MXene-reinforced supramolecular oleogel with dynamic reversibility for high-performance tribological and photothermal applications

Herein, cetyltrimethylammonium bromide (CTAB)-modified MXene nanosheets were combined with the bis-urea gelator N, N′-didodecyl-1,2-cyclohexyldiurea (DCHU) and base oils to construct MXene-based supramolecular oleogels. The oleogels, formed via hydrogen-bonding-mediated self-assembly, exhibited a gel transition temperature range of 67–75 °C and pronounced shear-thinning behavior, enabling shear-induced structural reconstruction and stable oil confinement. Compared to the 500SN base oil, the optimized rGel-CTAB-MX oleogel reduced the mean coefficient of friction (COF) by 44.22% to 0.111, decreased the wear volume by 89.91% to 12.73 × 10⁴ μm³, and enhanced the load-carrying capacity from 150 N to 450 N. These enhancements arise from the synergistic lubrication effects of CTAB-MX nanosheets and the oleogel network, including tribofilm formation, MXene interlayer sliding, and surface mending/polishing. Notably, the rGel-CTAB-MX oleogel demonstrates sensitive and reversible photothermal gel-state regulation with excellent cycling stability. This work provides a dynamically tunable MXene-based oleogel platform integrating tribological enhancement and light-responsive regulation for potential smart lubrication applications.