Crystal growth studies during aerosol synthesis of nanostructured fullerene particles

We have studied crystal growth during aerosol synthesis of nanostructured C60, C70 and mixed fullerene particles. Fullerene particles have been produced by aerosol droplet drying and crystallization as well as via vapor condensation starting from solutions of fullerenes in toluene. Morphology, crystallinity and crystal structure of fullerene particles produced in various processing temperatures were studied by scanning and transmission electron microscopy. The results show that both highly disordered and single crystal particles with a size of about 100 nm are formed at reactor operating temperatures of 500 °C and above. The ultrafine particles formed via vapor condensation are mostly polycrystalline. Many of crystalline particles have perfectly faceted morphology,i.e., hexagonal plate-like, decahedral and icosahedral shapes. The plate-like particles are lamellar-twinned and the decahedral and icosahedral particles are multiply twinned. Crystallite formation and growth mechanisms of the particles are discussed. In addition, electron diffraction results show that fullerene alloys with fcc structure can be produced via aerosol synthesis methods.