Synthesis and characterization of polystyrene-grafted magnetite nanoparticles

Magnetite (Fe 3 O 4 ) nanoparticles were synthesized by chemical precipitation. To reduce the aggregation of Fe 3 O 4 nanoparticles, an effective surface modification method was proposed by grafting polystyrene onto the Fe 3 O 4 particles. The results of Fourier transform infrared spectra and elemental analysis showed that the polymer chains have been successfully grafted from the surface of the Fe 3 O 4 nanoparticles and that the percentage of grafting can reach 73%. Transmission electron microscope showed that grafted polymer chains on nanoparticles could prevent the aggregation of Fe 3 O 4 nanoparticles markedly in toluene and improve their compatibility with organic phase. Another finding was the grafting reaction did not alter the crystalline structure of the Fe 3 O 4 nanoparticles according to the X-ray diffraction patterns, and the saturation magnetization of PS-Fe 3 O 4 nanoparticles was found to be lower than bulk magnetite.