[11][12][13]
. These models are expected to describe real situa-Random sequential adsorption (RSA) of polydisperse mixtures tions only when the electrostatic interactions among adof hard and interacting spherical particles was analyzed. Theoretisorbed and adsorbing particles (called often lateral interaccal results were derived by performing numerical MC simulations tions) are effectively reduced due to the addition of concenboth for Gaussian and for continuous distributions of particle sizes trated electrolytes.
characterized by standard deviations below 20%. Adsorption ki-
In general, however, these electrostatic interactions play netics of these mixtures was determined for a broad range of times a significant role in influencing both the kinetic and the showing that for t õ 5 the influence of polydispersity was rather structural aspects of colloid particle adsorption (3, 4). Then, minor for both Gauss and continuous particle size distributions. More significant deviations were predicted for the asymptotic ad-more elaborate RSA models, using the effective hard particle sorption regime close to jamming. In the case of continuous districoncept, become appropriate (14, 15).
butions this limiting kinetics could be described by the power law
Experiments verifying the theoretical predictions stemdependence u ϱ 0 u Ç t 01/3 in accordance with the predictions of ming from the RSA and related models were performed G. Tarjus and J. Talbot (1991, J. Phys. Math Gen. 24, L913). The using colloid particle suspensions in micrometer size ranges jamming concentration u ϱ for hard (noninteracting) particles was suitable for direct microscope observations (3, 4). These found to increase proportionally to s V . It was also shown that the involved polystyrene latexes of negatively and positively polydispersity of particle mixtures can exert an effect on the struccharged particles (14, 16-17) or melamine latex of amphoture of the adsorption layer (characterized in terms of the pair teric character (18, 19). Although the main features of the correlation function). The broadening of this function was confirmed experimentally by using colloid suspensions of spherical RSA model were confirmed, no estimation was done on the particles (polystyrene latex) characterized by s V Å 6-10%. ᭧ 1997 role of polydispersity of the colloid suspensions, which was Academic Press
of the order of 5-15% (expressed in terms of the standard Key Words: adsorption on polydisperse particles; kinetics of pardeviation s of the corresponding particle size distribution).