Oil-soluble Nanoparticles Preparation And Tribological Properties

In this thesis, four surface modified nanoparticles were synthesized, and their tribological properties as lubricant additives were investigated, the main results were as follows:1. Surface modified Cu, MgO, ZnO and Pb2O nanoparticles were synthesized by the solventless thermolysis of single-source precursor cupric oleate, magnesium stearate, zinc stearate and plumbous stearate respectively.2. The structure of the surface modified Cu, MgO, ZnO and Pb2O nanoparticles were characterized by FTIR, TGA, XRD, XPS, HR-TEM. Results show that the surface modified nanoparticles exhibit a rather uniform size distribution and consist of inorganic nanocores with organic capped-layer chemically adsorbed on the surface of the nanocores. Owing to the hydrophobic property of hydrocarbon chain in the organic modification layer, the nanoparticles show excellent oil dispersity in low polar organic solvents.3. The tribological properties of four kinds of surface modified nanoparticles as lubricant additives were evaluated by four-ball test machine, and the worn surfaces of the balls were analyzed by SEM and EDS. Results show that the nanoparticles exhibit good anti-wear capacity: as the additive concentration of Cu nanoparticles reach to 0.5 wt.%, the wear scar diameter can be reduced by 18% and the friction coefficient can be reduced by 13% as compared to pure PAO10; as the additive concentration of MgO nanoparticles reach to 0.75 wt.%, the wear scar diameter can be reduced by 46%; as the additive concentration of ZnO nanoparticles reach to 0.75 wt.%, the wear scar diameter can be reduced by 21%; as the additive concentration of Pb2O nanoparticles reach to 0.5 wt.%, the wear scar diameter can be reduced by 16%. SEM and EDS results of wear scar indicated that the main reason for the good tribological properties is the formation of a layer of surface film.