Kinetic analysis of nanodiamonds oxidation

Abstract

This study examines the oxidation kinetics of nanodiamonds (NDs) and carbon black (CB), taken for comparison, in air oxygen . The oxidation rate constants and parameters of the Arrhenius equation were determined under isothermal conditions within a temperature range from 430 to 560 °C. Thermal behavior of both carbon nanomaterials was investigated using non-isothermal thermogravimetric analysis (TGA) experiments in air and argon. Powders of NDs and CB were characterized by nitrogen adsorption, scanning electron microscopy and energy dispersion X-ray microanalysis, ATR Infrared spectroscopy, and the total titration. The effect of various parameters of the carbon nanomaterials on the oxidation rate, such as oxygen content, surface area, ash and admixture contents, and functional groups coverage, was investigated. Overall, this study confirms that the oxygen-containing surface groups generating active sites upon thermal decomposition have a major impact on the oxidation ability of NDs and CB.