Active fluids form system-spanning filamentary networks
arXiv:2410.07058 · doi:10.1103/PhysRevLett.134.138301
Abstract
Recent experimental realizations of liquid-liquid phase separation of active liquid crystals have offered an insight into the interaction between phase separation, ubiquitous in soft matter and biology, and chaotic active flows. In this Letter, we use continuum theory to examine phase separation of an active liquid crystal and a passive fluid and report two new results. First, we provide an analytical derivation of the activity-induced suppression of the phase boundary of the coexistence region - a result first reported in simulations and experiments. We show that the shift in the critical point is a result of the balance between self-stirring active flows and phase-separating diffusive fluxes. Second, we show that this same balance is responsible for dramatically changing the morphology of the phase separated state, resulting in the emergence of a new mixed active phase consisting of a dynamical filamentous active network that invades the entire system area, trapping droplets of passive material. This structure exists even for very low volume fractions of active material. Our work provides an important step towards the goal of understanding how to use activity as a new handle for sculpting interfaces.
6 pages, 4 figures
References in corpus (24)
- The Mechanics and Statistics of Active Matter
- Spontaneous motion in hierarchically assembled active matter
- Athermal Phase Separation of Self-Propelled Particles with no Alignment
- Hydrodynamic fluctuations and instabilities in ordered suspensions of self-propelled particles
- Statistical Mechanics of Interacting Run-and-Tumble Bacteria
- Scalar field theory for active-particle phase separation
- Spontaneous flow transition in active polar gels
- Activity-induced phase separation and self-assembly in mixtures of active and passive particles
- Active Turbulence
- Theories of Binary Fluid Mixtures: From Phase-Separation Kinetics to Active Emulsions
- Spontaneous division and motility in active nematic droplets
- Biphasic, Lyotropic, Active Nematics
- Excitable Patterns in Active Nematics
- Active Model H: Scalar Active Matter in a Momentum-Conserving Fluid
- Dynamics of active liquid interfaces
- Banding, Excitability and Chaos in Active Nematic Suspensions
- Tunable dynamics of microtubule based active isotropic gels
- Activity induced nematic order in isotropic liquid crystals
- Activity-suppressed phase separation
- Active Matter Invasion
- Phase Separation Driven by Active Flows
- Active nematics on flat surfaces: from droplet motility and scission to active wetting
- Asymmetric fluctuations and self-folding of active interfaces
- Traveling waves at the surface of active liquid crystals