Abstract

The active control of friction in oil-based lubricants was realized in the present study with the use of MoS₂ particle additives and the application of an electric field. By modifying the surface charging state of the MoS₂ particles, the dependence of potential-controlled boundary lubrication behavior on the electrical properties of the particles was demonstrated. For a diethyl succinate lubricant containing negatively charged MoS₂ particles, the coefficient of friction (COF) was reduced by 60–70% when a positive potential was applied to a lower friction pair of copper plates. After modification with poly(diallyldimethylammonium chloride), the particles were positively charged, and the COF was reduced with the application of a negative potential. The mechanisms underlying the potential control of the COF were investigated by observing the distributions of the particle additives and characterizing the tribofilms formed at different potentials. Most of the charged particles were locally concentrated near the opposite pole, and this was reversed when the electric field changed. For locally high concentrations of MoS₂ particles, a MoS₂/MoO_x tribofilm with a thickness of 100–500 nm and a loose structure formed on the lower friction pair, which significantly decreased the shear force during the friction process.

Graphical Abstract

中文翻译：

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在琥珀酸二乙酯中使用MoS 2添加剂进行势能控制的边界润滑

摘要

通过使用MoS ₂颗粒添加剂和施加电场，本研究实现了油基润滑剂中摩擦的主动控制。通过改变MoS ₂颗粒的表面带电状态，证明了电位控制的边界润滑行为对颗粒电性能的依赖性。对于含有带负电的MoS _2的琥珀酸二乙酯润滑剂当使用正电位施加到较低摩擦对的铜板上时，摩擦系数（COF）降低了60–70％。用聚二烯丙基二甲基氯化铵改性后，颗粒带正电，并通过施加负电势降低了COF。通过观察颗粒添加剂的分布并表征在不同电势下形成的摩擦膜，研究了COF电势控制的潜在机理。大多数带电粒子局部集中在相反的极点附近，当电场改变时，这种现象会逆转。对于局部高浓度的MoS ₂颗粒，MoS ₂ / MoO _x 摩擦膜的厚度为100–500 nm，在较低的摩擦副上形成了松散的结构，从而显着降低了摩擦过程中的剪切力。

图形概要