Modified Fe3O4 Nanoparticles Research Articles

A novel process to synthesize magnetic hollow silica microspheres

Magnetic hollow silica microspheres (MHSM) were successfully synthesized by combining a sol–gel technology with a low temperature drying. The oil-in-water Pickering emulsion droplets stabilized by the modified Fe 3O 4 nanoparticles (MFN) were used as the templates. It was found that a certain contact angle of MFN was required in the formation of oil-in-water Pickering emulsion. The average diameter of the oil droplets decreased with the increase for the amount of MFN. The MHSM obtained with strong magnetism were of hollow structures with a diameter of about 350 nm and an average thickness of 40 nm. Most of MFN arrayed in the interface compactly while the other MFN dispersed in the silica matrixes. It was noted that the magnetism of MFN was less affected during the preparation process. Each microsphere had a uniform magnetic fraction due to the template coming from the self-assembly of MFN at the oil–water interface. The as-prepared MHSM have potential application for adsorbent of heavy metal ions or organic pollutants.

Anthranilic acid assisted preparation of Fe3O4–poly(aniline-co-o-anthranilic acid) nanoparticles

Magnetic Fe3O4–poly(aniline-co-o-anthranilic acid) nanoparticles were prepared by a novel and simple method: anthranilic acid assisted polymerization. The synthetic strategy involved two steps. First, Fe3O4 nanoparticles capped by anthranilic acid were obtained by a chemical precipitation method, and then the aniline and oxidant were added to the modified Fe3O4 nanoparticles to prepare well-dispersed Fe3O4–poly(aniline-co-o-anthranilic acid) nanoparticles. Fe3O4–poly(aniline-co-o-anthranilic acid) nanoparticles exhibited a superparamagnetic behavior (i.e., no hysteresis loop) and high-saturated magnetization (Ms = 21.5 emu/g). The structure of the composite was characterized by Fourier-transform infrared spectra, X-ray powder diffraction patterns, and transmission electron microscopy, which proved that the Fe3O4–poly(aniline-co-o-anthranilic acid) nanoparticles were about 20 nm. Moreover, the thermal properties of the composite were evaluated by thermogravimetric analysis, and it showed excellent thermal stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1666–1671, 2006

Applications of magnetic targeting in diagnosis and therapy--possibilities and limitations: a mini-review.

Applications of magnetic targeting in diagnosis and therapy--possibilities and limitations: a mini-review.