LOW-FREQUENCY DIELECTROPHORESIS IN CLAY WATER-ELECTROLYTE SYSTEMS

The low-frequency dielectrophoresis in clay-water-electrolyte systems is governed by the electrical double layer surrounding the clay partic les. The dielectrophoretic force imposed on the double layer can be qu antitatively accounted in terms of the Stern-Gouy double layer model a nd its polarization and conduction in a non-uniform electric field. Th e magnitude and direction of dielectrophoretic force are determined by the effective polarizability and the intensity and configuration of t he field. In most clay-water-electrolyte systems, the dielectrophoreti c force imposed on clay particles through the electrical double layer is towards the lower field intensity, thus water will be forced moving to the central electrode. The theory was consistent with the experime ntal observations in synthetic and natural clays.