KINETICS OF LOCALIZED ADSORPTION OF PARTICLES ON HOMOGENEOUS SURFACES

The kinetics of localized, irreversible adsorption of particles interacting via exponentially decaying repulsive potentials on homogeneous interfaces was analyzed. Asymptotic analytical equations were derived for the surface blocking parameter B(0) and adsorption kinetics in the limit of low and high surface concentrations. In the general case, particle adsorption kinetics was simulated numerically for various values of the characteristic range of the interaction potential. Based on these calculations, a new fitting function was derived describing adsorption kinetics for long times in terms of the maximum surface concentration 0mx. Theoretical predictions were experimentally tested by applying the direct observation method based on the stagnation point flow cell. Suspensions of monodisperse latex particles, both positively and negatively charged, were used with mica sheets as the adsorbing surfaces. The experiments performed for various bulk particle concentrations and ionic strengths were in a good agreement with theoretical predictions. They confirmed also the validity of the proposed fitting functions for describing adsorption kinetics of interacting particles for the entire range of the surface concentrations. © 1992.