Adsorption of arsenic and chromium by mixed magnetite and maghemite nanoparticles from aqueous solution is a promising technology. In the present batch experimental study, a commercially grade nano-size 'magnetite', later identified in laboratory characterization to be mixed magnetite-maghemite nanoparticles, was used in the uptake of arsenic and chromium from different water samples. The inten...

. Early to middle Paleozoic arbonates ofeastern North America have been pervasively remagnetized. In order to determine the process of remagnetization, scanning and scanning transmission electron microscopy have been used to characterize magnetite in thin sections and in concentrated separates. Samples included Ordovician Knox carbonates from east Tennessee, Ordovician Trenton limestone and Dev...

Poly(methyl methacrylate) in the brush form is grown from the surface of magnetite nanoparticles by ambient temperature atom transfer radical polymerization (ATATRP) using a phosphonic acid based initiator. The surface initiator was prepared by the reaction of ethylene glycol with 2-bromoisobutyrl bromide, followed by the reaction with phosphorus oxychloride and hydrolysis. This initiator is an...

Magnetic nanoparticle-mediated intracellular hyperthermia has been a largely experimental modality of hyperthermia, but this treatment modality has the potential to achieve tumor targeted heating without any side effects. The technique consists of targeting magnetic nanoparticles to tumor tissue and then applying an external alternating magnetic field to induce heat generation by the magnetic n...

Magnetotactic bacteria contain magnetosomes--intracellular, membrane-bounded, magnetic nanocrystals of magnetite (Fe(3)O(4)) or greigite (Fe(3)S(4))--that cause the bacteria to swim along geomagnetic field lines. We isolated a greigite-producing magnetotactic bacterium from a brackish spring in Death Valley National Park, California, USA, strain BW-1, that is able to biomineralize greigite and ...

Formation of magnetite nanocrystals by magnetotactic bacteria is controlled by specific proteins which regulate the particles' nucleation and growth. One such protein is Mms6. This small, amphiphilic protein can self-assemble and bind ferric ions to aid in magnetite formation. To understand the role of Mms6 during in vitro iron oxide precipitation we have performed in situ pH titrations. We fin...

This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fou...

Iron (hydr)oxides are ubiquitous earth materials that have high adsorption capacities for toxic elements and degradation ability towards organic contaminants. Many studies have investigated the reactivity of synthetic magnetite, while little is known about natural magnetite. Here, we first report the reactivity of natural magnetites with a variety of elemental impurities for catalyzing the deco...

[1] Magnetic measurements of samples with precisely controlled magnetic mineralogy, grain size, and interparticle spacing are needed to provide crucial experimental rock magnetic underpinning for paleomagnetic studies. We report a novel nanofabrication method for producing two-dimensional arrays of cylindrical synthetic magnetite particles with well-defined composition, particle size, and inter...

The teeth of the Polyplacophora Chiton Acanthochiton Rubrolinestus contain biomineralized magnetite crystallites whose biological functions in relation to structure and magnetic properties are not well understood. Here, using superconducting quantum interference device (SQUID) magnetometry, we find that the saturation magnetization (σ(s)) and the Verwey transition temperature (T(v)) of tooth pa...