Preparation and characterization of PEG-PEI/Fe3O4 nano-magnetic fluid by co-precipitation method

PEG-PEI/Fe3O4 nano-magnetic fluids with different mass fractions of reactant were prepared by co-precipitation method. Besides particle size analyzer, the methods of XRD, IR, VSM and AFM were adopted to characterize the synthesized samples. Covalent bonding of PEG, PEI and Fe3O4 exhibits superparamagnetism. The TEM photograph shows that the particles are of stable dispersion and little aggregation, with smooth surface, spherical shape and a diameter of about 80 nm, which meets the requirements of nano-materials. When the mass fraction of PEI in reactant is 25%, the particle size, Zeta-potential and pEGFP-C1 DNA loading efficiency are all satisfactory. In this case, PEG-PEI/Fe3O4 nano-magnetic fluids can be used as gene vectors or targeted drug carriers.