Diazonium-based functionalization of carbon nanotubes: XPS and GC-MS analysis and mechanistic implications

A reaction product analysis of single wall carbon nanotubes functionalized by solvent-free and aqueous-based arenediazonium species is discussed. Both GC-MS on the thermolysis products along with XPS analysis of the materials, suggests that the only functionality on the SWNT is the arene group. The mechanism is indicative of either direct aryl radical addition to the SWNT or (a) electron injection from the nanotube to the arenediazonium species, (b) reaction of the SWNT-radical cation with an aryl radical, followed by (c) an electron transfer to the nanotube. A method for defunctionalizing the nanotubes is disclosed wherein the SWNTs are resuspendable in organic solvent.