On multiwalled carbon nanotubes oxidation: Thermogravimetric, spectral and macrokinetic studies

Abstract

Multiwalled carbon nanotubes (MWCNTs) were purified and then characterized by nitrogen adsorption, scanning electron microscopy, and energy dispersion X-ray microanalysis. Infrared spectroscopy, Boehm titration, and thermal analysis in air and argon were used to estimate the effect of surface chemistry on the oxidation ability of MWCNTs. From macrokinetic experiments conducted at 450–503°C, the rate constants of MWCNTs oxidation and the parameters of the Arrhenius equation were determined. The oxidation intensity depends on the concentration and nature of the oxygen-containing surface groups. In fact, their thermal decomposition enhances the oxidation rate since frees the surface sites becoming additional active centers of the reaction.