Electroconvective instability in concentration polarization and nonequilibrium electro-osmotic slip.
This paper concerns the comparison of electroconvective instability in concentration polarization at an ion-selective membrane with previously reported nonequilibrium electro-osmotic instability. Electro-osmotic formulation represents an asymptotic limit case of the electroconvective one. An improved nonequilibrium electro-osmotic slip formula is derived. Linear stability analysis for various nonequilibrium electro-osmotic formulations is carried out, including the analytic studies of the short- and long-wave limits. The obtained results are compared with those for a full electroconvective formulation. It is observed that the shortwave singularity typical for the nonequilibrium electro-osmotic instability is removed in the full electroconvective formulation. The effect of ionic diffusivities ratio on stability is discussed.
Rubinstein
Isaak
I
DSEEP, Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Israel.
Zaltzman
Boris
B
Lerman
Irina
I