(123b) Electroconvective Flows in Complex Fluid Electrolytes

This talk considers the stability of ion transport processes in viscoelastic liquid electrolytes bounded by ion-selective interfaces. I will discuss results from electroanalytical, particle tracking velocimetry, and theoretical analysis, which show that at potentials about 20 times the thermal voltage, ion transport in simple fluids is destabilized by strong convective flow. At these high potentials, an electrical body force exerted on a charged fluid layer near ion-selective interfaces is thought to drive the hydrodynamic instability termed electroconvection. I will show further that the spatial and temporal characteristics of the resultant convective flows are analogous to those observed in inertial turbulence. The talk considers the effect of electrolyte viscoelasticity on the underlying cascade of hydrodynamic instabilities responsible for electroconvection. In so doing, design rules for viscoelastic liquid electrolytes capable of suppressing morphological instability at metal/electrolyte interfaces will be presented.