INFLUENCE OF POLYDISPERSITY ON RANDOM SEQUENTIAL ADSORPTION OF SPHERICAL-PARTICLES

Random sequential adsorption (RSA) of polydisperse mixtures of hard an d interacting spherical particles was analyzed. Theoretical results we re derived by performing numerical MC simulations both for Gaussian an d for continuous distributions of particle sizes characterized by stan dard deviations below 20%. Adsorption kinetics of these mixtures was d etermined for a broad range of times showing that for tau < 5 the infl uence of polydispersity was rather minor for both Gauss and continuous particle size distributions. More significant deviations were predict ed for the asymptotic adsorption regime close to jamming. In the case of continuous distributions this limiting kinetics could be described by the power law dependence theta(infinity) - theta similar to tau(-1/ 3) in accordance with the predictions of G. Tarjus and J. Talbot (1991 , J. Phys. Math Gen. 24, L913). The jamming concentration theta(infini ty) for hard (noninteracting) particles was found to increase proporti onally to <(sigma)over bar>. It was also shown that the polydispersity of particle mixtures can exert an effect on the structure of the adso rption layer (characterized in terms of the pair correlation function) . The broadening of this function was confirmed experimentally by usin g colloid suspensions of spherical particles (polystyrene latex) chara cterized by <(sigma)over bar> = 6-10%. (C) 1997 Academic Press