Graphene Nanosheets\nModified with Diamines and C60\nfor Applications in Lubricating Oil

Research into the synergistic lubrication effects of\ngraphene oxide\n(GO) and fullerene (C60) is limited to basic mechanical mixing methods.\nThis research introduces a design strategy for composite nanomaterials\nwith sandwich structures. By reacting single-layer GO with amines\n(1,6-hexanediamine (HMD), 1,8-octanediamine (DAD), 1,10-decanediamine\n(DAO), 1,12-dodecanediamine (DDA)), the single-layer structure is\nconverted into a multilayer structure. C60 is simultaneously introduced\nduring synthesis, resulting in an oil-soluble nanolubricating additive\n(GO–R/C60, R = HMD, DAD, DAO, DDA) with remarkable antiwear\ncapabilities. The influence of diamine chain length on the capture\nand release of C60 and its tribological properties was investigated\nthrough dispersion experiments, tribological tests, and molecular\ndynamics simulations. The GO–DDA/C60 demonstrates outstanding\nantiwear performance under high contact stress (1.42 GPa), reducing\nthe friction coefficient and wear cross-sectional area by 30% and\n98%, respectively. The results indicate that the sandwich structure\nnanocomposite material significantly enhances the antiwear performance\nof lubricating oils by suppressing wrinkling at the edges of GO, releasing\nC60 under stress and shear, good interfacial adsorption performance,\nand a synergistic antiwear effect between GO and C60.