A New Route to Graphene Starting from Heavily Ozonized Fullerenes: Part 3 - an Electron SPIN Resonance Study

It is shown that graphite oxide (GO) and heavily ozonized C60 and C70 fullerenes known as "fullerene ozopolymers" are both paramagnetic materials with a very strong ESR signal at room temperature. When thermally annealed also the paramagnetic centres are gradually lost in large part. This occurs already at 350°C in the case of GO while for the fullerene ozopolymers a higher temperature is required, reaching at the end the same results. The half width of the ESR signal is linked to the distribution of the paramagnetic centres. Once again, striking analogies were found in the half width of the ESR signal measured on GO and on fullerene ozopolymers at least in the temperature range comprised between 25°C. and 450°C. Similarly, the same g-factor values, which are diagnostic for the understanding of the chemical nature of the paramagnetic centres, were found both on GO and on fullerene ozopolymers in all ranges of temperature considered.