Deposition of latex particles at heterogeneous surfaces

Irreversible adsorption (deposition) of colloid particles at heterogeneous surfaces was studied experimentally. The substrate surfaces of desired heterogeneity were produced by covering mica surfaces by positively charged polystyrene latex particles. Then, deposition kinetics of negatively charged latex was studied under diffusion-controlled transport conditions. Particle distributions over surfaces and coverage were quantitatively evaluated using the direct microscope observation technique. Using this method, jamming coverage of colloid particles as a function of the heterogeneity degree (smaller particle coverage) was determined. These experimental data confirmed, in accordance with numerical simulations that the adsorption site multiplicity exerted a pronounced effect on the structure of adsorbed layers and the jamming coverage. (C) 2004 Elsevier B.V. All rights reserved.