US Patent 7935175 - Magnetic trapping of CNTs

http://www.freepatentsonline.com/7935175.html

In some manufacturing methods filters are used to separate carbon nanotubes from an exhaust gas. However, these filtrers can become clogged which decresases the efficiency of nanotube extraction. This patent from Semes Co. teaches instead using a magnetic means for separation. Claim 1 reads:

1. A carbon nanotube trapping apparatus for trapping carbon nanotubes generated at a reaction tube, comprising:

a housing including an inner space through which an exhaust gas including carbon nanotubes grown on a metal catalyst passes, the housing having an inner circumferential surface of non-magnetized material; and

a magnetic block installed at the housing and configured to trap the carbon nanotubes grown on the metal catalyst on the inner surface of the housing by using a magnetic force.