyte network formation by interfacial reaction

A modified synthetic boundary experiment of analytical ultracentrifugation has been employed to examine, on-line, polyelectrolyte complex formation at flat interfaces yielding highly swollen membranes/networks. Systematic experiments with sodium alginate as a polyanion and chitosan and poly(l-lysine) as polycations identified the influence of concentration, pH, molar mass, and polycation type on the membrane characteristics and the formation process. The membranes have been evaluated by five characteristics defined herein: total thickness, compactness, heterogeneity, symmetry, and growth. The results confirm the sensitivity of the method suited to elaborate general relationships for polyelectrolyte membrane design.