In this study, the tribological behavior of an ammonium-based protic ionic liquid (PIL) as an additive in a base mineral oil (MO) is investigated on a steel-steel contact at room temperature and 100 °C. Tri-[bis(2-hydroxyethylammonium)] citrate (DCi) was synthesized in a simple and low-cost way, and the ionic structure of DCi was confirmed by proton nuclear magnetic resonance (¹H NMR). The stability measurement of 1 wt% DCi to a MO was investigated, and the lubricating ability and anti-wear properties of DCi as an additive in MO were also examined using a custom-designed reciprocating ball-on-flat tribometer. Optical microscope and profilometry were used to obtain the worn morphology of the steel disks. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were carried out to investigate the wear mechanism and to analyze the surface interactions between the rubbing components. When 1 wt% DCi is added into the base MO, frictional performance is improved at both temperatures studied with a friction reduction of 29.0% and 35.5%, respectively. Moreover, the addition of 1 wt% DCi to MO reduced the wear volume 59.4% compared to the use of MO. An oxygen-richened tribolayer is confirmed by EDS on the disk surface when DCi was used as additive under 100 °C.

在这项研究中，在室温和100°C的钢-钢接触下，研究了铵基质子离子液体（PIL）作为基础矿物油（MO）中添加剂的摩擦学行为。以简单且低成本的方式合成了柠檬酸三[双（2-羟乙基铵）]（DCi），并通过质子核磁共振证实了DCi的离子结构（¹1 H NMR）。研究了1％重量百分比的DCi对MO的稳定性，并使用定制设计的往复式平面球型摩擦计对DCi作为MO中添加剂的润滑能力和抗磨性能进行了研究。使用光学显微镜和轮廓仪来获得钢盘的磨损形态。进行了扫描电子显微镜（SEM）和能量色散X射线光谱（EDS），以研究磨损机理并分析摩擦成分之间的表面相互作用。当将1wt％的DCi添加到基础MO中时，在所研究的两个温度下摩擦性能均得到改善，摩擦降低分别为29.0％和35.5％。此外，与使用MO相比，向MO中添加1 wt％DCi可使磨损量降低59.4％。