A comparative study on the effect of hydrodynamic interactions in the non-sequential deposition of concentrated colloidal dispersions: stochastic rotation dynamics and Brownian dynamics simulations

Irreversible adsorption of particles onto a flat surface as a consequence of sedimentation colloidal suspension has been studied by two simulation techniques: Brownian dynamics (BD) and stochastic rotation dynamics (SRD). The purpose of using both methods is to investigate the effect of hydrodynamic interactions on adsorption kinetics and structure of the first monolayer of sediment obtained from the sedimentation of a concentrated and monodisperse colloidal suspension. Three systems were studied, characterised by the Péclet numbers: 0.1, 1.0 and 10. To physically understand the kinetic behaviour, simulation results were analysed using a kinetic model based on chemical reactions. High values of jamming limit (θ_∞ > 0.61) were obtained for both simulation techniques, with the SRD showing the highest figures (0.631) due to the hydrodynamics effect that takes into account the fluid backflow produced on particle sedimentation. A two-step adsorption mechanism was proposed based on the observed kinetic behaviour.