Investigation of the viscosity and stability of green nanofluids from coconut fibre carbon nanoparticles : effect of temperature and mass fraction

Abstract

This study entails the experimental measurements of the viscosity of 60:40% ethylene glycol (EG) and water (W) nanofluids containing nanoparticles obtained from coconut fibre. Furthermore, the effects of temperature and mass fraction of the synthesised nanoparticles on the relative viscosity of the green nanofluid was studied. The morphology of the prepared nanofluids was obtained using transmission electron microscope (TEM) while stability was determined by zeta potential, viscosity and UV spectroscopy measurements of nanofluids for 720 min. The nanofluids prepared were very stable for more than 720 min. The results of characterisation show that the average diameters of the spheres are between 30 nm to 60 nm. Also the results of experiments showed that with increase in temperature, the viscosity decreased. In addition, when the mass fraction was increased, there was an enhancement in viscosity of up to 50%.