Brownian dynamics in a confined geometry. Experiments and numerical simulations
Résumé
The Brownian dynamics of a colloidal suspension is measured in the immediate vicinity of a rigid surface by the Evanescent Quasielastic Light Scattering Technique. A net decrease of the measured diffusion coefficient is observed, due to the hydrodynamic slowing down of the particles very close to the wall. This effect is all the more important when the particles are allowed to get closer to the wall, i.e. when the range of the static wall/particle repulsive interaction decreases. It thus provides a mean for testing the particle/wall static interactions via a dynamic light scattering measurement. The data are analysed by a Brownian dynamic simulation which is proven to be quite valuable to interpret light scattering data from “hindered" scatterers, such as particles confined in the neighbourhood of a wall or trapped in a porous media or a gel.
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Articles anciensOrigine | Accord explicite pour ce dépôt |
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