The present invention is directed to novel processes for the functionalization (derivatization) of carbon nanotubes and, as an extension, to fullerenes and other carbon surfaces. Generally, such processes involve reductive pathways. In some embodiments, carbon nanotubes are reacted with alkali metal and organic halides in anhydrous liquid ammonia. In other embodiments, polymers are grown from carbon nanotube sidewalls by reacting carbon nanotubes with alkali metal and monomer species in anhydrous liquid ammonia.