Study on the purifying of carbon nanotubes

A new method of purifying carbón nanotubes was described. The raw nanotubes were first pretreated by alkali. Alkali is a dispersed agent, which can enhance carbon particles to react with oxide agent and separate carbon nanotubes from other forms of carbon. Mixture of H2SO4 and HNO3 is used as oxidation agent. The influences of temperature, ratio of H2SO4 to HNO3, reaction time were studied, and the optimum condition of reaction were obtained. The reaction time is 2 h, ratio of H2 SO4 to HNO3 ( ratio of volume) is 3:1. The mechanism of purifying has been explained.