▎ 摘　　要

In this article, thermal stability, viscosity, density and surface tension of graphene nano-platelet dispersed in sunflower oil are experimentally determined by varying the graphene concentration (0.1-1.1 wt.%) and temperature (40-100 degrees C). The SEM micrograph and the EDS spectra are used to characterize the graphene. Nanofluids are prepared by ultrasonication technique (two-step method) and the maximum thermal stability of about 280 degrees C is achieved at 1.1 wt.% graphene nanofluids. The dynamic viscosity diminishes in an exponential shape in acquiescence with the Arrhenius equation and the densities o f samples are characteristic with linear decrement in the estimated temperature range. Density and surface tension increase with the graphene concentration, while a reverse trend is observed with temperature raise. The maximum thermal stability, viscosity, density and surface tension is obtained in the nanofluid with 1.1 wt.% concentration and the minimum is obtained in the nanofluid with 0.1 wt.% concentration.