Microwave-assisted synthesis of magnetite nanoparticles for MR blood pool contrast agents

Microwave-assisted polyol process was developed for the synthesis of magnetite nanoparticles with precisely controlled size, high crystallinity and high water solubility. The process is simple, time-saving and low energy-consuming due to the advantages of polyols and microwave irradiation combined. The crystal phases of the nanoparticles were determined by transmission electron microscopy, X-ray powder diffraction and Raman spectrum. The coating materials of the nanoparticles were analyzed by Fourier transformed infrared spectroscopy and thermal gravimetric analysis. Precise size tuning enables an easier way to adjust the relaxation properties of the magnetite nanoparticles. The colloid nanoparticles with high longitudinal relaxivity (r1) and low ratio of transverse relaxivity (r2) to r1 have a potential application in magnetic resonance angiography. - Highlights: → Microwave-assisted process was developed for the synthesis of magnetite nanoparticles. → Process is simple, time-saving and low energy-consuming. → Colloid nanoparticles have a potential application in magnetic resonance angiography. → Carbonate surface of nanoparticles facilitates for further modification.