Electroprewetting near a flat charged surface

TL;DR

This paper investigates how a charged flat surface influences the wetting behavior of a van der Waals fluid with ions, revealing phase transition phenomena and potential implications for atmospheric droplet formation.

Contribution

It provides analytical and numerical analysis of electroprewetting near charged surfaces, identifying critical potentials and phase diagram features.

Findings

Critical surface potential for prewetting determined.

Phase diagram shows first- and second-order transition lines meeting at a critical point.

Results suggest implications for droplet nucleation in atmospheric conditions.

Abstract

We look at the wetting of a pure fluid in contact with a charged flat surface. In the bulk, the fluid is a classical van der Waals fluid containing dissociated ions. The presence of wall and ions leads to strong dielectrophoretic and electrophoretic forces that increase the fluid's density at the wall. We calculate the fluid's profiles analytically and numerically and obtain the energy integrals. The critical surface potential for prewetting is obtained. In the phase diagrams, the line of first-order transition meets a second-order transition line at a critical point whose temperature can be higher or lower than the bulk critical temperature. The results are relevant to droplet nucleation around charged particles in the atmosphere and could possibly explain deviations from expected nucleation rates.