Effects of Colloid Interactions on Active–Passive Collective Behavior

Active colloidal matter can exhibit different phases, such as flocking, rafting, and spinning, in response to changes in active particle properties (Soft Matter 14, 6969–6973 (2018)). The links between these phenomena and the catalytic, hydrodynamic, electrostatic, and phoretic properties of the colloids are disputed, in part because it is difficult to separate the impact of each force in experiment. Whereas current models can capture some aspects of a system’s collective behavior, oversimplification can lead to incorrectly attributing a particular behavior to a specific interaction (The European Physical Journal E 41, 145–169 (2018)). Using experimentally informed models, we employ lattice-Boltzmann and molecular dynamics simulations to deconvolute these interactions and make direct connections between particle properties and observed collective phenomena.