The effect of different kinds of inert gases and their pressures on the preparation of carbon nanotubes by carbon are method

The preparation of carbon nanotubes in argon atmosphere was compared with that in helium atmosphere by carbon are method at a pressure ranging from 80 to 680 Ton. The investigations of preparation conditions, the rate of graphite rod consumption, the growth rates of cathode deposits and the efficiency of converting consumed graphite into deposits in different inerts and their pressure have been carried out. The effect of Ar atmosphere and He atmosphere on the preparation of nanotubes and C-60/70 are compared. The diameter distributions of nanotubes produced in Ar and He gas are also examined by TEM observation. Oxidation process under the same conditions show that the sample prepared in Ar atmosphere has fewer nanoparticles and more nanotubes than those prepared in He atmosphere. (C) 1999 Elsevier Science S.A. All rights reserved.