Self-assembled SiO2@LDHs nanohybrids as oil-based lubricant additives for boosting tribological properties

The core/shell SiO 2 @LDHs nanohybrids were successfully synthesized utilizing a facile coprecipitation method. • The in-situ assembly of LDHs on the spherical SiO 2 greatly improved the synergistic lubrication effect between SiO 2 and LDHs. • The rheological and frictional properties of PAO40 containing SiO 2 @LDHs nanohybrids were studied. • The synergistic lubrication mechanism of core/shell SiO 2 @LDHs was proposed. The spherical SiO 2 wrapped with layered double hydroxides (LDHs) was accomplished and subsequently employed as a lubricant additive to enhance the friction-reducing and wear-resistance capabilities of poly α olefin 40 (PAO40). The results revealed that the as-synthesized core/shell SiO 2 @LDHs nanohybrids exhibited a remarkable lubrication effect in PAO40. Notably, when 1.00 wt% SiO 2 @LDHs were ‌incorporated into PAO40, the formulated lubricant exhibited the best tribological performance due to the synergistic effect between SiO 2 and LDHs, with wear rate and coefficient of friction decreased by 48.87% and 43.53% at 200 N, respectively. Meanwhile, the friction behaviors of PAO40 containing SiO 2 @LDHs were further investigated under various sliding conditions. Additionally, a synergistic lubricating mechanism for core/shell SiO 2 @LDHs nanohybrids was also proposed by exploring the microstructure and composition of the worn surface, which involves the formation of lubricating films composed of various metal oxides. This research could offer some guidance for the development and design of high-performance LDHs-based lubricant additives. Download: Download high-res image (198KB) Download: Download full-size image