Tee, Jia Chee and Aziz, Madzlan and Ismail, Ahmad Fauzi (2008) Effect of reaction temperature and flow rate of precursor on formation of multi-walled carbon nanotubes. Jurnal Teknologi, 49F . pp. 141-147. ISSN 0127-9696
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Abstract
The effect of reaction temperature and flow rate of precursor on the quantity and quality of the multi-walled carbon nanotubes (MWNTs) produced by catalytic chemical vapour deposition (CCVD) was studied. The MWNTs were grown over molecular sieve supported catalyst at 700 and 850 °C with flow rate of acetylene at 15 and 30 sccm. The effect of an in-situ heat treatment on the as-grown MWNTs at 200 °C was investigated. Thermogravimetric analysis (TGA) results show that CNT purity decreases with increasing reaction temperature, from 63.31 wt% at 700 °C to 61.68 wt% at 850 °C. However, the increase of acetylene flow rate from 15 sccm to 30 sccm has improved the yield of MWNT from 63.31 wt% to 69.28 wt%. The MWNTs grown at 850 °C with 30 sccm of acetylene show 68.23 wt% of purity, attributed to the higher acetylene flow rate. Acetylene flow rate of 30sccm produced higher purity of MWNTs whereas reaction temperature of 700 °C is more effective in generating MWNTs. The in-situ heat treatment at 200 °C gave the highest purity of MWNTs at 87.52 wt%. TEM and HRTEM images suggest that the impurities on the wall layers of MWNT yield were burn off at 200 °C. The in-situ heat treatment is able to reduce the impurities and hence yielded higher purity MWNTs.
Item Type: | Article |
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Uncontrolled Keywords: | reaction temperature, flow rate of precursor, multi-walled carbon nanotubes, in-situ heat treatment, purity |
Subjects: | T Technology > TP Chemical technology |
Divisions: | Chemical and Natural Resources Engineering |
ID Code: | 8661 |
Deposited By: | Norhayati Abu Ruddin |
Deposited On: | 06 May 2009 06:51 |
Last Modified: | 10 Aug 2014 03:16 |
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