Synthesis and Tribological Behavior of Surface Coated Cu Nanoparticles in Liquid Paraffin

Abstract

The Cu nanoparticle surface coated with S-hexyl N,N-dihydroxyethyldithiocarbamate (SHNDD) was synthesized by the controlled reduction ofaqueous copper salts using the modified Brust synthesis. Themorphology, structure and thermal properties of the modified Cunanoparticles (SHNDD-nano Cu) was investigated by means of transmissionelectron microscopy, X-ray powder diffraction, Fourier transforminfrared spectrum, and thermogravimetric analysis. As the results ofTEM and IR spectrum shown, the size of as-prepared nanoparticles isabout 6 rim and existence of the organic carbon chain on the surface ofnanoparticles is observed. The tribological behaviors of Cunanoparticles in liquid paraffin were evaluated on a four-ball testingmachine. The results show that Cu nanoparticles as oil additives canimprove the load-carrying capacity and antiwear property of the baseoil. The rubbed surfaces were investigated by scanning electronmicroscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It can beinferred that a tribological reaction film was formed, whichcontributed to the good tribological properties of surface modified Cunanoparticles.