Preparation of thermo-responsive hydrogel-coated magnetic nanoparticles

We propose and demonstrate a facile synthetic method for obtaining magnetic nanoparticle cores with a thermo-responsive polymeric hydrogel shell using the miniemulsion polymerization method. The magnetic nanoparticles approximately 9 nm in diameter were first prepared by a thermal decomposition method, and then, the magnetic nanoparticles were used as hydrophobes during the reaction, forming aggregated magnetic particles over-coated with a polymer layer. Transmission electron microscopy shows that as-prepared particles possess core-shell structures of 40-100 nm of aggregated magnetic-core nanospheres with an approximately 15 nm thick polymer shell over the iron oxide cores. The nanocomposites were also characterized by X-ray diffraction, vibration sample magnetometer and dynamic light scattering techniques. (C) 2012 Elsevier B.V. All rights reserved.