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 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.
Moncho-Jordá
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Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Granada, Campus Fuentenueva S/N, 18071 Granada, Spain.
Louis
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D003102:Colloids / Q000737:chemistry*; D013535:Suspensions; D013997:Time Factors
D003102:Colloids; D013535:Suspensions