Study of thermodynamic, transport and volumetric properties of nanofluids containing ZrO2 nanoparticles in polypropylene glycol, polyvinyl pyrrolidone and water

Abstract

Zirconium dioxide (ZrO₂) nanofluids are used in cooling systems, solar energy, and heat exchangers, offering improved heat transfer and efficiency across a wide temperature range. The aim of this work was to study the influence of polypropylene glycol (PPG) and polyvinyl pyrrolidone (PVP) and aqueous solutions of them as a base fluid on stability, volumetric properties, and viscosity of nanofluids containing Zirconium oxide (ZrO₂) nanoparticles. The stability of these nanofluids has been confirmed using UV-Vis spectroscopy, and the particle size distribution of the systems using dynamic light scattering (DLS). Among these systems ZrO₂–PPG and ZrO₂–H₂O–PVP30% have appropriate stability. The density, speed of sound and viscosity of these nanofluids have been measured at T = (293.15 to 318.15) K. From these data, the excess molar volume (V^E_m) and isentropic compressibility (κ_s) have been determined. The effects of ZrO₂ nanoparticles and temperature have also been investigated on volumetric and transport properties of aqueous solutions of PPG and PVP. The (V^E_m) values were fitted to the Redlich–Kister, Ott et al., and polynomial equations. Also, the isentropic compressibility (κ_s) values were correlated with the polynomial equation. The Eyring-NRTL and Eyring-mNRF models have been used for correlating of the viscosity of the nanofluids with temperature dependency. The performance of the Einstein, Brinkman, Lundgren and Batchelor models in the prediction of viscosity of the nanofluids has also been analyzed.