Superfast electrophoresis of electron-type conducting particles

The features of concentration polarization caused by electric current through a unipolar conductive particle are considered. The peculiarities of the formation of an induced space charge near a particle with electron-type conductivity are analysed. It has been shown that the theoretical values of electrophoretic velocity for these particles are essentially smaller than those calculated for particles with ion-type conductivity.A new method to observe the superfast electrophoresis is developed. The electrophoretic velocity of graphite and activated carbon particles of different size (diameter, 200–500 μm) displaced in distilled water and electrolyte solutions in strong electric fields (100–500 V cm⁻¹) was measured. It is shown that, in contrast to classical electrophoresis, the electrophoretic mobility of such particles increases with the particle size and the external field strength. The experimental and theoretical results are compared. The discrepancy between theory and experiment is analysed.