Nucleation of chemically active droplets

TL;DR

This paper investigates how driven chemical reactions influence droplet nucleation, showing that reactions generally delay nucleation by increasing the energy barrier, with implications for biological and chemical systems.

Contribution

The study introduces a surrogate model that predicts how reactions affect nucleation times and stability, providing a quantitative framework for understanding active droplet formation.

Findings

Reactions suppress nucleation by stabilizing the homogeneous phase.

The surrogate model accurately predicts increased nucleation times.

A phase diagram summarizes the impact of reactions on droplet stability.

Abstract

Driven chemical reactions can control the macroscopic properties of droplets, like their size. Such active droplets are critical in structuring the interior of biological cells. Cells also need to control where and when droplets appear, so they need to control droplet nucleation. Our numerical simulations demonstrate that reactions generally suppress nucleation if they stabilize the homogeneous state. An equilibrium surrogate model reveals that reactions increase the effective energy barrier of nucleation, enabling quantitative predictions of the increased nucleation times. Moreover, the surrogate model allows us to construct a phase diagram, which summarizes how reactions affect the stability of the homogeneous phase and the droplet state. This simple picture provides accurate predictions of how driven reactions delay nucleation, which is relevant for understanding droplets in biological cells and chemical engineering.