81,061 research outputs found

    Metal Oxide Core-shell Nanoparticles And Applications Thereof

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    In an aspect, a method of making a composite core-shell nanoparticle comprises forming a nanoparticle core comprising nickel oxide or iron oxide via thermal decomposition of a nickel complex or an iron complex; and forming an oxide shell over the core, the oxide shell comprising nickel, iron or a mixture thereof. In another aspect, a method of making composite nanoparticles comprises providing a mixture comprising nickel complex and iron complex; and thermally decomposing the nickel and iron complexes to provide the composite nanoparticles comprising (Ni,Fe)O.sub.x alloy. In yet another aspect, a composition comprises composite nanoparticles, the composite nanoparticles including a nickel oxide core and oxide shell, the oxide shell comprising a mixture of nickel and iron

    Metal Oxide Core-shell Nanoparticles And Applications Thereof

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    In an aspect, a method of making a composite core-shell nanoparticle comprises forming a nanoparticle core comprising nickel oxide or iron oxide via thermal decomposition of a nickel complex or an iron complex; and forming an oxide shell over the core, the oxide shell comprising nickel, iron or a mixture thereof. In another aspect, a method of making composite nanoparticles comprises providing a mixture comprising nickel complex and iron complex; and thermally decomposing the nickel and iron complexes to provide the composite nanoparticles comprising (Ni,Fe)O.sub.x alloy. In yet another aspect, a composition comprises composite nanoparticles, the composite nanoparticles including a nickel oxide core and oxide shell, the oxide shell comprising a mixture of nickel and iron

    THE EFFECT OF REVOLUTION PER MINUTE (RPM) ON IRON OXIDE NANOPARTICLES (Fe3O4NPS) SYNTHESIS THROUGH DIRECT OXIDATIVE ALKALINE HYDROLYSIS

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    Iron oxide nanoparticles are useful particles in many fields such as medical, biomedical and environmental applications. The nature, sizes, purity and composition of these nanoparticles plays important role in their applications especially in biomedical application. This allows for the efficient use of the unique properties of iron oxide nanoparticles for analysis. This paper reports the effect of revolution per minute on the synthesis of iron oxide nanoparticles through oxidative alkaline hydrolysis of iron salt (iron II sulphate). X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were used in the analysis of the nanoparticles. The result shows that increase revolution per minute decreases the iron oxide nanoparticles sizes (Fe₃O₄ Nps) with the smallest particle size of 50 nm at 1500 rpm and biggest size of 74 nm for the control sample (without rpm). The nanoparticles from TEM analysis have cubic structure at constant salt concentration of 0.035M. And no significant change in the composition of the nanoparticles synthesized at 200 rpm and the control was observed aside change in their particle size. Nanoparticles synthesized at high revolution per minute of 500 and 1500 rpm showed traces of hematite (α-Fe2O3) and iron oxy hydroxide (γ-FeOOH) as impurities mixed with iron oxide nanoparticles

    Magnetic properties of polypyrrole - coated iron oxide nanoparticles

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    Iron oxide nanoparticles were prepared by sol -gel process. Insitu polymerization of pyrrole monomer in the presence of oxygen in iron oxide ethanol suspension resulted in a iron oxide - polypyrrole nanocomposite. The structure and magnetic properties were investigated for varying pyrrole concentrations. The presence of the gamma - iron oxide phase and polypyrrole were confirmed by XRD and FTIR respectively. Agglomeration was found to be comparatively much reduced for the coated samples, as shown by TEM. AC susceptibility measurements confirmed the superparamagnetic behaviour. Numerical simulations performed for an interacting model system are performed to estimate the anisotropy and compare favourably with experimental results.Comment: 11 pages,8 figure

    SIMAROUBA GLAUCA BARK EXTRACT MEDIATED SYNTHESIS AND CHARACTERISATION OF IRON OXIDE AND SILVER NANOPARTICLES AND THEIR ANTIBACTERIAL, CYTOTOXIC AND PHOTOCATALYTIC ACTIVITY

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    Objective: The objective of the present study is the synthesis of iron oxide and silver nanoparticles using Simarouba glauca aqueous bark extract, characterization of the synthesized nanoparticles and evaluation of their antimicrobial, photocatalytic activity and cytotoxicity. Methods: The iron oxide and silver nanoparticles were synthesized using Simarouba glauca aqueous bark extract and crystal structures of the nanoparticles were determined by UV-Visible spectroscopy, Transmission Electron Microscopy, Scanning Electron Microscopy, X-ray Diffraction and Fourier Transform Infrared Spectroscopy. The in vitro cytotoxicity of the silver nanoparticles was evaluated using Dalton’s lymphoma ascites cells. The antibacterial assay of the silver nanoparticles was conducted using agar well diffusion method. Results: The UV-Visible spectrum of iron oxide nanoparticle showed an absorption maximum at 280 nm and silver nanoparticles showed an absorption maximum at 436 nm. This is XRD pattern of iron oxide nanoparticles exhibited a characteristic peak at 26.85 is of maghemite the corresponding miller indices is (211) and the synthesized iron oxide nanoparticles are amorphous in nature. TEM image reveals the size of the synthesized iron oxide nanoparticles in the range of 26-30 nm and the size of silver nanoparticles is in the range of 120-140 nm. Green synthesized iron nanoparticles using Simarouba glauca bark extract effectively degraded methylene blue dye. Conclusion: This study showed that the synthesized iron oxide and silver nanoparticles using Simarouba glauca aqueous bark extract exhibited pronounced antibacterial, anticancer and photocatalytic activity and can be used in the textile industry and also as an external antiseptic in prevention and treatment of bacterial infections

    Spontaneous selective deposition of iron oxide nanoparticles on graphite as model catalysts

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    Iron oxide nanomaterials participate in redox processes that give them ideal properties for their use as earth-abundant catalysts. Fabricating nanocatalysts for such applications requires detailed knowledge of the deposition and growth. We report the spontaneous deposition of iron oxide nanoparticles on HOPG in defect areas and on step edges from a metal precursor solution. To study the nucleation and growth of iron oxide nanoparticles, tailored defects were created on the surface of HOPG using various ion sources that serve as the target sites for iron oxide nucleation. After solution deposition and annealing, the iron oxide nanoparticles were found to nucleate and coalesce at 400 °C. AFM revealed that the particles on the sp3 carbon sites enabled the nanoparticles to aggregate into larger particles. The iron oxide nanoparticles were characterized as having an Fe3+ oxidation state and two different oxygen species, Fe–O and Fe–OH/Fe–OOH, as determined by XPS. STEM imaging and EDS mapping confirmed that the majority of the nanoparticles grown were converted to hematite after annealing at 400 °C. A mechanism of spontaneous and selective deposition on the HOPG surface and transformation of the iron oxide nanoparticles is proposed. These results suggest a simple method for growing nanoparticles as a model catalyst

    GREEN BIOSYNTHESIS OF MAGNETIC IRON OXIDE NANOPARTICLES OF VITEX NEGUNDO AQUEOUS EXTRACT

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    Objective: The green synthesis of magnetic iron oxide nanoparticles is a convenient, economical, rapid and eco-friendly method compared to physical and chemical synthesis methods.Methods: In the present study iron oxide nanoparticles synthesized by Vitex negundo leaves extract.Results: The formation of iron oxide nanoparticles was confirmed by the colour change and further characterized by UV-Visible Spectroscopy and XRD. The morphology and the size of nanoparticles were analyzed by SEM and HR-TEM analysis.Conclusion: On the basis of this research work, green synthesized iron oxide nanoparticles can be a good source for alternative therapy for human diseases

    Triple-Modal Imaging of Magnetically-Targeted Nanocapsules in Solid Tumours In Vivo

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    Triple-modal imaging magnetic nanocapsules, encapsulating hydrophobic superparamagnetic iron oxide nanoparticles, are formulated and used to magnetically target solid tumours after intravenous administration in tumour-bearing mice. The engineered magnetic polymeric nanocapsules m-NCs are ~200 nm in size with negative Zeta potential and shown to be spherical in shape. The loading efficiency of superparamagnetic iron oxide nanoparticles in the m-NC was ~100%. Up to ~3- and ~2.2-fold increase in tumour uptake at 1 and 24 h was achieved, when a static magnetic field was applied to the tumour for 1 hour. m-NCs, with multiple imaging probes (e.g. indocyanine green, superparamagnetic iron oxide nanoparticles and indium-111), were capable of triple-modal imaging (fluorescence/magnetic resonance/nuclear imaging) in vivo. Using triple-modal imaging is to overcome the intrinsic limitations of single modality imaging and provides complementary information on the spatial distribution of the nanocarrier within the tumour. The significant findings of this study could open up new research perspectives in using novel magnetically-responsive nanomaterials in magnetic-drug targeting combined with multi-modal imaging

    Preparation, Characterization and Application of Nanoparticles Iron Oxide Catalyst for the Treatment of Sulfidic Wastewater

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    Iron oxide nanoparticles were prepared by chemical reaction of iron chloride and ammonium hydroxide. The product were characterized by SEM, indicating that the fine particles are nanometer ofiron oxides. The produced iron oxide nanoparticles can be act as a catalyst. It was shown by the rate of the oxidation of the sodium sulfide in the wastewater by hydrogen peroxide is higher in the presence of iron oxide nanoparticles. For the oxidation of sodium sulfide by hydrogen peroxide in the presence of iron oxide nanoparticles, the optimum condition at which the rate ofthe oxidation is higher were investigated by investigating the effect of the parameters of initial sulfide concentration, catalyst loading, and temperature of the system
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