Synthesis and transport properties of metal oxide decorated graphene dispersed nanofluids

In the present work, a novel chemical reduction followed by calcination at considerably low temperature is used to synthesize copper oxide decorated graphene (CuO/HEG). Graphene has been synthesized via hydrogen induced exfoliation/reduction of graphite oxide. As-synthesized graphene is functionalized in acid medium to decorate copper oxide nanoparticles as well as to disperse it in polar medium. CuO/HEG is dispersed in deionized (DI) water and ethylene glycol without any surfactant, and the thermal transport properties of those nanofluids are studied. Thermal conductivity of CuO/HEG dispersed in DI water based nanofluid shows an enhancement of ∼28% at 25 AC for a volume fraction of 0.05%. In addition to thermal conductivity, the electrical conductivity of the nanofluids is also measured for different volume fractions at different temperatures. Heat transfer coefficient is measured in an indigenously fabricated setup for different volume fractions for different flow rates. © 2011 American Chemical Society.