(155d) Phase Behavior of Binary Active Colloidal Systems

Colloids often serve as excellent model systems for the study of complex molecular or biological phenomena. For example, by harvesting energy from their environment, active colloids display autonomous motion that resembles the behavior of microorganism. An emergent feature of active colloidal systems is phase separation. Active colloids can form regions of high and low concentrations that is similar to the coexistence of gas and liquid phases in equilibrium systems. Furthermore, simulations predict that phase separations should also occur in multicomponent colloidal systems based on apparent linear and even rotational mobilities. However, the systems in which phase separation have been observed are limited to single component systems that display interesting clustering and swarming behavior. In this talk, I will describe the collective dynamics in multicomponent systems of homogeneous and Janus particles that under AC electric fields exhibit different motions. In addition to small and large clusters, particles show a segregation behavior that depends on the properties of the particles, electric field parameters as well as on total and relative volume fractions. As we continue to explore these effects, we look to understand the dynamic assembly of these materials and the potential uses into reconfigurable materials.