  Patchy particles are a class of colloids with functionalized surfaces.
Through surface functionalization, the strength and directionality of the
colloidal interactions are tunable allowing control over coordination of the
particle. Exquisite equilibrium phase diagrams of mixtures of coordination two
and three have been reported. However, the kinetics of self-organization and
the feasibility of the predicted structures are still largely unexplored. Here,
we study the irreversible aggregation of these mixtures on a substrate, for
different fractions of two-patch particles. Two mechanisms of mass transport
are compared: diffusion and advection. In the diffusive case, an optimal
fraction is found that maximizes the density of the aggregate. By contrast, for
advective transport, the density decreases monotonically with the fraction of
two-patch colloids, in line with the behavior of the liquid density on the
spinodal of the equilibrium phase diagram.
