Chemical functionalization of single walled carbon nanotubes

Chemical modification has been performed on purified single walled carbon nanotubes. XPS spectrum shows that the peak corresponding to C (1s) centered at 284.38 eV in pure nanotubes (graphitic C) is 0.4 eV downshifted in chlorinated sample. Subsequent coupling reactions were carried out with diamine molecules to form intertube connections. Tripropylentetramine and phenylendiamine have been chosen as a molecular linker. End-to-side and end-to-end nanotube interconnections are formed and then observed by atomic force microscopy (AFM). Statistical analysis made from AFM images shows around 30% junctions in functionalized and less than 2% in pristine material. Remarkable features can be observed in the Raman spectra at different functionalization steps. Simple conductance measurements on bucky papers prepared from prestine nanotubes and from nanotubes modified at various steps have been made and are discussed.