Preparation and Characterization of Nano Composite Microspheres of Polystyrene and Fe_3O_4 by Emulsifier-Free Emulsion Polymerization

摘要

Composite microspheres of polystyrene and nano- Fe_3O_4 particles were prepared through emulsifier -free polymerization with ultrasonic dispersion. The properties of composite microsphere were investigated by FT-IR spectrum, X-ray diffraction analysis, TEM, SEM and VSM. The determine results showed that Fe_3O_4 particles prepared by coprecipitation in lab were about 7～8 nm and with a narrow size distribution and super paramagnetic characteristics. The composite microsphere of polystyrene and Fe_3O_4 showed a diameter around 20～30 nm under TEM and SEM. The data of XRD indicated crystal forms of Fe_3O_4 in the composite microsphere did not change. The XRD spectrum of composite microsphere was a overlap of Fe_3O_4 crystal and amorphous polystyrene. The result of hysteresis curve indicated that the composite microspheres still had super paramagnetic characteristics.