High-temperature lubrication has always been a hot topic in the lubricant and grease industry,and is also an essential concern in the high-end equipment sector to be addressed.Carbon quantum dots(CQDs)are an emerging ...High-temperature lubrication has always been a hot topic in the lubricant and grease industry,and is also an essential concern in the high-end equipment sector to be addressed.Carbon quantum dots(CQDs)are an emerging material widely applied in the field of lubrication,owing to their exceptional lubricity and high load-bearing capacity.However,the vulnerability of CQDs to oxidation in air and reduced stability dramatically restrict their high-temperature application capability.In this study,a nanocomposite of amphiphilic polyvinyl pyrrolidone(PVP)homopolymer with excellent lubricating properties and thermal stability,which is hydrogen bonded to CQDs(CQDs@PVP),was designed to achieve low friction and wear of lubricants at high temperatures.The CQDs@PVP are consistently dispersed in both PEG400 and water,and exhibit superior lubricity compared to unmodified CQDs at high temperatures(ranging from 200‒150°C and 90‒50°C).Meanwhile,the dense carbon film on the wear surface and the chemically reactive film of iron compounds directly contribute to the enhanced lubrication performance.These analytical results demonstrate the powerful candidacy of CQDs@PVP as a lubrication additive and promote future high-temperature applications of CQDs in industrial production.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB 0470301)the Key R&D Program of Shandong Province(Nos.2020CXGC011002 and 2022CXGC020309)the National Natural Science Foundation of China(No.51975560).
文摘High-temperature lubrication has always been a hot topic in the lubricant and grease industry,and is also an essential concern in the high-end equipment sector to be addressed.Carbon quantum dots(CQDs)are an emerging material widely applied in the field of lubrication,owing to their exceptional lubricity and high load-bearing capacity.However,the vulnerability of CQDs to oxidation in air and reduced stability dramatically restrict their high-temperature application capability.In this study,a nanocomposite of amphiphilic polyvinyl pyrrolidone(PVP)homopolymer with excellent lubricating properties and thermal stability,which is hydrogen bonded to CQDs(CQDs@PVP),was designed to achieve low friction and wear of lubricants at high temperatures.The CQDs@PVP are consistently dispersed in both PEG400 and water,and exhibit superior lubricity compared to unmodified CQDs at high temperatures(ranging from 200‒150°C and 90‒50°C).Meanwhile,the dense carbon film on the wear surface and the chemically reactive film of iron compounds directly contribute to the enhanced lubrication performance.These analytical results demonstrate the powerful candidacy of CQDs@PVP as a lubrication additive and promote future high-temperature applications of CQDs in industrial production.
