Gas-phase particle size distributions during vapor phase condensation of fullerenes

Nanometer-size fullerene particles were generated via vapor condensation in a continuous flow system starting from pure C60 and mixed fullerene extract (C60/C70). Vapor condensation was carried out by cooling a nitrogen gas stream containing fullerene vapors from 400–650°C to room temperature. Particles were partly amorphous at 400°C, and became crystalline C60 when processed above 500°C. The average particle diameter and particle number concentration increased with increasing processing temperature. The particles had average sizes of 30, 35 and 40 nm and total number concentrations of 2.2 × 106, 3.5 × 106, and 5.0 × 106 #/cm3, respectively at 500, 525 and 550°C.