Purification of boron nitride nanotubes

A purification process was developed for the first time for boron nitride (BN) nanotubes. BN nanotubes, prepared using a ball milling and annealing method, contain a high yield of nanotubes and a small amount of BN and metal catalyst particles. The metal particles can be dissolved in an HCl solution. Fine BN nanoparticles and thin layers were first converted to water soluble B₂O₃ via a partial oxidation treatment at 800 °C. The oxide particles and layers can then be dissolved in hot water. Thermogravimetric analysis has been used to determine an adequate oxidation temperature at which fine BN particles were oxidized.<br />