Laurent Fulcheri

Carbon nanostructures production by gas-phase plasma processes at atmospheric pressure

Carbon nanostructures have received much attention for a wide range of applications. This paper reviews the historical role of plasmas in the gas-phase synthesis of carbon nanostructures and the present plasma technologies for industrial production purposes. It enumerates the advantages and disadvantages with respect to concurrent technologies commonly employed nowadays. Finally, some carbon nanostructures produced in our laboratory will serve as examples of the plasma processes potential.

Unsteady state analysis of free-burning arcs in a 3-Phase AC plasma torch: comparison between parallel and coplanar electrode configurations

An MHD model with parallel electrode configuration was developed to determine the influence of the electrode configuration on 3-Phase arc discharge behavior. The results obtained with this model were compared to previous results obtained with coplanar graphite electrode configuration. Results show a different arc behavior in both cases. In a parallel electrode configuration, the arcs are not confined within the inter-electrode gap as in coplanar electrode configuration. These results were compared to the arc behavior observed with a high-speed video-camera in a nitrogen atmosphere with a high correlation. The influence of frequency and current was also investigated. By adjusting the electrode configuration, the arc elongation and the dissipated power could be controlled. According to the application, such as plasma-assisted combustion, plasma gasification, plasma spray or for different plasma gases, the electrode configuration could play a key role to improve the discharge or operation. This study gives us a better understanding of 3-Phase AC arc plasma discharge.

Synthesis of Titania Nanoparticles Using a Compact Nonequilibrium Plasma Torch

A compact plasma torch has been developed to synthesize titania nanoparticles at atmospheric pressure. It is operated at high-voltage (>700 V) and low-current (<0.4 A) conditions, and its typical discharge power is in the range 200–500 W. Titania nanoparticles were synthesized by oxidizing titanium tetraisopropoxide vapor in the plasma torch. The synthesized titania particles are a mixture of rutile and anatase with a mean crystallite size between 30 and 50 nm. This plasma torch can be used to generate atmospheric nonequilibrium plasmas for facile and environmental friendly synthesis of various nanoparticles.