Direct-flow method extraction of fullerenes from fullerene soot

The production of fullerene soot with a fullerene content of no higher than 0.1 wt % by fullerene extraction with aqueous solutions of organic compounds has been investigated. It is possible and promising to prepare molded composite sorbents consisting of depleted fullerene soot and a binder namely, polyacryla-mide or a fluoropolymer.

This review concerns the fullerene black, a poorly known nano-sized carbon material, the insoluble residue after extraction of fullerenes from fullerene soot obtained by arc vaporization of carbon material (usually graphite) in a helium atmosphere. This by-product of the production of fullerenes, whose yield reaches 80 wt %, is a finely dispersed material with a particle size of 40–50 nm. It includes amorphous carbon, graphitized particles, and graphite. Test reactions showed the presence in the structure of fullerene black of curved surfaces, and, like fullerenes, of alternating nonconjugated ordinary and double bonds. In addition to the double bonds, its structure includes dangling bonds in the concentration not higher than one per 1200 carbon atoms. Fullerene black absorbs oxygen from the atmosphere and water, and enters into the reactions of nucleophilic addition. The fullerene black cannot be graphitized, and its application is extremely important. The fullerene black was shown to activate hydrogen and thus to undergo a hydrogenolysis in the absence of a catalyst and to catalyze the dehydrogenation and dehydrocyclization of alkanes. This carbon nanomaterial can be used as a sorbent and a catalyst carrier, a tribotechnical additive; it can interact with carbide-forming metals and harden their surface.