Characterisation of commercially CVD grown multi-walled carbon nanotubes for paint applications

Commercially grown, multi-walled carbon nanotubes (MWNTs), available in kilogram quantities from three commercial suppliers have been characterised using a number of analytical techniques. The catalysts used in the growth of the MWNTs are identified by energy dispersive X-ray spectroscopy (EDX) and different growth mechanisms are postulated to explain the various structures present in the MWNT stock in its as-supplied form. A tightening of the agglomerate structures during purification and functionalisation is shown using scanning electron microscopy (SEM) and confirmed More qualitatively using pore-size distributions obtained using the Brunauer-Emmett-Teller (BET) method and non-local density functional theory (NLDFT) calculations. Differences in thermal stability are shown using thermogravimetric analysis (TGA) and are related back to the residual catalysts present. X-ray photoelectron spectroscopy (XPS) is used to confirm functionalisation of certain grades and Raman spectroscopy is used to investigate the level of defects present. (C) 2015 The Authors. Published by Elsevier B.V.