Activity-Induced Phase Separation and Self-Assembly in Mixtures of Active and Passive Particles

作者:Stenhammar, Joakim*; Wittkowski, Raphael; Marenduzzo, Davide; Cates, Michael E.
来源:Physical Review Letters, 2015, 114(1): 018301.
DOI:10.1103/PhysRevLett.114.018301

摘要

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.

  • 出版日期2015-1-6