Cu nanoparticles, water-soluble, lubricant additive, tribological properties


Efficient and sustainable use of water-based lubricants is essential for energy efficiency. Therefore, the use of water-lubricated mechanical systems instead of conventional oil lubricants is extremely attractive from the viewpoint of resource conservation. In this study, water-soluble Cu nanoparticles of size approximately 3 nm were prepared at room temperature (around 25 ℃) via in-situ surface modification. The tribological behavior of the as-synthesized Cu nanoparticles as an additive in distilled water was evaluated using a universal micro-tribotester. The results show that the as-synthesized Cu nanoparticles, as a water-based lubricant additive, can significantly improve the tribological properties of distilled water. In particular, the lowest friction coefficient of 0.06 was obtained via lubrication with a concentration of 0.6 wt% of Cu nanoparticles in distilled water, which is a reduction of 80.6% compared with that obtained via lubrication with distilled water alone. It is considered that some Cu nanoparticles entered the contact area of the friction pairs to form a complex lubricating film and prevent direct contact of the friction pairs. Furthermore, some Cu nanoparticles in the solution accelerate the heat transfer process, which also results in good tribological properties.


Tsinghua University Press