SOME APPLICATIONS OF THERMAL-ANALYSIS TO FULLERENES

Thermal analysis is a convenient means of characterizing the soot used as a source of the carbon clusters, the extracted mixture of fullerenes, and the individual clusters themselves. TG in an inert atmosphere will rapidly assay the volatile fractions, presumably the lower molecular weight clusters. TG in oxygen indicates - a slight weight gain for the soots and clusters prior to their combustion. DSC in oxygen is used to determine the heat of combustion for the separated C60 and C70 materials. The combustion occurs around 300-degrees-C for the clusters. There is a small exothermic peak before this which is attributed to the oxidation associated with the slight weight gain. The heats of combustion measured are -18.7 and -21.0 kJ mol-1 for the C60 and C70 respectively. MS-EGA indicates the loss of small amounts of water and argon at temperatures around 250-degrees-C in vacuum and of solvent at about 350-degrees-C prior to sublimation.