Wetting transition of active Brownian particles on a thin membrane

Abstract

We study non-equilibrium analogues of surface phase transitions in a minimal model of active particles in contact with a purely repulsive potential barrier that mimics a thin porous membrane. Under conditions of bulk motility-induced phase separation, the interaction strength ${\epsilon }_w$ of the barrier controls the affinity of the dense phase for the barrier region. We uncover clear signatures of a wetting phase transition as ${\epsilon }_w$ is varied. In common with its equilibrium counterpart, the character of this transition depends on the system dimensionality: a continuous transition with large density fluctuations and gas bubbles is uncovered in 2d while 3d systems exhibit a sharp transition absent of large correlations.

References in corpus (12)

• Motility-Induced Phase Separation
• Physics of Microswimmers - Single Particle Motion and Collective Behavior
• Tunable long range forces mediated by self-propelled colloidal hard spheres
• The molecular structure of the interface between water and a hydrophobic substrate is liquid-vapor like
• Phase Diagram of Active Brownian Spheres: Crystallization and the Metastability of Motility-Induced Phase Separation
• A unified description of hydrophilic and superhydrophobic surfaces in terms of the wetting and drying transitions of liquids
• Microscopic Origins of the Swim Pressure and the Anomalous Surface Tension of Active Matter
• Phase separation and multibody effects in three-dimensional active Brownian particles
• Critical Drying of Liquids
• Non-negative Interfacial Tension in Phase-Separated Active Brownian Particles
• Drying and Wetting Transitions of a Lennard-Jones Fluid: Simulations and Density Functional Theory
• Coexistence of active Brownian discs: Van der Waals theory and analytical results