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The oxidation of carbon nanotubes, C60 and graphite was studied by thermogravimetric (TG) analysis and differential thermal analysis (DTA) technique, and the oxidation kinetic models of three carbon materials studied were analyzed by mechanism-function method. The results indicate that three carbon species adopt different oxidation mechanisms due to their different structures. The oxidation of carbon nanotubes with cylindrical structure follows contracting volume reaction mechanism [R3 mechanism, 1-(1-α)1/3 = kt], indicating that the oxidation of carbon nanotubes takes place from the ends to the center. For graphite with planar sandwich structure, the oxidation starts at the edges initially and gradually moves toward the center, which corresponds to contracting area phase boundary reaction mechanism [R2 mechanism, 1-(1-α)1/2 = kt]. The oxidation of C60 with spherical structure, however, is complex and apparently cannot be illustrated with a single kinetic model. The values of apparent activation energy
The oxidation of carbon nanotubes, C60 and graphite was studied by thermogravimetric (TG) analysis and differential thermal analysis (DTA) technique, and the oxidation kinetic models of three carbon materials studied were analyzed by mechanism-function method. The results indicate that three carbon The phenomena of different oxidation mechanisms due to their different structures. The oxidation of carbon nanotubes with cylindrical structure following contracting volume reaction mechanism [R3 mechanism, 1- (1-α) 1/3 = kt], indicating that the oxidation of carbon nanotubes takes For graphite with a planar sandwich structure, the oxidation starts at the edges initially and gradually moves toward the center, which corresponds to a contracting area phase boundary reaction mechanism [R2 mechanism, 1- (1-α) 1 / 2 = kt]. The oxidation of C60 with spherical structure, however, is complex and apparently can not be illustrated with a single kinetic model. The values of apparen t activation energy