Preparation and structure of Fe3O4 nanoparticle-polystyrene uniformly dispersed system

The nano-particles of Fe3O4 were prepared by a chemical co-precipitation method. A stable polymerizable magnetic fluid of nano-Fe3O4 was obtained by dispersing oleic acid-coated Fe3O4 nano-particles in styrene as a carrier liquid. A uniformly dispersed system of nano-particles of Fe3O4 in polystyrene has been acquired by the free radical polymerization of polymerizable magnetic fluid. The crystallization behavior and the surface of Fe3O4 nano-particles before and after the modification by oleic acid were investigated by WXRD and FTIR, respectively. The particle size and size dispersion of Fe3O4 nano-particles in styrene and polystyrene were studied by TEM. The glass transition temperature (T-g) and the thermal stability of nano-Fe3O4/polystyrene dispersion system were also studied by means of DSC and TGA, respectively. The results indicate that the nano-Fe3O4 is a cubic crystal, the particle size is 10 nm on an average the oleic acid molecules are chemically adsorbed on the surface of Fe3O4 nano-particles, the modified Fe3O4 nano particles are dispersed homogeneously in styrene and in polystyrene. The temperature at sharp weight loss of polystyrene containing only 1.8% Fe3O4 nano-particles is 13 K higher than polystyrene and its saturation magnetization is 17.43 emu/g.