Wetting of a Solid Surface by Active Matter

TL;DR

This paper uses a lattice model and Kinetic Monte Carlo simulations to study how active particles wet a solid surface, revealing a complete wetting transition driven by activity-induced phase separation.

Contribution

It introduces a lattice model with a grand canonical-like ensemble to analyze wetting behavior of active matter, highlighting activity-driven phase separation and complete wetting.

Findings

Active particles exhibit a diverging film thickness near coexistence.

Mobility induces phase separation in active particle systems.

Complete wetting occurs along the full coexistence curve.

Abstract

A lattice model is used to study repulsive active particles at a planar surface. A rejection-free Kinetic Monte Carlo method is employed to characterize the wetting behaviour. The model predicts a mobility induced phase separation of active particles, and the bulk coexistence of dense liquid-like and dilute vapour-like steady states is determined. An "ensemble", with a varying number of particles, analogous to a grand canonical ensemble in equilibrium, is introduced. The formation and growth of the liquid film between the solid surface and the vapour phase is investigated. For all of the activities considered, the thickness of the adsorbed film exhibits a diverging behaviour as the system is brought towards coexistence from the vapour side, suggesting a complete wetting scenario along the full coexistence curve.