Process optimization and material properties for nanofluid manufacturing

Using an innovative nanofluid preparation method, ultrasonic-aidedsubmerged arc nanoparticle synthesis system, this paper employs the robustness design method to examine the optimal parameters, such as peak current, pulse duration, open voltage and amplitude of ultrasonic vibration, for obtaining the optimal process for TiO2 nanofluid preparation. Experimental results show that the proposed manufacturing system can successfully prepare uniformly distributed TiO2 nanoparticle using the optimal parameters. The pH of the as prepared TiO2 nanofluid is 7.5, which is much higher than that of isoelectric point, about 4.4. Hence, the suspended TiO2 nanoparticles already possess electrostatic stability properties. Regarding ultraviolet/visible absorbency, the produced TiO2 nanofluid would absorb UV energy when the wavelength is 280 nm to 400 nm. According to the UV-Vis absorption spectrum analysis, the energy band gap of the prepared TiO2 nanoparticle is 3.4 eV.