Magnetic iron oxide nanoparticles were successfully prepared by a novel reverse precipitation method with the irradiation of ultrasound. TEM, XRD and SQUID analyses showed that the formed particles were magnetite (Fe(3)O(4)) with about 10nm in their diameter. The magnetite nanoparticles exhibited superparamagnetism above 200K, and the saturation magnetization was 32.8 emu/g at 300 K. The sizes ...

We present a novel heterogeneous Fenton-like catalyst of LiFePO4 (LFP). LFP has been widely used as an electrode material of a lithium ion battery, but we observed that commercial LFP (LFP-C) could act as a good Fenton-like catalyst to decompose rhodamine 6G. The catalytic activity of LFP-C microparticles was much higher than a popular catalyst, magnetite nanoparticles. Furthermore, we found th...

Herein we report a new method for synthesizing stabilized magnetic nanoparticle (MNP) colloids. A new class of monodisperse water-soluble magnetite nano-particles was prepared by a simple and inexpensive co-precipitation method. Iron ions and iodine were prepared by the reaction between ferric chloride and potassium iodide. The ferrous and ferric ions were hydrolyzed at low temperature at pH 9 ...

A new facile coating strategy based on the hydrophobicity of methyl groups was developed to prevent nano-sized magnetite particles from strong acid corrosion. In this method, three steps of hydrolysis led to three layers of protection shell coating Fe3O4 nanoparticles. Filled with hydrophobic methyl groups, the middle layer mainly prevented the magnetic core from strong acid corrosion. These ma...

Magnetotactic bacteria contain chains of magnetically interacting crystals (magnetosome crystals), which they use for navigation (magnetotaxis). To improve magnetotaxis efficiency, the magnetosome crystals (usually magnetite or greigite in composition) should be magnetically stable single-domain (SSD) particles. Smaller single-domain particles become magnetically unstable owing to thermal fluct...

Atomic force microscopy (AFM) was used in concert with transmission electron microscopy (TEM) to image magnetotactic bacteria (Magnetospirillum gryphiswaldense MSR-1 and Magnetospirillum magneticum AMB-1), magnetosomes, and purified Mms6 proteins. Mms6 is a protein that is associated with magnetosomes in M. magneticum AMB-1 and is believed to control the synthesis of magnetite (Fe(3)O(4)) withi...

We report the synthesis of Fe3O4@mSiO2 nanostructures of different meso-silica (mSiO2) shell thickness, their biocompatibility and behaviors for loading and release of a model drug ibuprofen. The composite nanostructures have superparamagnetic magnetite cores of 208 nm average size and meso-silica shells of 15 to 40 nm thickness. A modified Stöber method was used to grow the meso-silica shells ...

In this study, iron reduction and concomitant biomineralization of a deep-sea iron reducing bacterium (IRB), Shewanella piezotolerans WP3, were systematically examined at different hydrostatic pressures (0.1, 5, 20, and 50 MPa). Our results indicate that bacterial iron reduction and induced biomineralization are influenced by hydrostatic pressure. Specifically, the iron reduction rate and exten...

Magnetite is an iron oxide found in rocks. Its magnetic properties are used for paleoclimatic reconstructions. It can also be synthesized in the laboratory to exploit its magnetic properties for bio- and nanotechnological applications. However, although the magnetic properties depend on particle size in a well-understood manner, they also depend on the structure of the oxide, because magnetite ...

Hollow magnetite microspheres have been synthesized by a simple process through a template-free hydrothermal approach. Hollow microspheres were surface modified by coating with a silica nanolayer. Pristine and modified hollow microparticles were characterized by field-emission electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, FT-IR and R...