Conductance of concentrated electrolytes: multivalency and the Wien effect

Abstract

The electric conductivity of ionic solutions is well understood at low ionic concentrations of up to a few millimolar but becomes difficult to unravel at higher concentrations that are still common in nature and technological applications. A model for the conductivity at high concentrations was recently put forth for monovalent electrolytes at low electric fields. The model relies on applying a stochastic density-functional theory and using a modified electrostatic pair-potential that suppresses unphysical, short-range electrostatic interactions. Here, we extend the theory to multivalent ions as well as to high electric fields where a deviation from Ohm's law known as the Wien effect occurs. Our results are in good agreement with experiments and recent simulations.

Perspective: New directions in dynamical density functional theory

“…Also apart from RDDFT, quite a number of recent applications of DDFT come from chemistry and chemical physics, broadly construed. In particular, DDFT has been used in electrochemistry to model systems and processes such as charging of electric double layers [78,79] and supercapacitors [80,81], counterions [82], dielectricity [83,84], electrolytes [85][86][87][88][89][90], impedance response [91], and ion adsorption [92]. A further example is solvation dynamics [93,94], which has a long tradition as an application of DDFT [95].…”

“…In addition, stochastic DDFT [9,10], commonly referred to as 'Dean-Kawasaki equation' (a name that is somewhat unfortunate as it fails to acknowledge the differences between Dean's and Kawasaki's approaches [16]), has remained an important tool in the study of interacting particles with stochastic dynamics. Recent examples include active matter [157,158], chemotaxis [159,160], electrolytes [85,[87][88][89][90], densely packed spheres [161], and proteins [162]. Satin [163] suggested a link between stochastic DDFT and theories of gravity.…”