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arXiv · 1101.4396

First-order virial expansion of short-time diffusion and sedimentation coefficients of permeable particles suspensions

Bogdan Cichocki·Maria L. Ekiel-Jezewska·G. Naegele·E. Wajnryb
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Abstract

For suspensions of permeable particles, the short-time translational and rotational self-diffusion coefficients, and collective diffusion and sedimentation coefficients are evaluated theoretically. An individual particle is modeled as a uniformly permeable sphere of a given permeability, with the internal solvent flow described by the Debye-Bueche-Brinkman equation. The particles are assumed to interact non-hydrodynamically by their excluded volumes. The virial expansion of the transport properties in powers of the volume fraction is performed up to the two-particle level. The first-order virial coefficients corresponding to two-body hydrodynamic interactions are evaluated with very high accuracy by the series expansion in inverse powers of the inter-particle distance. Results are obtained and discussed for a wide range of the ratio, x, of the particle radius to the hydrodynamic screening length inside a permeable sphere. It is shown that for x >= 10, the virial coefficients of the transport properties are well-approximated by the hydrodynamic radius (annulus) model developed by us earlier for the effective viscosity of porous-particle suspensions.

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Bogdan Cichocki, Maria L. Ekiel-Jezewska, G. Naegele, E. Wajnryb. 2011-01-23. First-order virial expansion of short-time diffusion and sedimentation coefficients of permeable particles suspensions. https://doi.org/10.1063/1.3626196

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