Nanofluids have shown great promise in the design of heat transfer equipment. In this study, the viscosity of γ -Al2O3
glycerol nanofluids was investigated in the Einstein’s volume concentration regime (≤2%). The effect of temperature, volume
concentration, electrical conductivity, and pH was investigated at a constant shear rate. The nanoparticles were 20–30 nm.
γ -Al2O3 glycerol nanofluids samples were prepared, followed by ultrasonication at two different time period of 3 and 6 h.
The effects of volume concentration on the effective viscosity, electrical conductivity, and pH were all monitored in the
temperature range of 20–70◦C. It was found that classical models underpredicted the experimental data while an empirical
model overpredicted the experimental data. Furthermore, the electrical conductivity and pH were significantly affected by
temperature and volume fraction.