Enhanced thermal conductivities of nanofluids containing graphene oxide nanosheets.

Stable ethylene-glycol-based nanofluids containing graphene oxide nanosheets have been prepared. The measurements of thermal conductivity indicate that the nanofluids have substantially higher thermal conductivities than the base fluid. The thermal conductivity enhancement depends strongly on the volume fraction of graphene oxide nanosheets and increases with the increasing loading. When the nanosheet loading is 5.0 vol%, the enhancement ratio is up to 61.0%. The thermal conductivity of the fluids remains almost constant for seven days, indicating their high stability. The level of enhancement is independent of temperature in the measured temperature range.