Preparation and thermal properties of oil-based nanofluid from multi-walled carbon nanotubes and engine oil as nano-lubricant☆

Abstract Nowadays, different materials with various nanostructures are used as additives for improving properties of lubricants. In this research, the effect of multi-walled carbon nanotubes (MWCNTs) in different concentrations on some of the properties of engine oils was studied. Viscosity, pour point, flash point and thermal conductivity as four quality parameters, which are effective in functionality of engine oil, were also studied. Among the different methods, which have been applied for dispersing nanotubes inside the base oil, the functionalization method for carbon nanotubes and using planetary ball mill have been determined as the best methods for stabilization of nanotubes inside the SAE 20 W50 engine oil. According to the obtained results, thermal conductivity and flash point of nano-lubricants with 0.1 wt% improved by 13.2% and 6.7%, respectively, with respect to the base oil.