Preparation and Characterization of Water-based Magnetic Fluids

Water-based magnetic fluids (Fe 3 O 4 ) with good dispersion were synthesized by co-precipitation method in this study. The synthesis conditions for the product were studied and results showed that the particle sizes were between 10-20 nm, and the nanoparticles proved to be Nano Fe 3 O 4 . Stability tests for the water-based magnetic fluids showed that the product had better dispersion both in ethanol and water, using the PEG-4000 as the surfactant. The nanoparticles can be placed in the air for a long time, which is good for preparation of core-shell composite materials when needed.