Propagation and synchronization of potential oscillations in multiple liquid membrane systems.

Two liquid membrane oscillators composed of aqueous solutions containing cetyltrimethylammonium chloride (CTACl) and alcohol, W1 and W1', a nitrobenzene solution containing picric acid, O, and pure water phase, W2, were connected through O and W2 as common phases. Two glass tubes including W1 and W1' were inserted into the O/W2 interface. Both membrane potential differences between W1 and W2 and that between W1' and W2 were recorded using a pair of Ag/AgCl electrodes located near the orifice of each tube. The oscillations of two membrane potentials synchronized each other when the distance between the tubes was less than 10 mm. The synchronization was attended by the propagation of a potential pulse from one side to another with an interval of approximately 70 ms at a distance of 10 mm. It was examined whether the propagation of the potential pulse was due to electric conduction in bulk phases, or due to the interfacial conduction by several experiments in the addition of indifferent electrolytes or nonionic surfactant. Consequently, it has been demonstrated that the propagation of oscillation pulse was dominated mainly by the interfacial conduction process, and additionally by the bulk ionic conduction and that the interfacial diffusion and distribution of Cl(-) played a crucial role.