Eco-Friendly Core–Shell Hollow C@SiO2@C Nanolubricating Additives for Friction Reduction and Antiwear

Conventional industrial friction modifiers mostly contain S and P elements in the liquid phase to satisfy the long-term stable operation of the lubricant. However, their corrosive property causes distress to the life of the equipment. To tackle this challenge, we selected poly(methyl methacrylate) (PMMA) and ethyl cellulose as the carbon sources to design and prepare nanocomposites of carbon-coated silica and hollow carbon spheres (C@SiO2@C) with homogeneous morphology. Tribological tests have confirmed the excellent antifriction and antiwear properties of PAO10 lubrication systems with 4.0 wt% C@SiO2@C particles, reducing the coefficient of friction (CoF) and wear volume by 45.8% and 75.6%, respectively. The spherical structure of C@SiO2@C nanocomposites ensures high load-bearing capacity of the lubrication system, while the carbon deposition film after extrusion and crushing prevents direct contact between the tribopair. Meanwhile, the heat in the friction process prompts the additives to react with the tribopair of the tribochemical film and carbon deposition film to further achieve excellent friction reduction and antiwear performance. It is believed that such multilayer-coated core–shell nanocomposites can be widely used in industry