Magnetic Iron Research Articles

Magnetically Guided Theranostics: Novel Nanotubular Magnetic Resonance Imaging Contrast System Using Halloysite Nanotubes Embedded with Iron–Platinum Nanoparticles for Hepatocellular Carcinoma Treatment

Halloysite nanotubes (HNTs) have a layered structure of clay silicate minerals and a tubular shape, which is suitable for the uniform loading of small substrates and drug molecules. The inner diameter of HNTs with an acidic solvent is selectively etched to increase the loading capacity of magnetic iron–platinum (FePt) nanoparticles. The FePt nanoparticles and etched HNTs (eHNT) are then composited by vacuum decompression. The resulting product is named FePt@eHNT and is used as a contrast agent for T2‐weighted magnetic resonance imaging. According to a comprehensive analysis of the material and its magnetic properties, by adding different proportions of HNTs before and after modification, the saturation magnetization can reach 23.769 emu g−1, which is higher than that of the composite materials studied in previous studies. This is because the tubular structure promotes the orderly displacement of the FePt nanoparticles under three‐dimensional space constraints and the uniform effect of the magnetic field. In addition, the magnetothermal effect of the composite material is observed and its potential as an imaging agent is investigated. In this study, the enhancement of its ferromagnetism and its potential to become a multifunctional composite material for applications in drug delivery, magnetic hyperthermia, and bioimaging is demonstrated.

Synthesis of Gd-DTPA Carborane-Containing Compound and Its Immobilization on Iron Oxide Nanoparticles for Potential Application in Neutron Capture Therapy.

Cancer is one of the leading causes of global mortality, and its incidence is increasing annually. Neutron capture therapy (NCT) is a unique anticancer modality capable of selectively eliminating tumor cells within normal tissues. The development of accelerator-based, clinically mountable neutron sources has stimulated a worldwide search for new, more effective compounds for NCT. We synthesized magnetic iron oxide nanoparticles (NPs) that concurrently incorporate boron and gadolinium, potentially enhancing the effectiveness of NCT. These magnetic nanoparticles underwent sequential modifications through silane polycondensation and allylamine graft polymerization, enabling the creation of functional amino groups on their surface. Characterization was performed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), dynamic light scattering (DLS), thermal gravimetric analysis (TGA), and transmission electron microscopy (TEM). ICP-AES measurements indicated that boron (B) content in the NPs reached 3.56 ppm/mg, while gadolinium (Gd) averaged 0.26 ppm/mg. Gadolinium desorption was observed within 4 h, with a peak rate of 61.74%. The biocompatibility of the NPs was confirmed through their relatively low cytotoxicity and sufficient cellular tolerability. Using NPs at non-toxic concentrations, we obtained B accumulation of up to 5.724 × 1010 atoms per cell, sufficient for successful NCT. Although limited by its content in the NP composition, the Gd amount may also contribute to NCT along with its diagnostic properties. Further development of the NPs is ongoing, focusing on increasing the boron and gadolinium content and creating active tumor targeting.

NEW MAGNETIC COLLOIDAL SYSTEMS BASED ON BIOMIMETIC POLYCOMPLEXES

This paper presents new colloidal systems that have prospects for use as carriers of medicinal compounds and are polymer complexes based on polyacrylic acid molecules of various molecular weights and biogenic polyamine, additionally modi ed with magnetic iron oxide nanoparticles. The main physicochemical characteristics of the resulting polycomplexes were determined. The possibility of incorporating the drug compound doxorubicin into polycomplexes was demonstrated and the magnetic properties of polycomplexes functionalized with magnetic iron oxide nanoparticles were studied.

Effect of bias magnetic field on transducer efficiency in electromagnetic ultrasonic non-destructive testing of Rock bolt

Non-destructive testing (NDT) of rock bolt anchoring quality is an important part of engineering quality and safety control, electromagnetic ultrasonic NDT is one of the promising detection methods, and improving the efficiency of ultrasonic transducer by optimizing the bias magnetic field is an important factor to obtain effective information. In this paper, several factors affecting the bias magnetic field are studied, and the work is divided into simulation and demonstration: COMSOL was used to simulate the electromagnetic ultrasonic transducer(EMAT) in order to analyze the influence of the number of magnetic circuit, the thickness of magnet and the thickness of yoke iron on the bias magnetic field. Then, an experimental platform was built, the magnetic circuit structure of the transducer was set with reference to the simulation results, and several important parameters of the bias magnetic field were determined by analyzing the collected signals. The results show that with the increase of the bias magnetic field magnetic circuit structure from independent to ring form, the magnetic field strength of the rock bolt increases, the magnetic field uniformity becomes better, and the efficiency of the transducer is also improved accordingly. In addition, under the same magnetic circuit condition, increasing the thickness of permanent magnet and yoke iron does not increase the magnetic flux density of the rock bolt axis proportionally, and has a limited effect on the efficiency of the transducer. In practical application, the corresponding structure is selected according to the needs, and the better bias magnetic field structure is selected while meeting the efficiency of the transducer.

Impacts of designed vanillic acid-polymer-magnetic iron oxide nanocomposite on breast cancer cells

The engineered nano-vehicle was constructed using magnetic iron oxide nanoparticles (MIONs) and chitosan (CTS) to stabilize anticancer agent vanillic acid (VNA) which was loaded on CTS-coated MIONs nanocarrier, and more importantly, to achieve sustained VNA release and subsequent proper anticancer activity. The new thermally stable VNA-CTS- MIONs nanocomposite was spherical with a middle diameter of 6 nm and had a high drug loading of about 11.8 %. The MIONs and resulting nanocomposite were composed of pure magnetite and therefore, were superparamagnetic with saturation magnetizations of 53.3 and 45.7 emu.g−1, respectively. The release profiles of VNA from VNA-CTS-MIONs nanocomposite in different pH values were sustained and showed controlled pH-responsive delivery of the loaded VNA with 89 % and 74 % percentage release within 2354 and 4046 min at pH 5 and 7.4, respectively, as well as were in accordance with the pseudo-second-order model. The VNA-CTS-MIONs nanocomposite treatment at diverse concentrations remarkably decreased the viability and promoted ROS accumulation and apoptosis in the MDA-MB-231 breast cancer cells. Hence, it can be a propitious candidate for the management of breast cancer in the future.

Biomass-derived carbon heterostructure composites modified with magnetic iron oxide for excellent EMW-absorbing materials

With the gradual spread of satellite navigation, broadcasting, and communication technologies, the problem of electromagnetic pollution in C- and Ku-band has increased. Electromagnetic wave (EMW) absorbing materials can effectively mitigate this problem. Here, we report the design of a biomass carbon heterostructure for the absorption of EMWs. This design takes advantage of the natural fiber mesh structure of the loofah and the voids, veins, and basal tissues surrounding the fibers. The material is then carbonized to create a radar antenna-like structure of fibers and nanosheets. This improves the material's conductive loss. In addition, modification with magnetic iron oxide in loofah sponges improves the impedance matching of the materials, enhances the magnetic loss, and increases the heterogeneous interface. We found that the maximum effective absorption frequency range of the prepared EMW-absorbing materials is 3.80 GHz, which is mainly concentrated in the C-band and Ku-band, and its maximum RLminvalue is −59.20 dB. The material's ability to absorb EMWs was also verified by simulating the radar cross section (RCS). In conclusion, this work develops a green and efficient composite material for absorbing EMWs and provides new design ideas for the development of EMW-absorbing materials.

A comprehensive study on RSM optimization of the influencing variables on loading/releasing of ciprofloxacin onto/from magnetic iron nanoparticles

Fe3O4 MNPs were synthesized by the co-precipitation method and characterized via SEM, EDX, FTIR, XRD, VSM, TGA, and x-ray map. Its pHpzc was obtained at 5.4. The loading and releasing conditions for Ciprofloxacin (CIP) on/from Fe3O4 magnetic nanoparticles (MNPs) were optimized via response surface methodology (RSM). We found that pH was the most influential factor in the loading and releasing processes. The center point conditions for the loading were pH 7, CIP concentration of 14 ppm, adsorbent dose of 11 mg, and shaking time of 9 h, while for the release process, were pH 5.1, sample dose of 11 mg, and releasing time of 5.1 h. The optimal RSM run conditions for loading were pH: 5, CCIP: 13 ppm, dose: 7 mg, time: 20 h, and for the releasing process were pH: 2.7, dose: 11 mg, time: 7 h.

Within-city spatial variations in PM2.5 magnetite nanoparticles and brain cancer incidence in Toronto and Montreal, Canada.

Magnetite nanoparticles are small, strongly magnetic iron oxide particles which are produced during high-temperature combustion and friction processes and form part of the outdoor air pollution mixture. These particles can translocate to the brain and have been found in human brain tissue. In this study, we estimated associations between within-city spatial variations in concentrations of magnetite nanoparticles in outdoor fine particulate matter (PM2.5) and brain cancer incidence. We performed a cohort study of 1.29 million participants in four cycles of the Canadian Census Health and Environment Cohort in Montreal and Toronto, Canada who were followed for malignant brain tumour (glioma) incidence. As a proxy for magnetite nanoparticle content, we measured the susceptibility of anhysteretic remanent magnetization (χARM) in PM2.5 samples (N = 124 in Montreal, N = 110 in Toronto), and values were assigned to residential locations. Stratified Cox proportional hazards models were used to estimate hazard ratios (per IQR change in volume-normalized χARM). ARM was not associated with brain tumour incidence (HR = 0.998, 95% CI 0.988, 1.009) after adjusting for relevant potential confounders. Although we found no evidence of an important relationship between within-city spatial variations in airborne magnetite nanoparticles and brain tumour incidence, further research is needed to evaluate this understudied exposure, and other measures of exposure to magnetite nanoparticles should be considered.

The enrichment and transformation mechanism of Pb and Cu in suspension magnetization roasting and magnetic separation from iron tailings

Magnetic iron concentrate (MIC) and nonmagnetic tailings (NT) are obtained from magnetization roasting of iron tailings (IT). MIC containing Pb adversely affects blast furnace ironmaking, while Cu in NT poses leaching risks. This study utilizes fast pyrolysis-suspension magnetization roasting to recover iron from IT. The enrichment of Pb, Cu, and the phase transformation mechanism of Cu in the process of suspension magnetization roasting and magnetic separation were clarified. Results show 96.13 % of Cu in IT is in limonite and 47.23 % of Pb is associated with iron. At 750 °C, with 10 % dosage of biomass pyrolysis and 10 min roasting, Pb, Cu and Fe contents in MIC are 0.96, 2.14 and 3.17 times that of NT. Increasing roasting temperature enhances Cu associated with iron enrichment into the MIC, while oxidation of free copper oxide associated with iron forms magnetic copper ferrite. Increased pyrolyzed biomass leads to over-reduction of magnetite associated with Cu to FeO associated with Cu, promoting magnetic copper ferrite decomposition into FeO and free copper oxide. This research holds significant importance in controlling the quality of MIC and the storage risk of IT, and provides theoretical guidance for the regulation and recovery of valuable metals in subsequent processes.

Synthesis of polyaniline-doped magnetic iron foam photo catalyst (PANI@mIF) for integrated adsorptive photocatalytic degradation of nicosulfuron

ABSTRACT Nicosulfuron have low volatility and slow biodegradation rate, leading to its long persistency in soil and crops, which further upraised the risk of contamination of nearby water and severe damage to the crop rotation as may be its precursors are more harmful than nicosulfuron itself. In the present work, we performed a degradation study for the efficient removal of nicosulfuron from soil and water using Polyaniline-doped magnetic iron foam (PANI@mIF). The Photo catalyst was synthesised by doping of polyaniline on magnetic iron foam at 70°C and applied for the efficient photocatalytic degradation of nicosulfuron. PANI@mIF was then characterised through FTIR, SEM, EDX and XRD. The degradation of nicosulfuron was investigated under UV radiations and the resulted data were examined by fitting isotherms models. The Langmair model is well fitted to the adsorption data with R2 of 0.925, which demonstrates monolayer adsorption of nicosulfuron on the surface of PANI@mIF. The maximum adsorption capacity and percent degradation of 87% was achieved with PANI@mIF. Comparatively, good adsorption capacity of PANI@mIF is attributed to a large number of H bonding and electrostatic interactions. Kinetic study indicates the adsorption of nicosulfuron by PANI@mIF followed 2nd order kinetics with R2 of 0.958.The negative values of Gibbs free energy (−18294.3, 19543.1,-7530.4, −7307.7 and −7969.8), enthalpy (−1.97 × 10−4) and entropy (−3.54 × 10−3) indicate spontaneous and exothermic nature of the process. The reusable nature of PANI@mIF with 5 batches reflected its inventive photo catalytic behaviour for real sample applications and waste water treatment.

Magnetic Iron Oxide Nanoparticles Coated by Coumarin-Bound Copolymer for Enhanced Magneto- and Photothermal Heating and Luminescent Thermometry.

In this work, we report on the synthesis and investigation of new hybrid multifunctional iron oxide nanoparticles (IONPs) coated by coumarin-bound copolymer, which combine magneto- or photothermal heating with luminescent thermometry. A series of amphiphilic block copolymers, including Coum-C11-PPhOx27-PMOx59 and Coum-C11-PButOx8-PMOx42 bearing luminescent and photodimerizable coumarin moiety, as well as coumarin-free PPhOx27-PMOx57, were evaluated for their utility as luminescent thermometers and for encapsulating spherical 26 nm IONPs. The obtained IONP@Coum-C11-PPhOx27-PMOx59 nano-objects are perfectly dispersible in water and able to provide macroscopic heating remotely triggered by an alternating current magnetic field (AMF) with a specific absorption rate (SAR) value of 240 W.g-1 or laser irradiation with a photothermal conversion efficiency of η = 68%. On the other hand, they exhibit temperature-dependent emission of coumarin offering the function of luminescent thermometer, which operates in the visible region between 20 °C and 60 °C in water displaying a maximal relative thermal sensitivity (Sr) of 1.53%·°C-1 at 60 °C.

Preparation and Identification of Magnetic Iron Nanoparticle based on a Natural Hydrogel and its Performance in Targeted Drug Delivery

Billions of dollars are spent annually in the world to treat and investigate problems caused by drug side effects. According to the estimates of health researchers, about 40%of people who take medicine suffer from side effects. In this way, the necessity of using a targeted system in order to deliver medicine to the desired place without damaging healthy tissues is felt more than ever. In recent years, targeted drug delivery systems based on nanoparticles have received much attention. Meanwhile, the use of natural polymers is more suitable for various purposes in drug delivery systems in terms of indicating greater biological compatibility with the body and being non-toxic.In this research, the natural hydrogel extracted from the seeds of the Plantago ovata, which is loaded on the bed of magnetic iron nanoparticles, was used to entrap the drugmefenamic acid. In order to achieve this goal, at the beginning, magnetic iron nanoparticles were prepared by co-precipitation method using iron (II) and iron (III) oxides, and then a coating of silica was created on its surface, then the hydrocolloid of Plantago ovata was extracted from its seed, in order to connect the magnetite nanoparticles and the polymer extracted from the Plantago ovata, the surface of both components was modified by vinyl-functional groups. Next, radical polymerization under heat was used to connect the particles and trap the drug, after that the release of the drug from the polymer capsule was checked by UV-Vis device. Before examining the drug release, the resulting product was identified by FT-IR, XRD, VSM, DLS, TGA, SEM analysis. Therefore, the obtained results indicated that the natural polymer was correctly loaded on the desired magnetic substrate and the drug mefenamic acid was trapped inside the hydrogel networks and polymer capsule. Therefore, the drug can be directed in a controlled and targeted manner by the magnetic field, and the release of the drug was done well and at an acceptable speed.

Magnetic Iron Oxide Nanomaterials for Lipase Immobilization: Promising Industrial Catalysts for Biodiesel Production

Magnetic Iron Oxide Nanomaterials for Lipase Immobilization: Promising Industrial Catalysts for Biodiesel Production

Innovative Agrowaste Banana Peel Extract-Based Magnetic Iron Oxide Nanoparticles for Eco-Friendly Oxidative Shield and Freshness Fortification

This study presents the synthesis of agro-waste banana peel extract-based magnetic iron oxide nanoparticles (BPEx-MIONPs), emphasizing antioxidant capacity and food preservation. Using iron (III) chloride hexahydrate (FeCl3 · 6 H2O) as a precursor and a reducing agent from agro-waste peel extract, a precisely controlled process yielded BPEx-MIONPs. Characterization involved X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). XRD revealed tetragonal Fe2O3, cubic magnetite structure, and monoclinic FexOy-NPs with an average size of 14.8 nm. TEM and SEM revealed diverse morphologies. TEM displayed both spherical and elongated nanoparticles, with some appearing as thin fibrils. In contrast, SEM images depicted an array primarily consisting of spherical nanoparticles, resembling coral reef formations. FTIR confirmed Fe–O bonds (1000 –400 cm-1). The antioxidant assessment showed robust DPPH free radical scavenging; BPEx achieved 100% inhibition at 18 min, and BPEx-MIONPs had an IC50 of ~ 136 µg/mL. BPEx-MIONPs, stabilized with banana-based bioplastic, effectively preserved grapes, reducing weight loss to 6.2% on day 3, compared to the control (19.0%). This pioneering study combines banana peel antioxidants with magnetic iron oxide nanoparticles, providing sustainable solutions for food preservation and nano-packaging. Ongoing research aims to refine conditions and explore broader applications of BPEx-MIONPs.Graphical

Discontinuous Shear Thickening of Suspensions of Magnetic Particles in Relation to the Polymer Coating on Their Surfaces

The phenomenon of discontinuous shear thickening (DST) is observed in suspensions of solid particles with a very high-volume fraction. It is characterized by an abrupt decrease in the shear rate for critical stress during a ramp of stress. This behavior can be reproduced in numerical simulations by introducing a local friction between two particles above a given local force. We present experimental results showing this DST behavior obtained with suspensions of magnetic (iron) and nonmagnetic (calcium carbonate) particles and different amounts of a superplasticizer molecule used in the cement industry. For both types of particles, the same behavior was observed with first an increase in critical stress with the amount of plasticizer followed by a decrease at higher concentrations but with a larger viscosity before critical stress was reached. At a low concentration of plasticizer, the low critical stress is interpreted by the local sliding of plasticizer molecules on the surface of particles. At higher concentrations, when total coverage is achieved, the critical stress is higher since it has to remove the molecules out of the surface. At still higher concentrations, the increase in viscosity is explained by the formation of multilayers of molecules on the surface of the particles. This interpretation is supported by the measurement of the adsorption isotherm of the plasticizer on the surface of the particles.

Research on magnetic field characteristics of amorphous alloy and grain‐oriented silicon steel hybrid magnetic circuit iron core

AbstractAmorphous alloy and grain‐oriented silicon steel are commonly employed as soft magnetic materials for the preparation of transformer cores, but both materials have their advantages and disadvantages. Using only silicon steel or amorphous alloy for the preparation of the core makes it difficult to achieve both high design density and low no‐load loss characteristics. In order to achieve the magnetic performance advantages of both amorphous alloy and silicon steel in transformer core development and application, the authors design and develop a kind of amorphous alloy and grain‐oriented silicon steel hybrid magnetic circuit core to explore the amorphous alloy and grain‐oriented silicon steel at different ratios under the magnetic properties of matching law. Based on the amorphous alloy and grain‐oriented silicon steel core magnetic performance comparison characteristics, the authors establish a core magnetic circuit model and design a hybrid magnetic circuit core structure with different material ratios. The hybrid magnetic circuit core model is simulated and analysed to obtain the magnetic density distribution of the hybrid magnetic circuit core. A number of hybrid magnetic circuit core experimental models are produced, and the use of a magnetic property measurement platform is made for the hybrid magnetic circuit core measurements, to reveal the magnetic performance matching law of the hybrid magnetic circuit core, providing a good solution for power distribution in the hybrid magnetic circuit.

Comparison of MAF-32 and a One-Pot Synthesized Superparamagnetic Iron Oxide/MAF-32 Composite for the Adsorption of Diclofenac.

The global presence of pharmaceutical pollutants in water sources represents a burgeoning public health concern. Recent studies underscore the urgency of addressing this class of emerging contaminants. In this context, our work focuses on synthesizing a composite material, FexOy/MAF-32, through a streamlined one-pot reaction process, as an adsorbent for diclofenac, an emerging environmental contaminant frequently found in freshwater environments and linked to potential toxicity towards several organisms such as fish and mussels. A thorough characterization was performed to elucidate the structural composition of the composite. The material presents magnetic properties attributed to its superparamagnetic behavior, which facilitates the recovery efficiency of the composite post-diclofenac adsorption. Our study further involves a comparative analysis between the FexOy/MAF-32 and a non-magnetic counterpart, comprised solely of 2-ethylimidazolate zinc polymer. This comparison aims to discern the relative advantages and disadvantages of incorporating magnetic iron oxide nanoparticles in the contaminant removal process facilitated by a coordination polymer. Our findings reveal that even a minimal incorporation of iron oxide nanoparticles substantially enhanced the composite's overall performance in pollutant adsorption.

Magnetic iron‐oxide coffee husk and khat waste biochar nanocomposites for removal of methylene blue from aqueous solution

AbstractWastewater from the textile and dyeing industries contains hazardous dyes. This study aims to determine the effectiveness of magnetic biochar nanocomposites synthesized from khat leftovers (KLs) and coffee husks (CHs) in removing methylene blue (MB) from wastewater. Magnetic biochar nanocomposites were synthesized by pretreating 25 g of biomass with a 12.5 mmol mixture of FeS and FeCl3 at a 1:1 molar ratio, followed by pyrolyzing at 300°C for 1 h. The resulting products were analyzed using X‐ray diffraction, Fourier transform infrared, scanning electron microscope, and Brunauer‐Emmett‐Teller. The results showed that the adsorbents are amorphous, and the activated biochars, are more porous and contain various functional groups such as C‐O, C = C, O‐H, C‐H, and Fe‐O. When 0.2 g of pristine biochars of CH and KL were applied to 20 mL aqueous solutions containing 20 mg/L of MB at pH 7.5 and 25°C, they removed 44.73% and 75.26% of MB, respectively. However, the resulting nanocomposites exhibited a maximum removal efficiency of 99.10% and 99.23% with magnetic iron oxide‐CH biochar nanocomposite (Fe3O4‐CHBNC) and magnetic iron oxide‐KL biochar nanocomposite (Fe3O4‐KLBNC), respectively, with maximum adsorption capacities of 51.02 and 78.13 mg/g. The reusability study also showed removal efficiencies of 77.57% and 83.49% up to six‐cycle reuse.

Magnetic iron oxide nanoparticle enhanced microwave pretreatment for anaerobic digestion of meat industry sludge

Our study investigates the effects of iron oxide (Fe3O4) nanoparticles combined microwave pretreatment on the anaerobic digestibility and soluble chemical oxygen demand (SCOD) of meat industry sludge. One of our main objectives was to see whether the different microwave-based pretreatment procedures can enhance biogas production by improving the biological availability of organic compounds. Results demonstrated that combining microwave irradiation with magnetic iron oxide nanoparticles considerably increased SCOD (enhancement ratio was above 1.5), the rate of specific biogas production, and the total cumulative specific biogas volume (more than a threefold increment), while having no negative effect on the biomethane content. Furthermore, the assessment of the sludge samples’ dielectric properties (dielectric constant and loss factor measured at the frequency of 500 MHz) showed a strong correlation with SCOD changes (r = 0.9942, R2 = 0.99), offering a novel method to evaluate pretreatment efficiency.

Spin disorder control of topological spin texture

Stabilization of topological spin textures in layered magnets has the potential to drive the development of advanced low-dimensional spintronics devices. However, achieving reliable and flexible manipulation of the topological spin textures beyond skyrmion in a two-dimensional magnet system remains challenging. Here, we demonstrate the introduction of magnetic iron atoms between the van der Waals gap of a layered magnet, Fe3GaTe2, to modify local anisotropic magnetic interactions. Consequently, we present direct observations of the order-disorder skyrmion lattices transition. In addition, non-trivial topological solitons, such as skyrmioniums and skyrmion bags, are realized at room temperature. Our work highlights the influence of random spin control of non-trivial topological spin textures.