To obtain magnetic nanoparticles (NPs) with good water dispersibility
Fe3O4 nanoparticles were synthesized by thermal decomposition of the iron(Ⅲ) acetylacetonate (Fe(acac)3) in poly(ethylene glycol) (PEG) containing poly(vinyl pyrrolidone) (PVP) of different molecular weight as modifying agents.The samples were characterized with X-ray diffraction (XRD)
transmission electron microscopy (TEM)
high resolution transmission electron microscopy (HRTEM)
and particles & zeta potential analyser.The stability of Fe3O4 nanoparticles dispersed in physiological saline and physiological buffers was investigated.The prepared Fe3O4 nanoparticles had high crystallinity
and showed superparamagnetic behavior at 300 K with higher saturate magnetization.The surfaces of Fe3O4 nanoparticles were modified by PEG and PVP which provided good water dispersibility.The Fe3O4 nanoparticles revealed high dissolubility and stability in physiological saline and physiological buffers.The surfaces of Fe3O4 nanoparticles were electrically neutral in water
and steric hindrance effect of the surface modified layer might be the main reason for high dispersion stability of the prepared nanoparticles in aqueous solution.