Preparation and tribological properties of surface-modified ZnS nanoparticles

Surface-modified ZnS nanoparticles have been fabricated, and the morphologies and crystalline structures of the powder have been characterised by transmission electron microscopy, X-ray diffraction and Fourier transformation infrared spectrum. The tribological properties of the surface-modified ZnS (SM-ZnS) nanoparticles as an additive in PEG400 were evaluated with a four-ball tester. It was found that the as-prepared SM-ZnS nanoparticles had a very narrow size distribution, with the average diameter about 5–10 nm. The SM-ZnS nanoparticles as the additive led to an obvious improvement in the anti-wear and friction-reduction properties of the synthetic PEG400. Analysis indicated that a boundary film was formed during the friction process. Copyright © 2014 John Wiley & Sons, Ltd.