Purification of carbon nanotubes by vacuum high temperature

Purification of carbon nanotubes by vacuum high temperature treatment (Chinese
Application Number(s): 03120818.5
Inventor Name(s): WANG Y, WEI F, LUO Guohua, HUANG Wei
Patent Assignee Name(s) and Code(s): UNIV QINGHUA (UYQI)
NOVELTY - The present invention relates to vacuum high temperature purification of
carbon nanotubes.
DETAILED DESCRIPTION – This invention provides a feasible method of obtaining
super-highly purified carbon nanotubes. Transition metal catalysts (Fe, Co, Ni, Mo)
and metal catalyst carriers (Al2O3, MgO, SiO2), which remain in the raw product of
carbon nanotubes produced by catalytic chemical vapor deposition method, can be
efficiently eliminated by a vacuum high temperature operation. After heated at
2000℃ for 5 hours, the purity of carbon nanotubes can be increased from 86% to
99.93%,and the content of the transition metal is reduced to 0.05%. Under the
permitted temperatures, the simple and efficient purification process will not cause
any damage to carbon nanotubes.