Abstract
A three phase liquid membrane system, consisting of an aqueous phase dissolved with a surfactant, a nitrobenzene phase with picric acid, and another aqueous phase, is known to generate electric pulses similar to the synapse system. The construction of a convenient apparatus consisting of a hollow tube and a beaker to form three phase system was described in this paper. The apparatus is capable of observing the electric pulses with relatively high reproducibility. It was found that the stability of oscillation depends considerably upon the material of the apparatus. When a Teflon hollow tube was used, the oscillation became more stable, compared to the case of glass tube. This stabilization seems to be caused by the change in the interface between three phases, aqueous phase, nitrobenzene phase, and the tube (solid phase). It can be concluded that the oscillation involves this interface. The amplitude, frequency, and profile of the oscillation, were found to change gradually in the course of time, and in total, three oscillation modes was observed. In the first stage, sharp electric pulses were observed at both interfaces between aqueous phases and nitrobenzene phase, while in the second stage, the periodic zigzags were observed only at one side of the interfaces. In the third stage, the oscillation was rather random and was observed only at a side where the second stage oscillation was observed. Based on these results, a new mechanism for the oscillation in the liquid membrane system is proposed.
