US Patent 7591989 - Plasma torch fabrication of SWCNTs

http://www.freepatentsonline.com/7591989.html

This patent teaches a new method of single walled carbon nanotube production requiring less energy than conventional methods while avoiding the simultaneous production of multiwall carbon nanotubes. Claim 1 reads:

1. A method for producing single-wall carbon nanotubes comprising:

feeding an inert gas through a plasma torch to form an inert gas plasma;

injecting a carbon-containing substance and a metal catalyst in said inert gas plasma, downstream of said inert gas feed, in order to form a plasma comprising atoms or molecules of carbon and atoms of said metal;

condensing said atoms or molecules of carbon and said atoms of said metal to form single-wall carbon nanotubes; and

recovering said single-wall carbon nanotubes.