Thermal and rheological properties of oil-based nanofluids from different carbon nanostructures

In this research, different carbon nanostructures including multi-walled carbon nanotubes (MWCNTs), graphene nanosheets (G), carbon nanoballs (CNBs) and fullerene nanoparticles (C60) were added to SAE 20W50 engine oil. The purpose of this research was to evaluate and compare effects of different carbon nanostructures on thermal and rheological properties of engine oil, including thermal conductivity coefficient, viscosity, pour point and flash point. Planetary ball mill method was used for dispersing nanomaterials inside the base fluid. The obtained results showed that changes in base oil's properties were different and depended on the type of additive structures. Spherical fullerene nanoparticles and carbon nanoball particles had the best stability conditions, respectively. Also, carbon nanoball particles had the most positive effect on thermal conductivity and flash point of base oil by about 18% and 13.8%, respectively.