ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
In a previous paper [M. Lozada-Cassou, J. Chem. Phys. 80, 3344 (1984)], we have proposed a three point extension for integral equation theories. Here we apply our formalism to the interaction of two charged plates of infinite extension, immersed in an electrolyte, and solve the three point extension to the hypernetted chain/mean spherical theory. We calculate the ionic profile around the plates and the pressure between the plates, as a function of distance between them, for a 1:1 and 2:2 electrolyte for different concentrations and potentials on the plates. We compare our results with the Verwey–Overbeek (VO) theory. We find excellent agreement with the VO theory for low potentials and concentrations. However, there is qualitative disagreement for higher potentials and/or concentrations. The interaction force between the plates becomes attractive at a sufficiently high potential and/or concentration. Since the VO force is always repulsive, in our theory the attraction is a consequence of the ionic size. As one would expect from an electrostatically correct theory, the charge on the plates depends on the distance between the plates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.458128
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