Two-Phase Ferrofluid Systems: Surfactants and Thermal Properties of Iron Oxide Nanofluids for Condensation

Abstract

Evaporation heat transfer with ferrofluids has the potential to improve heat and mass transfer compared to conventional two-phase systems. The ferromagnetic nanoparticles which control the rheology and heat transfer properties of the ferrofluid, must be coated with a dispersing agent, also referred to as a surfactant, to prevent particle agglomeration. This paper compares ferromagnetic iron-oxide particles coated with fatty acid, polymeric and hydrophobic surfactants after undergoing evaporation and condensation. The outcome was measured by assessing the dispersion of the ferrofluid after condensation. The fatty acid surfactants demonstrated the best dispersion after condensation proving temperature stability.