Xie Mengxin, Pan Bingli, Li Ning, Zhao Shuang, Yan Junjiang, Guo Shihao, Chen Zhe, Wang Honggang
Institute of Henan Polymer Composites, School of Chemical Engineering, Henan University of Science and Technology 471000 Luoyang PR China
National United Engineering Laboratory for Advanced Bearing Tribology, Henan University of Science and Technology 471000 Luoyang PR China.
RSC Adv. 2022 Jan 20;12(5):2759-2769. doi: 10.1039/d1ra06650a. eCollection 2022 Jan 18.
The purpose of this study is to prepare graphene/FeOCl (G/FeOCl) heterojunctions a microwave-pyrolysis approach and probe into the synergistic lubrication of G with FeOCl in liquid paraffin (LP). The morphology and chemical composition of specimens were analysed by utilizing scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques. The tribological property of G/FeOCl was determined, and the interaction between the G/FeOCl heterojunction and friction pair was carried out through simulation calculations. The results indicated that neither G nor FeOCl significantly improved the lubrication performance of LP. However, together with FeOCl, G as lubrication additives greatly improved the lubrication performance of LP. Under the load of 1.648 GPa, the mean friction coefficient and wear scar diameter of LP containing 0.20 wt% G/FeOCl were 66.1% and 44.7% inferior to those of pure LP, respectively. Scanning electron microscopy (SEM) and elemental mapping analyses of worn scars revealed the formation of G/FeOCl layer tribofilms that prevent direct contact between metals. In addition, the high interfacial energy between graphene and FeOCl calculated based on first-principles density functional theory (DFT) further confirmed that graphene and FeOCl simultaneously form friction films with wear resistance and wear reduction effect at the friction interface, which is consistent with the experimental results. This study, therefore, provides a pathway for low-friction lubricants by deploying G/FeOCl two-dimensional material systems.
本研究的目的是采用微波热解方法制备石墨烯/FeOCl（G/FeOCl）异质结，并探究G与FeOCl在液体石蜡（LP）中的协同润滑作用。利用扫描电子显微镜（SEM）结合能谱仪（EDS）、X射线衍射（XRD）、傅里叶变换红外（FTIR）光谱和X射线光电子能谱（XPS）技术对样品的形貌和化学成分进行了分析。测定了G/FeOCl的摩擦学性能，并通过模拟计算研究了G/FeOCl异质结与摩擦副之间的相互作用。结果表明，单独的G或FeOCl均未显著改善LP的润滑性能。然而，G作为润滑添加剂与FeOCl一起能大大提高LP的润滑性能。在1.648 GPa的载荷下，含有0.20 wt% G/FeOCl的LP的平均摩擦系数和磨损斑直径分别比纯LP低66.1%和44.7%。磨损斑的扫描电子显微镜（SEM）和元素映射分析表明形成了G/FeOCl层摩擦膜，可防止金属之间的直接接触。此外，基于第一性原理密度泛函理论（DFT）计算的石墨烯与FeOCl之间的高界面能进一步证实，石墨烯和FeOCl在摩擦界面同时形成具有耐磨和减磨效果的摩擦膜，这与实验结果一致。因此，本研究通过部署G/FeOCl二维材料体系为低摩擦润滑剂提供了一条途径。
