High-Temperature Superlubricity Microcapsules.

Abstract

Superlubricity, characterized by an ultra-low coefficient of friction (COF) below 0.01, is crucial for reducing energy losses in mechanical systems but remains challenging at high temperatures. This study designed a high-temperature-resistant solid-liquid coupled microcapsule containing perfluoropolyether (PFPE) and molybdenum disulfide (MoS₂) encapsulated in silica (SiO₂) to develop a self-lubricating composite material for high-temperature applications. By embedding these microcapsules into a polytetrafluoroethylene (PTFE) matrix, macroscopic superlubricity (minimum COF = 0.005) is achieved in atmospheric environments up to 200-250 °C. The excellent tribological performance is attributed to the synergistic effects of the stress-responsive release of trace lubricants, the decreased COF of the PTFE matrix at high temperatures, the low viscosity of PFPE oil reducing internal friction, and the formation of a boundary lubrication film by MoS₂. This work provided a new strategy for enabling low-wear operation of polymer materials under extreme thermal conditions and holds significant implications for expanding the application boundaries of superlubricity technology.