SYNTHESIS OF CARBON NANOSTRUCTURES BY INDUCTION HEATING
ASSISTED CCVD METHOD
D. Lupu 1 , A.R. Biriş 1 , I. Mişan 1 , G. Mihăilescu 1 , L. Olenic 1 , S. Pruneanu 1 , A.
Jianu 2 , C. Bunescu 3 , A. Weidenkaff 4 , C. Diecker 4
1
National Institute for Research and Development of Isotopic and
Molecular Technologies, P.O. Box 700, 400293 Cluj-Napoca,
Romania
2
National Institute of Materials Physics, P.O. Box MG-7, RO-
76900
3
Hochschule Wismar, PO Box 1210, D-23952, Wismar, Germany
4 Institute of Solid State Chemistry, Universität Augsburg,
Universitätsstr. 1, D-86159 Augsburg, Germany
The carbon-based materials and nano-scale sciences are envisaged as major fields of the 21 st
Century technology. The extensive work on carbon nanotubes, started just after their discovery resulted in thousands papers and patents regarding both fundamental and technical aspects.
The main challenge in working with carbon nanotubes is their synthesis [1] and new techniques are examined in many laboratories to develop methods able to lead to carbon nanotubes with controlled characteristics and suitable for large scale production.
It is usually accepted that the catalytic decomposition of hydrocarbons (CCVD) on solid
(catalyst) surfaces seems a viable method for large scale production with low energy consumption.
The induction heating was used [2] for high temperature laser synthesis of single wall carbon nanotubes and it seemed attractive to be coupled with the CCVD method. In this paper, some experiments are reported about the CCVD method assisted b y induction heating (IH). The common, outer furnace, technique is replaced by the inductive high frequency heating of a susceptor on which the catalyst is disposed. Various susceptors have been tried: titanium rod, graphite and molybdenum. The catalysts us ed were metal
(Fe, Co Ni)/oxide support with various hydrocarbons as carbon source, usually with the intent to reproduce literature data and to compare the effects of the two heating modes ( outer furnace and IH ) on the characteristics of the products. D epending on the experimental conditions, various carbon nanostructures have been obtained: carbon nanofibers, multiwall carbon nanotubes (MWNT) and single wall carbon nanotubes
(SWNT).
The IH heating mode allows very fast heating rates to reach the reacti on temperature and higher temperatures than those obtained with usual outer furnaces can be easily achieved. Some advantages of this modified, CCVD-IH, technique are: versatility, much lower energy consumption (at least 2-3 times) and overall reaction time shortening as compared to the outer furnace technique.
[1]. M . D r e s s e l h a us in Materials Today 2002, 5: 11: 48
[2]. T . G e n n e t t , A . C . D i l l o n , J . L. A l l e ma n, K . M . J o ne s , P . A . P a r i l l a , M . J . H e b e n, Mat. Res.
Soc. Symp. Proc. vol. 633 (2001): A2.3.1-6