Organic-Inorganic Hybrid Polysiloxane Brushes with Improved Lubrication and Load-Bearing Capacity

With the development of microelectromechanical systems (MEMS), ultrathin dry lubrication coatings have received significant attention. In this study, a nanoscale organic-inorganic hybrid lubricative coating (OHL) with a low friction coefficient and wear resistance was developed by grafting polysiloxane brushes on an inorganic silica sol layer. Friction evaluations, including the friction coefficient, load-bearing capacity, abrasion, and durability, were conducted. Compared with the surface of polysiloxane brushes without a silica sol layer, the introduction of a silica sol interlayer can effectively improve the mechanical stability of polysiloxane brushes; namely, the friction coefficient under high load pressure was able to remain low for a long time. In addition, the lubrication performance can also further improve by modifying the upper friction pair surface with the OHL. More importantly, the OHL has an excellent stability and general applicability. The OHL coating can be applied to various solid surfaces that provide a similar lubrication performance, which may provide a new vision for reducing the friction coefficient and enhancing the wear resistance, especially under dry friction conditions.