Self-perturbation of the salt partition at the water/1,2-dichloroethane interface

Abstract

Open circuit potential (OCP) measurements of the partition of tetrapentylammonium chloride (TPeACl) at the water/1,2-dichloroethane (DCE) interface reveal two remarkable processes. First one is characterized by a substantial drop and further decay of the OCP from its expected equilibrium value. This process has been previously investigated and ascribed to the anomalous extraction of the salt driven by its accumulation in the hydrated salt clusters in the DCE phase. The second process, which has been observed for the first time in the present study, is characterized by the short-term potential spikes overlapping the long-term OCP records. These spikes are assumed to be associated with the collision and fusion of the hydrated salt clusters or their aggregates produced by the former process with the water/DCE interface. Self-perturbation of the steady-state salt partition by a single cluster or aggregate impact offers a new approach to study kinetics and the mechanism of the hydrated salt cluster formation.