Preparation, Stability and Thermal Characteristic of Al₂O₃/Bio-Oil Based Nanofluids for Heat Transfer Applications

Conventional thermal fluids with suspended nanoparticles, known as nanofluids, have been developed for heat transfer applications. Heat transfer loss could be reduced significantly if the thermophysical properties of the heat transfer fluid are improved, which to some extent, could reduce the present global environmental challenges associated with energy utilization, such as climate change and global warming. In this work, the role of the concentration of sodium dodecyl-benzene sulfonate (SDBS) in the stability of Al₂O₃/bio-oil nanofluid is investigated the zeta potential value, and its implications to the viscosity and thermal conductivity of the nanofluid are explored. The bio-oil based nanofluid is fixed using a two-step method in which the prepared base fluid is added with 13-nm alumina nanoparticles powder. Various weight fractions of SDBS (0.1, 0.2, 0.4, 0.6, and 1.0 wt%) are used for both 0.1 and 0.2 wt% Al₂O₃ to investigate the significance of the stability of a nanofluid on its thermal conductivity and viscosity. Results indicate that a stable nanofluid has reduced viscosity and increased thermal conductivity.