A reaction model for plasma coating of nanoparticles in hydrocarbon plasma

A detailed chemical kinetics scheme of the reactions occurring in a CH₄/H₂ plasma is used to model the deposition of amorphous carbon films onto submicron particle suspended in the plasma. The model includes electron-neutral, ion-neutral, and neutral-neutral reactions and solves for the radial distribution of species in the vicinity of the particle. Concentration profiles are obtained by solving simultaneously the diffusion equation for all species that deposit on the particle surface, and the Poisson equation for the charge-carrying species. To accommodate the low-pressure environment, the continuum equations are solved to within one mean-free path from the particle surface while kinetic theory is used to treat phenomena inside the vacuum sphere, i.e., at distances shorter than one mean-free path. Calculations at various plasma conditions and the results observed trends in light of available experimental data are presented. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).