Stability of Binary Mixtures in Electric Field Gradients

TL;DR

This paper investigates how electric field gradients influence the phase separation and stability of nonpolar binary mixtures, deriving conditions for demixing and analyzing the effects on phase diagrams and interface locations.

Contribution

It provides a theoretical analysis of the critical electric fields and phase behavior modifications in binary mixtures under electric field gradients, including nonlinear dielectric effects.

Findings

Large electric fields induce phase separation in binary mixtures.

The critical field for demixing depends on system parameters.

Electric fields can shift the phase diagram and create interfaces far from boundaries.

Abstract

We consider the influence of electric field gradients on the phase behavior of nonpolar binary mixtures. Small fields give rise to smooth composition profiles, whereas large enough fields lead to a phase-separation transition. The critical field for demixing as well as the equilibrium phase separation interface are given as a function of the various system parameters. We show how the phase diagram in the temperature-composition plane is affected by electric fields, assuming a linear or nonlinear constitutive relations for the dielectric constant. Finally, we discuss the unusual case where the interface appears far from any bounding surface.