Synthesis of mono-dispersed nano-scale fullerene (C₆₀) crystals

Fullerene (C₆₀), which has a unique molecular structure, was used in the preparation of crystalline organic nano-crystals. Fullerene was dissolved in toluene and this fullerene solution was mixed with water drastically. During this process, fullerene transferred from toluene to water phase. The significantly different solubility of fullerene in a toluene/water solvent system played an important role in the self-assembly of single fullerene nano-crystals, as it is called drowning-out crystallization. In addition, pH of water was controlled to carry out the interfacial transference of fullerene. An optical spectrum analysis showed that the fullerene was transferred by a hydrolysis reaction from toluene to water, depending on the pH and toluene involved in the crystal structure. During the interfacial transference, the growth of nano-scale fullerene occurred at pH > 7. Importantly, fullerene nanocrystals were formed with a mono-dispersed square structure on a nano-scale (104 nm average size and 1.03 ± 0.24 aspect ratio) at pH 10.