| Numéro |
J. Phys. II France
Volume 4, Numéro 4, April 1994
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|
|---|---|---|
| Page(s) | 555 - 560 | |
| DOI | https://doi.org/10.1051/jp2:1994146 | |
DOI: 10.1051/jp2:1994146
J. Phys. II France 4 (1994) 555-560
High Magnetic Field Laboratory, Max-Planck Institut für Festkörperforschung and Centre National de la Recherche Scientifique, B.P. 166, F-38042 Grenoble Cedex 9, France
© Les Editions de Physique 1994
J. Phys. II France 4 (1994) 555-560
Friction coefficient of rod-like chains of spheres at very low Reynolds numbers. I. Experiment
K. Zahn, R. Lenke and G. MaretHigh Magnetic Field Laboratory, Max-Planck Institut für Festkörperforschung and Centre National de la Recherche Scientifique, B.P. 166, F-38042 Grenoble Cedex 9, France
(Received 30 November 1993, received in final form 11 February 1994, accepted 18 February 1994)
Abstract
We present a new method to measure hydrodynamic friction forces on colloidal particles at very low (
) Reynolds numbers with high accuracy. Exploiting magnetic field induced aggregation of microscopic paramagnetic spheres into
straight chains of calibrated length, we determine the anisotropic friction coefficient of the chains, with a range from one
to 100 particles, by video-microscopic observation of sedimentation speed. The results are found to agree well with the Slender-body
theory, even for small chain lengths. The effects of the proximity of a wall are also explored.
© Les Editions de Physique 1994