Thiadiazole Dimer-Functionalized Liquid Metal Nanoparticles for Anti-Corrosion and Friction Reduction

Thiadiazole compounds and their derivatives have good carrying capacity and lubricating properties. Herein, polydopamine can be in situ self-assembled onto gallium-based liquid metal (GLM) nanoparticles via ultrasound treatment of bulk GLM nanoparticles in dopamine-containing Tris aqueous solution followed by covalent bonding with a thiadiazole dimer (DMCT) through Michael addition reactions. The as-prepared thiadiazole dimer-functionalized liquid metal (GLM-DMCT) nanoparticles, with an average particle size of 380 nm, can be used as nanoadditives in the base oil (500SN). The tribological properties of GLM-DMCT as additives were evaluated under various loads, temperatures, and frequencies, and the results showed that GLM-DMCT additives have improved anti-friction and anti-wear performances of 500SN. The coefficient of friction can be reduced to 0.092 from 0.147 after adding 2 wt % GLM-DMCT, the wear volume reduces by 89.7%, and the load-carrying capacity is increased from 150 to 1050 N. The improved tribological performance is credited to the formation of a stable, protective layer on the friction pair via the complex tribo-chemical reaction of Ga, In, and S elements of GLM-DMCT. Furthermore, the as-prepared GLM-DMCT exhibits good anti-corrosion performance, which is attributed to the breaking of the disulfide bond of DMCT, releasing the corrosion inhibitor DMTD during the corrosion process.