Carbon Nanotubes and Graphene
Carbon nanotubes (CNTs) and graphene are allotropes of carbon which have interesting electrical, mechanical and other physical properties. Graphene is a two-dimensional material, fundamentally a single layer of graphite, with carbon particles arranged in a hexagonal, honeycomb grid. Carbon nanotubes are cylindrical and hollow structures, basically, a sheet of graphene rolled into a cylinder. The point at which they are rolled (their "chirality"), and their distance across, influence their properties. CNTs can be single-walled (SWCNTs or SWNTs) or can be multi-walled (MWCNTs or MWNTs).