Phase separation transition in liquids and polymers induced by electric field gradients

TL;DR

This paper investigates how spatially nonuniform electric fields induce phase separation in liquids and polymers, leading to demixing and interface formation, with implications for suspension stability and colloid interactions.

Contribution

It introduces the concept of electric field gradient-induced phase separation in liquids and polymers, providing analytical and numerical profiles of the demixing transition.

Findings

Phase separation occurs above a critical potential

Interface location depends on charge or voltage

Demixing influences suspension stability

Abstract

Spatially uniform electric fields have been used to induce instabilities in liquids and polymers, and to orient and deform ordered phases of block-copolymers. Here we discuss the demixing phase transition occurring in liquid mixtures when they are subject to spatially nonuniform fields. Above the critical value of potential, a phase-separation transition occurs, and two coexisting phases appear separated by a sharp interface. Analytical and numerical composition profiles are given, and the interface location as a function of charge or voltage is found. The possible influence of demixing on the stability of suspensions and on inter-colloid interaction is discussed.