Self-Assembly and Electrical Conductivity of Colloids

Abstract: Self-assembly is an astonishing phenomenon at the base of organized structures’ formation from disordered systems. It occurs in nature from atomic and molecular lengths to galactic distances. Nowadays self-assembly of colloidal solutions can be used to fabricate photonic crystals and metamaterials. This paper analyses the self-assembly and its effect on the electric conductivity of a colloid made up of carbon nanotubes and magnetite microparticles controlled by electrostatic potentials and magnetic fields. Alignment of the carbon nanotubes and creation of sparks and short-circuits are observed when the electrostatic field is applied. The magnetic field induces time-dependent and memory effects in the sample’s structure and conductivity. At constant potential, the electric current through the sample is reported to increase four times during and after the application of the magnetic fields.