Activity induced non-monotonic aggregation in a mixture of chemically active and passive particles

Abstract

Spontaneous symmetry breaking has been shown to be the genesis of self-assembly in a mixture of spherically symmetric chemically active and passive colloids, forming dense clusters. Here, we study the kinetics of such self-assembly, driven by the phoretic motion of passive colloids following the chemical gradient generated by the active seeds. A non-monotonic effect of activity on aggregation is the key observation in this work. We rationalize such non-monotonicity in the clustering by the hybrid coarse-grained simulations. The average cluster population and the variation of their size as a function of time, the stability of clusters, and their dynamics are the key quantifications that help us comprehend the aggregation.