Structure and Dynamics of a Phase-Separating Active Colloidal Fluid

Abstract

We examine a minimal model for an active colloidal fluid in the form of self-propelled Brownian hard spheres that interact purely through excluded volume. Despite the absence of an aligning interaction, this system shows the signature behaviors of an active fluid, including anomalous number fluctuations and phase separation behavior. Using simulations and analytic modeling, we quantify the phase diagram and separation kinetics. The dense phase is a unique material that we call an active hexatic, which exhibits the structural signatures of a crystalline solid near the crystal-hexatic transition point, but the rheological and transport properties associated with a viscoelastic fluid.

5 pages, 5 figures

References in corpus (15)

• Athermal Phase Separation of Self-Propelled Particles with no Alignment
• Statistical Mechanics of Interacting Run-and-Tumble Bacteria
• Non-equilibrium clustering of self-propelled rods
• Swarming and swirling in self-propelled polar granular rods
• Phase separation and rotor self-assembly in active particle suspensions
• Crystallization in a dense suspension of self-propelled particles
• Enhanced diffusion and ordering of self-propelled rods
• Hydrodynamics of self-propelled hard rods
• Spontaneous Segregation of Self-Propelled Particles with Different Motilities
• Swarm behavior of self-propelled rods and swimming flagella
• Shearing active gels close to the isotropic-nematic transition
• Traffic jams, gliders, and bands in the quest for collective motion
• Sheared active fluids: thickening, thinning and vanishing viscosity
• Active nematics are intrinsically phase-separated
• Spatial Structures and Giant Number Fluctuations in Models of Active Matter

Cited by in corpus (15)

• Scalar ${\varphi }^4$ field theory for active-particle phase separation
• Thermodynamic phases in two-dimensional active matter
• Lattice Boltzmann Methods and Active Fluids
• Active Brownian Motion with Directional Reversals
• Active dumbbells: dynamics and morphology in the coexisting region
• Systematic extension of the Cahn-Hilliard model for motility-induced phase separation
• Modelling persistence of motion in a crowded environment: the diffusive limit of excluding velocity-jump processes
• Collective dynamics of active dumbbells near a circular obstacle
• Spontaneous trail formation in populations of auto-chemotactic walkers
• Polarization and dynamic phases of aligning active matter in periodic obstacle arrays
• Emergent Gauge Symmetry in Active Brownian Matter
• Elastic interactions compete with persistent cell motility to drive durotaxis
• Jerky chiral active particles
• Discrete state model of a self-aggregating colloidal system with directional interactions
• Persistent exclusion process with time-periodic drive