Effect of copper oxide nanoparticles on thermophysical properties of hydraulic oil-based nanolubricants

Abstract

The effect of CuO nanoparticles on thermophysical properties of hydraulic oil (SAE 68) used in heavy earth moving machinery has been experimentally evaluated in this paper. The results of Fourier transform infrared red spectroscopy show that the lubricant remains chemically stable in the presence of CuO nanoparticles. Dynamic light scattering results for particle size distribution have depicted that the size of agglomeration increases with an increasing CuO particle volume fraction which is confirmed by field emission scanning electron microscope images as well. Nanolubricants exhibit non-Newtonian behaviours with increasing CuO nanoparticles volume fraction. The existing theoretical models are found to be inappropriate to predict the viscosity with nanoparticles volume fraction. A correlation has been proposed between viscosity and particle volume fraction on the basis of experimental results. Thermal conductivity of CuO-hydraulic oil also increases with an increase in CuO particle volume fraction.