Electrochemical irreversibility of ion transfers at liquid/liquid interfaces: Part II. Quasi-thermodynamic analysis and time dependences for single ion transfers

Abstract

Structure of the double layer at immiscible liquid electrolyte interfaces is a controversial topic. and is essential to correct interpretation of ion-crossing kinetics. For single partitioned salt systems, (NR 4 +X − at H 2O/PhNO 2 interfaces for example. single ion free energies in each phase determine equilibrium charge and control pds in part. For non-equilibrium applied pds and currents. the overpotential may be entirely accounted for in space-charge perturbations, or as pds in compact layers in each phase, or as combinations of both. Experimental results for irreversible and quasi-reversible ion transfers, at constant current, suggest a pd across a compact layer. New results in the absence of supporting electrolyte are crucial to the argument. Log analytical plots are now available for pd dependences on time for various cases, including a compact layer whose order and capacitance depends upon charge. These plots are described and used in the analysis of experimental data.