THERMOANALYTICAL INVESTIGATIONS OF FULLERENES

Based on the results of decomposition studies by means of TG it was possible to show the differences of air oxidation of C60 and C70. Mixtures containing both fullerenes form solid solutions and cannot be distinguished by thermoanalytical methods. It was found that these mixtures adsorb oxygen before they decompose. The effect of the heating rate and atmosphere was investigated. DSC curves of pure C60-Fullerite show a sharp endothermic peak between 200 and 270 K which is due to a phase transition. The shape of the peak and the reversible character of this phase transition depends strongly on the sample preparation and purity. Vapor pressure measurements on C60 samples were carried out by the Knudsen method.