Generation of nanometer size fullerene particles via vapor condensation

Ultrafine (30–40 nm) fullerene particles were generated via vapor condensation in a continuous flow system starting from pure C₆₀ and mixed fullerene extract (C₆₀/C₇₀). Gas-phase particle size distributions were measured using a condensation particle counter and differential mobility analyzer. Particle morphology and crystallinity were studied by SEM and TEM. Particles were partly amorphous at 400°C, and became crystalline C₆₀ when processed above 500°C. The particles had an average size of 30, 35 and 40 nm and total number concentrations of 2.2×10⁶, 3.5×10⁶, and 5.0×10⁶ number of particles/cm³, respectively at 500, 525 and 550°C.