Graphenes and CNTs: adatoms, islands, nanocrystals, and intercalants as interacting multipoles

Abstract

The functionalization (adsorption) of graphene and carbon nanotubes (CNT) is investigated in the case of charge transfer between a functionalizing molecule (adatom) and a substrate (graphenes or CNT), and the first principles charge transfer calculations are briefly reviewed. It is shown that electrostatic dipoles caused by charge transfer describe the interaction between the adsorbed atoms or islands (clusters) at low concentration, that is, at the initial and intermediate stages of functionalization. It is shown that intercalated atoms in graphite, bi-, and tri-graphene can be described by the electrostatic quadrupoles, their magnitudes are found. The quadrupoles’ axes are perpendicular to the layers. On the surface of the CNT, the adsorbed nanocrystals (clusters) are described as electrostatic quadrupoles, their magnitudes are found. The quadrupoles’ axes are directed along the CNT. At long distances, the interaction energies and repulsion forces are calculated for the clusters. The results explain the experimentally found homogeneous distribution of the adsorbed particles and clusters.