Experimental Studies of the Sedimentation, Stability and Thermal Conductivity of Two Different Nanofluids

: Fluids containing nanometer-sized particles (nanofluids, NFs) are potential candidates to improve the performance and efficiency of several thermal devices at micro- macro-scale levels. However, problem sedimentation instability these colloidal dispersions has been biggest obstacle for industrial-scale applications. In this work, two different NFs were tested using distilled water (DI-Water) as base fluid. The first is a traditional NF formed by Al2O3 nanoparticles (NPs) with 50 nm diameter, second novel poly (acrylic acid)-coated iron oxide NPs (Fe3O4@PAA) ~10 obtained through hydrothermal synthesis process. main objective study was evaluate stability over time volume fractions compare it DI-Water. Results involving studies zeta measurements showed that proposed Fe3O4@PAA presents higher compared NF. Additionally, conductivity performed in both NP concentrations, transient plane source technique. values those NFs. linear enhancement increasing concentration observed whole range concentrations tested, whereas regimes