(471f) Magnetic Filed-Assisted Synthesis of Fe3O4/Chitosan Nanocomposites by Co-Precipitation Method

Chitosan coated magnetite nanocomposites (Fe3O4/chitosan) were synthesized under external magnetic fields by the method of co-precipitation. The obtained Fe3O4/chitosan were characterized by X-ray diffractometer (XRD), Fourier transform infrared analysis(FT-IR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis. XRD and FT-IR results showed that the Fe3O4/chitosan nanocomposites were validated as the binding of Fe3O4 and chitosan. The images of TEM also revealed the magnetite crystals were encapsulated by chitosan. In our study, Fe3O4/chitosan nanocomposites with different structures could be synthesized by changing the intensity of the external magnetic fields in the reaction process. SEM images showed that Fe3O4/ chitosan nanocomposites were spherical particles with an average size of about 30nm and distributed randomly without magnetic field placed. However, the morphology of Fe3O4/chitosan nanocomposites was obviously changed when there was an external magnetic field applied. Some particles assembled and presented chain-net cluster structures in the present of a magnetic field at 0.25 T. In addition, Fe3O4/chitosan nanocomposites formed to rod cluster structures with the length diameter ratio rang of 5~10, when the magnetic field intensity reached 0.45 T. The effect of magnetic field on magnetic properties of Fe3O4/chitosan nanocomposites was also evaluated by the vibrating sample magnetometer (VSM). It symptomatized that the nanostructures obtained from our experiments all had the characteristics of superparamagnetism with and without the external magnetic field.