Preparation of Well-Dispersed Lubricant Additives with Excellent Antiwear Ability Under High Load.

The reduced graphene oxide (RGO) decorated with rare earth organic complex, Eu(Phen)(OA)3, was successfully synthesized by a simple hydrothermal process. The prepared RGO/Eu(Phen)(OA)3 composites (RGECs) served as lubricating oil additives in Polyalphaolefin-8 (PAO8) and their tribological properties were investigated by SRV-IV fretting friction and wear testing machine. Experimental results indicate that the dispersion stability of RGECs in base oil PAO8 has been optimized greatly compared with that of graphene. The friction coefficient has no obvious change; however, the service life of the base oil, that is effective lubrication time is greatly extended, which is better than the commercial additive Zinc Dialkyldithiophosphate (ZDDP). Furthermore, adding appropriate amount (0.08 wt%) of RGECs is able to reduce the wear spot area by about 56%, the wear rate by about 37% compared with ZDDP. Moreover, these excellent results are attributed to the synergistic effects of RGO nanosheets and Eu(Phen)(OA)3 powders. [ABSTRACT FROM AUTHOR]