KINETICS OF IRREVERSIBLE ADSORPTION OF NONSPHERICAL PARTICLES

Kinetics of localized adsorption of interacting nonspherical particles on homogeneous interfaces was analysed theoretically. By applying the random sequential adsorption (RSA) approach the asymptotic expression s were derived for the surface blocking parameter B in the limit of lo w and moderate surface concentrations. In order to simplify the cumber some analysis of electrostatically interacting particles the concept o f the equivalent hard particle was introduced. It was demonstrated tha t the surface blocking effects become especially important for elongat ed particles having the width to length ratio (aspect ratio = A) small er than 0.5. The range of validity of the approximate analytical resul ts was determined by numerical simulations of adsorption kinetics perf ormed for cubes, cylinders and spheroids using the Monte Carlo (MC) si mulation technique. These ''exact'' numerical results valid for arbitr ary adsorption times demonstrated that the analytical approximation ca n be used with a good accuracy for surface concentrations smaller than 20%. It was also revealed that adsorption kinetics of interacting col loid particles deviates considerably from the Langmuir model, especial ly for low ionic strength of the suspension and elongated particles.