Diffusion in charge stabilized colloidal suspensions: from short- to long-time regime

ADOLFO J. BANCHIO; MARCO HEINEN; PETER HOLMQVIST; GERHARD NÄGELE

San Luis Potosi

Workshop; 1st International Workshop on Matter Out of Equilibrium; 2014

Univ. Autonoma de Mexico, Univ. Autonoma de San Luis Potosi, Univ. de Guanajuato, Mesoamerican Center for Theoretical Physics, American Physical Society

Collective and self-difusion in concentrated suspensions of charge-stabilized colloidal spheres are ex-tensively studied. Theoretical calculations, from mode-coupling theory and simulations are confrontedwith experimental results. Correlation times ranging from colloidal short-time to long-time regime areconsidered. The intermediate, and self-intermediate scattering functions, the mean square displacement,and other dynamic quantities, are calculated by accelerated Stokesian Dynamics (ASD) simulations wheremany-body hydrodynamic interactions (HIs) are included, and additionally Brownian Dynamics (BD)simulations and mode-coupling theory (MCT) calculations without HIs included. On the basis of thisresults, the in uence of HIs on the dynamics, and the accuracy of the MCT method are analized. In the-ory and simulation, the spheres are assumed to interact directly by a hard-core plus screened Coulombeffective pair potential. The system size corrected dynamic scattering functions obtained in the ASDsimulations are in decent accord with our dynamic light scattering (DLS) data for a concentration seriesof charged silica spheres in an organic solvent mixture, within the experimentally accessed time window.We hereby provide a full overview on diffusion processes in charge-stabilized suspensions.