Viscosity and rheology of the ethylene glycol based nanofluids with single-walled carbon nanotubes

The work is devoted to the experimental study of the viscosity and rheology of nanofluids based on ethylene glycol with single-walled nanotubes. Polyvinylpyrrolidone is used as a dispersant. The weight concentration of nanotubes ranged from 0.01 to 1%. In all cases, the weight concentration of the dispersant was controlled. The measurements were carried out in the temperature range from 20 to 40 degrees C. It was shown that at all weight concentrations the solution of ethylene glycol and dispersant is a Newtonian liquid, and at a maximum concentration (4%) the viscosity of the solution is two and a half times higher than the viscosity of ethylene glycol. At the same time, all the studied nanofluids turned out to be non-Newtonian and have a pseudoplastic character. It was established that ultrasonic treatment of nanofluids leads to partial degradation of the dispersant and a decrease the base fluid viscosity. The degree of this degradation increases with increasing ultrasonic processing power. With the considered low weight concentrations of nanotubes, the dependence of the viscosity coefficient of the nanofluid on temperature is determined by the corresponding dependence of the base fluid.