2015-05-042015-05-042012-03-06Mackeyev, Yuri and Wilson, Lon J., "Facile purification of carbon nanotubes with liquid bromine at room temperature." Patent US8128901B2. issued 2012-03-06. Retrieved from https://hdl.handle.net/1911/80083.https://hdl.handle.net/1911/80083A method of removing metal impurities from carbon nanotubes includes treating carbon nanotubes with distilled bromine in a substantially oxygen- and water-free atmosphere and then removing the distilled bromine from the carbon nanotubes. Purified carbon nanotubes having an iron content from about 2.5 to about 3.5 by weight that are substantially free of derivatization at the ends and defect sites are made available via this method.15 ppengUtility patentUS8128901B2