Core-rim structured MXene@SiO2 composites as oil-based additives for enhanced tribological properties

Abstract

AbstractHerein, we have prepared SiO2 particles uploaded MXene nanosheets via in-situ hydrolysis of tetraetholothosilicate. Due to the large number of groups at the edges of MXene, SiO2 grows at the edges first, forming MXene@SiO2 composites with a unique core-rim structure. The tribological properties of MXene@SiO2 as lubricating additive in 500 SN are evaluated by SRV-5. The results show that MXene@SiO2 can reduce the friction coefficient of 500 SN from 0.572 to 0.108, the wear volume is reduced by 73.7%, and the load capacity is increased to 800 N. The superior lubricity of MXene@SiO2 is attributed to the synergistic effect of MXene and SiO2. The rolling friction caused by SiO2 not only improves the bearing capacity but also increases the interlayer distance of MXene, avoiding accumulation and making it more prone to interlayer slip. MXene@SiO2 is adsorbed on the friction interface to form a physical adsorption film and isolate the friction pair. In addition, the high temperature and high load induce the tribochemical reaction and form a chemical protection film during in the friction process. Ultimately, the presence of these protective films results in MXene@SiO2 having good lubricating properties.