Assembly of open clusters of colloidal dumbbells via droplet evaporation

Abstract

We investigate the behavior of a mixture of asymmetric colloidal dumbbells and emulsion droplets by means of kinetic Monte Carlo simulations. The evaporation of the droplets and the competition between droplet-colloid attraction and colloid-colloid interactions lead to the formation of clusters built up of colloid aggregates with both closed and open structures. We find that stable packings and hence complex colloidal structures can be obtained by changing the relative size of the colloidal spheres and/or their interfacial tension with the droplets.

Assembly of One-Patch Colloids into Clusters via Emulsion Droplet Evaporation

“…From the Einstein relation and the Stokes–Einstein equation for diffusion of spherical particles, we roughly estimate the physical time of the evaporation process to be on the order of seconds. For details of the calculation, see reference [11]. Although this physical time is quite small compared to experimental timescales that typically last tens of minutes, we do not expect the MC timescale to affect the final outcomes [25].…”

“…Peng and cowokers [10] prepared clusters of dumbbell-shaped particles and indicated that minimization of $M_2$ is not a general rule for aggregation of shape-anisotropic particles. Open clusters with a compact core and protruding arms were obtained by varying the relative size of colloidal spheres in dumbbells [11]. Besides extending the colloidal shape, anisotropic surface chemistry has attracted considerable attention [12].…”