| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for purifying a tubular inorganic substance, whereby the tubular inorganic substance can be prevented from being broken, and the yields can therefore be improved. SOLUTION: A dielectric liquid 20 is previously placed in a container 12, and unpurified carbon nanotubes (CNT) are fed into a dielectric liquid 20 in a feed container 19 and dispersed therein. While the dielectric liquid 20 in the container 19 is kept in a state in which an alternating high voltage is applied thereto, the dielectric liquid 20 in the container 19 is fed into the container 12. When the voltage is applied, the CNTs are electrostatically oriented to establish a state in which one end of each CNT is directed toward the side of an electrode 14, and the other end is directed toward the side of an electrode 15 and are arranged on a line as the result of the attraction among the ends on each side. Due to the difference in sedimentation rate, the lowermost layer comprising the metal catalyst residues, the CNTs thereon, and the uppermost layer comprising graphite, fullerene, etc., are deposited on the bottom of the container 12. The dielectric liquid 20 is discharged by opening a cock 18, the graphite, etc., are withdrawn from the top, and then the CNTs are withdrawn from the top. COPYRIGHT: (C)2004,JPO
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