Thermal conductivity and thermal diffusivity of fullerene-based nanofluids

Owing to their outstanding characteristics, carbon based nanofluids (CbNFs) have been applied to various advanced heat transfer and cooling technologies. It was claimed that these CbNFs can considerably improve the properties of the base working fluids. Among all the thermal characteristics, the thermal conductivity (λ) is regarded as the primary parameter to be considered for the application of nanofluids (NFs). In the present research study we measured for the first time both λ and thermal diffusivity (a_T) of very stable fullerene (C₆₀)-based NFs in liquid phase (1,2,3,4-tetrahydronaphthalene and 1,2-dicholorobenzene) by the transient multi-current hot wire technique at atmospheric pressure in a wide range of temperature (254-323 K). Similar to the base liquids (BLs), we observed a slight decrease in λ with an increase in temperature. Additionally, compared to the BLs λ was reduced upon the addition of C₆₀. The results were compared with the predicted ones using different theoretical models. Not much variation in a_T was observed between the C₆₀ NFs and the corresponding BLs due partly to the small variation of λ with the addition of C₆₀.