Influence of the Dukhin and Reynolds numbers on the apparent zeta potential of granular porous media - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Journal of Colloid and Interface Science Year : 2007

Influence of the Dukhin and Reynolds numbers on the apparent zeta potential of granular porous media

Abstract

The Helmholtz–Smoluchowski (HS) equation is widely used to determine the apparent zeta potential of porous materials using the streaming potential method. We present a model able to correct this apparent zeta potential of granular media of the influence of the Dukhin and Reynolds numbers. The Dukhin number represents the ratio between the surface conductivity (mainly occurring in the Stern layer) and the pore water conductivity. The Reynolds number represents the ratio between inertial and viscous forces in the Navier–Stokes equation. We show here that the HS equation can lead to serious errors if it is used to predict the dependence of zeta potential on flow in the inertial laminar flow regime without taking into account these corrections. For indifferent 1:1 electrolytes (such as sodium chloride), we derived two simple scaling laws for the dependence of the streaming potential coupling coefficient (or the apparent zeta potential) on the Dukhin and Reynolds numbers. Our model is compared with a new set of experimental data obtained on glass bead packs saturated with NaCl solutions at different salinities and pH. We find fairly good agreement between the model and these experimental data.

Dates and versions

insu-00404275 , version 1 (16-07-2009)

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Cite

Agnès Crespy, Alexandre Boleve, André Revil. Influence of the Dukhin and Reynolds numbers on the apparent zeta potential of granular porous media. Journal of Colloid and Interface Science, 2007, 305 (1), pp.188 à 194. ⟨10.1016/j.jcis.2006.09.038⟩. ⟨insu-00404275⟩
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