Kinetics of sedimentation in colloidal suspensions
Research output: Contribution to journal › Article › peer-review
Authors
Colleges, School and Institutes
External organisations
- Politecnico di Milano
- Harvard University
Abstract
Measuring the concentration profiles induced by gravity settling is known to be an efficient route to obtain the equation of state of a colloidal suspension, to inspect the fine details of the phase diagram and to provide clues on the nature of metastable phases. Here we show that a careful analysis of the transient settling profiles may add valuable information for what concerns colloidal hydrodynamics. In particular, we show that a numerical inversion of a kinetic profile yields the full hydrodynamic factor K(Φ) up to the concentration of the original unsettled suspension, and that the dilute part of the profile yields a 'dynamic' gravitation length also related to K(Φ). These predictions are tested on a suspension of monodisperse hard and sticky spheres. Finally we describe and test a novel optical method, allowing us to measure sedimentation profiles on a wide class of colloidal systems, even in the presence of a noticeable turbidity.
Details
Original language | English |
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Article number | 494219 |
Journal | Journal of Physics: Condensed Matter |
Volume | 20 |
Issue number | 49 |
Publication status | Published - 10 Dec 2008 |