Date: Wednesday 5th of July 2023, 13:00 (BST).
Location: Isaac Newton Building (INB3305) and online via Teams.

‘Activity-induced emulsification of phase-separating binary mixtures’

by Dr Javier Diaz, Universitat de Barcelona, Spain.

Abstract:

Binary mixtures that phase-separate via Ostwald ripening display a monotonic growth in the droplet size following a power law, until macrophase separation is achieved in equilibrium. On the other hand, active particles are intrinsically out-of-equilibrium as they consume energy from the medium to produce work. Using a hybrid discrete/continuous model we show that self-propelled non-surfactant active particles can arrest the phase separation of binary mixtures. Due to the activity of the particles, they can accumulate at the droplet interfaces exerting active pressure that competes with the interfacial tension, leading to a morphology characterised by isotropic droplets with a well-defined size and emerging hexatic global order. The emulsification of fluid-fluid mixtures shows the ability of activity to disrupt the kinetic pathway towards equilibrium of a passive system.