Dependence of Discharge Conditions on Characteristics of Nano-Carbon Material Synthesized by Plasma in Liquid

Abstract

Plasma generated in xylene by an application of bipolar pulsed voltage is used to synthesize nano-carbon materials. Characteristics of the synthesized materials such as structure, surface area, and pore diameter are evaluated for various discharge conditions. The synthesized carbon consists of spherical primary particles with sizes ranging from 20 to 50 nm which has a randomly stacked lattice structure with aliphatic chains. Although the structure is not dependent on voltage parameters, surface area decreases with increasing frequency while voltage amplitude and pulse width have less effect. When plasma is generated with high speed solvent flow accompanied by generation of cavitation bubbles, tubular structure in synthesized materials is observed in addition to the spherical particles. Fast transportation of radicals from the plasma reaction field may change the synthesis mechanism of carbon materials.