Nanostructure evolution in heat-treated porous carbons derived from PBO polymer
Résumé
The aim of this work was to investigate the effect of porosity development on the subsequent thermal evolution from turbostratic to lamellar nanostructure in carbon fibres derived from poly(p-phenylene benzobisoxazole) (PBO). To this end, PBO chars were activated with carbon dioxide to a burn-off degree of 51 wt.% and then heat-treated at various temperatures comprised between 1600 and 2700 ◦C. The resulting materials were characterised by X-ray scattering and transmission electron microscopy. The observed graphitization mechanism is similar to that previously observed for non-activated materials, despite the fact that more than 51 wt.% of the carbon matrix was removed by the activation stage.