Tuesday, December 18, 2007

US Patent 7309404 - Arc discharge CNT manufacture using charcoal electrodes


The three main methods of carbon nanotube manufacture are laser ablation, CVD, and arc discharge. The arc discharge method forms carbon nanotubes via the application of a direct current discharge between graphite electrodes in a reduced pressure, inert gas atmosphere. This patent from Fuji Xerox teaches using charcoal in place of the graphite for cheaper cost production. Claim 1 reads:

1. A manufacturing method for a carbon nanotube, comprising: applying a voltage between two electrodes whose tips are opposed to each other; generating discharge plasma in a discharge area between the two electrodes; and using an electrode made of a porous carbonaceous material, wherein said porous carbonaceous material is charcoal as at least one of the two electrodes whose tips are opposed to each other.