# Active phase separation in mixtures of chemically interacting particles

## TL;DR

This paper presents a theoretical study of chemically-interacting particle mixtures, revealing a novel active phase separation driven by nonequilibrium chemical interactions that break action-reaction symmetry, with implications for biological and colloidal systems.

## Contribution

It introduces a new class of active phase separation phenomena caused by nonequilibrium chemical interactions in mixtures of particles.

## Key findings

- Chemically-interacting particles can undergo phase separation due to nonequilibrium interactions.
- The model explains self-organization in biological and colloidal systems.
- Action-reaction symmetry breaking is key to the observed phenomena.

## Abstract

We theoretically study mixtures of chemically-interacting particles, which produce or consume a chemical to which they are attracted or repelled, in the most general case of many coexisting species. We find a new class of active phase separation phenomena in which the nonequilibrium chemical interactions between particles, which break action-reaction symmetry, can lead to separation into phases with distinct density and stoichiometry. Due to the generic nature of our minimal model, our results shed light on the underlying fundamental principles behind nonequilibrium self-organization of cells and bacteria, catalytic enzymes, or phoretic colloids.