Capillary interfacial tension in active phase separation

Abstract

In passive fluid-fluid phase separation, a single interfacial tension sets both the capillary fluctuations of the interface and the rate of Ostwald ripening. We show that these phenomena are governed by two different tensions in active systems, and compute the capillary tension ${\sigma }_{cw}$ which sets the relaxation rate of interfacial fluctuations in accordance with capillary wave theory. We discover that strong enough activity can cause negative ${\sigma }_{cw}$. In this regime, depending on the global composition, the system self-organizes, either into a microphase-separated state in which coalescence is highly inhibited, or into an `active foam' state. Our results are obtained for Active Model B+, a minimal continuum model which, although generic, admits significant analytical progress.

as accepted for publication in Phys. Rev. Lett

References in corpus (12)

• Motility-Induced Phase Separation
• Statistical Mechanics of Interacting Run-and-Tumble Bacteria
• Active matter
• Effective Interactions in Active Brownian Suspensions
• Multidimensional Stationary Probability Distribution for Interacting Active Particles
• Motility-Induced Microphase and Macrophase Separation in a Two-Dimensional Active Brownian Particle System
• Self-Organized Critical Coexistence Phase in Repulsive Active Particles
• Microscopic Origins of the Swim Pressure and the Anomalous Surface Tension of Active Matter
• Non-negative Interfacial Tension in Phase-Separated Active Brownian Particles
• Stealth entropy production in active field theories near Ising critical points
• Collective dynamics of active Brownian particles in three spatial dimensions: a predictive field theory
• Periodic patterns displace active phase separation

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