PAIRING OF PENTAGONAL AND HEPTAGONAL CARBON RINGS IN THE GROWTH OF NANOSIZE CARBON SPHERES SYNTHESIZED BY A MIXED-VALENT OXIDE-CATALYTIC CARBONIZATION PROCESS

Carbon spheres have been synthesized using a mixed-valent oxide-cataly tic carbonization process in macroscopic quantities and at low cost. T he technique uses natural gas and reusable catalysts and produces no e nvironmental waste or pollution. The product is all solid spheres (sim ilar to 210 nm) comprised of layered graphitic flakes. Microstructures of the spheres are studied by transmission electron microscopy. The s phere is believed to be nucleated from a pentagon carbon ring followed by a spiral shell growth. When the sphere grows larger, graphitic fla kes are nucleated on the surface due to the formation of paired pentag onal-heptagonal (P-H) carbon rings. A combination of the P-H pairs wit h the hexagonal networks produces eight basic graphitic configurations for forming the sphere, and they have been observed experimentally.