Patent ID: 7781635

Claim:
A method for producing purified nanotubes, said method comprising the steps: (a) providing unrefined nanotubes; (b) providing a nonpolar solvent; (c) mixing into said nonpolar solvent a cation to form a purifying phase, said cation having the formula: wherein each R independently is H or a halogen; R 1 and R 2 independently are H, a halogen, or CH 3 ; and R 3 is an aliphatic moiety of formula C n A m with n≧1 and m≧n, and where each A independently is H or a halogen; (d) mixing into said purifying phase said unrefined nanotubes; (e) combining with said purifying phase and said unrefined nanotubes a polar solvent, said polar solvent being substantially immiscible with said nonpolar solvent; (f) allowing said purifying phase and said polar solvent to substantially separate, whereby purified nanotubes remain suspended in said purifying phase; and (g) extracting said purified nanotubes from said purifying phase.