Experimental study on the effect of different surfactants on the thermophysical properties of graphene filled nanofluids

In this study, the effects of different surfactants on the stability and thermophysical properties of graphene (GR) filled water (W) nanofluids were investigated in an experimental manner. Nanofluids filled by 0.05% mass fraction of GR nanoparticles with a surfactant concentration of 0.02%, 0.04%, 0.06%, 0.08%, and 0.1% were studied. The effects of surfactants on stability, viscosity, and thermophysical properties of prepared nanofluids were analyzed experimentally. The results show that the nonionic surfactants displayed best performance in terms of static stability, and the anionic surfactants stand in the second position. Further study reveals that thermal conductivity enhancement of nanofluids could reach 2.0% by filling only 0.05% mass fraction of GR and the heat transfer coefficient of nanofluids up to 27%.