Friction and wear remain as the main concerns in the mechanical mobility systems due to the significant energy consumption and the main mode of component failures, and achieving direct superlubricity has attracted enormous attention by fundamentally minimizing friction and wear. In this work, we have prepared polyalcohol lubricant mixtures of ethylene glycol and glycerol to precisely enhance the in-situ formation of passivation film on the friction surfaces, and remarkable direct superlubricity of 0.0057 combined with negligible wear has been successfully achieved at ethylene glycol/glycerol weight ratio of 0.6 for steel tribopairs. Lubrication state analysis indicates that the achieved superlubricity state is in the boundary lubrication regime, and further adsorption analysis indicates that there is a strong interaction between lubricant molecules and friction surfaces via the hydroxyl groups. A sliding simulation of polyalcohol lubricant mixtures of ethylene glycol and glycerol indicates that ethylene glycol could be induced to accumulate near the friction surfaces to form easy-to-shear layers. Furthermore, both the experimental analysis and the molecular dynamics simulation demonstrate that a tribochemical reaction could be induced for the lubricant molecules at the interface, with water molecules formed to further strengthen the formation of easy-to-shear layers and oligomers formed to more effectively passivate the asperity contacts. This work provides a new strategy to direct liquid superlubricity and could advance the application of liquid superlubricity in the industry field.

中文翻译：

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使用乙二醇和甘油的多元醇润滑剂混合物实现钢摩擦副的直接超润滑性和可忽略不计的磨损


由于巨大的能源消耗和部件故障的主要模式，摩擦和磨损仍然是机械移动系统中的主要问题，而通过从根本上最小化摩擦和磨损来实现直接超润滑引起了极大的关注。在这项工作中，我们制备了乙二醇和甘油的多元醇润滑剂混合物，以精确增强摩擦表面钝化膜的原位形成，并在乙二醇/甘油上成功实现了 0.0057 的显着直接超润滑性和可忽略不计的磨损钢摩擦副的重量比为 0.6。润滑状态分析表明所达到的超润滑状态处于边界润滑状态，进一步的吸附分析表明润滑剂分子与摩擦表面之间通过羟基存在强烈的相互作用。乙二醇和甘油的多元醇润滑剂混合物的滑动模拟表明，乙二醇可以被诱导在摩擦表面附近积聚，形成易剪切层。此外，实验分析和分子动力学模拟都表明，界面处的润滑剂分子可以引发摩擦化学反应，形成水分子以进一步加强易剪切层的形成，并形成低聚物以更有效地钝化粗糙的接触。该工作为指导液体超润滑提供了新的策略，可推动液体超润滑在工业领域的应用。