Alkyl Titanate-Modified Graphene Oxide as Friction and Wear Reduction Additives in PAO Oil.

Abstract

Diacetoxy-stearoyloxy-titanium-modified graphene oxide (Titanate-GO) was successfully prepared using titanium tetraisopropanolate, stearic acid, acetic acid, and graphene oxide (GO). The morphology and structure of the as-prepared materials were tested by FT-IR, Raman, TG/DSC, SEM, and TEM instruments. The results indicate that long alkyl titanium chains have been grafted on the surface of a GO sheet, which guaranteed the dispersibility of Titanate-GO in PAO10 base oil. Then, the lubrication properties of Titanate-GO as a lubricating additive in PAO10 base oil were evaluated on a four-ball machine. The results show that the average coefficient of friction and wear scar diameter were reduced by 49.5 and 28.2%, respectively, compared with bare PAO10 base oil. Finally, the lubrication mechanism was discussed based on the Raman analysis, which was carried out on the worn surface of the steel ball.