Carbon Nanotubes and Other Nanostructured Materials

The discovery of fullerenes in 1985 sparked the interest of researchers in novel crystalline forms of carbon. Nobel laureate Richard Smalley, co-discoverer of fullerenes, was a strong advocate of carbon nanotube research and his endorsement strengthened the field. The results of such an extensive effort quickly demonstrated the unique properties of these carbon structures, as well as a cornucopia of potential applications in many fields of technology.

The unique properties of carbon nanotubes are due to their distinctive structure, which is composed of C-C bonds more closely related to those in graphite than to those in diamond. Fullerenes, graphene, and nanotubes also have carbon bonds with sp2 hybridization as graphite. The well-known strength of carbon nanotubes is related to the intrinsic strength of the sp2 carbon-carbon bonds. Young's modulus values near 1,000 GPa have been predicted or measured on individual nanotubes or nanotubes ropes. This is around 50 times higher than the modulus of steel, which coupled with their light weight make carbon nanotubes an attractive filler for high-strength composites.

The electronic properties of carbon nanotubes are also astounding. Depending on their geometric structure they can either be metallic or semiconducting since, as discussed below, slight changes in the geometric configuration can result in significant changes in electronic structure. This offers materials scientists the opportunity to design -- at the nano-scale -- the best material for each specific application.

Many of the potential applications of Nanotubes are still limited by the complexity involved in their synthesis, dispersion, and manipulation at the industrial scale. These are all areas in which the involvement of Chemical Engineers with background in catalysis, reactor design, separation processes, and colloidal chemistry is highly valuable.