Interface Hysteresis and Negative Differential Conductance at Liquid–Liquid Junction between Non-miscible Ionic Solutions

Abstract

WE have carried out an investigation of systems in which two non-miscible liquid phases are in contact. The “upper phase” was an aqueous K⁺Cl⁻ solution (for example, KCl 10⁻² M) and the “lower phase” a nitrobenzene solution of a long chain alkyl trimethyl ammonium picrate R⁺Pi⁻ (for example, tetradecyl trimethyl ammonium picrate, 3 × 10⁻³ M). At equilibrium, the hydrophilic ions, K⁺ and Cl⁻, remain localized in the upper phase and the lipophilic ions, R⁺ and Pi⁻, remain in the lower phase. In each phase the dissolved substance is almost completely dissociated. We have shown in an earlier article how overvoltage phenomena occur at the interface between such solutions¹.