Conductivity of Concentrated Electrolytes

Abstract

The conductivity of ionic solutions is arguably their most important trait, being widely used in electrochemical, biochemical, and environmental applications. The Debye-Hückel-Onsager theory successfully predicts the conductivity at very low ionic concentrations of up to a few millimolars, but there is no well-established theory applicable at higher concentrations. We study the conductivity of ionic solutions using a stochastic density functional theory, paired with a modified Coulomb interaction that accounts for the hard-core repulsion between the ions. The modified potential suppresses unphysical, short-range electrostatic interactions, which are present in the Debye-Hückel-Onsager theory. Our results for the conductivity show very good agreement with experimental data up to 3 molars, without any fit parameters. We provide a compact expression for the conductivity, accompanied by a simple analytical approximation.

References in corpus (3)

• The Electrostatic Screening Length in Concentrated Electrolytes Increases with Concentration
• Scaling analysis of the screening length in concentrated electrolytes
• Glasslike Behavior in Aqueous Electrolyte Solutions

Cited by in corpus (7)

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• Conductance of concentrated electrolytes: multivalency and the Wien effect
• Perspective: New directions in dynamical density functional theory
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• Diffusion of a tracer in a dense mixture of soft particles connected to different thermostats
• Electric-field-induced oscillations in ionic fluids: a unified formulation of modified Poisson-Nernst-Planck models and its relevance to correlation function analysis
• Fluctuating hydrodynamics of dilute electrolyte solutions: systematic perturbation calculation of effective transport coefficients governing large-scale dynamics