Shape-induced capillary interactions of colloidal particles

Abstract

\n \nWe show that near-spherical micrometer-sized colloidal particles at an interface of two fluids\nexperience inter-particle forces merely as a consequence of their shape-induced capillary\ninteraction. The interaction is strong even if the deviations from sphericity are on the nm-scale,\nand can hardly be avoided in experiment. For particles of 2$\\un\\mu$m radius, a deformation of\n$20\\un{nm}$ can result in an attractive potential of 2kBT at a distance of 4 particle radii.\nDynamical simulations of many particles confirm that the forces lead to aggregates of dendritic or\nhexagonal-lattice type. The latter pattern exhibits strong herringbone-phase orientational order.\n\n