Surface-Functionalized Ti3C2Tx MXene as a Kind of Efficient Lubricating Additive for Supramolecular Gel

Low interlaminar shear stress, high mechanical strength, and tunable structure make Ti₃C₂T_x MXene a burgeoning star as solid lubricants and lubricant additives. Although surface modification strategy can improve its compatibility with base oils, it will eventually settle due to gravity. Additionally, base oils are prone to leakage, creep, and volatilization, which limit their application. To address these issues, supramolecular gels with surface-modified Ti₃C₂T_x were conceived. Apart from the lubrication effect, the high thermal conductivity of Ti₃C₂T_x MXene accelerated the phase transition rate of supramolecular gels. The thermal-reversible and creep-resistant properties distinguish them from other conventional lubricants. The tribological tests showed that the 500 solvent neutral (SN) supramolecular gel with 0.10 wt % Ti₃C₂T_x-octadecylphosphonic acid (Ti₃C₂T_x-ODPA) reduced the coefficient of friction (COF) by 46.32% and wear volume by 81.18% compared with pure 500SN oil. Moreover, they also performed well in load-carrying capacity, temperature tolerance, and speed adaptability. This work puts forward a new approach to prepare MXene-based lubricants tailored for some severe lubrication conditions. These exceptional features enable their application in rolling bearings, some gears, and other low maintenance mechanisms.