Fluctuating Hydrodynamics and Debye-H\"uckel-Onsager Theory for Electrolytes

TL;DR

This paper applies fluctuating hydrodynamics to electrolyte mixtures to derive concentration corrections for key properties, aligning with classical theories and explaining experimental observations of negative diffusion coefficients.

Contribution

It introduces a novel application of fluctuating hydrodynamics to electrolytes, deriving explicit corrections consistent with Debye-Hückel-Onsager theory.

Findings

Corrections agree with classical limiting laws

Co-ion Maxwell-Stefan diffusion coefficients can be negative

Explicit corrections computed for symmetric ternary mixtures

Abstract

We apply fluctuating hydrodynamics to strong electrolyte mixtures to compute the concentration corrections for chemical potential, diffusivity, and conductivity. We show these corrections to be in agreement with the limiting laws of Debye, H\"uckel, and Onsager. We compute explicit corrections for a symmetric ternary mixture and find that the co-ion Maxwell-Stefan diffusion coefficients can be negative, in agreement with experimental findings.