Highly stable graphene oxide (GO) based-nanofluids were simply prepared by dispersing graphite oxide with the average crystallite size of 20 nm, in polar base fluids without using any surfactant. Electrical conductivity, thermal conductivity, and rheological properties of the nanofluids were measured at different mass fractions and various temperatures. An enormous enhancement, 25678 %, in electrical conductivity of distilled water was observed by loading 0.0006 mass fraction of GO at 25 ºC. GO-ethylene glycol nanofluids exhibited a non-Newtonian shear-thinning behavior followed by a shear-independent region. This shear thinning behavior becomes more pronounced at the higher GO concentrations. The maximum ratio of the viscosity of nanofluid to that of the ethylene glycol as a base fluid was 3.4 for the mass fraction of 0.005 of GO at 20 ºC under shear rate of 27.5 . Thermal conductivity enhancement of 30 % was obtained for GO-ethylene glycol nanofluid for mass fraction of 0.07. The measurement of the transport properties of this new kind of nanofluid showed that it could provide an ideal fluid for heat transfer and electronic applications.

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