The Rheology of Nanolubricants Based on Fe2O3, Al2O3, and ZnO Oxide Nanoparticles: A Comparative Study

This article reports the results of a comparative study of the rheological characteristics of nanolubricants carried out based on Fe2O3, Al2O3, and ZnO nanoparticles. The base fluid used was 20W40 engine oil. The nanofluid samples were prepared in solid volume fractions (0.25%; 0.50%; 0.75%, and 1%). The measurements were performed at different temperatures, ranging between 20 degrees C and 60 degrees C, and at shear rates, ranging from 100 s(-1) to 300 s(-1). The results obtained showed that nanofluids based on Fe2O3 and ZnO nanoparticles exhibited a non-Newtonian shear thinning behaviour while the nanofluid based on the Al2O3 nanoparticle exhibited a Newtonian behaviour. The Al2O3/oil nanofluid had a lower dynamic viscosity than the Fe2O3/oil and ZnO/oil nanofluids. The increase in temperature led to a reduction of more than 80% in viscosity for all nanofluids. On the other hand, the increase in the volume concentration of nanoparticles clearly increased the dynamic viscosity.