Effect of surface modification on the stability and friction and wear properties of ZrO2 / lubricating oil nanofluids

In this paper, ZrO ₂ / lubricating oil nanofluids modified by silane coupling agent γ-methacryloxypropyltrimethoxysilane ( KH570 ) were prepared by surface modification technology. Four surfactants and unmodified nanoparticles were added to the lubricating oil to prepare nanofluids with surfactants. Firstly, the characteristics of modified particles were studied. The results showed that the highest grafting rate of KH570 was found in the modified nanoparticles with 20ml KH570, and the grafting rate was 4.818%. At the same time, it was found that the modified nano-zirconia changed from hydrophilicity to hydrophobicity, and the lipophilicity and dispersion stability were also improved. The stability and friction and wear properties of the prepared nanofluids were studied. The results show that the nanofluids prepared by adding sodium dodecyl benzene sulfonate ( SDBS ) and unmodified nanoparticles in the surfactant have better stability. In contrast, the nanofluids prepared by KH570 modified nanoparticles showed more excellent stability. The modified nano- ZrO ₂ has better tribological properties than the unmodified ZrO ₂ . The best friction coefficient of the modified nano- ZrO ₂ lubricating oil is 0.0753, and the L-TSA46 base oil is reduced by 40.71%.