Amphiphilic and magnetic behavior of Fe3O4 nanocrystals.

Fe(3)O(4) (magnetite) nanocrystals with an average size of 13 nm were prepared using a specially synthesized polymeric stabilizer (poly-4-vinylpyridine-co-acrylamidoethylamine-co-polyethyleneglycol-co-polyethyleneglycolic acid) that bears reactive groups for further functionalization. The polymer shell made the nanocrystals amphiphilic, i.e. they are soluble in pentanol, water and dichloromethane, and they distribute over the three solvents in a three phase system. The Fe(3)O(4) nanocrystals exhibited the well-known and typical magnetic properties.