纳米Cu在聚乙二醇溶液中的摩擦磨损性能研究IntroductionWith the development of nanotechnology, nanomaterials have attracted increasing attention in the field of tribology. Among them, copper nanoparticles (CuNPs) have been widely used due to their excellent properties, such as high thermal conductivity, good electrical conductivity, and high antibacterial activity. Furthermore, polymer matrices, such as polyethylene glycol (PEG), provide an ideal environment for the dispersion of nanoparticles, thereby enhancing the lubrication properties. In this study, we investigated the friction and wear performance of CuNPs in PEG.Experimental methodsCuNPs were synthesized via a wet-chemical method, and the synthesized CuNPs were characterized using a transmission electron microscope (TEM) and X-ray diffraction (XRD). PEG was used as a dispersion medium to produce a transparent solution of CuNPs with different concentrations, namely 0.1, 0.5, 1, 2, and 5 wt%. The tribological measurements were performed using a pin-on-disk tribometer at different sliding speeds, namely 0.1, 0.25, 0.5, and 1 m/s, and different loads, namely 5, 10, and 15 N, for 5000 testing cycles.Results and discussionTEM images showed that the synthesized CuNPs had an average diameter of 20 nm, and the XRD patterns indicated the presence of crystalline CuNPs with a face-centered cubic structure. The tribological test results indicated that the friction coefficient of the CuNPs/PEG nanofluid decreased with increasing concentration of CuNPs, and the lowest friction coefficient of 0.05 was observed for a concentration of 5 wt% at a sliding speed of 0.1 m/s and a load of 5 N. The wear rate of the CuNPs/PEG nanofluid also decreased with increasing concentration of CuNPs, and the lowest wear rate of 4.410-7 mm3/Nm was observed for a concentration of 5 wt% at a sliding speed of 0.1 m/s and a load of 5 N. The excellent tribological properties of the CuNPs/PEG nanofluid were attributed to the improved boundary lubrication and reduced adhesion and abrasive wear between the sliding surfaces.ConclusionCuNPs were successfully synthesized via a wet-chemical method and dispersed in PEG to form a nanofluid with different concentrations. The tribological results showed that the CuNPs/PEG nanofluid exhibited excellent friction and wear properties compared to the pure PEG. Moreover, the lowest friction coefficient and wear rate were observed for a concentration of 5 wt% at a sliding speed of 0.1 m/s and a load of 5 N. This study provides a theoretical basis for the practical application of CuNPs in PEG for improving the tribological properties of materials.Furthermore, the mechanism of the enhanced tribological properties of the CuNPs/PEG nanofluid was explored. The addition of CuNPs in PEG increased the lubricity of the nanofluid by forming a stable boundary lubricating film on the sliding surfaces due to their excellent thermal and electrical conductivity properties. In addition, CuNPs reduced the adhesion between the sliding surfaces by preventing the welding and tearing of the contact surfaces, hence reducing the friction and wear of the materials. The synergy between the boundary lubrication and adhesion reduction properties resulted in the excellent tribological properties of the CuNPs/PEG nanofluid.In conclusion, the CuNPs/PEG nanofluid showed excellent friction and wear performance due to the improved boundary lubrication and reduced adhesion and abrasive wear between the sliding surfaces. This study provides a practical application of CuNPs in PEG for improving the tribological properties of materials, particularly in the field of lubrication. Further studies to optimize the concentration of CuNPs in PEG and to investigate its long-term tribological performance are required for their practical application in industry.Furthermore, the use of nanofluids in tribology has gained significant attention due to their potential to improve the lubrication properties of materials. Nanofluids are suspensions of solid nanoparticles in a base fluid and have shown promising results in terms of reducing friction and wear on sliding surfaces. However, it is essential to study the interaction between the nanoparticles and the base fluid to understand the enhanced tribological properties.In addition to CuNPs, other nanoparticles such as SiO2, TiO2, and Al2O3, have been used in different base fluids such as water, oil, and glycol to improve their lubrication properties. The addition of these nanoparticles has altered the physical and chemical properties of the base fluid such as viscosity, thermal conductivity, and hardness, resulting in improved tribological performance.Further studies are required to optimize the concentration and size of nanoparticles to achieve the desired tribological properties. Additionally, the effect of nanoparticles on the degradation and corrosion of the materials must also be studied to ensure their practical application in industr