Enhancing the tribological performance of Ti3C2 MXene modified with tetradecylphosphonic acid

Abstract

MXene is a new two-dimensional (2D) material with excellent physical and chemical properties. However, the MXene nanosheets have high surface energy and exhibit poor dispersibility and stability in oil, owing to the presence of ‒OH, ‒O, and ‒F functional groups on the surface. Herein, 2D Ti 3 C 2 MXene material was chemically modified with tetradecylphosphonic acid (TDPA). Through the condensation reaction of the phosphoric acid groups with hydroxyl groups on the Ti 3 C 2 surface, a modified Ti 3 C 2 nanosheet (TDPA-Ti 3 C 2 ) was obtained. We dispersed TDPA-Ti 3 C 2 into castor oil to study its tribological properties. Compared with pure castor oil, the coefficient of friction (COF) and wear rate (W r ) of castor oil with 0.1 wt% TDPA-Ti 3 C 2 are reduced by 27.9% and 55.1%, respectively. The possible friction-reducing and anti-wear mechanisms of TDPA-Ti 3 C 2 in castor oil were explored by analyzing the surface morphologies of the wear scars. The improvement of lubrication performance is attributed to the deposition and adsorption of TDPA-Ti 3 C 2 on the friction surface during the lubrication process, forming a physical transfer film to prevent direct contact with the friction pair. The research results show that the modified Ti 3 C 2 has broad application prospects in lubrication and tribology. • A high grafting density TDPA-Ti 3 C 2 nanosheet was obtained by modifying Ti 3 C 2 with tetradecylphosphonic acid (TDPA). • Ti 3 C 2 decorated with TDPA exhibits excellent friction-reducing and anti-wear performance. • The synergistic effect of Ti 3 C 2 and TDPA can significantly improve the tribological properties of castor oil. • The uniform dispersion of TDPA-Ti 3 C 2 in the castor oil helps form a protective film during the friction process.