scope:

This document specifies a mild oxidation method to determine the content of carbon impurities (carbon material content not in the form of CNT, include amorphous carbon and trace amount of other types of structured carbon) less stable than multiwall carbon nanotube (MWCNT) by thermogravimetric analysis (TGA) under carbon dioxide atmosphere. This document is applicable to the characterization of carbon impurities content in MWCNT samples prepared by chemical vapour deposition (CVD). Measurement of carbon impurities in MWCNT samples prepared by other method can refer to this document. This method is not applicable to functionalized MWCNT samples or MWCNT samples with encapsulant species. NOTE - This method is applicable for the case of TG curve with a single-stage.