The invention incorporates new processes for the 
chemical modification of carbon nanotubes. Such processes involve the 
derivatization of multi- and single-wall carbon nanotubes, including small 
diameter (ca. 0.7 nm) single-wall carbon nanotubes, with diazonium species. The method allows the chemical attachment of a variety of organic compounds to the side and ends of carbon nanotubes. These chemically modified nanotubes have applications in 
polymer composite materials, molecular electronic applications, and-sensor devices. The methods of 
derivatization include electrochemical induced reactions, thermally induced reactions (via in-situ generation of 
diazonium compounds or pre-formed 
diazonium compounds), and photochemically induced reactions. The 
derivatization causes significant changes in the spectroscopic properties of the nanotubes. The estimated degree of functionality is ca. 1 out of every 20 to 30 carbons in a 
nanotube bearing a functionality 
moiety. Such electrochemical reduction processes can be adapted to apply site-selective 
chemical functionalization of nanotubes. Moreover, when modified with suitable 
chemical groups, the derivatized nanotubes are chemically compatible with a 
polymer matrix, allowing transfer of the properties of the nanotubes (such as, 
mechanical strength or electrical 
conductivity) to the properties of the 
composite material as a whole. Furthermore, when modified with suitable 
chemical groups, the groups can be polymerized to form a 
polymer that includes carbon nanotubes.