Method for purification of as-produced fullerene nanotubes
US7354563B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 2006 |
| Grant date | Apr 8, 2008 |
| Priority date | — |
| Expiry date | Aug 22, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/30
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
This invention relates generally to a fullerene nanotube purification process and more particularly to a purification process that comprises heating the fullerene nanotube-containing felt under oxidizing conditions to remove the amorphous carbon deposits and other contaminating materials. In a preferred mode of this purification procedure, the felt is heated in an aqueous solution of an inorganic oxidant, such as nitric acid, a mixture of hydrogen peroxide and sulfuric acid, or a potassium permanganate. Preferably, fullerene nanotube-containing felts are refluxed in an aqueous solution of an oxidizing acid at a concentration high enough to etch away amorphous carbon deposits within a practical time frame, but not so high that the fullerene nanotube material will be etched to a significant degree. When material having a high proportion of fullerene nanotubes is purified, the preparation produced will be enriched in fullerene nanotubes, so that the fullerene nanotubes are substantially free of other material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.