In modern high-tech industries,such as aerospace,nuclear energy,and electric power,there is increasing demand for materials with high-temperature adaptability and superior lubrication properties.Grease is an essential...In modern high-tech industries,such as aerospace,nuclear energy,and electric power,there is increasing demand for materials with high-temperature adaptability and superior lubrication properties.Grease is an essential mechanical component that is widely used to reduce mechanical friction,wear,and vibration.This paper comprehensively reviews recent progress in high-temperature grease,including design,performance indices,lubrication characteristics,development,and applications.This paper starts by outlining novel insights into the relationship between the composition and physicochemical properties of high-temperature greases,as well as other factors,emphasizing typical strategies for matrix reinforcement and high-temperature performance enhancement.The gravity analysis focuses on the intrinsic properties of high-temperature grease and the influence of working conditions on its tribological properties,leading to a detailed discussion of the lubrication mechanism.The innovative fusion of high-temperature grease with new materials such as nanomaterials and ionic liquids(ILs)and interdisciplinary research involving modern emerging fields such as artificial intelligence have led to further progress in the development of high-temperature grease,which has a wide range of applications in aerospace components,automotive parts,and turbines.Finally,this review concludes briefly with prospects for the challenges and future directions in high-temperature grease.展开更多
Two lithium-based ionic liquids(ILs,L-C3N3,and L-P3N3)were synthesized and evaluated as novel lubricant additives for multiply alkylated cyclopentanes(MACs).They were found to be approximately 1.0%soluble in MACs at r...Two lithium-based ionic liquids(ILs,L-C3N3,and L-P3N3)were synthesized and evaluated as novel lubricant additives for multiply alkylated cyclopentanes(MACs).They were found to be approximately 1.0%soluble in MACs at room temperature(RT),whereas traditional ILs,such as 1-ethyl-3-methylimidazolium tetrafluoroborate(L-B102),1-hexyl-3-methylimidazolium hexafluorophosphate(L-P106),and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(L-F102),could not be dissolved in this base oil.Friction tests indicated that these ILs exhibit excellent friction-reducing and anti-wear properties both at RT and at 100°C.They can improve the tribological properties of MACs at RT to a greater extent than the commonly used lubricant zinc dialkyldithiophosphate(T204),even at a concentration of 0.1%.The load ramp test showed that MACs with L-C3N3 and L-P3N3 also exhibit high load-carrying capabilities.Scanning electron microscope(SEM)and X-ray photoelectron spectrometer(XPS)results indicated that physical adsorption and complex tribochemical reactions occurred between the ILs and metal surfaces during the sliding process,thereby forming a surface protective film that significantly contributed to the excellent tribological properties of the new ILs.展开更多
The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind ...The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind of ester lubricating oil,isooctyl furan dicarboxylate(isooctyl-FD),was prepared from bio-based 2,5-furandicarboxylic acid.The structure of isooctyl-FD was evaluated using nuclear magnetic resonance imaging and high-resolution mass spectroscopy.Its physicochemical and tribological properties including thermal and oxidation stabilities,flash point and pour point,viscosity and viscosity index,and friction-reducing and anti-wear properties were systematically evaluated.The results show that isooctyl-FD has comparable thermal and oxidation stability to the synthetic ester lubricating oil,isooctyl sebacate(isooctyl-S).Its friction-reducing and anti-wear properties are superior to isooctyl-S;however,its viscosity-temperature and low-temperature properties are inferior to isooctyl-S.展开更多
An intermolecular two C-C bond formation procedure for the synthesis of carbocycles mediated by hyperva-lent iodine(III)reagents was developed.This metal free protocol provided a new approach for the synthesis of use-...An intermolecular two C-C bond formation procedure for the synthesis of carbocycles mediated by hyperva-lent iodine(III)reagents was developed.This metal free protocol provided a new approach for the synthesis of use-ful substituted 1-amino-2-naphthoic acid derivatives via benzannulation reactions.Various N-unsubstituted and N-alkyl substituted aromatic enamines with terminal alkynes and non-terminal alkynes can be converted into corre-sponding 1-amino-2-naphthoic acid derivatives under mild reaction conditions.When meta-substituted phenyl enamines were employed in the reaction,two cyclization paths were detected in the reaction and ortho-cyclization products were the only or major products.Good functional group tolerance,readily available material and high atom utilization efficiency make this method a potential procedure which may find broad application in organic synthesis.展开更多
Development of energy-efficient lubricants is a way to reduce energy consumption for transportation,with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic oils.Oligoether este...Development of energy-efficient lubricants is a way to reduce energy consumption for transportation,with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic oils.Oligoether esters(OEEs),as a low-viscosity ester base oil,have characteristics such as simple synthesis and excellent lubrication effect;however,the application of OEEs in tribology field has rarely been investigated.The objective of the present study is to investigate the effect of structure on the lubricating performance of OEEs and to develop a predictive model for OEEs based on quantitative structure‒property relationship(QSPR)through a combination of experiment and statistical modeling.Results showed that glycol chains contribute positively to lubrication with the ether functional groups increasing the sites of adsorption.Compared to branched-chain OEEs,straight-chain OEEs exhibited reduced wear,which was mainly due to the thicker adsorption film formed by the straight-chain structure.Furthermore,carbon films were detected on lightly worn surfaces,indicating that OEEs underwent oxidation during the friction process.Based on the results of principal component analysis(PCA)and partial least squares(PLS),it could be found that the predictive models of viscosity‒temperature performance,thermal stability performance,coefficient of friction(COF),and wear volume(WV)performed well and robustly.Among them,COF and WV can be best predicted with an R^(2) of about 0.90.展开更多
Erratum to Friction 1(3):222-231(2013)DOI 10.1007/s40544‐013‐0019‐x The original version of this article unfortunately contained the incorrect E‐mail address of the corresponding author Mingjin Fan on page 222,ins...Erratum to Friction 1(3):222-231(2013)DOI 10.1007/s40544‐013‐0019‐x The original version of this article unfortunately contained the incorrect E‐mail address of the corresponding author Mingjin Fan on page 222,instead of farmingjin@licp.cus.cn It should read fanmingjin@licp.cas.cn.展开更多
基金supported by the Natural Science Basic Research Plan in Shaanxi Province of China(2022JM-251)the National Natural Science Foundation of China(51675409)the Liaoning Key Laboratory of Aeroengine Materials Tribology(LKLAMTF202401).
文摘In modern high-tech industries,such as aerospace,nuclear energy,and electric power,there is increasing demand for materials with high-temperature adaptability and superior lubrication properties.Grease is an essential mechanical component that is widely used to reduce mechanical friction,wear,and vibration.This paper comprehensively reviews recent progress in high-temperature grease,including design,performance indices,lubrication characteristics,development,and applications.This paper starts by outlining novel insights into the relationship between the composition and physicochemical properties of high-temperature greases,as well as other factors,emphasizing typical strategies for matrix reinforcement and high-temperature performance enhancement.The gravity analysis focuses on the intrinsic properties of high-temperature grease and the influence of working conditions on its tribological properties,leading to a detailed discussion of the lubrication mechanism.The innovative fusion of high-temperature grease with new materials such as nanomaterials and ionic liquids(ILs)and interdisciplinary research involving modern emerging fields such as artificial intelligence have led to further progress in the development of high-temperature grease,which has a wide range of applications in aerospace components,automotive parts,and turbines.Finally,this review concludes briefly with prospects for the challenges and future directions in high-temperature grease.
基金The National Natural Science Foundation of China(NSFC)(Nos.51105353,51175492,and 21173243)The National Key Basic Research and Development(973)Program of China project(2013CB632300).
文摘Two lithium-based ionic liquids(ILs,L-C3N3,and L-P3N3)were synthesized and evaluated as novel lubricant additives for multiply alkylated cyclopentanes(MACs).They were found to be approximately 1.0%soluble in MACs at room temperature(RT),whereas traditional ILs,such as 1-ethyl-3-methylimidazolium tetrafluoroborate(L-B102),1-hexyl-3-methylimidazolium hexafluorophosphate(L-P106),and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(L-F102),could not be dissolved in this base oil.Friction tests indicated that these ILs exhibit excellent friction-reducing and anti-wear properties both at RT and at 100°C.They can improve the tribological properties of MACs at RT to a greater extent than the commonly used lubricant zinc dialkyldithiophosphate(T204),even at a concentration of 0.1%.The load ramp test showed that MACs with L-C3N3 and L-P3N3 also exhibit high load-carrying capabilities.Scanning electron microscope(SEM)and X-ray photoelectron spectrometer(XPS)results indicated that physical adsorption and complex tribochemical reactions occurred between the ILs and metal surfaces during the sliding process,thereby forming a surface protective film that significantly contributed to the excellent tribological properties of the new ILs.
基金National Natural Science Fund(51675006)the project of Science and Technology Department of Shaanxi Province(2016JZ017)the Local Servicing Research Project of the Education Department of Shanxi Province(15JF007).
文摘The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind of ester lubricating oil,isooctyl furan dicarboxylate(isooctyl-FD),was prepared from bio-based 2,5-furandicarboxylic acid.The structure of isooctyl-FD was evaluated using nuclear magnetic resonance imaging and high-resolution mass spectroscopy.Its physicochemical and tribological properties including thermal and oxidation stabilities,flash point and pour point,viscosity and viscosity index,and friction-reducing and anti-wear properties were systematically evaluated.The results show that isooctyl-FD has comparable thermal and oxidation stability to the synthetic ester lubricating oil,isooctyl sebacate(isooctyl-S).Its friction-reducing and anti-wear properties are superior to isooctyl-S;however,its viscosity-temperature and low-temperature properties are inferior to isooctyl-S.
基金support of this work by Baoji University of Arts and Sciences(No.ZK15046).
文摘An intermolecular two C-C bond formation procedure for the synthesis of carbocycles mediated by hyperva-lent iodine(III)reagents was developed.This metal free protocol provided a new approach for the synthesis of use-ful substituted 1-amino-2-naphthoic acid derivatives via benzannulation reactions.Various N-unsubstituted and N-alkyl substituted aromatic enamines with terminal alkynes and non-terminal alkynes can be converted into corre-sponding 1-amino-2-naphthoic acid derivatives under mild reaction conditions.When meta-substituted phenyl enamines were employed in the reaction,two cyclization paths were detected in the reaction and ortho-cyclization products were the only or major products.Good functional group tolerance,readily available material and high atom utilization efficiency make this method a potential procedure which may find broad application in organic synthesis.
基金the National Natural Science Foundation of China(No.52175156)the Key Research and Development Projects of Shaanxi Province(No.2021GY-157)+1 种基金the Young Talent fund of University Association for Science and Technology in Shaanxi(No.20220615)the Special Fund for Basic Scientific Research of Central Colleges(Chang an University)with Nos.300102221512,300102221510,and 300102222502.
文摘Development of energy-efficient lubricants is a way to reduce energy consumption for transportation,with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic oils.Oligoether esters(OEEs),as a low-viscosity ester base oil,have characteristics such as simple synthesis and excellent lubrication effect;however,the application of OEEs in tribology field has rarely been investigated.The objective of the present study is to investigate the effect of structure on the lubricating performance of OEEs and to develop a predictive model for OEEs based on quantitative structure‒property relationship(QSPR)through a combination of experiment and statistical modeling.Results showed that glycol chains contribute positively to lubrication with the ether functional groups increasing the sites of adsorption.Compared to branched-chain OEEs,straight-chain OEEs exhibited reduced wear,which was mainly due to the thicker adsorption film formed by the straight-chain structure.Furthermore,carbon films were detected on lightly worn surfaces,indicating that OEEs underwent oxidation during the friction process.Based on the results of principal component analysis(PCA)and partial least squares(PLS),it could be found that the predictive models of viscosity‒temperature performance,thermal stability performance,coefficient of friction(COF),and wear volume(WV)performed well and robustly.Among them,COF and WV can be best predicted with an R^(2) of about 0.90.
文摘Erratum to Friction 1(3):222-231(2013)DOI 10.1007/s40544‐013‐0019‐x The original version of this article unfortunately contained the incorrect E‐mail address of the corresponding author Mingjin Fan on page 222,instead of farmingjin@licp.cus.cn It should read fanmingjin@licp.cas.cn.
