Magnetic Fluids as Colloidal Extracants
Geoffrey Moeser, W.H. Green
Collaboration with Prof. T.A. Hatton, Prof. P.E. Laibinis
Supported by NSF and the Singapore-MIT Alliance

Magentic fluids are colloidal dispersions of magnetic nanoparticles that are stable with respect to gravitational and moderate magnetic fields due to their small particle size (~10nm). In addition, they are stable to unbounded aggregation owing to their surface caotings. Our work focuses on developing magnetic fluids for seperation applications by tailoring the surface coatings of the particles. To date we have developed water-based magnetic fluids capable of seperating organic contaminants such as polyaromatic hydrocarbons from water. Other seperation applications under investigation include the removal of sulfur compounds from hydrocarbon fuels. Magnetic fluids have many potential advantages over traditional seperation techniques. Due to the nanoscale size of the particles, very high surface areas can be achieved without the use of porous adsorbents with a high mass transfer resistance. However, as the nanoparticles are magnetic, they can be recovered relatively easily by magnetic seperation after they are loaded with a target solute.