Friction and wear properties of a surface-modified TiO2 nanoparticle as an additive in liquid paraffin

A 2-ethyl hexoic acid (EHA) surface-modified TiO2 nanoparticle with an average diameter of 5 nm was chemically synthesized. The friction-reduction and antiwear behaviors of the prepared EHA-TiO2 as an oil additive in liquid paraffin were evaluated with a four-ball wear tester. The rubbed surfaces after friction tests were investigated with X-ray photoelectron spectroscopy (XPS). Friction tests indicate that EHA-TiO2 exhibits good performance in friction and wear reduction as well as in load-carrying capacity. Results of XPS analysis show that a boundary film mainly composed of TiO2 and titanates was formed on the rubbed surfaces.