Chemistry of aromatic growth and carbon formation in CVDand correlations with carbon textures

摘要

Experimental results on the composition of gaseous and condensable products obtained for a CVD experiment leading to ahigh-textured carbon (surface area / volume ratio of the substrate of 3.2 mm-1, 1100℃, 40 kPa methane pressure) were usedto investigate the most probable reaction mechanisms of aromatic growth. The major mechanisms are aryl-aryl addition,intramolecular dehydrocyclization and ethine addition reactions. It is postulated that the formation of planar, fully condensedstructures is favored from a gas phase with a special or optimum ratio of aromatic species to small linear species with ethineas the major component. This model is called the particle-filler model in analogy to the formation of dense packings.Aromatic species are the molecular particles undergoing aryl addition and dehydrocyclization reactions, small linearhydrocarbons are the molecular filler, mainly necessary for closing bays of open, not fully condensed aromatic structures.