ABSTRACT
This study aimed to analyze the effect of the pH value on the synthesis co-precipitation method on the test results of X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infra-red (FTIR) of zinc ferrite nanoparticles (ZnFe2O4) and to determine the effectiveness of ZnFe2O4 nanofluids compared to conventional fluids. This study used zinc oxide (ZnO) and ferrite (III) oxide (Fe2O3) as precursors and ethylene glycol as a solvent with various pH values such as pH 10, pH 11, and pH 12. XRD test results showed that there was a difference in crystal size, namely, 84.67, 38.5, and 84.68 nm for pH values of 10, 11, and 12, respectively. SEM test results showed that samples of ZnFe2O4 powder with a pH value of 11 experienced higher accumulation or agglomeration. FTIR test results showed that the metal-oxide functional group of ZnFe2O4 powder samples was known to be at a wavenumber of 501 cm–1, which is confirmed by the Fe–O bond at the tetrahedral position, and the wavenumber of 418 cm–1 confirmed the Zn bond. O is in the octahedral position. The heat exchanger test indicated that the heat transfer efficiency increased from 13.19% for conventional fluids to 14.49% for ZnFe2O4 nanofluid.
