One-step gas-liquid detonation synthesis of carbon nano-onions and their tribological performance as lubricant additives

摘要

Carbon nano-onions (CNOs) were synthesized in a few milliseconds by a detonation method using a gas-liquid mixture as the precursor. The composition, morphology and microstructure of products were studied by TEM, XRD, Raman and XPS. Furthermore, the four-ball tests were carried out to investigate the tribological properties of CNOs as lubricant additives. The results showed that the CNOs consisting of spherically concentric graphitic shells with a narrow size distribution about 15.8 nm, which plays the role of "micro bearing" in mechanical lubrication. From the four-ball tests, the friction coefficient and wear scar diameter become slighter and uniform with the addition of CNOs to the base lubricant. When the content of CNOs is about 0.06 wt%, there are minimum frictional coefficient and wear scar diameter.