US Patent 7481990 - Nanotube segregation via osmylation or ruthenylation

http://www.freepatentsonline.com/7481990.html

This patent from the State University of New York (SUNY) teaches separation chemistries for sorting nanotubes based on osmium tetroxide or ruthenium tetroxide. Claims 1 and 2 read:

1. A method of aggregating carbon nanotubes, the method comprising:

(a) providing a nanotube dispersion, wherein the nanotube dispersion comprises a plurality of carbon nanotubes, osmium tetroxide and a solvent; and

(b) irradiating the nanotube dispersion with ultraviolet light until the carbon nanotubes aggregate, wherein the metallic carbon nanotubes are selectively osmylated.

2. A method of aggregating carbon nanotubes, the method comprising:

(a) providing a nanotube dispersion, wherein the nanotube dispersion comprises a plurality of carbon nanotubes, ruthenium tetroxide and a solvent; and

(b) irradiating the nanotube dispersion with ultraviolet light until the carbon nanotubes aggregate, wherein the metallic carbon nanotubes are selectively ruthenylated.