The Mechanics of Nucleation and Growth and the Surface Tensions of Active Matter

Abstract

Homogeneous nucleation, a textbook transition path for phase transitions, is typically understood on thermodynamic grounds through the prism of classical nucleation theory. However, recent studies have suggested the applicability of classical nucleation theory to systems far from equilibrium. In this Article, we formulate a purely mechanical perspective of homogeneous nucleation and growth, elucidating the criteria for the properties of a critical nucleus without appealing to equilibrium notions. Applying this theory to active fluids undergoing motility-induced phase separation, we find that nucleation proceeds in a qualitatively similar fashion to equilibrium systems, with concepts such as the Gibbs-Thomson effect and nucleation barriers remaining valid. We further demonstrate that the recovery of such concepts allows us to extend classical theories of nucleation rates and coarsening dynamics to active systems upon using the mechanically-derived definitions of the nucleation barrier and surface tensions. Three distinct surface tensions -- the mechanical, capillary, and Ostwald tensions -- play a central role in our theory. While these three surface tensions are identical in equilibrium, our work highlights the distinctive role of each tension in the stability of active interfaces and the nucleation and growth of motility-induced phases.

References in corpus (34)

• Theory of Phase Ordering Kinetics
• Phase behaviour of active Brownian particles: The role of dimensionality
• Scalar ${\varphi }^4$ field theory for active-particle phase separation
• Pressure and Phase Equilibria in Interacting Active Brownian Spheres
• Towards a 'Thermodynamics' of Active Matter
• Crystal nucleation of hard spheres using molecular dynamics, umbrella sampling and forward flux sampling: A comparison of simulation techniques
• Negative interfacial tension in phase-separated active suspensions
• Generalized Thermodynamics of Phase Equilibria in Scalar Active Matter
• Cluster phases and bubbly phase separation in active fluids: Reversal of the Ostwald process
• Generalized thermodynamics of Motility-Induced Phase Separation: Phase equilibria, Laplace pressure, and change of ensembles
• Motility-Induced Microphase and Macrophase Separation in a Two-Dimensional Active Brownian Particle System
• Active phase separation by turning toward regions of higher density
• A self-driven phase transition drives Myxococcus xanthus fruiting body formation
• Phase Diagram of Active Brownian Spheres: Crystallization and the Metastability of Motility-Induced Phase Separation
• A classical nucleation theory description of active colloid assembly
• Colloidal Hard Spheres: Triumphs, Challenges and Mysteries
• Self-Organized Critical Coexistence Phase in Repulsive Active Particles
• New Hydrodynamic Mechanism for Drop Coarsening
• Microscopic Origins of the Swim Pressure and the Anomalous Surface Tension of Active Matter
• Capillary interfacial tension in active phase separation
• Derivation of the fundamental equations of continuum thermodynamics from statistical mechanics
• Phase separation and multibody effects in three-dimensional active Brownian particles
• Mechanical Theory of Nonequilibrium Coexistence and Motility-Induced Phase Separation
• Dynamical Clustering Interrupts Motility Induced Phase Separation in Chiral Active Brownian Particles
• Non-negative Interfacial Tension in Phase-Separated Active Brownian Particles
• Classical Nucleation Theory for Active Fluid Phase Separation
• Interface stability, interface fluctuations, and the Gibbs-Thomson relation in motility-induced phase separations
• Nucleation pathway and kinetics of phase-separating active Brownian particles
• Statistical mechanics of transport processes in active fluids: Equations of hydrodynamics
• Theory of Capillary Tension and Interfacial Dynamics of Motility-Induced Phases
• Brute-force nucleation rates of hard spheres compared with rare-event methods and classical nucleation theory
• Phase Separation, Capillarity, and Odd Surface Flows in Chiral Active Matter
• The effect of thermal non-equilibrium on kinetic nucleation
• Surface Tension Between Coexisting Phases of Active Brownian Particles

Cited by in corpus (6)

• Hyperuniform interfaces in non-equilibrium phase coexistence
• Wetting by active fluids
• What is active wetting?
• Conservation laws and slow dynamics determine the universality class of interfaces in active matter
• Hyperuniformity in active fluids reshapes nucleation and capillary-wave dynamics
• Active Cahn-Hilliard theory for nonequilibrium phase separation: quantitative macroscopic predictions and a microscopic derivation