KINETICS OF LOCALIZED ADSORPTION OF COLLOID PARTICLES

Kinetics of localized adsorption of charged colloid particles on homogeneous solid/liquid interfaces was analyzed. Limiting analytical equations were formulated for the maximum surface concentration theta(mx), the blocking parameter B(theta), and adsorption kinetics in terms of the lateral interaction parameter h* depending on the ionic strength of the colloid suspension. In the general case particle adsorption kinetics proceeding according to the random sequential adsorption (RSA) mechanism was simulated numerically by using the Monte Carlo method. The theoretical predictions were experimentally tested by applying the direct observation method based on the stagnation point flow cell. Monodisperse suspensions of negatively charged latex particles of micrometer size range were used with freshly cleaved mica sheets as the adsorbing surfaces. The theoretical predictions were quantitatively confirmed showing that the RSA model describes well the kinetics of localized adsorption of interacting colloid particles especially for higher flow intensity. The widely used Langmuir model was found inappropriate for colloid particle adsorption from liquid phases.