Method for purification of as-produced single-wall carbon nanotubes

US6936233B2 · kind B2 · utility

Assignee

• William Marsh Rice University · US

Inventors

• Richard E. Smalley · Houston, US
• Daniel T. Colbert · Houston, US
• Hongjie Dai · Sunnyvale, US
• Jie Liu · Houston, US
• Andrew G. Rinzler · Newberry, US
• Jason H. Hafner · Houston, US
• Kenneth A. Smith · Houston, US
• Ting Guo · Davis, US
• Pavel Nikolaev · Houston, US
• Andreas Thess · Aspenhausiedlung, DE

Key dates

• Filing date: Dec 28, 2001
• Grant date: Aug 30, 2005
• Expiry date: Mar 23, 2023

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/30
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

This invention relates generally to a single-wall carbon nanotube (SWNT) purification process and more particularly to a purification process that comprises heating the SWNT-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, SWNT-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 single-wall carbon nanotube material will be etched to a significant degree. When material having a high proportion of SWNT is purified, the preparation produced will be enriched in single-wall nanotubes, so that the SWNT are substantially free of other material.