Surfactant prevented growth and enhanced thermophysical properties of CuO nanofluid

Abstract

In recent work, CuO nanofluid is prepared with and without PVA (poly(vinyl alcohol)) coated surfactant nanoparticles suspension in distilled water: ethylene glycol (DW:EG) (60:40) ratio for 0.1 wt% and 0.5 wt% concentration of fluid by two-step technique. Our work describes a simple and cost effective chemical precipitation method to synthesis CuO nanoparticles with the addition of synthetic polymer (PVA) allows the modification of physical properties of copper oxide (CuO) nanoparticles. The scanning electron microscopy (SEM) shows the morphological difference in nanocrystallite size and shape between without surfactant coated nanoparticles and with PVA coated particles. XRD pattern of CuO particles reveal that high crystal quality with the monoclinic crystal structure where PVA coated particles have crystallite size 15 nm and without coating it is 31 nm. UV-Vis (ultraviolet absorption spectroscopy) spectra confirmed that the CuO absorption peak at 292 nm and 445 nm for CuO+ PVA. Fourier transform infrared spectra (FTIR) spectroscopy studies show the interaction between PVA and CuO nanoparticles. Experimental results concluded that for CuO + PVA nanofluid, particle size is smaller and showing more stable fluid from zeta potential values. Thermal conductivity results are carried from sound velocity of fluid by Bridgman's equation. As the particle concentration increases in fluid, thermal enhancement is noted. It was found that the viscosity of nanofluid is lower with a larger size particle at the same temperature and for the same concentration. Therefore, our result shows that CuO nanofluids have good potential for effective heat transfer application.