Oil-dispersible LDH solvent-free nanofluids as effective lubricant additives for friction and wear reduction

Solvent-free nanofluids (NFs) hold significant potential as lubricant additives, however, their dispersion in non-polar oils is hindered by polar shell components. To address this issue, we designed and synthesized a core-shell structured MgAl-LDH-NFs comprising a flower-like MgAl-LDH core with inherent lubricating properties and a hydrophobic KH560-FL1000 shell. This design achieved improved dispersion stability in liquid paraffin. At an optimal concentration of 0.75   wt%, the MgAl-LDH-NFs significantly reduced the coefficient of friction by 48.5% and wear volume by 88.8%. This enhancement is attributed to the synergistic effect of the shell’s adsorption capacity and the core’s lubricity, which promoted the formation of a robust protective tribofilm. Solvent-free LDH-based nanofluids demonstrate considerable promise for demanding industrial applications for high-load machinery and precision manufacturing.