Shear flow behavior and dynamic viscosity of few-layer graphene nanofluids based on propylene glycol-water mixture

Abstract We report the shear flow behavior of few layer graphene (FLG) based nanofluids produced with a commercial mixture of water and propylene glycol and three nonionic surfactants, Triton X-100, Pluronic® P123, and Gum Arabic respectively. The flow properties of these nanofluids were experimentally investigated between 283.15 and 323.15 K and for FLG content from 0.05 to 0.5 wt%. The nanofluids were subjected to different experiments, at rest at fixed temperature, under steady shear flow at fixed temperature and under temperature ramp at fixed shear rate in order to evaluate their stability and behavior under shear and temperature influence. These results were compared and correlated to visual aspect of the samples at the end of measurements. This experimental study evidences that the temperature, the shearing and the shearing duration have an important influence on the stability under shear of nanofluids in function of concentration and surfactant used. Finally, for all stable nanofluids under shear, the dynamic viscosity evolution of nanofluids with temperature is correlated to Vogel-Fulcher-Tammann model.