The Formation of Black Carbon

Abstract

Electron microscopic evidence is presented in support of the hypothesis that black carbon resulting from pyrolysis of gaseous hydrocarbons is produced through the intermediate formation of droplets of complex hydrocarbons. Electron diffraction studies further confirm this hypothesis if, as has been found for particles of carbon blacks, the droplets consist in part of graphitic nuclei arranged with their basal planes tangential to the droplet surface. The carbonization of small solid spherules of highly cross‐linked organic polymers is described, and it is shown that the morphology of the carbonization products is wholly analogous to those for pyrolytic carbon and carbon blacks. It is suggested, therefore, that the formation of carbon by the carbonization of solids and by deposition from the gas phase occurs through similar mechanisms and that the two processes are simply two extremes in an infinite series of processes which are all fundamentally alike.