Application of the Suzuki–Fraser function in modelling the non-isothermal dehydroxylation kinetics of fullerol

Abstract

The possibility of fitting the non-isothermal kinetics of C60(OH)27 dehydroxylation by the Frazer–Suzuki equation has been investigated. Thermogravimetric curves of fullerol dehydroxylation have been recorded at different heating rates ranging from 5 to 25 K min−1. The curves of fullerol dehydroxylation reaction rate were completely deconvoluted with the two Frazer–Suzuki functions at all heating rates and hence, it was concluded that mechanism of C60(OH)27 dehydroxylation consisted from two dehydroxylation reactions. Reaction components can be connected with the existence of two clusters on fullerene surface that are formed from OH groups. Using Vyazovkin’s isoconversional method, it was found that, for both components, apparent activation energy changes with dehydroxylation degree, meaning that deconvolution using the Frazer–Suzuki function do not decomposes complex reaction of fullerol dehydroxylation on elementary steps. The dependence of activation energies on their dehydroxylation degree for each of the reaction components is the consequence of the existence of activation energy distribution in the form of a narrow peak, which can be further related with unique reaction model function for each dehydroxylation component.