Controllable preparation of submicrometer single-crystal C60 rods and tubes trough concentration depletion at the surfaces of seeds

Single-crystal submicrometer rods and tubes of C-60 with highly uniform size and shape were produced from a solvent-induced and surfactant assisted self-assembly technique. The length and length-to-width ratio of both rods and tubes were tunable by controlling the concentration of C-60 in the stock solution. The transformation from rod to tube was achieved by simply varying the volume ratio of two solvents. Fourier-transform infrared and Raman spectroscopy, X-ray diffraction and high-resolution transmission electron microscopy revealed the detailed structures of the rods and tubes. We proposed a concentration profile based growth model to describe the self-assembly process of C-60 subunits. This study may contribute to better understanding of chemistry of fullerenes in solutions and extend the surfactant-assisted self-organization of inorganic system to fullerene system.