Surface modified indium nanoparticles were prepared by a simple and rapid process from bulk indium via ultrasound dispersion. The morphology and structure of synthesized nanoparticles were characterized by TEM, XRD, XPS and FTIR. The results show that the morphology of indium nanoparticles is spherical and the structure of indium nanoparticles is the tetragonal phase. The surface of indium nanoparticles was coated by 2 ethyl hexanoic acid, which could almost hold back oxidation of the indium nanoparticles. In addition, the tribological property of indium nanoparticles as additives in oil was evaluated on a four-ball tester and the results show that indium nanoparticles exhibit good performance in wear.
Copper nanoparticles and nanorods were prepared by the replacement reaction of copper 2-ethylhexoate with sodium metal in the non-aqueous solution under ultrasonic irradiation. The morphology, structure and thermal properties of the prepared samples were characterized by TEM, XRD and TGA, respectively. TEM photograph shows that the samples have two main shapes: rods and roughly spherical shape. Powder X-ray diffraction studies prove that the synthesized samples possess the same crystal structure as bulk copper. Thermal analysis reveals that the samples contain ca. 7wt% organic component. In addition, the tribological properties of the samples as an additive in lubricating oil were evaluated on a four-ball tester. The results indicate that the produced samples have relatively good antiwear properties.