Graphene has been widely investigated as an additive in lubricating oils to enhance their tribological performance. Here, the effects of the nature and size of the graphene nanosheets on the tribological performance were investigated with the hydrogenated hydroxyl-terminated polybutadiene dioctoate (O-HHTPB-O) as a model base oil after alkylation of the graphene oxide (GO) of different sizes with 1-dodecylamine (DA) and reduction. The 1-dodecylamine-modified graphene oxide (DA-GO) showed better dispersibility in the O-HHTPB-O base oil and subsequently better tribological performance than the reduced one (DA-rGO) for both the larger graphene oxide nanosheets (GO_L) and the smaller graphene oxide nanosheets (GO_S). The DA-GO_S exhibited better wear-reduction performance than the DA-GO_L, owing to its smaller size and higher polarity. Although the DA-GO_L could be ground during the friction, the friction and wear in the original period affected the complete period lubricating performance.

中文翻译：

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石墨烯纳米片作为润滑剂添加剂：性质和尺寸对润滑性能的影响

石墨烯已被广泛研究作为润滑油中的添加剂，以提高其摩擦学性能。在这里，研究了石墨烯纳米片的性质和尺寸对摩擦学性能的影响，以氢化端羟基聚二辛酸丁二酯（O-HHTPB-O）为模型基础油，将不同的氧化石墨烯（GO）烷基化后尺寸与 1-十二胺 (DA) 和还原。对于较大的氧化石墨烯纳米片 (GO _L ) ，1-十二胺改性氧化石墨烯 (DA-GO) 在 O-HHTPB-O 基础油中表现出更好的分散性，随后比还原的氧化石墨烯 (DA-rGO) 具有更好的摩擦学性能和较小的氧化石墨烯纳米片（GO _S）。DA-GO _S由于其较小的尺寸和较高的极性，因此表现出比 DA-GO _{L更好的磨损减少性能。}虽然DA-GO _L在摩擦过程中可能会被磨碎，但原始时期的摩擦和磨损影响了整个时期的润滑性能。