A facile method for transesterification was reported. Under catalysis by samarium tri-2-propoxide the yields of transesterification are good to excellent, and this reaction has surprising selectivity and mildness due ...A facile method for transesterification was reported. Under catalysis by samarium tri-2-propoxide the yields of transesterification are good to excellent, and this reaction has surprising selectivity and mildness due to the neutral condition during the reaction.展开更多
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℃. Tri-[bis(2-hydro...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℃. 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(^(1)H 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℃.展开更多
文摘A facile method for transesterification was reported. Under catalysis by samarium tri-2-propoxide the yields of transesterification are good to excellent, and this reaction has surprising selectivity and mildness due to the neutral condition during the reaction.
文摘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℃. 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(^(1)H 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℃.
