  The study of competitive and cooperative adsorption of functionalized
molecules such as polymers, rheology modifiers and surfactant molecules on
colloidal particles immersed in a solvent is undertaken using coarse grained,
dissipative particle dynamics simulations. The results show that a complex
picture emerges from the simulations, one where dispersants and surfactants
adsorb cooperatively up to certain concentrations, on colloidal particles, but
as the surfactant concentration increases it leads to dispersant desorption.
The presence of rheology modifying agents in the colloidal dispersion adds
complexity through the association of surfactant micelles to hydrophobic sites
of these agents. Analysis of the simulation results reported here point clearly
to the self association of the hydrophobic sites along the different polymer
molecules as the mechanism responsible for their competitive and cooperative
adsorption.
