title: Activity-induced phase separation and self-assembly in mixtures of active and passive particles.
abstract: We investigate the phase behavior and kinetics of a monodisperse mixture of active (i.e., self-propelled) and passive isometric Brownian particles through Brownian dynamics simulations and theory. As in a purely active system, motility of the active component triggers phase separation into a dense and a dilute phase; in the dense phase, we further find active-passive segregation, with "rafts" of passive particles in a "sea" of active particles. We find that phase separation from an initially disordered mixture can occur with as little as 15% of the particles being active. Finally, we show that a system prepared in a suitable fully segregated initial state reproducibly self-assembles an active "corona," which triggers crystallization of the passive core by initiating a compression wave. Our findings are relevant to the experimental pursuit of directed self-assembly using active particles.
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom.
authors.forename: Joakim
authors.initials: J
authors.lastname: Stenhammar
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom.
authors.forename: Raphael
authors.initials: R
authors.lastname: Wittkowski
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom.
authors.forename: Davide
authors.initials: D
authors.lastname: Marenduzzo
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Cates
mesh_terms: D003460:Crystallization; D008956:Models, Chemical; D044367:Phase Transition