Abstract: The present invention is generally directed to methods of functionalizing carbon nanotubes (CNTs) in acidic media. By first dispersing CNTs in an acidic medium, bundled CNTs can be separated as individual CNTs, affording exposure of the CNT sidewalls, and thereby facilitating the functionalization of such CNTs, wherein functional groups are attached to the subsequently exposed sidewalls of these individualized CNTs. Once dispersed in this substantially unhundled state, the CNTs are functionalized according to one or more of a variety of functionalization processes. Typically, ultrasonication or non-covalent wrapping is not needed to afford such dispersion and subsequent functionalization. Additionally, such methods are easily scalable and can provide for sidewall-functionalized CNTs in large, industrial-scale quantities.

Abstract: The present invention is directed towards methods of thermally defunctionalizing functionalized (derivatized) carbon nanotubes (CNTs) in solution or suspended in a liquid medium. Such defunctionalization largely comprises the removal of sidewall functionality from the CNTs, but can also serve to remove functionality from the CNT ends. Such methods facilitate the resuspension of such defunctionalized CNTs in various solvents and permit the defunctionalization of functionalized CNTs that would normally decompose (or partially decompose) upon thermal treatment. Such methods of defunctionalization can typically lead to defunctionalized CNTs that are essentially pristine (or nearly pristine), and which, in contrast to prior art methods of thermal defunctionalization, can be easily resuspended in a variety of solvents.

Abstract: The present invention provides methods by which carbon nanotubes can be functionalized under solvent-free conditions. As extremely large quantities are typically required to dissolve or disperse carbon nanotubes, solvent elimination the processes more favorable for scale-up. Such processes are also amenable to a wide variety of chemical reactions are functionalizing agents.