Method of purifying carbon nanotubes
US5641466A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1994 |
| Grant date | Jun 24, 1997 |
| Priority date | — |
| Expiry date | Jun 2, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/90
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
A mixture of carbon nanotubes and impurity carbon materials, which include carbon nanoparticles and may possibly include amorphous carbon, is purified into carbon nanotubes of high purity by utilizing a significant difference in oxidizability between the nanotubes and the nanoparticles. The mixture is pulverized and heated in the presence of an oxidizing agent at a temperature in the range from 600.degree. to 1000.degree. C. until the impurity carbon materials are oxidized and dissipated into gas phase. The nanotubes remain almost unoxidized except for loss of some lengths from the tube tips. It is suitable to perform the heating in air or oxygen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.