A Study of Electroconvection during Uniform Flow of an Electrolyte Solution through an Ion-Selective Region

This paper presents the results of theoretical studying electroconvection emergence and development near an ion-selective region during uniform flow of an electrolyte solution through this region. The analysis of the linear stability of the stationary solution of the problem has made it possible to determine the critical electric potential difference that causes the electrokinetic instability as a function of the external flow velocity. The two-dimensional numerical simulation has revealed the peculiarities of the nonlinear electroconvection regimes. The research has shown the stabilizing effect of the external flow: the electroconvection begins at higher potential differences, whereas its regimes change each other faster with increasing potential difference. Understanding of these effects is useful for practical applications, such as the development of systems for analyte preconcentration in microlaboratories before the chemical analysis of biological liquids.