Combined negative dielectrophoresis and phase separation in nondilute suspensions subject to a high-gradient ac electric field

The combined negative dielectrophoresis and phase separation in concentrated suspensions of neutrally buoyant particles were studied. It was observed that when the suspensions were subjected to a high-gradient ac field, a phase separation occurred. The interparticle electric interactions were found to be responsible for the phenomenon. A electrohydrodynamic model for the one and two-phase states of a suspension, which was a generalization of the theory for thermodynamics of the field-induced phase transitions in the suspensions of polarized particles, was also discussed.