Abstract
•A novel deep eutectic solvents were prepared and made into nanofluids.•Thermophysical properties of nanofluids were subjected to comprehensively studied.•Thermophysical mechanism was proposed and studied from the atomic point of view.
With the development of electronic machinery, the traditional heat exchange working fluid can no longer be used in some extreme working environments. As a new type of fluid, deep eutectic solvent has the advantages of promising thermal stability, low cost and non-toxicity through the hydrogen bond association of hydrogen bond acceptor and hydrogen bond donor, and is also coined to be an efficient heat transfer working fluid. In this work, three kinds of nanofluids filled with TiO2, Al2O3 and Fe2O3 nanoparticles were prepared with glycerol/sodium acetate trihydrate deep eutectic solvent as the base solution, and the mechanism of thermal conductivity change of nanofluids were discussed from atomic and microscopic levels. The experimental results showed that the prepared glycerol/ sodium acetate trihydrate 2:1 deep eutectic solvent system reduced the viscosity by 58.03% compared with glycerol, and increased the thermal conductivity by 17.2% compared with glycerol at 25 ℃. The effects of nanoparticles on thermal conductivity and specific heat capacity were also investigated. Compared with deep eutectic solvent, the thermal conductivity was improved after adding Fe2O3 nanoparticles; it is worth noting that the specific heat capacity of nanofluids was more than doubled after adding nanoparticles.