University of Kashan Journal of Nanostructures 2251-7871 2 4 2012 12 01 Surveying and Comparing Thermal Conductivity and Physical Properties of Oil Base NanoFluids Containing Carbon and Metal Oxide Nanotubes 405 412 5411 10.7508/jns.2012.04.001 EN H. Ahmadi School a Department of Mechanical Engineering of Agricultural Machinery, University of Tehran, Karaj, Iran. E. Ettefaghi School a Department of Mechanical Engineering of Agricultural Machinery, University of Tehran, Karaj, Iran. A. M. Rashidi Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), Tehran, Iran. S. S. Mohtasebi School a Department of Mechanical Engineering of Agricultural Machinery, University of Tehran, Karaj, Iran. A. Nouralishahi Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, University of Tehran, Tehran, Iran Journal Article 2014 05 14 In this research, nano materials with tubular structures are added to SAE 20W50 engine oil to study the rate of their effects on the properties of engine oil. Multi-walled carbon nanotubes (MWCNTs) and vanadium oxide nanotubes (VONTs) has been used as two different additive materials, one of them is carbonic and the other is metallic oxides and their effect on  different parameters containing viscosity, thermal conductivity coefficient, flash point and pour point of engine oil as the quality properties of engine oil has been studied and compared. The samples of two concentrations 0.1 and 0.2 wt% with using planetary ball mill were made. The obtained results show that MWCNTs in all cases, which  have been evaluated, had better functionality with respect to vanadium oxide nanotubes. In the 0.1 wt% concentration, flash point of MWCNTs/oil and VONTs/oil increased about 9.3% and 5.8% respectively. In addition, thermal conductivity of them increased 13.2% and 10.2% respectively. https://jns.kashanu.ac.ir/article_5411_989d5cc9e3e1a0d92f8e60ed2047aaaa.pdf