Electrokinetic phenomena of the second kind and their applications

Abstract The special features of the concentration polarization generated by an electric current passing through the boundary separating two conducting media are considered. When the electric current is strong a bulk charge is induced inside the concentration polarization zone. In the case of curved interfaces this charge is determined by the normal component of the external electric field. The tangential component of the external electric field exerts a force on this bulk charge, leading to liquid movement along the interface; this process is analogous to electro-osmotic slip. It is predicted that due to these charges conducting particles move in external electric fields. This phenomenon is called electrophoresis of the second kind. An approximate theory for this phenomenon is proposed and experimentally verified. Possible applications of electrokinetic phenomena of the second kind are discussed.