Osmosis with active solutes

Abstract

Despite much current interest in active matter, little is known about osmosis in active systems. Using molecular dynamics simulations, we investigate how active solutes perturb osmotic steady states. We find that solute activity increases the osmotic pressure, and can also expel solvent from the solution - i.e. cause reverse osmosis. The latter effect cannot be described by an effective temperature, but can be reproduced by mapping the active solution onto a passive one with the same degree of local structuring as the passive solvent component. Our results provide a basic framework for understanding active osmosis, and suggest that activity-induced structuring of the passive component may play a key role in the physics of active-passive mixtures.

6 pages

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Cited by in corpus (9)

• Pressure and Phase Equilibria in Interacting Active Brownian Spheres
• Osmosis, from molecular insights to large-scale applications
• Pressure of a gas of underdamped active dumbbells
• Van't Hoff's law for active suspensions: the role of the solvent chemical potential
• How statistical forces depend on thermodynamics and kinetics of driven media
• Active fluids at circular boundaries: Swim pressure and anomalous droplet ripening
• Resonant osmosis across active switchable membranes
• Shape-shifting droplet networks
• Recovery of mechanical pressure in a gas of underdamped active dumbbells with Brownian noise