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
As an excellent anti-wear and friction-reducing additive,nano-copper has attracted extensive researches and attention in tribology field.However,the existing researches are still limited to zero-dimensional nano-coppe...As an excellent anti-wear and friction-reducing additive,nano-copper has attracted extensive researches and attention in tribology field.However,the existing researches are still limited to zero-dimensional nano-copper,that is,the effect of copper nanoparticles on the tribological properties of lubricants.In this paper,the effects of nano-coppers with different dimensions(copper nanoparticles,copper nanowires and copper nanoplates)on the anti-wear ability and frictionreducing performance of lithium grease were systematically investigated.And the mechanism of interaction between dimension and tribological properties was explained in detail.It is concluded that the tribological properties of lithium grease can be improved by the addition of nano-coppers due to the formation of the molten copper film and the CuO tribochemical reaction film on the worn surface.And the dimension of nano-copper has a great influence on its tribological property.The copper nanoparticles can play the role of nano-bearing to change the friction form from sliding friction to rolling friction,which would decrease the wear loss of friction pairs.The wear loss can be sharply decreased by addition of copper nanoplates with micron-scale diameter and lamellar structure which significantly prevents the direct contact of micro-protrusions on the surface of friction pairs and reduces the“welding”between micro-protrusions due to local high temperature caused by friction.展开更多
The current SARS-CoV-2 pandemic has resulted in the widespread use of personal protective equipment,particularly face masks.However,the use of commercial disposable face masks puts great pressure on the environment.In...The current SARS-CoV-2 pandemic has resulted in the widespread use of personal protective equipment,particularly face masks.However,the use of commercial disposable face masks puts great pressure on the environment.In this study,nano-copper ions assembled cotton fabric used in face masks to impart antibacterial activity has been discussed.To produce the nanocomposite,the cotton fabric was modified by sodium chloroacetate after its mercerization,and assembled with bactericidal nano-copper ions(about 10.61 mg·g^(–1))through electrostatic adsorption.It demonstrated excellent antibacterial activity against Staphylococcus aureus and Escherichia coli because the gaps between fibers in the cotton fabric allow the nano-copper ions to be fully released.Moreover,the antibacterial efficiency was maintained even after 50 washing cycles.Furthermore,the face mask constructed with this novel nanocomposite upper layer exhibited a high particle filtration efficiency(96.08%±0.91%)without compromising the air permeability(28.9 min·L^(–1)).This green,economical,facile,and scalable process of depositing nano-copper ions onto modified cotton fibric has great potential to reduce disease transmission,resource consumption,and environmental impact of waste,while also expanding the range of protective fabrics.展开更多
VARIOUS small inorganic solid grain catalysts, alloys and films consisting of various nano-size particles were prepared by chemical methods. The study of catalytic properties of nanostructured materials integrated mat...VARIOUS small inorganic solid grain catalysts, alloys and films consisting of various nano-size particles were prepared by chemical methods. The study of catalytic properties of nanostructured materials integrated material physics with chemistry, which promoted the development of materials science.展开更多
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.
文摘As an excellent anti-wear and friction-reducing additive,nano-copper has attracted extensive researches and attention in tribology field.However,the existing researches are still limited to zero-dimensional nano-copper,that is,the effect of copper nanoparticles on the tribological properties of lubricants.In this paper,the effects of nano-coppers with different dimensions(copper nanoparticles,copper nanowires and copper nanoplates)on the anti-wear ability and frictionreducing performance of lithium grease were systematically investigated.And the mechanism of interaction between dimension and tribological properties was explained in detail.It is concluded that the tribological properties of lithium grease can be improved by the addition of nano-coppers due to the formation of the molten copper film and the CuO tribochemical reaction film on the worn surface.And the dimension of nano-copper has a great influence on its tribological property.The copper nanoparticles can play the role of nano-bearing to change the friction form from sliding friction to rolling friction,which would decrease the wear loss of friction pairs.The wear loss can be sharply decreased by addition of copper nanoplates with micron-scale diameter and lamellar structure which significantly prevents the direct contact of micro-protrusions on the surface of friction pairs and reduces the“welding”between micro-protrusions due to local high temperature caused by friction.
基金This work was financially supported by the Foundation of State Key Laboratory of Biobased Material and Green Papermaking(Grant No.GZKF202131)Qilu University of Technology,Shandong Academy of Sciences,and High-level Foreign Experts Project(Grant No.GDT20186100425).
文摘The current SARS-CoV-2 pandemic has resulted in the widespread use of personal protective equipment,particularly face masks.However,the use of commercial disposable face masks puts great pressure on the environment.In this study,nano-copper ions assembled cotton fabric used in face masks to impart antibacterial activity has been discussed.To produce the nanocomposite,the cotton fabric was modified by sodium chloroacetate after its mercerization,and assembled with bactericidal nano-copper ions(about 10.61 mg·g^(–1))through electrostatic adsorption.It demonstrated excellent antibacterial activity against Staphylococcus aureus and Escherichia coli because the gaps between fibers in the cotton fabric allow the nano-copper ions to be fully released.Moreover,the antibacterial efficiency was maintained even after 50 washing cycles.Furthermore,the face mask constructed with this novel nanocomposite upper layer exhibited a high particle filtration efficiency(96.08%±0.91%)without compromising the air permeability(28.9 min·L^(–1)).This green,economical,facile,and scalable process of depositing nano-copper ions onto modified cotton fibric has great potential to reduce disease transmission,resource consumption,and environmental impact of waste,while also expanding the range of protective fabrics.
文摘VARIOUS small inorganic solid grain catalysts, alloys and films consisting of various nano-size particles were prepared by chemical methods. The study of catalytic properties of nanostructured materials integrated material physics with chemistry, which promoted the development of materials science.
