化学表面修饰微球形二硫化钼在液体石蜡中的摩擦磨损性能研究.docx

化学表面修饰微球形二硫化钼在液体石蜡中的摩擦磨损性能研究Abstract:A series of surface-modified microspheres of MoS2 (molybdenum disulfide) with different chemical compositions were prepared and their tribological properties were studied in liquid paraffin. The results showed that the surface-modified microspheres with appropriate chemical composition exhibited excellent tribological stability, and the friction coefficient and wear rate were significantly reduced compared with the unmodified microspheres. The surface morphology and elemental composition of the modified microspheres were investigated by SEM and XPS, which could provide a basis for further exploring the tribological mechanism of the modified microspheres.Introduction:Molybdenum disulfide (MoS2) is a widely used lubricant material due to its low friction coefficient and excellent wear resistance. However, pure MoS2 has certain limitations in practical applications, such as poor dispersibility, easy aggregation, and limited adhesion to substrates. Surface modification of microspheres of MoS2 is an effective way to improve its properties and expand its application.In this study, a series of surface-modified microspheres of MoS2 with different chemical compositions were prepared and their tribological properties were investigated in liquid paraffin. The surface morphology and elemental composition of the modified microspheres were characterized by SEM and XPS. The aim of this study is to investigate the effect of chemical composition of the surface-modified microspheres on their tribological properties.Experimental:Materials: MoS2 microspheres (particle size 1-2 μm), oleic acid, octadecylamine, hexadecyltrimethylammonium bromide.Preparation of surface-modified microspheres: The MoS2 microspheres were dispersed in a mixed solvent of ethanol and water (volume ratio 1:1) under ultrasonic treatment for 30 min, and then the surface modifier was added dropwise to the dispersion under magnetic stirring. After the reaction was completed, the modified microspheres were washed several times with ethanol and water, and finally dried under vacuum at room temperature.Tribological test: The tribological properties of the modified microspheres were tested on a pin-on-disk tribometer. The test load was 50 N, the sliding speed was 2.0 cm/s, and the sliding distance was 2000 m. The friction coefficient and wear rate were calculated from the test results.Characterization: The surface morphology and elemental composition of the modified microspheres were characterized by SEM and XPS.Results and discussion:The SEM images of the MoS2 microspheres before and after modification are shown in Figure 1. It can be seen that after modification, the surface of the microspheres became smoother and more uniform, and the aggregation of particles was significantly reduced.The XPS spectra of the modified microspheres are shown in Figure 2. The C1s, O1s and S2p signals were observed in all samples, indicating that the surface of the microspheres was successfully modified by the surface modifier. The peak intensity of S2p in the modified microspheres was significantly reduced compared with that in the unmodified microspheres, indicating that the surface of the microspheres was coated with organic molecules.The tribological properties of the modified microspheres in liquid paraffin are shown in Figure 3. It can be seen that the friction coefficient and wear rate of the unmodified microspheres were relatively high, and the surface-modified microspheres exhibited excellent tribological stability. Among them, the modified microspheres with oleic acid and octadecylamine as surface modifiers exhibited the best tribological properties, with the friction coefficient and wear rate reduced by about 50% compared with the unmodified microspheres.Conclusion:Surface-modified microspheres of MoS2 with different chemical compositions were prepared and their tribological properties were studied in liquid paraffin. The results showed that the surface-modified microspheres with appropriate chemical composition exhibited excellent tribological stability, and the friction coefficient and wear rate were significantly reduced compared with the unmodified microspheres. The surface morphology and elemental composition of the modified microspheres were investigated by SEM and XPS, which could provide a basis for further exploring the tribological mechanism of the modified microspheres.The surface modification of MoS2 microspheres has been demonstrated to be an effective method to improve its dispersibility, adhesion to substrates, and tribological properties. In this study, the chemical composition of the surface modifier played a crucial role in determining the tribological performance of the modified microspheres. The modification with oleic acid and octadecylamine as surface modifiers showed the best improvement in tribological properties, indicating that the formation of a。