Tribological behavior of a novel fullerene complex

A novel cucurbit[8]uril–fullerene complex was synthesized via ultrasonic. The product was characterized by UV/vis, FTIR, elemental analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results of elemental analysis demonstrate that the cucurbit[8]uril–fullerene complex was formed by the 1:2 intermolecular inclusion mode. TEM analysis shows that it exists some sphere structures with size in the range of 15–20 nm, which are joined together through approximately 6–8 units of the inclusion complex of cucurbit[8]uril with two fullerene molecules. Four-ball tests shows that the addition of a certain concentration of the fullerene complex to base stock (2 wt.% triethanolamine aqueous solution) can effectively increase both the load-carrying capacity (PB value), and resistance to wear. SEM observations confirm that the additive results in a reduced diameter of the wear scar and decreased wear.