Preparation of CuO/Water Nanofluids Using Polyvinylpyrolidone and a Survey on Its Stability and Thermal Conductivity

Abstract

In this article CuO/water nanofluid was synthesized by using polyvinylpyrolidone (PVP) as the dispersant.  Thenanofluid stability period and the heat transfer enhancement were determinedby measuring the thermal conductivities. To study the nano-fluid stability, zeta (ζ) potential, and absorbency were measured under different pH values and PVP surfactant concentrations; also thermal conductivity enhancement was measured based on different volume fraction of CuO nanoparticles and temperature. The results showed that the nano-fluid with PVP surfactant has a good stability of about a week in the optimum pH and PVP concentration which are 8 and 0.095,respectively. Furthermore, in the abovementioned concentration of pH and PVP, optimum CuO volume fraction of 6% was obtained, in which, the thermal conductivity enhancement is 17% at 25oC. Finally, with changing temperature at optimum values (for PVP surfactant and CuO nanoparticles), 31% increase in thermal conductivity was obtained at 50oC.