Monday, December 22, 2008

US patent 7466072 - Low FWHM CNTs

Full width at half maximum (FWHM) diffraction is used to characterize carbon nanotubes and provide an indication of the field emission behavior for the nanotubes. This patent from Samsung includes a very basic claim to a low FWHM diffraction carbon nanotube formed via the arc discharge method and combined with glass frit, ethyl cellulose, methyl acrylic acid, and butyl carbitol acetate. Claim 1 reads:

1. A carbon nanotube having a Full-Width at Half-Maximum of X-ray diffraction that is less than or equal to 0.6.

However, it is not entirely clear to me how this is different from data determined by Smalley's group at Rice back in 1998 (see Fig. 6 and section 3.2 of the article "Large-scale purification of single walled carbon nanotubes: process, product, and characterizations" published in Applied Physics A) which seems to disclose a FWHM of 0.1.