title: Colloidal Swarms Can Settle Faster than Isolated Particles: Enhanced Sedimentation near Phase Separation.
abstract: By experimenting on model colloids where depletion forces can be carefully tuned and quantified, we show that attractive interactions consistently "promote" particle settling, so much that the sedimentation velocity of a moderately concentrated dispersion can even exceed its single-particle value. At larger particle volume fraction ϕ, however, hydrodynamic hindrance eventually takes over. Hence, v(ϕ) actually displays a nonmonotonic trend that may threaten the stability of the settling front to thermal perturbations. Finally, by discussing a representative case, we show that these results are relevant to the investigation of protein association effects by ultracentrifugation.
authors: Department of Chemistry, Material Science, and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Enrico
authors: E
authors: Lattuada
authors: Department of Chemistry, Material Science, and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Stefano
authors: S
authors: Buzzaccaro
authors: Department of Chemistry, Material Science, and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Roberto
authors: R
authors: Piazza