Effects of interparticle attractions on colloidal sedimentation.

We use a mesoscopic simulation technique to study the effect of short-ranged interparticle attractions on the steady-state sedimentation of colloidal suspensions. Attractions increase the average sedimentation velocity v(s) compared to the pure hard-sphere case, and for strong enough attractions, a...

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Bibliographic Details
Main Authors: Moncho-Jordá, A, Louis, A, Padding, J
Format: Journal article
Language:English
Published: 2010
Description
Summary:We use a mesoscopic simulation technique to study the effect of short-ranged interparticle attractions on the steady-state sedimentation of colloidal suspensions. Attractions increase the average sedimentation velocity v(s) compared to the pure hard-sphere case, and for strong enough attractions, a nonmonotonic dependence on the packing fraction phi with a maximum velocity at intermediate phi is observed. Attractions also strongly enhance hydrodynamic velocity fluctuations, which show a pronounced maximum size as a function of phi. These phenomena arise from a complex interplay between nonequilibrium hydrodynamic effects and the thermodynamics of transient cluster formation.