A kind of novel core-shell Cu-Sn bimetallic nanoparticles has been prepared by a new method (displacement method), in which Sn was made to cover on the surface of Cu nano-core. The preparation method and reaction mechanism have been discussed. This reaction happened under the existence of coordinate agent-(NH2)(2)CS and protective agent PVP. The nanoparticles prepared were with a core-shell structure, granule diameter between 50100 nm and good dispersing capability. The Cu-Sn nanoparticles proposed has better oxidation-resistant ability than Cu nanoparticles with corresponding granule diameter and can be applied as lubricant additives as well as antibacterial agent. When the additive amount is very low (0.1wtparts per thousandsimilar to0.5wtparts per thousand), it can improve the P, of the lubricant by 92%similar to106%, and also enhance its antiwear characteristics and friction-reducing properties. At the concentration of 1000 ppm, it can reach an antibacterial ratio of 99.99%.
