Experimental Investigations on Stability and Viscosity of Carboxymethyl Cellulose (CMC)-Based Non-Newtonian Nanofluids with Different Nanoparticles with the Combination of Distilled Water

This paper presents the experimental analysis of stability and rheological studies of three different types of nanoparticles (Al 2 O 3 , CuO, and TiO 2 ) with carboxymethyl cellulose (CMC)-based nanofluids. The two-step method was adopted for the preparation of nanofluids. In the present study, nanoparticles were characterized by X-ray diffraction (XRD) analysis. The sedimentation tests and UV–Vis absorbance tests were performed to predict the stability of nanofluids. For all prepared nanofluids when CMC concentration was zero, TiO 2 nanofluids was found to be more stable in the visual tests for a period of 18–20 days and CMC (0.4 % by weight) -based TiO 2 nanofluid took 28–30 days to sediment. For rheological study of nanofluids, viscosity was measured under the influence of increasing particle concentration (0.01 % to 0.04 %) and increasing temperature (25 °C to 55 °C). The experimental results reveal that on increasing particle concentration the viscosity of nanofluids increases by 27 %, 21.5 % and 17.4 % for TiO 2 , Al 2 O 3 and CuO nanofluids respectively as compared to the base fluid. While on the increasing temperature from 25 °C to 55 °C, the viscosity of nanofluids decreases by 11 %, 12 % and 9 % for Al 2 O 3 , CuO, and TiO 2 , respectively. Moreover, from the shear stress vs. shear rate trends, it was concluded that all three nanofluids exhibit pseudoplastic or shear-thinning nature.