Precision Assembly of Oppositely- and Like-Charged Nano-Objects

The field of electrostatics is thought, by many, to be ‘fully understood' - however at the nano-scale we continue to discover intriguing and counter-intuitive phenomena. Here we present the results from a recent fundamental study investigating the electrostatic interactions of non-spherically symmetric nanoparticles. We show, through a series of experiments supported by theoretical models, that electrostatic interactions can be used to control the assemblies of charged nano-objects with precision down to 7 nm. Specifically, we demonstrate that polarization effects and charge-induced dipoles within the metallic core of the nanoparticles can, under certain conditions, dominate the well known charge-charge interactions. Remarkably, these charge-induced dipole interactions can then mediate orientation specific aggregation between both oppositely- and like-charged particles.