Density and Thermal Conductivity Measurements of Alcohol/Water-Based Ternary Nanofluids Containing GO–Al2O3–SiO2 Nanoparticles

The dispersion stability and thermophysical properties of ternary composite nanofluids (NF) containing graphene oxide (GO), aluminum oxide (Al 2 O 3 ), and silica (SiO 2 ) at different concentrations and ratios, with water-based ethylene glycol and 1,2-butanediol added as antifreeze agents, were investigated. First, the ternary nanofluid was prepared using a two-step method, and the prepared nanoparticles were characterized using field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The influence of surfactant addition on the stability of the nanofluid was analyzed. The density and thermal conductivity (TC) of NF were measured at different volume concentrations (0.2–0.6 vol%) and temperature ranges (298.15–333.15 K and 293.15–363.15 K, respectively). As the GO concentration increased, the proportion of thermal conductivity improvement showed a stepwise increase with concentration changes. When the GO concentration reached 80 % in the three types of nanoparticles, the thermal conductivity of NF at 363.15 K was 58 % higher than that of the base fluid. For the two different base fluids, under the same ratio, concentration, and temperature conditions, the base fluid containing 1,2-butanediol showed a more significant effect in enhancing thermal conductivity.