ELECTROOSMOSIS OF THE 2ND KIND

The features of concentration polarization caused by an electric current passing through a unipolar conductive particle are considered. A space charge appears inside the concentration polarization zone under the action of a strong electric field. In the case of a curved surface, its appearance is connected with the normal component of the electric field. The action of the tangential component on this space charge leads to liquid movement along the surface which is similar to electroosmotic slip. This phenomenon was called ''electroosmosis of the second kind''. The dependences of electroosmosis of the second kind on the tangential drift of the induced space charge, water dissociation, electrolyte concentration and heat processes are analyzed. The main properties of electoosmotic slip have been experimentally investigated. When the particle conductivity is higher than the medium conductivity, the velocity of liquid movement is proportional to the particle size and to the square of the electric field strength and exceeds the Smoluchowsky velocity by one or two orders of magnitude. The experimental results are in good agreement with theoretical dependences.