Experimental evaluation of engine oil properties containing copper oxide nanoparticles as a nanoadditive

Background: The properties of lubricants are mainly the result of adding a material for improving or producing the required properties. Today, different materials with various nanostructures are used as new additives which, because of their unique properties, are used for improving the lubricant s properties. The purpose of the present research is to add copper oxide (CuO) nanoparticles to engine oil and evaluate the produced changes in some of its properties. Also, viscosity, pour point, and flash point of nanolubricants, which are made at different concentrations (0.1, 0.2, and 0.5 wt.%), and also their thermal conductivity coefficient as four quality parameters which are effective in the functionality of engine oil are evaluated. Results: Upon the obtained results, thermal conductivity coefficient and flash point of nanolubricants with 0.1 wt.% concentration, respectively, had 3% and 7.9% improvement with respect to the base oil. Also, the oil s viscosity, as a very important factor in lubricating issue, at a lower concentration with respect to the engine oil without CuO had no appreciable change. Conclusion: Among the different methods which have been used for dispersing nanoparticles inside the base oil, using planetary ball mill was determined as the most important method for stabilization of nanoparticles inside SAE 20W50 engine oil. Also, the physical properties of nanolubricants were measured based on the American Society for Testing and Materials standard methods.