title: Thermoelectroconvection near charge-selective surfaces.
abstract: A new kind of instability caused by Joule heating near charge-selective surfaces (permselective membranes, electrodes, or systems of micro- and nanochannels) is investigated theoretically using a model based on the Rubinstein-Zaltzman approach. A simple relation is derived for the marginal stability curves: Joule heating can either destabilize or stabilize the steady state, depending on the location of the space charge region relative to the gravity vector. For the destabilizing case, the short-wave Rubinstein-Zaltzman instability is replaced by a long-wave thermal instability. The physical mechanism of the thermal instability is found to be very different from Rayleigh-Bénard convection, and is based on a nonuniform distribution of the electrical conductivity in the electrolyte. The study is complemented by numerical investigations both of linear and nonlinear instabilities near a charge-selective surface. There is a good qualitative agreement with the analytics. A possible explanation of the discrepancy between the experimental data and our previous theoretical voltage-current characteristics is highlighted.
authors.affiliation: Laboratory of Electro-Hydrodynamics of Micro- and Nanoscales, Department of Mathematics and Computer Science, Financial University, Krasnodar, 350051, Russian Federation.|Laboratory of General Aeromechanics, Institute of Mechanics, Moscow State University, Moscow, 117192, Russian Federation.
authors.forename: E A
authors.initials: EA
authors.lastname: Demekhin
authors.affiliation: Université Bordeaux, I2M, UMR CNRS 5295, 16 Av. Pey-Berland, 33607 Pessac, France.
authors.forename: S
authors.initials: S
authors.lastname: Amiroudine
authors.affiliation: Department of Computational Mathematics and Computer Science, Kuban State University, Krasnodar, 350040, Russian Federation.
authors.forename: G S
authors.initials: GS
authors.lastname: Ganchenko
authors.affiliation: Department of Mathematical Modelling, Kuban State University, Krasnodar, 350040, Russian Federation.
authors.forename: N Yu
authors.initials: NY
authors.lastname: Khasmatulina
mesh_terms: D018481:Convection; D004553:Electric Conductivity; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D009995:Osmosis; D013499:Surface Properties