A size-controllable preparation of monodisperse PAA/Fe_3O_4 magnetic microspheres

Monodispersed PAA/Fe3O4 magnetic microspheres with 100-500 nm average sizes were synthesized according to hydrothermal method to overcome the disadvantages of past particles(30nm)which was difficult to get the high saturation magnetization.These microparticles are composed of small primary nanocrystals with a size of 13 nm.As the same time,the size of the PAA/Fe3O4 magnetic microspheres can be controlled via altering of the quantity of reagent,the reaction temperature and the reaction time.It shows that with the increase of the microspheres sizes,Mswas increased.Moreover,when the size of PAA/Fe3O4 magnetic microspheres was 490 nm,the Mscan be 104.52A·m2/kg.Finally,the morphologies,magnetic properties had been characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD),Fourier transform infrared spectrometer,vibrating sample magnetometer(VSM).