SURFACE MODIFICATION OF Fe3O4 NANOPARTICLES FOR PREPARING STABLE WATER-BASED NANOFLUIDS

Nanofluids are known as suspension of nanoparticles in a base fluid having improved thermophysical properties, which can be used in different applications. However, instability of the nanofluids is a problem that causes a decrease in the performance of heat exchangers and other energy systems. Nanofluid stability has an important role in its thermophysical properties which can highly affect the performance of the systems. In this study, Fe3O4based nanoparticles have been synthesized by performing surface modification to prepare water-based nanofluids with superior stability. In order to evaluate the properties of the proposed nanoparticles, relevant analysis including FT-IR, XRD, EDS, TEM and SEM analysis was performed. In continue, the nanofluid with volume concentration 0.2% Fe3O4based NPs were prepared and their viscosity was studied. The temperature varied within the range from 20 to 60 °C. Additionally, the thermal conductivity of the prepared nanofluids were examined to find out the effect of surface modification on the stability of the nanofluids during the time.