Towards Understanding of Arc-Based Synthesis of Carbon Nanotubes*

This work reports on studies of arc-based synthesis of carbon nanomaterials. Applying a set of the in-situ diagnostics of plasma and nanoparticles, our synthesis experiments revealed that the carbon arc forms a highly inhomogeneous plasma consisting of distinguishable regions with different dominant species, including ions, atoms, molecules and clusters, and nanoparticles. Measurements revealed clouds of nanoparticles in the arc periphery bordering the region with a high density of diatomic carbon molecules. Two-dimensional CFD simulations of the arc combined with thermodynamic modeling show that this is due to the interplay of the condensation of carbon molecular species and the convection flow pattern. The formation of nanoparticles is strongly affected by unstable arc behavior.
References are available at nano.pppl.gov