Electrostatic tunability of charged, binary nanoparticle assemblies in dielectric colloidal systems

Abstract

Charged nanoparticles exhibit anomalous electrostatic interactions, which can lead to stable, non-touching equilibria in inverted dielectric systems. In this study, we analytically demonstrate minimum-potential energy configurations for binary systems of charged nanoparticles and control of constituent spacing by externally applied electrostatic fields. The field–matter interactions are governed by the electrostatic forces of high order multipoles induced by the charged nanoparticles submerged in dielectric liquids. The particles bind in non-touching configurations due to electrostatic potential wells for each particle induced by other dissimilar particles in their vicinity. Such binary systems are proposed as building blocks with the potential of electromagnetic tunability of novel photonic surfaces.