KINETICS OF POLYELECTROLYTE ADSORPTION

The kinetics of polyelectrolyte adsorption has been investigated theor etically. In analogy with Kramers' rate theory for chemical reactions we present a model which is based on the assumption that a polyelectro lyte encounters a barrier in its motion towards an adsorbing surface. The height of the barrier, which is of electrostatic origin, is calcul ated with a self-consistent-field (SCF) model. The salt concentration strongly affects the height of the barrier. At moderate salt concentra tions (similar to 0.2 mol l(-1)) equilibrium in the adsorption is atta ined; at low salt concentration (similar to 0.01 mol l(-1)) equilibriu m is not reached on the time scale of experiments. The attachment proc ess shows resemblances to the classical DLVO theory.