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.
Original language | English |
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Article number | 494219 |
Journal | Journal of Physics: Condensed Matter |
Volume | 20 |
Issue number | 49 |
DOIs | |
Publication status | Published - 10 Dec 2008 |
ASJC Scopus subject areas
- Condensed Matter Physics
- General Materials Science