Nonequilibrium interfacial properties of chemically driven fluids

TL;DR

This paper investigates how nonequilibrium chemical reactions influence the interfacial tension of phase-separated fluids, revealing that such reactions can either increase or decrease interfacial tension depending on their acceleration or deceleration within droplets.

Contribution

It introduces a minimal model and a predictive theory to understand nonequilibrium interfacial properties in chemically driven fluids, highlighting effects on interfacial tension.

Findings

Nonequilibrium interfacial tension can be higher or lower than equilibrium.

Chemical reaction rates within droplets determine interfacial tension changes.

A predictive theory based on effective thermodynamics explains these phenomena.

Abstract

Chemically driven fluids can demix to form condensed droplets that exhibit phase behaviors not observed at equilibrium. In particular, nonequilibrium interfacial properties can emerge when the chemical reactions are driven differentially between the interior and exterior of the phase-separated droplets. Here, we use a minimal model to study changes in the interfacial tension between coexisting phases away from equilibrium. Simulations of both droplet nucleation and interface roughness indicate that the nonequilibrium interfacial tension can either be increased or decreased relative to its equilibrium value, depending on whether the driven chemical reactions are accelerated or decelerated within the droplets. Finally, we show that these observations can be understood using a predictive theory based on an effective thermodynamic equilibrium.