Increasing environmental concerns about limiting harmful emissions has necessitated sulfur-and phosphorus-free green lubricant additives.Although boron-containing compounds have been widely investigated as green lubri...Increasing environmental concerns about limiting harmful emissions has necessitated sulfur-and phosphorus-free green lubricant additives.Although boron-containing compounds have been widely investigated as green lubricant additives,their macromolecular analogs have been rarely considered yet to develop environmentally friendly lubricant additives.In this work,a series of boron-containing copolymers have been synthesized by free-radical copolymerization of stearyl methacrylate and isopropenyl boronic acid pinacol ester with different feeding ratios(S_(n)-r-B_(m),n=1,m=1/3,1,2,3,5,9).The resulting copolymers of S_(n)-r-B_(m)(n=1,m=1/3,1,2,3,5)are readily dispersed in the PAO-10 base oil and form micelle-like aggregates with hydrodynamic diameters ranging from 9.7 to 52 nm.SRV-IV oscillating reciprocating tribological tests on ball-on-flat steel pairs show that compared with the base oil of PAO-10,the friction coefficients and wear volumes of the base oil solutions of S_(n)-r-B_(m)decrease considerably up to 62%and 97%,respectively.Moreover,the base oil solution of S_(1)-r-B_(1)exhibits an excellent load-bearing capacity of(850±100)N.These superior lubricating properties are due to the formation of protective tribofilms comprising S_(n)-r-B_(m),boron oxide,and iron oxide compounds on the lubricated steel surface.Therefore,the boron-containing copolymers can be regarded as a novel class of environmentally friendly lubricating oil macroadditives for efficient friction and wear reduction without sulfur and phosphorus elements.展开更多
Nano-copper used as lubrication oil additive has good tribological property and active self-repairing effect for friction pairs. The reduction in liquid phase for preparing nano-additive is one of the most common meth...Nano-copper used as lubrication oil additive has good tribological property and active self-repairing effect for friction pairs. The reduction in liquid phase for preparing nano-additive is one of the most common method. Nano-copper was prepared by reduction in liquid phase. The different project and routine practice for preparing nano-copper were researched. The dispersion problem of nano-copper was investigated by surface treatment and high dispersion. The particles dimension, the dispersion stability and the purity of nano-copper were characterized by TEM and XRD. The conclusion indicates that the methods of the preparation and dispersion can obtain 20nm copper additive with good dispersion property in lubrication oil.展开更多
Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite ...Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite into graphite nanoplatelets with high efficiency. The obtained graphite nanoplatelets are highly crystalline, and the thickness is less than 10 nm. Moreover, the surface area could reached 738.1 m^2/g with a grinding time of 4 h. Silanized graphite nanoplatelets can disperse well in SG 15W-40 engine oil and serve as lubricant additive. Tribological results indicate that the friction coefficient and wear-scar of the friction pairs are lower than 76% and 41%, respectively, by adding 1.5‰(mass fraction) of silanized graphite nanoplatelets. Notably, the functionalized graphite nanoplatelets can realize large-scale production and commercial application.展开更多
Due to the biological risks of using the conventional lubricants,the vegetable oils have been considered nowadays.Besides,to improve the tribological properties of the vegetable oils in various applications like metal...Due to the biological risks of using the conventional lubricants,the vegetable oils have been considered nowadays.Besides,to improve the tribological properties of the vegetable oils in various applications like metal forming processes,nanoparticles have been used as additives.This research evaluated the lubrication performance of the Al2O3 and TiO2 nanoparticles dispersed in rapeseed oil during the parallel tubular channel angular pressing (PTCAP) process.The experimental PTCAP tests have been fulfilled under three lubrication conditions and the comparison between the PTCAP processed tubes has been performed in terms of the maximum forming force,surface roughness,and microhardness.The experimental results indicate that adding the mentioned nanoparticles has caused at least a 50% reduction in the maximum deformation load.Moreover,a remarkable decrement in the surface roughness of the formed tubes has been obtained.展开更多
Oleic acid surface-modified Cu nanoparticles with an average size of 20 nm were prepared by liquid phase reducing reaction. The tribological performance and mechanism of nanocopper as additive were studied by means of...Oleic acid surface-modified Cu nanoparticles with an average size of 20 nm were prepared by liquid phase reducing reaction. The tribological performance and mechanism of nanocopper as additive were studied by means of tribotester, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and nanoindentation instrument. The results indicate that the modified nanocopper additive can significantly improve the wear resistance and reduce friction coefficient of base oil. A copper protective film is formed and contributes to the excellent tribological properties of nanocopper additive. On the basis of the film forming mechanism, a new in-situ repair method was designed and used to repair wear-out-failure injection pump plunger and barrel. Furthermore, the current research progress of nanoparticles as green energy-saving lubricating oil additives were presented.展开更多
本文中以美国食品药品监督管理局(Food and Drug Administration,FDA)批准的食品添加剂月桂酰肌氨酸钠和氨基酸为原料,采用简单的质子交换反应合成了2种氨基酸基离子液体Lys-LS和Arg-LS,并将其用作水基润滑添加剂.利用SRV-V微动摩擦磨...本文中以美国食品药品监督管理局(Food and Drug Administration,FDA)批准的食品添加剂月桂酰肌氨酸钠和氨基酸为原料,采用简单的质子交换反应合成了2种氨基酸基离子液体Lys-LS和Arg-LS,并将其用作水基润滑添加剂.利用SRV-V微动摩擦磨损试验机和全自动真彩共聚焦显微镜考察了2种离子液体添加剂的摩擦学性能,并采用扫描电镜(SEM)、石英晶体微天平(QCM)和X射线光电子能谱仪(XPS)深入探究了其润滑机理.研究结果表明:2种氨基酸基离子液体添加剂具有良好的热稳定性且可以显著抑制铸铁在水中的腐蚀.与去离子水相比,当Lys-LS和Arg-LS的添加质量分数为0.5%时,水基润滑液的摩擦系数和磨损体积分别降低了约70%和85%,具有显著的减摩抗磨效果.机理分析结果表明,离子液体在界面处形成的摩擦化学反应膜与物理/化学吸附膜协同作用,有效地阻止了滑动摩擦副之间的直接接触,进而赋予水基润滑液优异的摩擦学性能.2种润滑添加剂制备简单,安全无毒且绿色环保,有望作为水基金属加工液和难燃液压液的关键润滑添加剂使用.展开更多
文摘Increasing environmental concerns about limiting harmful emissions has necessitated sulfur-and phosphorus-free green lubricant additives.Although boron-containing compounds have been widely investigated as green lubricant additives,their macromolecular analogs have been rarely considered yet to develop environmentally friendly lubricant additives.In this work,a series of boron-containing copolymers have been synthesized by free-radical copolymerization of stearyl methacrylate and isopropenyl boronic acid pinacol ester with different feeding ratios(S_(n)-r-B_(m),n=1,m=1/3,1,2,3,5,9).The resulting copolymers of S_(n)-r-B_(m)(n=1,m=1/3,1,2,3,5)are readily dispersed in the PAO-10 base oil and form micelle-like aggregates with hydrodynamic diameters ranging from 9.7 to 52 nm.SRV-IV oscillating reciprocating tribological tests on ball-on-flat steel pairs show that compared with the base oil of PAO-10,the friction coefficients and wear volumes of the base oil solutions of S_(n)-r-B_(m)decrease considerably up to 62%and 97%,respectively.Moreover,the base oil solution of S_(1)-r-B_(1)exhibits an excellent load-bearing capacity of(850±100)N.These superior lubricating properties are due to the formation of protective tribofilms comprising S_(n)-r-B_(m),boron oxide,and iron oxide compounds on the lubricated steel surface.Therefore,the boron-containing copolymers can be regarded as a novel class of environmentally friendly lubricating oil macroadditives for efficient friction and wear reduction without sulfur and phosphorus elements.
文摘Nano-copper used as lubrication oil additive has good tribological property and active self-repairing effect for friction pairs. The reduction in liquid phase for preparing nano-additive is one of the most common method. Nano-copper was prepared by reduction in liquid phase. The different project and routine practice for preparing nano-copper were researched. The dispersion problem of nano-copper was investigated by surface treatment and high dispersion. The particles dimension, the dispersion stability and the purity of nano-copper were characterized by TEM and XRD. The conclusion indicates that the methods of the preparation and dispersion can obtain 20nm copper additive with good dispersion property in lubrication oil.
基金Project(ZR2011BL005)supported by the Natural Science Foundation of Shandong Province,China
文摘Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite into graphite nanoplatelets with high efficiency. The obtained graphite nanoplatelets are highly crystalline, and the thickness is less than 10 nm. Moreover, the surface area could reached 738.1 m^2/g with a grinding time of 4 h. Silanized graphite nanoplatelets can disperse well in SG 15W-40 engine oil and serve as lubricant additive. Tribological results indicate that the friction coefficient and wear-scar of the friction pairs are lower than 76% and 41%, respectively, by adding 1.5‰(mass fraction) of silanized graphite nanoplatelets. Notably, the functionalized graphite nanoplatelets can realize large-scale production and commercial application.
文摘Due to the biological risks of using the conventional lubricants,the vegetable oils have been considered nowadays.Besides,to improve the tribological properties of the vegetable oils in various applications like metal forming processes,nanoparticles have been used as additives.This research evaluated the lubrication performance of the Al2O3 and TiO2 nanoparticles dispersed in rapeseed oil during the parallel tubular channel angular pressing (PTCAP) process.The experimental PTCAP tests have been fulfilled under three lubrication conditions and the comparison between the PTCAP processed tubes has been performed in terms of the maximum forming force,surface roughness,and microhardness.The experimental results indicate that adding the mentioned nanoparticles has caused at least a 50% reduction in the maximum deformation load.Moreover,a remarkable decrement in the surface roughness of the formed tubes has been obtained.
文摘Oleic acid surface-modified Cu nanoparticles with an average size of 20 nm were prepared by liquid phase reducing reaction. The tribological performance and mechanism of nanocopper as additive were studied by means of tribotester, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and nanoindentation instrument. The results indicate that the modified nanocopper additive can significantly improve the wear resistance and reduce friction coefficient of base oil. A copper protective film is formed and contributes to the excellent tribological properties of nanocopper additive. On the basis of the film forming mechanism, a new in-situ repair method was designed and used to repair wear-out-failure injection pump plunger and barrel. Furthermore, the current research progress of nanoparticles as green energy-saving lubricating oil additives were presented.
文摘本文中以美国食品药品监督管理局(Food and Drug Administration,FDA)批准的食品添加剂月桂酰肌氨酸钠和氨基酸为原料,采用简单的质子交换反应合成了2种氨基酸基离子液体Lys-LS和Arg-LS,并将其用作水基润滑添加剂.利用SRV-V微动摩擦磨损试验机和全自动真彩共聚焦显微镜考察了2种离子液体添加剂的摩擦学性能,并采用扫描电镜(SEM)、石英晶体微天平(QCM)和X射线光电子能谱仪(XPS)深入探究了其润滑机理.研究结果表明:2种氨基酸基离子液体添加剂具有良好的热稳定性且可以显著抑制铸铁在水中的腐蚀.与去离子水相比,当Lys-LS和Arg-LS的添加质量分数为0.5%时,水基润滑液的摩擦系数和磨损体积分别降低了约70%和85%,具有显著的减摩抗磨效果.机理分析结果表明,离子液体在界面处形成的摩擦化学反应膜与物理/化学吸附膜协同作用,有效地阻止了滑动摩擦副之间的直接接触,进而赋予水基润滑液优异的摩擦学性能.2种润滑添加剂制备简单,安全无毒且绿色环保,有望作为水基金属加工液和难燃液压液的关键润滑添加剂使用.
