| Abstract
| - This paper describes a class of water-based magnetic fluids that are specifically tailored to extractsoluble organic compounds from water. These magnetic fluids are prepared by precipitation andconsist of a suspension of ∼7.5 nm magnetite (Fe3O4) nanoparticles coated with a ∼9 nmbifunctional polymer layer comprised of an outer hydrophilic poly(ethylene oxide) (PEO) regionfor colloidal stability and an inner hydrophobic poly(propylene oxide) (PPO) region forsolubilization of organic compounds. The particles exhibit a high capacity for organic solutes,with partition coefficients between the polymer coating and water on the order of 103−105, whichis consistent with values reported for solubilization of these organics in PEO−PPO−PEO blockcopolymer micelles. In bench-scale experiments, high-gradient magnetic separation (HGMS) isable to recover the nanoparticles with 98% efficiency. Process options for particle regenerationin water purification applications are discussed.
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