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Field theoretic calculation of the surface tension for a model electrolyte system

D. S. Dean·R. R. Horgan
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Abstract

We carry out the calculation of the surface tension for a model electrolyte to first order in a cumulant expansion about a free field theory equivalent to the Debye-Hückel approximation. In contrast with previous calculations, the surface tension is calculated directly without recourse to integrating thermodynamic relations. The system considered is a monovalent electrolyte with a region at the interface, of width h, from which the ionic species are excluded. In the case where the external dielectric constant epsilon_0 is smaller than the electrolyte solution's dielectric constant epsilon we show that the calculation at this order can be fully regularized. In the case where h is taken to be zero the Onsager-Samaras limiting law for the excess surface tension of dilute electrolyte solutions is recovered, with corrections coming from a non-zero value of epsilon_0/epsilon.

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D. S. Dean, R. R. Horgan. 2003-11-07. Field theoretic calculation of the surface tension for a model electrolyte system. https://doi.org/10.1103/physreve.69.061603

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