A Thermodynamic Model of Electric-Field-Induced Pattern Formation in Binary Dielectric Fluids

摘要

An electric-field-induced phase transition and pattern formation in a binarydielectric fluid layer are studied using a coarse-grained free energyfunctional. The electrostatic part of the free energy is a nonlinear functionalof the dielectric function, which depends in turn on the local colloidalconcentration. We determine the phase co-existence curve and find that beyond acritical electric field the system phase separates. Accompanying the phaseseparation are patterns similar to those observed in a spinodal decompositionof an ordinary binary fluid. The temporal evolution of the phase separatingpatterns are discussed both analytically and numerically by integrating aCahn-Hilliard type of equation.