Thermal Decomposition Of Iron Acetylacetonate Research Articles

Increasing the Particle Size and Magnetic Property of Iron Oxide Nanoparticles through a Segregated Nucleation and Growth Process.

Iron oxide nanoparticles (IONs) with good water dispersibility were prepared by the thermal decomposition of iron acetylacetonate (Fe(acac)3) in the high-boiling organic solvent polyethylene glycol (PEG) using polyethyleneimine (PEI) as a modifier. The nucleation and growth processes of the crystals were separated during the reaction process by batch additions of the reaction material, which could inhibit the nucleation but maintain the crystal growth, and products with larger particle sizes and high saturation magnetization were obtained. The method of batch addition of the reactant prepared IONs with the largest particle size and the highest saturation magnetization compared with IONs reported using PEG as the reaction solvent. The IONs prepared by this method also retained good water dispersibility. Therefore, these IONs are potentially suitable for the magnetic separation of cells, proteins, or nucleic acids when large magnetic responses are needed.

Synthesis of Sandwiched Composite Nanomagnets by Epitaxial Growth of Fe3O4 Layers on SrFe10Cr2O19 Nanoplates in High-Boiling Organic Solvent

Herein, we demonstrate the synthesis of sandwiched composite nanomagnets, which consist of hard magnetic Cr-substituted hexaferrite cores and magnetite outer layers. The hexaferrite plate-like nanoparticles, with average dimensions of 36.3 nm × 5.2 nm, were prepared via a glass crystallization method and were covered by spinel-type iron oxide via thermal decomposition of iron acetylacetonate in a hexadecane solution. The hexaferrite nanoplates act as seeds for the epitaxial growth of the magnetite, which results in uniform continuous outer layers on both sides. The thickness of the layers can be adjusted by controlling the concentration of metal ions. In this way, layers with an average thickness of 3.7 and 4.9 nm were obtained. Due to an atomically smooth interface, the magnetic composites demonstrate the exchange coupling effect, acting as single phases during remagnetization. The developed approach can be applied to any spinel-type material with matching lattice parameters and opens the way to expand the performance of hexaferrite nanomagnets due to a combination of various functional properties.

Synthesis of ZnO@γ-Fe2O3 core–shell nanocomposites by a facile thermal decomposition approach and their application in photocatalytic degradation of congo red

ZnO@γ-Fe2O3 core–shell nanocomposites were synthesized by a facile thermal decomposition approach. ZnO nanorods were first synthesized by calcination of zinc acetate at 300 °C, in air. γ-Fe2O3 nanoparticles were then deposited on the surface of ZnO nanorods by the thermal decomposition of iron acetylacetonate at 200 °C in diphenyl ether. The structure, composition, optical and magnetic properties of the nanocomposites were studied using an array of techniques. XRD results suggest the presence of γ-Fe2O3 nanoparticles and ZnO, and FE-SEM images indicate formation of shell of iron oxide on the ZnO nanorods. Transmission electron microscopy studies clearly show that ZnO possesses rod morphology (length = 1.1 ± 0.1 μm, diameter = 40.1 ± 7 nm) and TEM images of the ZnO@γ-Fe2O3 nanocomposites show uniform shell of γ-Fe2O3 coated on the ZnO nanorods and thickness of the γ-Fe2O3 shell varies from 10 to 20 nm. Diffuse reflectance spectra of ZnO@γ-Fe2O3 nanocomposites reveal extended optical absorption in the visible range (400–600 nm) and photoluminescence spectra indicate that the ZnO@γ-Fe2O3 nanocomposites exhibit enhanced defect emission. The ZnO@γ-Fe2O3 core–shell nanocomposites show superparamagnetic behaviour at room temperature. The core–shell nanocomposites exhibit enhanced visible-light driven photocatalytic degradation of congo red in an aqueous solution as compared to pure ZnO nanorods and γ-Fe2O3 nanoparticles. The enhanced photocatalytic activity is attributed to good visible-light absorption and effective charge separation at the interface of ZnO@γ-Fe2O3 core–shell nanocomposites.

Microemulsion synthesis and electromagnetic wave absorption properties of monodispersed Fe3O4/polyaniline core–shell nanocomposites

Monodispersed Fe3O4/PANI core–shell nanocomposites were synthesized by microemulsion polymerization. Before the polymerization of aniline, Fe3O4 nanoparticles were prepared by thermal decomposition of iron acetylacetonate using benzyl alcohol as the solvent and were surface-modified by oleic acid. Then aniline monomer was polymerized on the surface of Fe3O4 nanoparticles by microemulsion polymerization with sodium dodecyl benzene sulfonate as the surfactant and ammonium persulfate as the oxidant. Fourier transform infrared (FT-IR) spectra indicated that the oleic acid was chemisorbed on the surface of Fe3O4 nanoparticles. Transmission electron microscopy (TEM) analysis showed that the oleic acid modified Fe3O4 nanoparticles had a better dispersity with a diameter around 10nm. The Fe3O4/PANI nanocomposites were monodisperse with Fe3O4 as the magnetic core and PANI as the conductive shell. The as-prepared Fe3O4/PANI nanocomposites showed a superparamagnetic behavior. The paraffin composites with 70wt.% Fe3O4/PANI powders provided good electromagnetic wave absorption performance (RL<−20dB) in the range of 10.01–16.98GHz with absorber thicknesses of 3–4mm. A minimum RL value of −25.40dB was observed at 10.52GHz with a thickness of 3mm.

Selective Conjugation of Proteins by Mining Active Proteomes through Click-Functionalized Magnetic Nanoparticles

Superparamagnetic iron oxide nanoparticles (SPIONs) coated with azide groups were functionalized at the surface with biotin (biotin@SPIONs) and cysteine protease inhibitor E-64 (E-64@SPIONs) with the purpose of developing nanoparticle-based assays for identifying cysteine proteases in proteomes. Magnetite particles (ca. 6 nm) were synthesized by microwave-assisted thermal decomposition of iron acetylacetonate and subsequently functionalized following a click chemistry protocol to obtain biotin and E-64 labeled particulate systems. Successful surface modification and covalent attachment of functional groups and molecules were confirmed by FT-IR spectroscopy and thermal gravimetric analysis. The ability of the surface-grafted biotin terminal groups to specifically interact with streptavidin (either horseradish peroxidase [(HRP)-luminol-H2O2] or rhodamine) was confirmed by chemiluminescent assay. A quantitative assessment showed a capture limit of 0.55-1.65 μg protein/100 μg particles. Furthermore, E-64@SPIONs were successfully used to specifically label papain-like cysteine proteases from crude plant extracts. Owing to the simplicity and versatility of the technique, together with the superparamagnetic behavior of FeOx-nanoparticles, the results demonstrate that click chemistry on surface anchored azide group is a viable approach toward bioconjugations that can be extended to other nanoparticles surfaces with different functional groups to target specific therapeutic and diagnostic applications.

Surface Functionalization of Iron Oxide Nanoparticles and their Stability in Different Media

AbstractSize‐selective synthesis of very small iron oxide nanoparticles (IONP; 4–8 nm) was achieved by the thermal decomposition of iron acetylacetonate in diethylenglycol by a simple one‐pot reaction. The particles were functionalized on the one hand with poly(vinylpyrrolidone) (PVP) directly during the formation of the particles and on the other hand by a simple postsynthetic reaction with citrate, ascorbate, tartrate, dextran 60, gum Arabic, PVP, or poly(ethyleneglycol) (PEG). In view of medical and environmental applications, the stability of the particles was measured with dynamic light scattering in water as well as in physiological media containing buffers (4‐(2‐hydroxyethyl)‐1‐piperazineethanesulfonic acid (IP‐HEPES), phosphate buffered saline (PBS)), high salt concentrations (Elendt M7), or proteins (Dulbecco’s modified eagle medium (DMEM) with and without 10 % fetal calf serum (FCS)). The effect of the functionalization of the nanoparticles on the production of radical oxygen species (ROS) was investigated during the Fenton reaction, showing that the nature of the functionalization can raise the production of ROS drastically. To extend the range of applications, the one‐pot reaction with PVP was expanded by an additional step, allowing tagging of the particles with various fluorescein derivatives. In this way, fluorescent nanoparticles exhibiting emissions in the range of 475–553 nm were obtained.

Single step thermal decomposition approach to prepare supported γ-Fe2O3 nanoparticles

γ-Fe2O3 nanoparticles supported on MgO (macro-crystalline and nanocrystalline) were prepared by an easy single step thermal decomposition method. Thermal decomposition of iron acetylacetonate in diphenyl ether, in the presence of the supports followed by calcination, leads to iron oxide nanoparticles supported on MgO. The X-ray diffraction results indicate the stability of γ-Fe2O3 phase on MgO (macro-crystalline and nanocrystalline) up to 1150°C. The scanning electron microscopy images show that the supported iron oxide nanoparticles are agglomerated while the energy dispersive X-ray analysis indicates the presence of iron, magnesium and oxygen in the samples. Transmission electron microscopy images indicate the presence of smaller γ-Fe2O3 nanoparticles on nanocrystalline MgO. The magnetic properties of the supported magnetic nanoparticles at various calcination temperatures (350–1150°C) were studied using a superconducting quantum interference device which indicates superparamagnetic behavior.

Synthesis and ageing effect in FeO nanoparticles: Transformation to core–shell FeO/Fe 3O 4 and their magnetic characterization

This paper reports the magnetic properties of partially oxidized FeO nanoparticles (NPs) prepared using thermal decomposition of iron acetylacetonate at high temperature. X-ray diffraction (XRD) analysis confirmed that the resulting NPs comprise a mixture of wüstite and magnetite phases, which are subsequently confirmed using high resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED) pattern. Magnetic properties were investigated using vibrating sample magnetometer (VSM), which exhibit superparamagnetic (SPM) behavior at room temperature. Alternatively, below 200 K, a large exchange bias field has been observed in field cooled mode whose magnitude increases with the decrease in measuring temperature attaining a maximum value of ∼2.3 kOe at 2 K accompanied by coercivity enhancement (∼3.4 kOe) and high field of irreversibility (>50 kOe). The results are discussed taking into account the role of interface exchange coupling on the macroscopic magnetic properties of the nanoparticles.

Preparation of magnetite aqueous dispersion for magnetic fluid hyperthermia

An aqueous magnetic suspension was prepared by dispersing amphiphilic co-polymer-coated monodispersed magnetite nanoparticles synthesized through thermal decomposition of iron acetylacetonate (Fe(acac) 3) in a mixture of oleic acid and oleylamine. The average diameter of narrow-size-distributed magnetite nanoparticles varied between 5 and 12 nm depending on the experimental parameters such as reaction temperature, metal salt concentration and oleic acid/oleylamine ratio. Though the as-synthesized particles were coated with oleate and were dispersible in organic solvent, their surfaces were modified using amphiphilic co-polymers composed of poly(maleic anhydride-alt-1-octadecene) and polyethylene glycol-methyl ether and made dispersible in water. Infrared spectra of the sample indicated the existence of −COOH groups on the surface for further conjugation with biomolecules for targeted cancer therapy.

A facile green approach for synthesizing monodisperse magnetite nanoparticles

The synthesis of monodisperse magnetite nanoparticles (Fe3O4 NPs) has been widely investigated over the last decade. Among the various synthetic methods, thermal decomposition of iron acetylacetonate, Fe(acac)3, or the premade iron-surfactant complex, was demonstrated to be promising to obtain monodisperse Fe3O4 NPs with controllable size and morphology. However, toxic and expensive precursors or tedious experimental procedures are normally required in these approaches. In this communication, we report a facile chemical top-down method to synthesize monodisperse magnetite NPs by using rust, which is mainly composed of γ-Fe2O3, as the iron source and oleic acid as the capping agent. The particle size, and hence the magnetization, of NPs can be readily controlled by adjusting the rust/oleic acid ratio and reaction temperature. This process is a green chemical approach and is easy to be reproduced and scaled up, which could be developed as an effective way to convert waste materials into high quality nanocrystals.

Synthesis and Characterization of Magnetic Polyurethane Nanocomposite Foams

New magnetic polyurethane nanocomposite foams have been synthesized by the one-shot method. The opened-cell soft foams contain a dispersion of uniformly sized nanocrystalline iron oxide prepared ex situ by the high temperature thermal decomposition of iron acetylacetonate in phenyl ether in the presence of oleic acid. The magnetic particles were dispersed in polyol by sonication prior to the reaction of the latter with isocyanate to produce the magnetic foams. A 7 wt% loading of iron oxide yielded a soft, flexible foam with a room temperature magnetization of 3.5 emu/g at one Tesla. Higher loadings of iron oxide are possible without destruction of the soft open-cell polyurethane structure. Physicochemical characterization of the foams will be presented along with magnetic and mechanical properties. Potential applications include smart materials such as magnetic shape memory foams, adhesive-free metal to foam seals, inductively coupled thermal foams and applications for conformable foams having a magnetic component such as healthcare products.

Synthesis and Characterization of Ferroferriborate (Fe3BO5) Nanorods

AbstractFe3BO5 nanorods with diameters from 4 nm to 16 nm and length from 43 nm to 60 nm are synthesized by a facile thermal decomposition of iron acetylacetonate and t‐butylamine borane (TBAB). TBAB is used to control the 1D growth and the aspect ratio of the nanorods. These Fe3BO5 nanorods are antiferromagnetic with TN = 174 K, which is higher than that of bulk Fe3BO5 (114 K).

Preparation of Fe3O4Spherical Nanoporous Particles Facilitated by Polyethylene Glycol 4000

Much interest has been attracted to the magnetic materials with porous structure because of their unique properties and potential applications. In this report, Fe3O4nanoporous particles assembled from small Fe3O4nanoparticles have been prepared by thermal decomposition of iron acetylacetonate in the presence of polyethylene glycol 4000. The size of the spherical nanoporous particles is 100–200 nm. Surface area measurement shows that these Fe3O4nanoporous particles have a high surface area of 87.5 m2/g. Magnetization measurement and Mössbauer spectrum indicate that these particles are nearly superparamagnetic at room temperature. It is found that the morphology of the products is greatly influenced by polyethylene glycol concentration and the polymerization degree of polyethylene glycol. Polyethylene glycol molecules are believed to facilitate the formation of the spherical assembly.

Controlled Synthesis and Characterization of Monodisperse Fe3O4 Nanoparticles

AbstractMonodisperse Fe3O4 nanoparticles were successfully synthesized through the thermal decomposition of iron acetylacetonate in octadecene solvent in the presence of oleic acid and oleylamine. The influences of experimental parameters, such as reacting temperature, amounts and kinds of surfactants, solvents, oleic acid and oleylamine, on the size and shape of monodisperse Fe3O4 nanoparticles were discussed. The phase structures, morphology, and size of the as‐prepared products were investigated in detail by X‐ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and high‐resolution transmission electron microscopy (HRTEM). Magnetic property was measured using a vibrating sample magnetometer (VSM) at room temperature, which revealed that Fe3O4 nanoparticles were of ferromagnetism with a saturation magnetization (Ms) of 74.0 emu/g and coercivity (Hc) of 72.6 Oe.