LAUSR

Eco-friendly two-dimensional (2D) nanolubricants have emerged as promising candidates for advanced functional materials. However, challenges such as poor dispersion stability and weak interfacial adhesion limit their widespread application. Herein, we developed a method to tailor WS2 nanosheets functionalized with γ-aminopropyltriethoxysilane (γ-APS), enhancing their interaction with phosphate ester groups from di(2-ethylhexyl) phosphate (DEPS), which leads to the creation of gel-like WS2-NH-DEPS additives with excellent dispersive and tribological properties in polyalphaolefin (PAO6). Specifically, a 0.5 wt % WS2-NH-DEPS/PAO6 dispersion achieves the reduction of ∼40% in the coefficient of friction (COF) and the decrease of ∼70% in the wear scar diameter (WSD) compared to pure PAO6. Surface analysis reveals that the unique structure of exfoliated WS2 nanosheets and their synergistic interactions with phosphonate groups facilitate the formation of a hybrid protective film composed of embedded WS2 nanosheets, phosphoric acid compounds, and other oxides such as FeOX, FeNOX, and FeSOX to enhance the tribological performance, providing essential insights for developing nanomaterial-based lubricants in advanced mechanical systems.