Role of water splitting in development of electroconvection in ion-exchange membrane systems

It is found that under certain conditions (a dilute solution, a relatively small inter-membrane distance, and a significant forced convection), the contribution of the gravitational convection in the ion transfer is negligible. Considerable electroconvective mixing of the depleted solution starts at an overpotential threshold close to 1.5 V. With increasing current density, intensive potential oscillations appear in a MA-40M membrane system where the water splitting is weak. The scenario of oscillation development there is in an excellent agreement with that predicted theoretically by I. This study is supported by INTAS, grant no. 04-83-3878, and RFBR, grant no 04-03-32365.