Interfacial tension and impedance measurements of interfaces between two immiscible electrolyte solutions

Interfacial tension and impedance measurements were used to study the elect rochemical properties of the interface between 0.1 M LiCl in water and 0.05 M tetrabutylammonium tetraphenylborate in nitrobenzene in the absence and the presence of various tetraalkylammonium ions. While the presence of thes e ions has no effect on the interfacial tension, the interfacial capacity c an be considerably enhanced. This enhancement appears to be an artefact ari sing from the inadequate representation of the interface or the electrochem ical cell by the Randles equivalent circuit employed for impedance data ana lysis. Modifications to this equivalent circuit are discussed. (C) 2000 Els evier Science S.A. All rights reserved.