Evaluation of physico-thermal properties of TiO2–water mixture dispersed with MWCNTs

Carbon nanotube-based solar thermal fluids are being studied in this field for their thermo-physical characteristics. Using TiO2and water as the basic fluids in 100:0, 75:25, and 50:50 ratios, nano-fluids were generated. The MWCNTs were dispersed in these three base fluids at a weight fraction of 0.25, and 0.5% and 0.75%, respectively. For the duration of two months, the zeta potential variation is studied to determine the stability of dispersion. The hot disk method and Anton Paar viscometer were used to measure thermal conductivity and dynamic viscosity. Adding MWCNTs to the basic fluids resulted in a 12–21% increase in thermal conductivity. Although viscosity was shown to increase in the 50–70 °C range, it was found to have a less impact at higher temperatures.