Simulating ion transfer across a liquid–liquid interface and electrocapillarity based on the electrochemical potential of all ions in the system

Abstract

The liquid–liquid interface between two immiscible electrolyte solutions is an important subject in electrochemistry because ion-transfer reactions can be controlled externally. The electrochemical potentials of ions determine their behavior in a liquid–liquid two-phase system. The electrochemical potential is a continuous function of the system assuming a linear transition region at the interface. A simulation model that considers the electrochemical potential of all ions in the system was constructed for the liquid–liquid interface under electrochemical-measurement conditions. This model facilitates evaluating ion-transfer voltammograms affected by IR drops and separating charging currents from Faraday currents. Moreover, the model enables electrocapillary curves to be determined.