Description:
Understanding the gist of graphene in fluid lubrication is crucial to develop graphene-enhanced industrial lubricants, yet the prerequisite for modulating high-performance graphene hybrid lubricants is to change its inherent surface characteristics and obtain good dispersion stability. Herein, the tribological properties of poly alpha-olefin (PAO 20) was improved by adding the well-dispersion alcohol ethoxylate (MOA) functionalized graphene oxide (MOAGO). The chemical and structural features of MOA@GO illustrated that MOA was successfully grafted on the plane or interlayer of GO via the esterification reaction. The good dispersibility of MOA@GO in PAO 20 was demonstrated by sedimentation experiment and UV-vis absorption spectra (good stability and no sedimentation after 20 days). More importantly, the introduction of 0.08 wt% MOA@GO into PAO 20 can reduce the friction and wear by 30% and 42%, respectively, ensuring the excellent tribological properties of the as-prepared hybrid oil with the optimum concentration of MOA@GO. The formation of graphene-like tribo-film and multi-layer structure composite at the contact interface contributed to the friction reduction and wear resistance abilities. Of great significance in this work is to achieve the environment-friendly functionalization of graphene oxide and high dispersion stability in PAO with poor sensitivity to additive