Preferential Gas Phase Reactions of Carbon Nanotubes (CNTs)
Fahd M Rajab
Correspondence Address :
Fahd M Rajab
Centre of Sensors and Electronic Devices
Department of Chemical Engineering
Received on: September 27, 2018, Accepted on: October 01, 2018, Published on: October 08, 2018
Citation: Fahd M Rajab (2018). Preferential Gas Phase Reactions of Carbon Nanotubes (CNTs)
Copyright: 2018 Fahd M Rajab. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Gas phase reactions including metal catalysts at elevated temperatures and pressures can be used for both growth and purification of carbon nanotubes. Chemical vapor deposition (CVD) is used at optimized conditions to grow multiwall carbon nanotubes (MWCNTs) utilizing iron seed catalysts. Carbon dioxide (CO2) extractions are performed at the optimum extraction conditions to enhance metal catalyst removal efficiency. The analytical studies included Thermogravimetric analysis to evaluate metal catalyst removal, Raman spectroscopy and fluorescence spectroscopy to assess the properties of the treated carbon nanotubes as well as Transmission electron microscopy to evaluate metal size and size distribution of metal impurities before and after purification. A significant result is that using carbon dioxide leads to better extraction efficiency at higher temperatures and intermediate pressures. A single extraction at 65 degree C and 325 atm shows 16.7 wt % of final ash content compared with 20 wt % for multiple extractions at 45 degree C and 325 atm.
Keywords: Single wall carbon nanotubes, Metal catalyst impurities, Carbon dioxide