Generation of nanophase fullerene particles via aerosol routes

Nanocrystalline and nanometer-size fullerene particles have been generated by aerosol routes starting from a solution of mixed fullerene extract in toluene. Nanocrystalline fullerene particles have been produced by spray drying, and ultrafine particles have been formed by vapor condensation. Gas-phase particle size distributions were determined with a differential mobility analyzer, and particle morphology and crystallinity were studied by scanning and transmission electron microscopies. When the processing temperature was increased from 20 to 400 °C, the average particle size was reduced from 140 to 100 nm due to particle densification. At higher temperatures of 500 and 600 °C, nanometer-size (about 20 nm), spherical fullerene particles were formed via vapor condensation. Transmission electron microscopy analysis indicated that a few nanometer-size crystallites were formed already at 200 °C and the crystallite size was increased to about 10 nm at 500 °C.