Does carbon prefer flat or curved surfaces?

The presence of fullerene- and nanotube-like elements in carbons prepared from saccharose and anthracene by slow pyrolysis and then heat treated at 1000 degreesC, 1900 degreesC, and 2300 degreesC has been revealed using Raman spectroscopy. High energy X-ray diffraction has been used to examine the effect on these carbons of heat treatment. Tendency to graphitization of the anthracene-based carbon and resistance to graphitization of the saccharose carbon will be considered in the light of the formation of curved graphitic networks and cages. The obtained results lead us to propose a model of the structure of non-graphitizing and graphitizing carbons.