LAUSR

Abstract An investigation of the saturated vapor pressure for the solutions of Al2O3 nanoparticles in the isopropanol and fullerenes C60 in o-xylene is presented in this paper. An average size of Al2O3 nanoparticles was measured by transmission electron microscopy (TEM) and found to be equal 27.3 nm whereas a hydrodynamic diameter for the same nanoparticles in isopropanol does not exceed 50 nm. The measurement of the saturated vapor pressure is conducted using a static method in a temperature range from 300 K to 350 K for the nanofluids with the mass concentrations 0–9.55% of the nanoparticles Al2O3 in isopropanol and the mass concentration 0–0.55% of fullerenes C60 in o-xylene. An analysis revealed that the total uncertainty of the measured saturated vapor pressure for the nanofluids does not exceed 242 Pa and 559 Pa for the solutions of the isopropanol/Al2O3 and o-xylene/C60 respectively. The temperature and concentration dependences of the saturated vapor pressure for the nanofluids have been discussed. The latent heat of evaporation was calculated and examined using experimental information on the saturated vapor pressure of the nanofluids. It was proven that additives of the nanoparticles Al2O3 and fullerenes C60 could both increase and decrease the saturated vapor pressure and the latent heat of evaporation of the isopropanol and o-xylene. We also discussed a hypothesis that explains changes in the saturated vapor pressure and the latent heat of evaporation of the nanofluids not only by the temperature and concentration of the nanoparticles in the nanofluids but also through structural changes in the base fluids due to a presence of Al2O3 and C60 additives.