Solvent-free functionalization of carbon nanotubes

fundamentally new single-walled and multiwalled carbon nanotube sidewall functionalization technique has been developed in which solvent is not required and the reaction times are greatly shortened (1 h at 60 °C). Exploiting the long linear dimension of the nanotube ropes by macroscopic mechanical deformation, reactive sites are generated merely by mechanically deforming the tubes using a stir bar. This approach eliminates the need for large volumes of solvent (2- L/g), which were formerly considered essential due to the insolubility of carbon nanotubes. Using a series of 4-substituted anilines and a nitrite, the aryl diazonium intermediates were generated in situ and permitted to react with the tubes. Raman, IR, and UV spectroscopies, coupled with thermogravimetric analyses and solubility studies, support the assignments. Copyright © 2003 American Chemical Society.