Opening and purification of carbon nanotubes in high yields


  • We thank M. M. J. Tracey and M. E. Bisher for the micro X-ray analysis of the sample. Since submission of this manuscript, a method for opening nanotubes by nitric acid has been reported (Tsang et al., Nature1994, 372, 159) and also confirming that nanotubes are wet by low surface tension liquids such as solvents as predicted in [7].


Gram-quantities of pure carbon nanotubes (see Figure) can be produced using a new method reported here. The nanotubes, which can be thought of as cylindrical graphitic microcrystals, are opened and purified by treating them with a mixtue of sulfuric acid and potassium permanganate. The opening of the nanotubes on a large scale is also of interest in terms of filling the tubes with interesting guest molecules.

original image