Gas-phase process for purifying single-wall carbon nanotubes and compositions thereof
US7090819B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 2002 |
| Grant date | Aug 15, 2006 |
| Priority date | — |
| Expiry date | Mar 2, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B2202/02
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
The present invention relates to an all gas-phase process for the purification of single-wall carbon nanotubes and the purified single-wall carbon nanotube material. Known methods of single-wall carbon nanotube production result in a single-wall carbon nanotube product that contains single-wall carbon nanotubes in addition to impurities including residual metal catalyst particles and amounts of small amorphous carbon sheets that surround the catalyst particles and appear on the sides of the single-wall carbon nanotubes and “ropes” of single-wall carbon nanotubes. The purification process removes the extraneous carbon as well as metal-containing residual catalyst particles. The process comprises oxidation of the single-wall carbon nanotube material, reduction and reaction of a halogen-containing gas with the metal-containing species. The oxidation step may be done dry or in the presence of water vapor. The present invention provides a scalable means for producing high-purity single-wall carbon nanotube material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.