105 Study on the Dispersion Stability Influencing Factors of Nanofluids Available to Purchase

The dispersion stability of nanofluids is very important for the heat and mass transfer performance, therefore it is necessary to study and analyze influencing factors to the dispersion stability of nano-fluids. In this study, FeO-water and A12O3-water nano-fluids have been prepared, respectively. We analyzed a variety of influencing factors to the dispersion stability of the prepared nano-fluids, such as the dispersants' type, the mass proportion of the dispersant in base-liquid, the PH value of base-liquid, the ultrasonic power and the ultrasonic time. The optimum conditions of dispersion stability for preparation were explored through observing the sediment, measuring the absorbency, and analyzing the viscosity of nano-fluids. The results showed that, the ammonium citrate (ACT) is the best dispersant for preparing FeO-water nanofluids, and the sodium dodecyl benzene sulfonate (SDBS) is the best dispersant for the Al₂O₃-water nano-fluids, and that the SDBS of 0.2 wt%, the ultrasonic time of 1 hour, the ultrasonic power of 300 W and the pH of 4 are the optimum conditions for preparing A1₂O₃ nano-fluids. The possible mechanisms have also been analyzed.