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Fe3O4 Particles (fe3o4 + particle)
Selected AbstractsEstimation of cobalt coating layer thickness on acicular Fe3O4 powder using HR-TEMJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2001Keitarou Sakai The thicknesses of cobalt coating layers grown on four different types of acicular Fe3O4 particles were estimated from the analysis of lattice images and from the determination of the Co depth profile using high-resolution transmission electron microscopy (HR-TEM) coupled with an energy dispersive X-ray (EDX) analysis system. It was observed that the coating thickness might vary with the crystallite size resulting from the growth mechanism of the coating layer. In this study, two different layer thicknesses, 40,Å and less than 10,Å, were evidenced for crystallite sizes of 390,Å and 350,Å, respectively. [source] Effects of Fe,AOT complex on the properties of iron oxide particles formed by an AOT isooctane/water emulsion systemASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2008J. Oshitani Abstract Formation of iron oxide particles with aerosol-OT (AOT)/isooctane/water emulsion was carried out employing a coprecipitation reaction for Fe3O4 particles. Emulsions containing Fe2+/Fe3+ were mixed with those containing OH,. Iron oxide particles were formed by changing the concentration ratio of AOT to iron ions and maintaining the volume fraction of water in the emulsion at 0.25. Particle formation was also carried out using nonemulsified aqueous solutions as a reference. The morphology, crystal structure, magnetic property and hydration degree of the particles formed under various conditions were compared. The ,-FeOOH or amorphous particles are formed instead of Fe3O4 when the AOT concentration is comparable to, or higher than, the iron ion concentration. These particles contain an OH group and water, and are oxidized to become ,-Fe2O3 by heating in N2. The Fe,AOT complex as the origin of OH-rich particle formation was the focus of this investigation. The IR measurement was carried out for the Fe,AOT complex, separately prepared with the aqueous solution. It was found that the Fe,AOT complex was hydrated, indicating that hydration of the complex affects the properties of particles formed by the emulsion. A possible mechanism for formation of ,-FeOOH or amorphous particles with emulsion is proposed. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Encapsulation and Sustained Release of Curcumin using Superparamagnetic Silica ReservoirsCHEMISTRY - A EUROPEAN JOURNAL, Issue 23 2009Fun Chin Abstract For controlled release and targeted delivery of curcumin in an aqueous medium a method of encapsulating curcumin and magnetic nanoparticles inside porous silica matrix has been developed. Curcumin and superparamagnetic nanoparticles are loaded inside porous silica in a single process. The graphic shows the TEM image of microtomed sample of Fe3O4 particles surrounded by a silica matrix. [source] Growing ZnO Crystals on Magnetite NanoparticlesCHEMISTRY - A EUROPEAN JOURNAL, Issue 7 2004Rachel Turgeman Abstract We report herein on the oriented growth of ZnO crystals on magnetite nanoparticles. The ZnO crystals were grown by hydrolyzing a supersaturated aqueous solution of zinc nitrate. The seeds for the growth were magnetite nanoparticles with a diameter of 5.7 nm and a narrow size distribution. Hollowed ZnO hexagons of 0.15 ,m width and 0.5 ,m length filled with Fe3O4 particles were obtained. HR-TEM (high-resolution transmission electron microscopy) and selected-area EDS (energy-dispersive spectroscopy) show that the nanoparticles are homogenously spread in the ZnO tubes. Zeta potential measurements were employed to understand the relationship between the nanoparticles and the oriented growth of the ZnO crystals. The results show that the surfactants induced the directional growth of the ZnO crystals. [source] | ||||||||||