Agency of Industrial Science and Technology

Kunio Uchida

Fumikazu Ikazaki

Motoo Yumura

Satoshi Ohshima

Yasunori Kuriki

Shigemitsu Shin

Kunio Suzuki

Yoshimichi Kiyozumi

Kiyoshi Yase

Tadao Sekine

Hiroshi Hayakawa

Michiko Yonemura

A process for the isolation of carbon nanotubes from a mixture containing carbon nanotubes and graphite is disclosed, which includes the steps of:

Process for the separation of carbon nanotubes from graphite

Soot containing fullerenes is produced by impressing a DC voltage between a carbonaceous anode and a cathode in an airtight chamber maintained in an inert gas atmosphere to cause arc discharge to occur. After termination of the impression of the DC voltage, an inert gas is blown into the chamber to fluidize the soot. The fluidized soot is discharged from the chamber and is brought into contact with a solvent to recover the fullerenes.

Method and device for the production of fullerenes

Carbon nanotubes are isolated from a mixture containing the carbon nanotubes and graphite particles by a process including the steps of: finely pulverizing the mixture; dispersing the pulverized product in a liquid medium; centrifuging the resulting dispersion to obtain a supernatant containing carbon nanotubes and graphite particles having a particle size of 0.3 .mu.m or less; separating the supernatant into a solid phase and a liquid phase; and calcining the solid phase in an oxygen-containing atmosphere at a temperature sufficient to burn the graphite particles and to leave the nanotubes.

Process of isolating carbon nanotubes from a mixture containing carbon

Carbon nanotubes are produced by successively repositioning an axially extending rod-like carbonaceous anode relative to a cathode surface such that a tip end surface of the anode successively faces on different portions of the cathode surface while impressing a direct current voltage therebetween, so that an arc discharge occur with the simultaneous formation of carbonaceous deposits containing carbon nanotubes on each of the portions of the cathode surface. The carbonaceous deposits are scraped and collected. A device for carrying out the above method includes a driving member for displacing the cathode surface relative to the anode.

Method and device for the production of carbon nanotubes

A novel ceramic material affording a ceramic molded bodies having a high toughness and a high tensile strength is disclosed which comprises a smectite clay mineral having at least a portion of ion-exchangeable cations thereof ion-exchanged with bismuth ions. The ceramic material is prepared by treating a smectite clay mineral with an aqueous solution containing bismuth ions to ion-exchange at least a portion of ion-exchangeable cations thereof with bismuth ions.

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Tsukuba, Japan

Kunio Uchida