Process for derivatizing carbon nanotubes with diazonium species and compositions thereof
Methods for the chemical modification of carbon nanotubes 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, and photochemically induced reactions. 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.
1. A method comprising:
a) selecting a plurality of carbon nanotubes comprising at least semiconducting carbon nanotubes; and
b) reacting the plurality of carbon nanotubes with a sufficient amount of a pre-formed aryl diazonium salt such that at least a portion of the semiconducting carbon nanotubes react to form derivatized carbon nanotubes;
wherein the aryl diazonium salt is pre-formed from an aniline derivative via the aryl amine of the aniline derivative; and
wherein the derivatized carbon nanotubes comprise functional groups introduced by the pre-formed aryl diazonium salt.
2. The method of claim 1 , wherein the plurality of carbon nanotubes is electrochemically reacted with the pre-formed aryl diazonium salt in the presence of a potential.
3. The method of claim 2 , wherein the potential is a negative potential.
4. The method of claim 1 , wherein the plurality of carbon nanotubes is thermally reacted with the pre-formed aryl diazonium salt at a temperature of at most about 200° C.
5. The method of claim 1 , wherein the plurality of carbon nanotubes is thermally reacted with the pre-formed aryl diazonium salt at a temperature of at most about 60° C.
6. The method of claim 1 , wherein the plurality of carbon nanotubes is photochemically reacted with the pre-formed aryl diazonium salt in the presence of a light source.
7. The method of claim 6 , wherein the light source is selected from the group consisting of an ultraviolet light source and a visible light source.
8. The method of claim 1 , wherein the plurality of carbon nanotubes comprises an assembly of carbon nanotubes.
9. The method of claim 8 , wherein the assembly of carbon nanotubes is selected from the group consisting of a bucky paper and a mat.
10. The method of claim 1 , wherein the functional groups are attached to at least the sidewalls of the derivatized carbon nanotubes.
11. The method of claim 1 , wherein the derivatized carbon nanotubes comprise at least about one functional group per about forty carbon nanotube carbon atoms.
12. The method of claim 1 , wherein the derivatized carbon nanotubes comprise at least about one functional group per about thirty carbon nanotube carbon atoms.
13. The method of claim 1 , further comprising:
heating the derivatized carbon nanotubes;
wherein the heating removes at least a portion of the functional groups.
14. The method of claim 13 , wherein the heating is conducted at a temperature of at least about 250° C.
15. The method of claim 13 , wherein the heating is conducted at a temperature of at least about 600° C.
16. The method of claim 1 , wherein the plurality of carbon nanotubes comprises single-wall carbon nanotubes.
17. The method of claim 1 , wherein the plurality of carbon nanotubes comprises multi-wall carbon nanotubes.
18. The method of claim 1 , wherein the functional groups are polymerizable.
19. The method of claim 18 , further comprising:
polymerizing the functional groups.