Inclusion of the concentration dependence of the diffusion coefficient in the sand equation
- Authors: Dammak L.1, Larchet C.1, Nikonenko V.V.2, Mareev S.A.2, Butyl’skii D.Y.2, Kovalenko A.V.2, Pis’menskaya N.D.2
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Affiliations:
- Institut de Chimie et des Matériaux Paris-Est, UMR 7182 CNRS-
- Kuban State University
- Issue: Vol 52, No 10 (2016)
- Pages: 996-1000
- Section: Short Communications
- URL: https://journals.rcsi.science/1023-1935/article/view/188222
- DOI: https://doi.org/10.1134/S1023193516100098
- ID: 188222
Cite item
Abstract
The applications of the Sand equation in potentiometry of electrode and membrane systems for precise measurements of the transition time (τ) have been determined. An approach was suggested for choosing the diffusion coefficient of electrolyte (D) in the case when the concentration changes from its value in the agitated solution (where D = Db) to the nearly zero value at the surface (D = D0 corresponds to an infinitely dilute solution), Db and D0 being substantially different. The Nernst–Planck–Poisson nonstationary equations were numerically solved in a one-dimensional system including an ion-exchange membrane and two adjacent diffusion layers (for the electrode–solution system, the result is a particular case). An effective value Def was found, whose substitution in the Sand equation gave τ identical to that obtained by numerical solution. The neglect of the concentration dependence D(с) can lead to a nonadequate determination of the ion transport numbers in the membrane.
Keywords
About the authors
L. Dammak
Institut de Chimie et des Matériaux Paris-Est, UMR 7182 CNRS-
Email: nikon@chem.kubsu.ru
France, Rue Henri Dunant 2, Thiais, 94320
C. Larchet
Institut de Chimie et des Matériaux Paris-Est, UMR 7182 CNRS-
Email: nikon@chem.kubsu.ru
France, Rue Henri Dunant 2, Thiais, 94320
V. V. Nikonenko
Kuban State University
Author for correspondence.
Email: nikon@chem.kubsu.ru
Russian Federation, ul. Stavropol’skaya 149, Krasnodar, 350040
S. A. Mareev
Kuban State University
Email: nikon@chem.kubsu.ru
Russian Federation, ul. Stavropol’skaya 149, Krasnodar, 350040
D. Yu. Butyl’skii
Kuban State University
Email: nikon@chem.kubsu.ru
Russian Federation, ul. Stavropol’skaya 149, Krasnodar, 350040
A. V. Kovalenko
Kuban State University
Email: nikon@chem.kubsu.ru
Russian Federation, ul. Stavropol’skaya 149, Krasnodar, 350040
N. D. Pis’menskaya
Kuban State University
Email: nikon@chem.kubsu.ru
Russian Federation, ul. Stavropol’skaya 149, Krasnodar, 350040