Preparation and characterization of Fe3O4/polystyrene composite particles via inverse emulsion polymerization

Superparamagnetic magnetite/polystyrene (PS) composite particles were prepared by inverse emulsion polymerization with water-based ferrofluid as dispersing phase and organic solvent and styrene (St) as continuous phase. The resultant brownish Fe3O4/PS emulsion showed magnetic behavior in an applied magnetic field. The obtained magnetic Fe3O4/PS microspheres were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and thermogravimetry (TG). The magnetic Fe3O4/PS microspheres with a diameter of 200 nm were observed. The results showed that magnetite particles were well encapsulated in PS and the composite particles have high magnetite contents, which were more than 15%. In addition, the influences of magnetic field intensity on the theological properties of ferrofluids were investigated using a rotating rheometer. (C) 2008 Elsevier B.V. All rights reserved.