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Depletion potentials near geometrically structured substrates

P. Bryk·R. Roth·M. Schoen·S. Dietrich
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Abstract

Using the recently developed so-called White Bear version of Rosenfeld's Fundamental Measure Theory we calculate the depletion potentials between a hard-sphere colloidal particle in a solvent of small hard spheres and simple models of geometrically structured substrates: a right-angled wedge or edge. In the wedge geometry, there is a strong attraction beyond the corresponding one near a planar wall that significantly influences the structure of colloidal suspensions in wedges. In accordance with an experimental study, for the edge geometry we find a free energy barrier of the order of several $k_B T$ which repels a big colloidal particle from the edge.

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P. Bryk, R. Roth, M. Schoen, S. Dietrich. 2003-03-07. Depletion potentials near geometrically structured substrates. https://doi.org/10.1209/epl%2Fi2003-00517-6

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