Uncoated Iron Research Articles

Coated and Uncoated Magnetic Iron Oxide Nanoparticles: Toxicity Assessment and Properties of Non Accumulation in Biological Tissues

Background: There are an increasing number of studies on magnetic nanofeeders with multiple applications in agriculture and food processing. Among the magnetic separation oxides, iron oxide has emerged as an indispensable tool in nanoscale differentiation, especially bio-nanoscale. This is attributed to the characteristics of such as size, shape, magnetism and coexistence. Aim of the study: The aim of this study feeding experiment is to prove the non-toxicity of magnetic nano-iron oxides, whether coated when dosed with distilled water or uncoated in milk or distilled water. Subject, materials and methods: Materials: magnetic iron oxide nanoparticles was obtained from SkySpring Nanomaterials (U.S.A.) at a size of 30 nm. Acacia gum (Gum Arabic) is prepared from Thomas Baker (Indian), Sodium hydroxide from Riedel-de Haën (Germany), Potassium phosphate dibasic from CDH (Indian), Potassium phosphate mono basic from HIMEDIA (Indian),Potassium bromide from AVONCHEM(UK), MNPs are characterized by various tools to examine their physicochemical properties. The size of NPs plays a major role in exhibiting different physicochemical properties, and even a small difference in their nanoscale dimensions can alter their properties. Some of the instruments used for their characterization are Atomic Force Microscopy (AFM), Energy Dispersive X-ray Diffraction (EDXD), Field-Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared Spectrometer. Results: After the completion of the experimental period for this study (28 days), the laboratory animals were sacrificed using ether anesthesia. The animals were then dissected using dissection tools to remove these organs. The organs were weighed using a sensitive balance after being washed with 0.9% normal saline solution and dried with filter paper [1][2]. The liver, kidneysamples were collected in pre-labeled plastic containers and preserved in 10% formalin until histological sectioning could be performed. Tissue sections were performed for all organs - liver, kidney and they were placed under a microscope. The results showed no damage to these organs. Conclusion: The findings suggest that both arabic gum-coated and milk-coated magnetic iron oxide nanoparticles, at the tested doses and treatment durations, did not induce observable tissue damage or pathological alterations in the kidneys or liver of the treated rats.

In-situ resistance mapping of surface corrosion of iron using contact-mode carbon fibre as potentiometric tip

Scanning Probe Microscopy (SPM) has recently gained significant attention from both scientists and engineers for its unique capability to investigate localized corrosion phenomena. This paper introduces a novel application of SPM that offers a unique in-situ means to quantitatively evaluate the resistance of a spontaneously formed oxide layer on the conductive surface of an uncoated iron sample. This approach involved rastering a thin carbon fibre on the iron sample immersed on a corrosive medium while maintaining direct contact between the tip of the carbon fibre and the studied surface. Depending on the resistance between the tip and the sample, the measured voltage proportionally varied between 0 and the potential of the potentiometric circuit formed by the iron sample, the electrolyte and the carbon fibre. Through the application of the voltage divider formula, the measured potential map was transformed into a resistance map. This process allowed us to render a visual representation of the resistance distribution across the surface of the iron sample, providing some insights into the properties of the oxide layer.

Meat crust as a novel food ingredient to regulate lipid peroxidation and oxidative stress

Pan Fry (PF) is a common heating treatment however, there is limited data on meat oxidation after PF using direct contact with an uncoated iron pan. After PF, a crust is formed, and in this study, we aim to evaluate the potential anti-oxidation and anti-lipid peroxidation capacity of such crust. Ground beef and turkey meat were heat treated using PF or microwave. Lipid peroxidation was evaluated using malondialdehyde accumulation. PF meat generated lower lipid peroxidation levels versus microwave-heated meat. Iron PF has decreased lipid peroxidation versus Teflon pan heating. The crust significantly lowered lipid peroxidation and possessed millard reaction products (MRPs), strong reducing abilities, iodine removal capacity, and some iron chelation capacity. We demonstrated that the crust substantially decreases lipid peroxidation levels in various systems and can be used as a novel seminatural antioxidant ingredient, which may lead to extended shelf life and protects various food products.

Immobilizing arsenic in contaminated anoxic aquifer sediment using sulfidated and uncoated zero-valent iron (ZVI)

Arsenic (As) is carcinogenic and of major concern in groundwater. We collected sediment material from a contaminated anoxic aquifer in Sweden and investigated the immobilization of As by four commercial zero-valent iron (ZVI) particles. Solid-phase As and Fe speciation was assessed using X-ray absorption spectroscopy (XAS) and solution-phase As speciation using chromatographic separation. Without ZVI addition, arsenite dominated in solution and As(V) species in the solid phase. Adding ZVI caused a sharp increase in solution pH (9.3–9.8), favoring As oxidation despite a lowered redox potential. ZVI greatly improved As retention by complex binding of arsenate to the Fe(III) (hydr)oxides formed by ZVI corrosion. Uncoated ZVI, both in nano- and microscale, performed better than their sulfidated counterparts, partly due to occlusion of As by the Fe(III) (hydr)oxides formed. The effect of particle size (micro vs. nano ZVI) on As immobilization was small, likely because immobilization was related to the corrosion products formed, rather than the initial size of the particles. Our results provide a strong geochemical background for the application of ZVI particles to remove As in contaminated aquifers under anoxic conditions and illustrate that immobilization mechanisms can differ between ZVI in As spiked solutions and sediment suspensions. Environmental implicationArsenic ranks first on the list by the US ATSDR of substances posing a threat to human health and the WHO considers groundwater the riskiest source for human intake of As. However, dealing with As contamination remains a scientific challenge. We studied the immobilization of groundwater As by commercially available ZVI particles at field-realistic conditions. Arsenic immobilization was highly efficient in most cases, and the results suggest this is a promising in situ strategy with long-term performance. Our results provide a strong geochemical background for using ZVI to remove As in contaminated anoxic aquifers.

Anti-biofouling potential of extremely water-repellent carbon soot coatings immersed in a highly-contaminated seawater swamp

The undesired translocation of marine microorganisms during sailing and the excessive expenditures for ship hull repairment due to biofouling could be circumvented using superhydrophobic coatings. Unfortunately, the combined effect of underwater currents and colonizing activity of multitudinous foulants on the anti-microbial performance of existing non-wettable materials is still at infant stage. The paramount objective here is to evaluate for the first time the potential of two mechanically durable water-repellent soot coatings towards the inhibition of bacterial proliferation in “real-life” outdoor conditions. We demonstrate that upon one-week immersion in a seawater swamp, both specimens lose non-wettability due to dissolution of the trapped gas layer into the water basin, but yet manage to retard the biofilm development, compared to uncoated iron surfaces, and halt the settlement of some Gram-negative and Gram-positive bacterial strains. The noticed selectiveness in the anti-fouling behavior of tested samples is presumably attributed to differences in the cell envelopes, the extent of elicit oxidative stress and soot-mediated formation of toxic ammonia molecules via hydrogen bonding. These unknown so far anti-bacterial mechanisms of the soot expand the horizons of practical applicability beyond the conventional framework and emphasize on its possible future use as a therapeutic agent.

Oil-lubricated sliding wear performance of TiSiCN-coated ductile iron

Improvements to internal combustion engine performance can be achieved by the application of advanced coatings to piston rings and cylinder bores. Here, the sliding wear performance of TiSiCN coatings on ductile iron was evaluated in heavy-duty diesel engine oil using a block-on-ring tribometer. The coatings were deposited by plasma-enhanced magnetron sputtering of titanium in a reactive environment containing nitrogen, acetylene, and hexamethyldisilazane. Coating characterization was conducted using X-ray spectroscopy and diffraction, electron microscopy, and nanoindentation. TiSiCN adhesion to ductile iron was qualified by Rockwell indentation testing. Wearing surface and counter surface material pairs were systematically varied. Intermittent friction oscillation was observed for self-mated TiSiCN, while tribosystems with only one TiSiCN surface exhibited improved friction stability relative to uncoated ductile iron. A 24% reduction in block wear rate was achieved by coating the block surface with TiSiCN. Solely coating ring surfaces with TiSiCN, however, increased the uncoated block wear rate by over 300%.

Textural Thermo-gravimetric and Magnetic Properties of Green Synthesised Water Dispersible Pristine and Gold Coated Superparamagnetic Iron Oxide Nanoparticles

Gold-coated magnetic nanoparticles have received a lot of attention in recent years due to their multifunctional attributes and their prospective unique characteristics in environmental and biomedical applications. This paper reports the textural, thermo-gravimetric, and magnetic properties of green synthesized gluconic acid-capped uncoated and gold-coated superparamagnetic iron oxide nanoparticles (SPION@Au). The as-synthesized nanomaterials were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), and superconducting quantum interference device (SQUID) magnetometry. The XRD and SEM measurements showed that the gluconic acid-capped magnetic core was coated with gold with cubical spinel crystalline structures. TGA results revealed the thermal stability of the nanoparticles. Textural properties indicated that the gold-coated nanoparticles were in naturally mesoporous and exhibited the type IV isotherm with an H2 hysteresis loop. The estimated maximum pore diameter and surface area of SPION@Au were 3.33 nm and 134.02 m²/g respectively. Furthermore, the SQUID results showed the nanocrystals were superparamagnetic with a blocking temperature (TB) of 214 K at 500 Oe and saturation magnetization of 11.38 emu/g. These noteworthy results demonstrated that the as-synthesized SPION@Au are promising nanomaterials for biomedical and analytical applications.

Characterization, wear and emission properties of MnS containing laser cladded brake disc

In this study, the laser cladding of gray cast iron brake discs using a Fe-based coating material was investigated. A 5 wt% MnS was added as a solid lubricant to the coating formulation to track the improvement of wear and emissions. Microstructural and tribological characteristics of the coated discs (with and without MnS) were studied comparatively. Three different friction materials, that are typically used for commercial brake pads, were adopted to evaluate the performance of the coatings. The pin on disc results indicated that, with the addition of MnS, both friction coefficient and wear rate have been reduced to levels comparable with those obtained in case of uncoated gray cast iron discs. The tribological behavior of MnS containing coating showed the best results when sliding against a Cu full friction material.

Improvement of the saturation magnetization of PEG coated superparamagnetic iron oxide nanoparticles

Polyethylene glycol (PEG) coated iron oxide nanoparticles are of interest because of their distinctive properties and potential applications such as magnetic resonance imaging, magnetic hyperthermia and drug delivery. In this study, PEG coated iron oxide nanoparticles were obtained by a two-step synthesis route including coprecipitation and coating. Different amounts of PEG6000 were used for coating and the effect of PEG amount on the structural and magnetic properties of the nanoparticles was investigated. Crystal structure, surface coating and particle size of the nanoparticles were characterized by X-ray diffraction technique, Fourier transform infrared spectroscopy and transmission electron microscopy. The particle size of iron oxide nanoparticles remained almost constant (7–8 nm) with the increase of PEG amount. It was determined from thermogravimetric analysis that the coating percentage of the nanoparticles steadily increased from 2.6 to 6.9 % with the increase of PEG amount from 5 to 15 g. Magnetic properties of the nanoparticles were studied by vibrating sample magnetometer and all samples were found to be superparamagnetic. PEG coated iron oxide nanoparticles showed higher saturation magnetization, Ms values than the uncoated iron oxide nanoparticles. Also, Ms of the coated nanoparticles increased with the increase of PEG coating and reached a value of 62.4 emu/g showing an increase of 19 % over uncoated iron oxide nanoparticles while maintaining the superparamagnetic behavior. This remarkable rise in the Ms of PEG coated iron oxide nanoparticles may improve the control and delivery of the nanoparticles for potential applications.

Corrosion in Tinplate Cans Used for Food Storage, Part 3: Effects of Cysteine, NaCl, and Tomatoes on Corrosion of Tin, Iron, and Tinplate

Tinplate cans used to contain foodstuff are fabricated from steel coated with a thin layer of tin and then overcoated with a thin polymeric layer. Previous papers in this series investigated the corrosion behavior of tinplate cans containing chopped tomatoes or one of the chemical components found in cans of chopped tomatoes. The amino acid cysteine was found to be an aggressive agent that can cause corrosion and blackening of the can headspace region. In this study, the corrosion phenomena associated with tinplate cans were investigated by studying the behavior, individually, of uncoated pure tin, iron, and tinplate in chopped tomato, NaCl, and cysteine solutions using electrochemistry, optical microscopy, x-ray diffraction, scanning electron microscopy, and Raman spectroscopy. Black corrosion products, identified as sulfides, formed when the tin, iron, and tinplate specimens were exposed to cysteine solution at three different pH values. The black corrosion products were also found on both iron and tinplate when the samples were immersed in tomato solution. These results indicate that blackening on bare iron and tinplate could form easily from the decomposition of chemical compounds in heated tomatoes.

The Effect of Synthesis Parameters on the Size, Composition, and Stability of Iron Nanoparticles

Magnetic nanoparticles (MNPs) have many uses for biomedical applications including drug delivery, magnetic resonance imaging (MRI) contrast agents, theranostics and hyperthermia. MNPs photo-thermally heated by laser light could be used to treat the typically difficult to access tumors such as glioblastomas. Due to their high magnetic saturation, monometallic iron nanoparticles would have an edge over iron oxide nanoparticles currently being investigated for hyperthermia. The goal of this study was to synthesize spherical iron nanoparticles less than 10 nm in diameter by thermal decomposition. The ability of various biocompatible coatings to protect the metallic iron nanoparticles from oxidation was investigated. Coatings studied included Brij, polyethylene glycol and iron oxide. Transmission electron microscopy and Mössbauer spectroscopy were utilized to characterize the coated and uncoated iron nanoparticles’ size and oxidation state to evaluate the effectiveness of the coatings and the procedures in which the coatings were applied. A ferrite shell was found to provide the best stabilization; however, its longer synthesis time increased particle size distribution. Polymer coatings provided biocompatibility but did not prevent oxidation.

Self-heating properties of iron oxide nanoparticles prepared at room temperature via ultrasonic-assisted co-precipitation process

ABSTRACT Preparation of iron oxide nanoparticles by a simple and environmentally friendly technique with high hyperthermia performance is highly desirable for biomedical application. These can potentially develop room temperature nanoparticles through the ultrasonic-assisted co-precipitation process. In this work, two types of iron oxide nanoparticles, un-coated iron oxide (IONPs) and coated iron oxide nanoparticles with tetraethoxysilane (IONPs-TEOS), were prepared at room temperature via ultrasonic-assisted co-precipitation process. The prepared nanoparticles were characterized using multiple techniques, such as Fourier transform infrared spectroscopy (FTIR), Thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), and X-ray diffraction (XRD). Self-heating properties and heating efficiency of the prepared nanoparticles were investigated under an alternative magnetic field in the function of carriers’ viscosity (water and ethanol) and induction time (0–6 minutes). It was found that the highest specific absorption rate (SAR) value for IONPs was 22.9 W/g when using water as a carrier. The viscosity affects the heating properties by changing the carrier through a Brownian mechanism and thus causes a significant SAR. Brownian relaxation is hindered by the particle’s hydrodynamic volume and the viscosity that tends to inhibit the particle rotation in the medium. Hence, the prepared room temperature iron oxide nanoparticles by this route can be applicable as hyperthermic agents for biomedical applications.

Design and Optimization of an Eddy Current Speed Sensor for Rotating Rods

This paper presents the design and optimization of a novel eddy current speed sensor for rotating rods and cylindrical shafts. The sensor consists of one excitation coil and two pick-up coils. All coils are stationary; we consider air coils, and we also use a magnetic yoke. We utilize a copper coating on an iron rod to increase the sensitivity, and we compare the performance with the performance achieved for an uncoated iron rod. 3D FEM is utilized for analyzing and for optimizing the design of the proposed sensor. The main advantages of the novel sensors are their simplicity, their low cost and their robust configuration. A linearity error of 0.5% has been achieved. The level of accuracy is limited by mechanical factors. A 1D analytical model has also been developed for rapid analysis and optimization of the sensor. An aluminum rod was also used in the measurements for a comparison with the results achieved with the iron rod.

Detection of Cells Containing Internalized Multidomain Magnetic Iron (II, III) Oxide Nanoparticles Using the Magnetic Resonance Imaging Method

This study evaluated the feasibility of using uncoated iron (II, III) oxide nanoparticles (IONP) obtained by electric explosion of wire in air for labelling living mesenchymal stromal cells and their subsequent visualization by magnetic resonance imaging (MRI) using the 1T and 1.5T clinical MRI scanners. The uptake of uncoated IONP by MSC was demonstrated for the wide range of IONP concentration in the cell culture medium. The cells did not change their proliferative activity, viability, and the set of surface markers. Iron oxide nanoparticles obtained by an electric explosion of wire in an atmosphere of air had a shape close to spherical. According to dynamic lateral light scattering, laser diffraction, and transmission electron microscopy, the particle size varied from 14 to 136 nm. Particles up to 136 nm accounted for 75%, while particles less than 36 nm accounted for 10%. A wide range of particle sizes made it possible to select MRI parameters suitable for labelled cells detection in animal tissues in both the T2 and the T1 relaxation mode.

The effect of PEGylated iron oxide nanoparticles on sheep ovarian tissue: An ex-vivo nanosafety study

Today, nanotechnology plays an important role in our ever-continuous quest to improve the quality of human life. Because of their infinitesimal size, nanostructures can actively interact and alter cellular functions. Therefore, while the clinical benefits of nanotechnology may outweigh most of the associated risks, assessment of the cytotoxicity of nanostructures in respect to cells and tissues early in product development processes is of great significance. To the best of our knowledge, no such assessment has been performed for nanomaterials on the ovarian cortex before. Herein, silica-coated, PEGylated silica-coated, and uncoated iron oxide nanoparticles (IONP) with core diameter of 11 nm (±4.2 nm) were synthesized. The oxidative stress in cultured ovarian tissue exposed to the various IONP was subsequently assessed. The results indicate that among the four groups, uncoated IONP induce the most oxidative stress on the ovarian cortex while tissues treated with PEGylated IONP exhibit no significant change in oxidative stress.

Magnetically induced heating by iron oxide nanoparticles dispersed in liquids of different viscosities

The AC magnetically induced heating characteristics of uncoated and silica-coated magnetic iron oxide nanoparticles dispersed in liquids of different viscosities were investigated. The aim was to synthesize and prepare uncoated and silica-coated nanoparticles of maghemite, and evaluate their ability to hyperthermically dissipate heat under an applied AC magnetic field when they are dispersed in liquids of different viscosities. A conceptual approach on the relative contributions of the Néel and the Brownian relaxation mechanisms to the hyperthermic heating of these suspensions is proposed. The microstructure, the physical and chemical properties of the uncoated and silica-coated nanoparticles were assessed by transmission electron microscopy; powder X-ray diffraction; 57Fe Mössbauer spectroscopy; Fourier transform infrared spectroscopy; zeta potential measurements; and conventional chemical analysis. Results of the Rietveld refinement of the XRD patterns and analysis of the collected Mössbauer data are well consistent with maghemite as being the only iron oxide phase. The mean diameters of the uncoated nanoparticles increased from ~6 to 7 nm, to 35 and 78 nm, for added silica coating amounts varying from 1 to 6-fold, respectively. Zeta potential measurements confirmed the efficiency of the nanoparticles sol-gel coating method. When dispersed in low viscosity media (water, triethanolamine, ethylene glycol), uncoated nanoparticles efficiently release heat via both Néel and Brown relaxation mechanisms under an applied oscillating magnetic field, achieving a temperature raise of approximately 21 °C. The silica layers tend to inhibit the Brownian motion of coated particles, making heat dissipation to be preferentially governed by the Néel relaxation of the magnetization vector. This leads to modest rises in temperature of 9 °C when they are dispersed in water or in the PVC (polyvinyl chloride). SAR tests indicate that the maghemite-silica core-shell systems might be useful for advanced technologies in medical practices based on local hyperthermia, particularly in oncology.

Magnetic resonance imaging of mesenchymal stromal cells labeled with uncoated multidomain iron oxide nanoparticles

Background & Aim The development of regenerative therapy makes necessary the creation of a method for in vivo labeling of cells for subsequent in vivo imaging. In case of large organisms such as humans, magnetic resonance imaging (MRI) seems to be the optimal visualisation technique. Single domain (i.e. with the size The aim of the work was to evaluate the possibility of using uncoated iron (II, III) oxide nanoparticles obtained by wire explosion in an air atmosphere to obtain labeled mesenchymal stromal cells (MSC) for subsequent visualization by MRI in tissues using clinical 1.5T MRI scanners. Methods, Results & Conclusion The viability, trilineage differentiation potential, immunophenotype were evaluated with flow cytometry. The size of the particles was measured with the DLS and electron microscopy methods. The colocalisation of IONP with lysosomes, autophagosomes and endosomes was studied with immunochemistry methods.The imaging of labeled cells injected post mortem into the bovine liver was performed with Siemens Espree and PHILIPS Ingenia 1,5T MRI scanners. MSC internalise IONP without reducing proliferative activity, viability, and changing the set of surface markers. IONP obtained by the method of explosion had a shape close to spherical. Particle size varied from 14 to 136 nm with IONP up to 136 nm composing 75% of particles, and IONP less than 36 nm - 10%. All IONP were localised in late endosomes and autophagosomes in 10 h of incubation with IONP being thus covered with a membrane. A wide range of particle sizes made it possible to select imaging parameters during MRI in animal tissues both in the T2 mode and in the T1 relaxation mode because of combination of IONP with ferro- and superparamagnetic properties. We conclude that IONP obtained with dry wire explosion can be used for MSC labelling in vivo for subsequent MRI imaging.

Coupled effect of colloids and surface chemical heterogeneity on the transport of antibiotics in porous media

Release of antibiotics into the environment has caused ecological and human health concerns in recent years. However, little is known about their transport behaviors in chemically heterogeneous porous media. In this study, we investigated the coupled effects of surface chemistry and soil colloids on the transport of ciprofloxacin and tetracycline through sand under steady state saturated flow conditions. Both antibiotics had a much higher capacity of adsorption on soil colloids (17,500 mg/kg for ciprofloxacin and 8600 mg/kg for tetracycline) than on sand (5.11 mg/kg for ciprofloxacin and 2.80 mg/kg for tetracycline). However, ciprofloxacin adsorption increased to 8.91 mg/kg after the sand was coated with iron oxide and to 8.73 mg/kg after the sand was coated with humic acid. Tetracycline, adsorption increased to 7.99 mg/kg after sand was coated with iron oxide coated sand and to 8.35 mg/kg after the sand was coated with humic acid coated The high adsorption capacity of ciprofloxacin led to a recovery rate of <4% in the effluents of the columns containing 0%, 20% and 50% of iron oxide/humic acid coated sand. The surface coating decreased the recovery rates of tetracycline from 35.4% (in uncoated sand) to 12.0% (in column containing 50% iron oxide coated sand) and 0.010% (in column containing 50% humic acid coated sand), respectively. Once adsorbed to soil colloids, the recovery rate of ciprofloxacin increased by 26.7% in uncoated sand column, 21.1% in iron oxide coated sand column, and 32.7% in humic acid coated sand column. Similarly, the presence of the colloids increased the recovery rate of tetracycline from 13.8% to 33.2% after the sand was coated with humic acid. Colloids did not significantly influence the transport and recovery of tetracycline in the uncoated sand and iron oxide coated sand due likely to its lower adsorption affinity.

Детектирование клеток, содержащих интернализованные мультидоменные магнитные наночастицы оксида железа (II, III), методом магнитно-резонансной томографии

This study evaluated the feasibility of using uncoated iron (II, III) oxide nanoparticles (IONP) obtained by electric explosion of wire in air for labelling living mesenchymal stromal cells and their subsequent visualization by magnetic resonance imaging (MRI) using 1.5T clinical MRI scanners. The uptake of uncoated IONP by MSC was demonstrated for the wide range of IONP concentration in the cell culture medium. The cells did not change their proliferative activity, viability, and the set of surface markers. IONP obtained by electric explosion of wire in an atmosphere of air had a shape close to spherical. The size of nanoparticles varied from 14 to 136 nm according to dynamic lateral light scattering, laser diffraction, and transmission electron microscopy. Particles up to 136 nm comprised 75%, and particles less than 36 nm --- 10% of the IONP powder. A wide range of particle sizes made it possible to select MRI parameters suitable for labelled cells detection in animal tissues both in the T2 mode and in the T1 relaxation mode.

Magnetic properties and microstructure of iron-based soft magnetic composites with Al2O3 insulating coating by one-pot synthesis method

In this work, the effects of the Al2O3 insulating coating and surfactant on magnetic properties of the iron powders coated with Al2O3 by one-pot synthesis method were investigated. The morphology, phase composition and magnetoelectric properties of iron powders coated with Al2O3 were tested respectively. Compared with uncoated iron powder, the composite powder of Al2O3 insulating layer not only has better permeability stability in the frequency range of 5–300 kHz, but also has lower core loss, especially eddy current loss in the frequency range of 5–100 kHz. The surface of iron powder modified by surfactant will change crystallization process of aluminum hydroxide. After the addition of dodecyl trimethyl ammonium bromide (DTAB) as the surfactant, the Al2O3 insulating coating becomes denser and smoother, and the core loss of coated powders is further reduced.