A Facile Ultrasound Assisted Synthesis of Dextran-Stabilized Co 0.2 Fe 0.8 Fe 2 O 4 Nanoparticles for Hyperthermia Application

In this paper, nanocomposites with core–shell structure of dextran coated Co 0.2 Fe 0.8 Fe 2 O 4 nanoparticles (NPs) were synthesized by a facile sono-chemical method. The characterization of nanocomposites such as crystallinity, particle size, and the linking between coating layer and magnetic NPs (MNPs) were analyzed by X-ray diffraction, field-emission scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis–differential thermal analysis. Using this method, the obtained colloidal composite NPs with size around 50 nm are well dispersed in aqueous solution at the highest concentration of 14.4 mg/mL. The MNPs present superparamagnetic behavior at high blocking temperature with saturation magnetization of 53 emu/g and coercivity of 120 Oe. The induction magnetic heating property of nanocomposite was determined by calorimetric measurements in alternating magnetic field of 390 kHz frequency and various amplitudes. The hysteresis loss of magnetic fluid containing nanocomposites strongly depends on the amplitude of the applied field while the heating capacity was enhanced by significant contribution of hysteresis loss. The nanocomposites show great potential in hyperthermia applications.