Oxidative treatment and characterization of plasma carbon blacks
Résumé
A series of carbon blacks and fullerene soot was produced by a 3-phase Alternative Current (AC) plasma technology. Surface properties of parent materials and their oxidized homologues were studied by Fourier transform infra red spectroscopy (FT-IR), pH of the point zero charge (pHPZC) and acid/base titration. Presence of chemically bounded oxygen and hydrogen in the parent materials was attributed to the ageing of the materials, while the considerable differences observed in the material reactivity toward nitric acid were associated with properties of nanostructure, governed by conditions of plasma synthesis method. The most stable materials are the carbon blacks having the highly ordered graphitic structure, prepared in thermal plasma process by hydrocarbons cracking. These materials present a low surface reactivity. On the other hand, the fullerene soot, obtained in helium atmosphere from pure carbon, exhibits a very high surface reactivity, induced by structure desorganization and probably the presence of dangling bonds.