Homogenization of nonuniform electric fields in mixtures of liquid dielectrics

Inhomogeneous electric fields in mixtures of liquid dielectrics are investigated theoretically in the framework of thermodynamics of binary mixtures. Due to dielectrophoretic forces, the local dielectric constant is increased in high-field regions, which in turn leads to a decrease of field enhancements. This effect could be extremely useful for field-grading applications in insulation devices. Although the effect is usually weak due to dominant entropic forces, it can be strongly enhanced close to the critical point where the effective (mutual) diffusion constant becomes small. (C) 2000 American Institute of Physics. [S0003-6951(00)01502-3].