Adsorption kinetics of complexes formed by oppositely charged polyelectrolytes

The objective of this study is to gain an understanding of the kinetics of adsorption of complexes formed in aqueous solution by oppositely charged po lyelectrolytes. The properties of the complexes were characterized by means of dynamic light scattering and electrophoretic mobility and the reaction stoichiometry was studied by titration. The stoichiometry in the complexes depends on the polymer weight ratio w(p). Their point of zero charge (pzc) is shifted toward lower w(p) when simple cations of higher valence are adde d to the solution. The adsorption kinetics of the complexes on silica was s tudied by stagnation point reflectometry. The sign of charge of the complex es as well as the valence and concentration of simple cations governs the o ccurrence of adsorption in the electrolytes studied. Five different types o f adsorption kinetics were found, (C) 2001 Academic Press.