New mechanisms of droplet coarsening in phase-separating fluid mixtures

TL;DR

This paper introduces a novel droplet coarsening mechanism in phase-separating fluids, highlighting interactions driven by concentration coupling and their interplay with hydrodynamics, challenging traditional views of late-stage spinodal decomposition.

Contribution

It presents a new interaction mechanism between droplets caused by concentration coupling, expanding understanding of phase separation dynamics.

Findings

Droplet interactions occur via concentration coupling.

The new mechanism influences droplet coarsening alongside Brownian coagulation.

Coupling between hydrodynamic and diffusion modes affects phase separation.

Abstract

We propose here a new mechanism of droplet coarsening in phase-separating fluid mixtures. In contrast to the conventional understanding that there are no interactions between droplets in the late stage of spinodal decomposition, we demonstrate the existence of interactions between droplets that is caused by the coupling between diffuse concentration change around droplets. We show the possibility that this mechanism plays an important role in droplet phase separation together with Brownian-coagulation mechanism. We also discuss the coupling between hydrodynamic and diffusion modes, namely, "collision-induced collision" phenomena.