Living organisms can produce inorganic materials with unique structure and properties. The biomineralization process is of great interest as it forms a source of inspiration for the development of methods for production of diverse inorganic materials under mild conditions. Nonetheless, regulation of biomineralization is still a challenging task. Magnetotactic bacteria produce chains of a prokar...

While the role of magnetic cues for compass orientation has been confirmed in numerous animals, the mechanism of detection is still debated. Two hypotheses have been proposed, one based on a light dependent mechanism, apparently used by birds and another based on a "compass organelle" containing the iron oxide particles magnetite (Fe(3)O(4)). Bats have recently been shown to use magnetic cues f...

This work presents a new method to prepare monodisperse magnetite nanoparticles capping with new cationic surfactants based on rosin. Core/shell type magnetite nanoparticles were synthesized using bis-N-(3-levopimaric maleic acid adduct-2-hydroxy) propyl-triethyl ammonium chloride (LPMQA) as capping agent. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanoparti...

We report the use of a simple yet highly effective magnetite-waste tea composite to remove lead(II) (Pb(2+)) ions from water. Magnetite-waste tea composites were dispersed in four different types of water-deionized (DI), artificial rainwater, artificial groundwater and artificial freshwater-that mimic actual environmental conditions. The water samples had varying initial concentrations (0.16-5....

An ~1:1 mixture of ferrihydrite and nanocrystalline akaganeite (β-FeOOH; 10–15 nm) was incubated with Shewanella putrefaciens (strain CN32) under anoxic conditions with lactate as an electron donor and anthraquinone-2,6-disulfonate (AQDS) as an electron shuttle. The incubation was carried out in a 1,4-piperazinediethanesulfonic acid (PIPES)-buffered medium, without PO4 at circumneutral pH. Iron...

BACKGROUND Reductive precipitation of hexavalent chromium (Cr(VI)) with magnetite is a well-known Cr(VI) remediation method to improve water quality. The rapid (<a few hr) reduction of soluble Cr(VI) to insoluble Cr(III) species by Fe(II) in magnetite has been the primary focus of the Cr(VI) removal process in the past. However, the contribution of simultaneous Cr(VI) adsorption processes in ag...

Bacterial magnetosomes are intracellular compartments that house highly ordered magnetite crystals. By using Magnetospirillum sp. AMB-1 as a model system, we show that magnetosome vesicles exist in the absence of magnetite, biomineralization of magnetite proceeds simultaneously in multiple vesicles, and biomineralization proceeds from the same location in each vesicle. The magnetosome-associate...

We report the thermal annealing-induced formation of ring-like structure of Zn(II)-doped magnetite from iron alkoxide leaf-like nanoplate precusor. The phase, structure and morphology of magnetite nanorings were comprehensively characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscope, scanning electron microscope, and transmission electron microscope....

A conducting-electroactive polyaniline/magnetite (PAni/Fe304) nanocomposite was synthesized using anilinium dodecylbenzene sulfonate (S1) as a reactive surfactant. First, S1 allowed magnetite dispersion in the aqueous phase and second, S1 performed as the monomer of polyaniline emeraldine base salt. Electron microscopy suggested core-shell morphology based on S1 amphiphilic character; that is, ...

Reduced graphene oxide-magnetite hybrid aerogels attract great interest thanks to their potential applications, e.g., as magnetic actuators. However, the tendency of magnetite particles to migrate within the matrix and, ultimately, escape from the aerogel structure, remains a technological challenge. In this article we show that coating magnetite particles with polydopamine anchors them on grap...