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Fluid Flow and Spatiotemporal Chaos in Chemically Active Emulsions
Charu Datt1,2, Jonathan Bauermann1,3, Nazmi Burak Budanur1
1Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany.
Physical Review Letters
|July 10, 2026
Summary
Chemically active emulsions exhibit spatiotemporal chaos driven by interfacial stresses, not fluid inertia. This complex self-organization arises from reactions, phase separation, and hydrodynamics in non-equilibrium fluid mixtures.
Area of Science:
- Soft Matter Physics
- Non-equilibrium Thermodynamics
- Fluid Dynamics
Background:
- Phase-separating fluid mixtures are typically studied at thermodynamic equilibrium.
- Understanding non-equilibrium systems is crucial for various applications, including materials science and biology.
- Active emulsions, driven by chemical reactions, present unique challenges and opportunities for self-organization.
Purpose of the Study:
- To investigate the complex dynamics and pattern formation in chemically active emulsions.
- To identify the driving mechanisms behind spatiotemporal chaos in these systems.
- To establish a connection between the dynamics of active emulsions and established models of nonlinear dynamics.
Main Methods:
- Analysis of phase-separating fluid mixtures undergoing chemical reactions.
- Investigation within the Stokes flow regime to isolate non-inertial effects.
- Derivation of amplitude equations to model the system's nonlinear dynamics.
Main Results:
- Demonstration of complex self-organization and pattern formation leading to spatiotemporal chaos.
- Identification that chaotic dynamics are driven by interfacial stresses, not fluid inertia.
- Found amplitude equations identical to those for Rayleigh-Benard convection with specific boundary conditions.
Conclusions:
- Chemically active emulsions, despite lacking internal orientational order, can exhibit chaotic dynamics.
- Interfacial stresses are the primary drivers of chaos in these non-equilibrium fluid mixtures.
- The derived amplitude equations provide a generic model for understanding nonlinear dynamics in such systems.
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