Electric current oscillation in a liquid membrane under voltage clamp conditions

It was found that sustained current oscillations are generated under the application of d.c. voltage for a water-oil-water liquid membrane, where in one of the aqueous phases sodium oleate was added. This is an extension of our previous studies on the self-oscillatory phenomena in oil-water systems, which are driven by the transfer of surfactant molecules through the oil-water interface accompanied by the dissipation of chemical free energy. It is shown that the manners of oscillations are characteristically dependent on the applied voltage, temperature, and added chemical substances. The mechanism of sustained oscillation is attributed to the repetitive formation and destruction of the surfactant monolayer modulated by the applied d.c. voltage. The oscillatory phenomenon of electric current is discussed with the aid of the computer simulation based on a set of phenomenological nonlinear kinetic equations.