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Thermal decomposition of iron oleate is a simple and widespread method for synthesizing monodispersed iron oxide nanoparticles (IONPs) with well‐defined morphology. However, the complexity of the underlying mechanism makes this method rather sensitive to variations in experimental conditions, and the lack of simple techniques to monitor the reaction progress in situ usually results in poor reproducibility and time‐consuming optimizations. Here, a simple, robust, and versatile in situ marker to monitor particle formation based on a sudden change in the temperature during reflux is reported. A linear relationship between the onset of particle formation and the concentration of surfactants is unveiled, corroborating a ‘chemically activated’ burst nucleation mechanism. Using this linear relationship as a guide, highly uniform spherical, cubic, and star‐shaped particles between 12 and 30 nm can be obtained. This temperature marker and the derived linear relationship not only deepen the understanding of the reaction process, but also provide a powerful tool for the straightforward optimization of IONPs. [ABSTRACT FROM AUTHOR]

Ferrofluids based on magnetic iron oxide nanoparticles (IONPs) have been widely studied as multipurpose agents in various medical applications including magnetic hyperthermia, targeted drug delivery and magnetic resonance imaging (MRI). To increase their stability and compatibility with the living cells and thus improve their suitability for these purposes, the IONPs are often functionalized with different organic or inorganic molecules. In this work we report on the preparation of polyvinilpyrrolidone (PVP) functionalized IONPs through a simple co-precipitation method and investigated their suitability for magnetic hyperthermia and as a MRI contrast agent. Spherical PVP-coated IONPs, with an average particle size of ≈ 15 nm, showed superparamagnetic behavior and high saturation magnetization Ms = 80.7 emug−1, at room temperature. The specific absorption rate (SAR), a measure of the heating ability, ranged from 17 W/g to 721 W/g (evaluated for various combinations of AC magnetic field amplitudes and frequencies), while the intrinsic loss power (ILP) was in the range from 0.53 nHm2 kg−1 to 2.34 nHm2 kg−1. In addition to relatively good heating ability, high T2 relaxivity, r2 = 126 mM−1 s−1 and high r2/r1 ratio demonstrated that the preparation procedure used here can yield nanoparticles suitable for MRI guided localized magnetic hyperthermia. [ABSTRACT FROM AUTHOR]

The photocatalysis technology is widely applied for effective degradation of environmental contaminants. This study aims to examine the effectiveness of heat-treated iron oxide nanoparticles photocatalysts in the photocatalytic degradation of oxalic acid. To provide a comprehensive characterization of the photocatalysts, a range of techniques were utilized. These techniques included transmission electron microscopy (TEM) for the analysis of particle morphology, diffuse reflectance spectroscopy for the calculation of the energy bandgap, Brunauer–Emmett–Teller (BET) analysis for the determination of surface area, and X-ray diffraction (XRD) for the identification of crystal structure. The catalyst that was produced demonstrated an increased specific surface area, as well as a band gap of 2.2 eV. These characteristics provide a basis for understanding its photocatalytic performance. This work additionally examines the phenomenon of oxalic acid adsorption on iron oxide nanoparticles that have undergone heat treatment at different temperatures, employing Operando ATR-FTIR spectroscopy. Following this, the same approach is used to investigate the photocatalytic breakdown of the adsorbed oxalic acid. Subsequently, a study was undertaken to examine the surface electronic configuration of iron oxide nanoparticles that had undergone heat treatment. This analysis employed Fe–L edge X-ray absorption spectroscopy in the total electron yield (TEY) mode. It yielded valuable insights regarding the distribution of Fe3+/Fe2+ sites on the surface of the nanoparticles. The presence of Fe2+/Fe3+ ions are determined using operando ATR—FTIR spectroscopy, by analyzing the adsorption of oxalic acid onto the surface of iron oxide nanoparticles. The sample subjected to low-heat treatment showed an improved effectiveness in absorbing the oxalic acid, which is related to the presence of Fe2+ sites. The photocatalytic process was further investigated using quantitative analysis methods, namely through kinetic studies. The observed kinetics followed a pseudo first- order model, with a rate constant of 0.010 M−1S−1. The low heat-treated nanoparticles shows greater photocatalytic rate constant and these results highlight the efficient and quick degradation capabilities of these nanoparticles. [ABSTRACT FROM AUTHOR]

In recent years, electronic devices with trendy flexibility and compatibility have become the competitive alternative to conventional electronics. In the present work, flexible polymer nanocomposite films composed of poly(vinylidene fluoride-co-hexafluoropropylene), iron oxide, and strontium titanate (PVDF-HFP/SrTiO3/Fe2O3) were synthesized by the solution-casting method. The formation and structural features of this composite material have been analyzed by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric (TGA), and SEM. SEM results confirm the homogeneous dispersion of SrTiO3 and Fe2O3 within the host polymer. The uniform dispersion of the embedded metal species enhances the dielectric values up to 462 on optimization with infused rigidity. The impedance studies of PVDF-HFP/SrTiO3/Fe2O3 were performed in the temperature region of 50–150 °C at various frequencies ranging from 50 Hz to 10 MHz and the AC conductivity studies suggested that synthesized polymer nanocomposite shows higher conductivity with the maximum conductivity value was 8.20 × 10−3S/m. Polymer nanocomposite films with large dielectric constant and minimum dielectric loss are highly recommendable for flexible energy storage applications. Also, rapid development of novel material for flexible electronics is in great demand, which suggests it is an alternate source for future energy storage application. [ABSTRACT FROM AUTHOR]

Iron oxide-modified 1Pd0.5Fe and 1Pd10Fe catalysts with a target content of 1 wt % Pd and 0.5 or 10 wt % Fe have been synthesized by the wet impregnation of Al2O3 with iron and palladium nitrates. The catalysts have been compared with each other and with a monometallic 1Pd catalyst in diclofenac (DCF) hydrodechlorination (HDC) in dilute aqueous solutions at 30°C in batch and flow reactors after high-temperature (320°C) and mild reduction (30°C), the latter being run in a batch or flow reactor. X-ray photoelectron spectroscopy (XPS) has revealed that, after reduction at 320°C, the catalysts contain mostly Pd0, Fe2+, and Fe3+. The Fe2+/Fe3+ ratio on the surface increases with a decrease in the iron content. The reduction of Pd2+ to Pd0 can occur even at 30°C; however, on the 1Pd0.5Fe surface, it is significantly less effective than that on 1Pd10Fe. According to XPS, temperature-programmed reduction, and diffuse reflectance infrared Fourier transform spectroscopy of adsorbed CO, modification with iron oxides leads to an increase in the palladium content on the surface compared with that on 1Pd, contributes to the formation of new Pd–O–Fe sites, and affects the reducibility of palladium. These effects enhance with an increase in the iron content. The iron-modified catalysts reduced at 320°C exhibit similar activity and stability in DCF conversion in flow and batch systems. The 1Pd10Fe catalyst, unlike 1Pd0.5Fe, is highly efficient and stable even after mild reduction at 30°C. Under flow conditions, it provides a DCF conversion comparable to that provided by 1Pd and a selectivity in the DCF HDC reaction that is higher than that provided by 1Pd, which is also active in hydrogenation. [ABSTRACT FROM AUTHOR]

The objective of this research is to manufacture new filter pellets based on polyacrylamide (PAM) activated carbon (GAC), iron oxide (Fe2O3), zinc oxide (ZnO) and kaolin and to evaluate their effectiveness in removing chromium and nickel from water. The synthesized filter pellets were characterized by FTIR, XRD and X-ray fluorescence. The XRF validation method would involve known amounts of chromium and nickel being retained by the filter pellets. the application of XRF gave precise measurements of the concentrations of Cr(VI) and Ni(II) fixed in the filter pellets. It was found that the values of the retention rates of Cr(VI) ions are higher in comparison with Ni(II) ions .The inclusion of inorganic additives influences the ability of filter pellets (FP) to retain Cr(VI) and Ni(II). FP2 (ZnO) showed reduced retention for both ions in comparison to FP1 (Fe2O3) and FP3 (Kaolin). FP3 (Kaolin) displayed better retention capacities for Cr(VI) and Ni(II) ions. The conductometric approach was also used to evaluate the retention of ions by the filter pellets. Comparing the conductivity of the feed solution with that of the filtered solution and the comparison between the different materials provided information on the most effective filter pellets for this purpose. [ABSTRACT FROM AUTHOR]

The work reported here deals with fabricating iron oxide nanoparticles incorporated polyvinyl alcohol nanocomposite films via the solution‐casting green route, characterized using various characterization techniques. X‐ray diffraction analysis shows interaction of nanoparticles with the polyvinyl alcohol matrix, scanning electron microscopy shows surface morphology of crack‐free films, energy dispersive spectroscopy indicates elemental purity, tensiometer analysis shows changing behavior of hydrophilic to hydrophobic, thermogravimetric analysis shows improved thermal stability, ultraviolet‐visible spectroscopy shows tunable optical properties, and frequency response analysis shows improved electrical properties. A small incorporation (1 wt. %) of iron oxide nanoparticles has induced significant alternations in structural, wetting, thermal, optical, and electrical properties of the polyvinyl alcohol‐based nanocomposite films. Results showed notable changes in the structural phases, water contact angle (39.5° to 97.7°), optical absorption edge (5.12 eV to 4.84 eV), indirect band gap (4.99 eV to 4.68 eV), direct bandgap (5.41 eV to 5.21 eV), and band tail (0.57 eV to 0.89 eV) from native polyvinyl alcohol to polyvinyl alcohol/iron oxide nanocomposite films. Enhancements were observed in refractive indices, optical conductivity, optical dielectric loss, thermal stability, dielectric constant, and dielectric loss on incorporating iron oxide nanoparticles into the polyvinyl alcohol matrix. The fabricated nanocomposite films might be a potential material for optoelectronic and microelectronics applications. [ABSTRACT FROM AUTHOR]

The iron industry is the largest energy-consuming manufacturing sector in the world, emitting 4–5% of the total carbon dioxide (CO2). The development of iron-based systems for CO2 capture and storage could effectively contribute to reducing CO2 emissions. A wide set of different iron oxides, such as hematite (Fe2O3), magnetite (Fe3O4), and wüstite (Fe(1−y)O) could in fact be employed for CO2 capture at room temperature and pressure upon an investigation of their capturing properties. In order to achieve the most functional iron oxide form for CO2 capture, starting from Fe2O3, a reducing agent such as hydrogen (H2) or carbon monoxide (CO) can be employed. In this review, we present the state-of-the-art and recent advances on the different iron oxide materials employed, as well as on their reduction reactions with H2 and CO. [ABSTRACT FROM AUTHOR]

The synthesis of novel catalysts for the oxygen reduction reaction, by means of a fast one-pot microwave-assisted procedure, is reported herein and deeply explained. In particular, the important role of doping atoms, like sulfur and nitrogen, in Fe2O3-reduced graphene oxide nanocomposites is described to address the modification of catalytic performance. The presence of dopants is confirmed by X-ray Photoelectron Spectroscopy analysis, while the integration of iron oxide nanoparticles, by means of decoration of the graphene structure, is corroborated by electron microscopy, which also confirms that there is no damage to the graphene sheets induced by the synthesis procedure. The electrochemical characterizations put in evidence the synergistic catalysis effects of dopant atoms with Fe2O3 and, in particular, the importance of sulfur introduction into the graphene lattice. Catalytic performance of as-prepared materials toward oxygen reduction shows values close to the Pt/C reference material, commonly used for fuel cell and metal–air battery applications. [ABSTRACT FROM AUTHOR]

A consensus has not yet been reached on effects of climate change and driving mechanisms between the Tibetan Plateau (TP) and adjacent monsoonal areas during the Marine Isotope Stage 3 (MIS 3). Loess–paleosol sequences from the TP provide valuable information about the MIS 3 environmental history. Detailed color index and a diffuse reflectance spectral (DRS) analysis of Zhouqu (ZQ) loess from the Western Qinling Mountains were conducted to investigate climate change on the eastern margin of the TP during the MIS 3. Our results show that the variations in color index and iron oxide content in ZQ loess are mainly caused by the pedogenesis and climate conditions. The lightness (L*) value and hematite (Hm) content were used to reconstruct the precipitation history and temperature changes, respectively. The reconstructed records revealed that climate change during the MIS 3 was characterized by high frequency and large amplitude, with millennial-scale changes superimposed on orbital-scale changes. Warm–humid climate occurred in the late MIS 3, while the early climate of MIS 3 was relatively cold–dry. The Indian summer monsoon (ISM) and temperature variations during the MIS 3 mainly occurred due to obliquity and precession. The North Atlantic cooling led to the southward movement of the Intertropical Convergence Zone, and the downstream cooling of the atmosphere by the westerly jet could result in events on a millennial-scale in the eastern margin of the TP. The interhemispheric forcing may play an important role in driving the strong summer monsoon in the late MIS 3. [ABSTRACT FROM AUTHOR]

Standard materials are often used to obtain spectra that can be compared to those from unknown samples. Spectra measured from these known substances are also used as a means of computing sensitivity factors to allow quantification by X‐ray photoelectron spectroscopy (XPS) of less well‐defined materials. Spectra from known materials also provide line shapes suitable for inclusion in spectral models which, when fitted to spectra, permit the chemical state for a sample to be assessed. Both types of information depend on isolating photoemission signals from the inelastically scattered signal. In this Insight note, technical issues associated with the use of XPS of as received Fe3O4 powder sample surface are discussed. The Insight note is designed to show how linear algebraic techniques applied to data collected from a sample marketed as pure Fe3O4 powder are used to verify that XPS has been performed on chemistry representative of the sample. The methods described in this Insight note can further be utilized in elucidating complex XPS data obtained from thin films formed or evolved during cyclic/non‐steady use of complex (electro)catalyst surfaces, especially in the presence of contaminants. [ABSTRACT FROM AUTHOR]

Iron oxide-based ferrite ceramics, widely applied in high-frequency applications, are conventionally produced through high-temperature sintering processes, often resulting in grain growth and phase transformation. In this study, we used a cold sintering process (CSP) with oxalic acid (OA) as a solvent to consolidate iron oxide (Fe 3 O 4) ceramics at a low temperature of 160 °C. The OA-assisted CSP technique has demonstrated a remarkable capacity to facilitate the dissolution and redeposition of iron oxide ions, leading to the interconnection of Fe 3 O 4 particles, forming densely packed ceramics even at low-temperature sintering. Importantly, CSP maintained particle sizes and hindered phase transitions of Fe 3 O 4. The OA concentrations in CSP had a minimal impact on crystal structure and magnetic properties, but it significantly enhanced microstructural features, density, hardness, and electrical resistance. Compared to reference samples prepared without an aqueous solution or with water alone, the CSP-prepared Fe 3 O 4 ceramics with OA exhibited substantially improved density (a relative density of ∼80 %), mechanical properties (Vickers hardness of 3.5–4.0 GPa), magnetic properties (saturation magnetization >70 emu/g), and electrical resistance (electrical conductivity ∼10−3 S/cm at 102–106 Hz). These findings demonstrate a novel approach to fabricating Fe 3 O 4 ceramics at significantly lower temperatures while still achieving properties comparable to those sintered at high temperatures. [ABSTRACT FROM AUTHOR]

Hyaluronic acid (HA) has attracted much attention in tumor-targeted drug delivery due to its ability to specifically bind to the CD44 cellular receptor, which is widely expressed on cancer cells. We present HA-capped magnetic nanoparticles (HA-MNPs) obtained via the co-precipitation method, followed by the electrostatic adsorption of HA onto the nanoparticles' surfaces. A theoretical study carried out with the PM3 method evidenced a dipole moment of 3.34 D and negatively charged atom groups able to participate in interactions with nanoparticle surface cations and surrounding water molecules. The ATR-FTIR spectrum evidenced the hyaluronic acid binding to the surface of the ferrophase, ensuring colloidal stability in the water dispersion. To verify the success of the synthesis and stabilization, HA-MNPs were also characterized using other investigation techniques: TEM, EDS, XRD, DSC, TG, NTA, and VSM. The results showed that the HA-MNPs had a mean physical size of 9.05 nm (TEM investigation), a crystallite dimension of about 8.35 nm (XRD investigation), and a magnetic core diameter of about 8.31 nm (VSM investigation). The HA-MNPs exhibited superparamagnetic behavior, with the magnetization curve showing saturation at a high magnetic field and a very small coercive field, corresponding to the net dominance of single-domain magnetic nanoparticles that were not aggregated with reversible magnetizability. These features satisfy the requirement for magnetic nanoparticles with a small size and good dispersibility for long-term stability. We performed some preliminary tests regarding the nanotoxicity in the environment, and some chromosomal aberrations were found to be induced in corn root meristems, especially in the anaphase and metaphase of mitotic cells. Due to their properties, HA-MNPs also seem to be suitable for use in the biomedical field. [ABSTRACT FROM AUTHOR]

The phase equilibria of the ZnO-"FeO 1..5 ", ZnO-"FeO 1.5 "-SiO 2 , PbO–ZnO-"FeO 1.5 " and PbO–ZnO-"FeO 1.5 "-SiO 2 slag systems in equilibrium with air or metallic lead/iron were studied as part of the investigation of the 19-component PbO–ZnO–Cu 2 O–FeO–Fe 2 O 3 –CaO–SiO 2 –Al 2 O 3 –MgO–S-(As, Sn, Sb, Bi, Ag, Au, Ni, Cr, Co as minor elements) slag/matte/metal/speiss/gas system, supporting the operation/development of existing and emerging pyrometallurgical processes. In the experimental part of the study, samples underwent high temperature equilibration followed by quenching, and the direct measurement of the lead, zinc, iron and silicon concentrations in the liquid slag, solid oxide, and metal phases by electron probe microanalysis (EPMA). The a) massicot (PbO), b) spinel ((Zn, Fe)Fe 2 O 4), c) zincite ((Zn,Fe)O 1+x , 2 polymorphs), d) lead ferrite (Pb 2+x Fe 2 O 5+x), e) plumboferrite (Pb 4 Fe 22-x Zn x O 37), f) magnetoplumbite (Pb(Fe 2 O 3 ,PbFeO 2 ,PbZnO 2)Fe 10 O 16), and g) W-ferrite (PbZn 2-x Fe 16+x O 27) primary phase fields of the PbO–ZnO-"FeO 1.5 " system in equilibrium with air were studied between 780 and 1300 °C. The ZnO-"FeO 1.5 ", ZnO-"FeO 1.5 "-SiO 2 and PbO–ZnO-"FeO 1.5 "-SiO 2 systems in equilibrium with air were studied up to 1745 °C, significantly improving the availability of information on the composition range of the high- and low-Fe zincite ((Zn,Fe)O 1+x) phases, and on the liquid slag composition at the boundaries of their primary phase fields. Lastly, the solubilities of iron in larsenite (Pb(Zn,Fe)SiO 4) and melilite (Pb 2 (Zn,Fe)Si 2 O 7) in equilibrium with air or metal were studied between 700 and 800 °C. The newly obtained and existing experimental data were used to develop a self-consistent set of thermodynamic parameters describing all phases in the system using the FactSage computer package. [ABSTRACT FROM AUTHOR]

Nanocrystalline cellulose (NCC) can be converted into carbon materials for the fabrication of lithium-ion batteries (LIBs) as well as serve as a substrate for the incorporation of transition metal oxides (TMOs) to restrain the volume expansion, one of the most significant challenges of TMO-based LIBs. To improve the electrochemical performance and enhance the longer cycling stability of LIBs, a nanocrystalline cellulose-supported iron oxide (Fe2O3) composite (denoted as NCC–Fe2O3) is synthesized and utilized as electrodes in LIBs. The obtained NCC–Fe2O3 electrode exhibited stable cycling performance, better capacity, and high-rate capacity, and delivered a specific discharge capacity of 576.70 mAh g−1 at 100 mA g−1 after 1000 cycles. Moreover, the NCC–Fe2O3 electrode was restored and showed an upward trend of capacity after working at high current densities, indicating the fabricated composite is a promising approach to designing next-generation high-energy density lithium-ion batteries. [ABSTRACT FROM AUTHOR]

This study comprehensively investigated the effect of iron-oxide nanoparticles (NPs) on weathering durability and thermal resistance of wood-plastic composites (WPCs). The hydrophobic nature of NPs improved the dimensional stability of WPCs. The small size of NPs deposits the voids in the matrix, which helps to increase the mechanical properties, even after weathering test. The decrease of modulus of rupture (MOR) reached up to 16% for control samples, while it was 2% for IO40-1. Despite the intensive weathering conditions, NPs cover the surface of materials like a UV shield, improving WPCs' UV resistance. Moreover, the increase in the wood and NPs content limited the UV degradation, which resulted in lower color changes. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) analysis also proved that there were nearly no changes in the characteristic bands of polymer (2916 and 2846 cm−1) and wood (1512 cm−1). The microscopic investigation, however, revealed the deterioration on the surface of WPCs after weathering exposure. Even though UV degradation is inevitable, iron oxide NPs significantly preserved the WPCs surface. However, there were also crack formations, which were also inhibited. On the other hand, NPs decelerated the thermal degradation by acting as a heat barrier. Thermogravimetric analysis (TGA) analysis revealed an increase in the degradation temperature. Limit oxygen index (LOI) values also increased up to 27.6%, which demonstrated an improvement against flammability. [ABSTRACT FROM AUTHOR]

Phosphorus is a limiting factor for eutrophication while also an important nonrenewable resource. Adsorption is one of the most efficient phosphorus pollution control technologies and phosphorus recovery can be promisingly achieved after desorption. The use of iron oxides as adsorbents to remove phosphorus has been extensively studied, due to merits of high adsorption capacity, high selectivity, as well as environmental benign. However, their effectiveness and feasibility in practical applications are still challenged. This review summarized the current achievements of using iron oxides and their modified products to remove phosphorus from wastewater. Phosphorus removal mechanisms and strategies for improving the performance of different types of iron oxide-based adsorbents were summarized. Moreover, the potential methods of phosphorus desorption and subsequent recovery were summarized. Finally, the future challenges on the practical application of iron oxides in phosphorus recovery from wastewater were discussed. This review might provide guidance for the development and application of adsorption-based phosphorus recovery technology. [ABSTRACT FROM AUTHOR]

The composition and magnetic properties of foraminifers from bottom sediments of the Mid-Atlantic Ridge and their artificial analogs obtained by hydrothermal synthesis were studied. The presence of magnetic hysteresis and theoretical modeling of hysteresis characteristics made it possible to assume the presence of grains of nonstoichiometric magnetite in single- and few-domain states. [ABSTRACT FROM AUTHOR]

Magnetic iron oxide nanoparticles immobilized on microcrystalline cellulose (MCC) are studied for the adsorption of Pb(II) ions from an aqueous solution. Composites of iron oxide and MCC were synthesized with a 5%–20% loading of iron (w/w%). The effect of pH, concentration, and contact time was studied. The adsorption isotherms were fitted to nonlinear Langmuir, Freundlich, and Dubinin–Radushkevich (D‐R) isotherms, and kinetics were studied for pseudo‐first and second‐order kinetic fit models. Adsorption of Pb(II) ions increased with increasing pH value up to 5. Maximum adsorption of Pb(II) was observed up to 299.91 mg−1 in D‐R equilibrium for onto MCC‐Iron oxide composite for composite with iron loading of 20% at pH 5. [ABSTRACT FROM AUTHOR]

Root-to-shoot translocation of nanoparticles (NPs) is a matter of interest due to their possible unprecedented effects on biota. Properties of NPs, such as structure, surface charge or coating, and size, determine their uptake by cells. This study investigates the size effect of iron oxide (Fe3O4) NPs on plant uptake, translocation, and physiology. For this purpose, Fe3O4 NPs having about 10 and 100 nm in average sizes (namely NP10 and NP100) were hydroponically subjected to barley (Hordeum vulgare L.) in different doses (50, 100, and 200 mg/L) at germination (5 days) and seedling (3 weeks) stages. Results revealed that particle size does not significantly influence the seedlings' growth but improves germination. The iron content in root and leaf tissues gradually increased with increasing NP10 and NP100 concentrations, revealing their root-to-shoot translocation. This result was confirmed by vibrating sample magnetometry analysis, where the magnetic signals increased with increasing NP doses. The translocation of NPs enhanced chlorophyll and carotenoid contents, suggesting their contribution to plant pigmentation. On the other hand, catalase activity and H2O2 production were higher in NP10-treated roots compared to NP100-treated ones. Besides, confocal microscopy revealed that NP10 leads to cell membrane damages. These findings showed that Fe3O4 NPs were efficiently taken up by the roots and transported to the leaves regardless of the size factor. However, small-sized Fe3O4 NPs may be more reactive due to their size properties and may cause cell stress and membrane damage. This study may help us better understand the size effect of NPs in nanoparticle-plant interaction. [ABSTRACT FROM AUTHOR]

Separation and mapping of alteration zones is of special importance in the exploration of porphyry copper types. In order to highlight these alteration zones, remote sensing techniques have been applied. Zafarghand region is located in the southeast of Ardestan and northeast of Isfahan. Based on the division of geological structural zones, it is located in the Central Iran zone and also in the middle part of Urmia-Dokhtar magmatic volcanic arc. In this area, there are different alteration halos, including phyllic, potassic, propylitic, argillic, and slightly siliceous. In this study, argillic, phyllic, propylitic, and clay alterations have been identified using ASTER sensor images. Moreover, LANDSAT 8 images have been employed to identify clay and iron oxide alterations. In this regard, after performing the necessary pre-processing, methods of False Color Combination (FCC), Band Ratio (BR), Least Squares-Fit (LS-Fit), Matched Filtering (MF), and Principal Combination Analysis (PCA) were applied to reveal the zones containing these alterations. Among the applied methods, the LS-Fit and MF in Aster images, as well as the BR method in both images, and the PCA method in Landsat 8 have brought good results. [ABSTRACT FROM AUTHOR]

In the present study, low-cost iron oxide catalysts have been prepared by a simple precipitation method using tin food can waste as a source of iron and sodium hydroxide or ammonium hydroxide solution as a precipitating agent. The prepared catalysts were characterized by thermogravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD), FT-IR spectra, scanning electron microscopy (SEM), EDAX quantitative elemental analysis, and BET surface area measurements. Surface basicity of iron oxide catalysts was measured by adsorption of carbon dioxide as an acidic probe molecule, followed by desorption measurements using the TGA technique. The prepared iron oxide catalysts were tested by dehydrogenation of 2-butanol to methyl ethyl ketone (MEK) at a temperature range of 275–375 °C. Commercial iron oxide was tested under identical reaction conditions for comparison with the prepared catalysts. The results indicated the superiority of the prepared catalysts over the commercial one and the superiority of the catalyst prepared using NaOH over that prepared using NH4OH as precipitating agents. The use of different precipitating agents affects the surface morphology and, consequently, the catalytic activity of the produced iron oxide catalysts. [ABSTRACT FROM AUTHOR]

Here, amino acids-functionalized iron oxide nanoparticles were synthesized by utilizing the co-precipitation methodology. The synthesized nanoparticles (including alanine, valine, and phenylalanine-functionalized nanoparticles) were characterized by utilizing several analytical techniques. Acquired outcomes validated the successful formation of amino acid-functionalized iron oxide nanoparticles. The X-ray diffraction and scanning electron microscopy indicated that phenylalanine-based iron oxide nanoparticles exhibited high crystallinity and better fabrication, respectively, in comparison with other amino acids. This was attributed to the development of high hydrophobic interactions of the phenylalanine with the iron oxide nanoparticles. The photocatalytic efficacy of the iron oxide nanoparticles against the methylene blue was investigated by implementing two different optimization strategies (i.e., traditional one-variable-at-a-time kinetics and advanced response surface methodology). The experiment performed by using phenylalanine-functionalized iron oxide nanoparticles as a photocatalyst under optimized conditions revealed that the highest efficacy of 92.91 and 97.12% was obtained by using the one-variable-at-a-time and response surface methodology approaches, respectively, indicating that the latter approach is more effective for the optimization of the understudy reactions. In terms of comparative effectiveness of the reaction parameters, the photocatalyst dose was found to be the most effective emphasizing that special emphasis should be given to this parameter when dealing with the optimization of this reaction on an industrial scale. The total organic carbon analysis further revealed that the mineralization of 90.216% was achieved under optimized reaction conditions. The prepared iron oxide nanoparticles exhibited strong photocatalytic potential for the understudy chemical reaction. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles have been attracted extensively due to their supermagnetic properties, preferred in biomedicine because of their biocompatibility and potential nontoxicity to human beings. Synthesis of iron nanoparticles (FeNPs) was prepared with the help of ferric chloride and ferrous sulphate by using the coprecipitation method. The variation and combination of ferric and ferrous concentrations affect the physical and magnetic properties of iron oxide nanoparticles. The effect of 0.1 M ferric and ferrous concentration on iron oxide nanoparticles was studied separately and in combination. The obtained nanoparticles were characterized by Particle size, zeta potential, Ultraviolet (UV-visible), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Thermal gravimetric analysis (TGA), and Vibratingsample magnetometer (VSM) techniques. Particle size was below 200 nm and zeta potential was within the limit for all the batches. UV visible spectra at 224 nm, and FTIR exhibit two peaks at 510 and 594 cm-1, indicating iron oxide NPs and XRD confirmed the crystalline nature of Fe. SEM showed a spherical shape for all batches. The use of a combination of ferric and ferrous is more effective than its individual use. TGA and VSM studies confirmed its magnetic properties. [ABSTRACT FROM AUTHOR]

Development of sustainable routes for nanoparticle synthesis is one of the important research issues in waste management. Herein, we synthesized the nano iron oxide-cubic (NIO-C) nanoparticles from iron waste sludge for application as additive in polyethylene glycol (PAG46) lubricant. X-ray diffraction (XRD) evidenced the presence of maghemite as a dominant phase of the NIO-C nanoparticles, having (311) crystallographic plane at the diffraction angle of 35.27°. High-resolution transmission electron microscopy (HR-TEM) confirmed the presence of cubic maghemite of ~ 20 nm in size. The NIO-C nanoparticles served as the additive in the PAG46 lubricant, showing a decrease in the coefficient of friction by 46% at 25 °C and by 36% at 80 °C. Reducing the coefficient of friction was assigned to the cubic NIO-C fractions, enhancing the smoothness of the metal plates. This study describes economic and environmentally sustainable method for producing cubic maghemite nanoparticles. [ABSTRACT FROM AUTHOR]

Sol-gel derived nano-composites silica-gel doped with different iron oxide concentrations at (3.5, 11, 33 and 37 mol. %) sintered at constant temperature at 1170°C, are illustrated in this work. Structure, surface morphology, high frequency dielectric and magnetic trends of the mentioned nano-composites analyzed and investigated through XRD, UV-Vis, TEM, FESEM and Magnetic hysteresis curves. Raman micro-spectroscopy gives rise to samples homogenous distribution. XRD illustrate that the Hematite (α-Fe2O3) is the optimum phase rather than the Maghemite (γ-Fe2O3) and Magnetite (Ԑ- Fe2O3). Big amount of Hematite (α-Fe2O3) crystalline nano-particles are expected at 37 mol. % of Fe2¬O3. XRD confirmed that the average crystallite size increased from (25-31) nm with increasing the concentration of (α-Fe2O3) from 3.5 up to 37 mol%. The A.C. conductivity σac increased by increasing the α-Fe2O3 content, according to the presence of oxygen vacancy and the crystalline size increases. The decreasing behavior in magnetization value (Ms) is related to the changes of the crystallite size, magnetic iron oxide particles and concentration. All analysis explains Hematite is extremely stable at ambient conditions and at high temperatures, so it is the better for particular applications.

Organonitrates (ON) and nitroxy-organosulfates (NOS) are important components of secondary organic aerosols (SOAs). Gas-phase reactions of α-pinene (C10H16), a primary precursor for several ON compounds, are fairly well understood although formation pathways for NOS largely remain unknown. NOS formation may occur via reactions of ON and organic peroxides with sulfates as well as through radical-initiated photochemical processes. Despite the fact that organosulfates (OS) represent a significant portion of the organic aerosol mass, ON and NOS formation from OS is less understood, especially through nighttime heterogeneous and multiphase chemistry pathways. In the current study, surface reactions of adsorbed α-pinene-derived OS with nitrogen oxides on hematite and kaolinite surfaces, common components of mineral dust, have been investigated. α-Pinene reacts with sulfated mineral surfaces, forming a range of OS compounds on the surface. These OS compounds when adsorbed on mineral surfaces can further react with HNO3 and NO2, producing several ON and NOS compounds as well as several oxidation products. Overall, this study reveals the complexity of reactions of prevalent organic compounds leading to the formation of OS, ON, and NOS via heterogeneous and multiphase reaction pathways on mineral surfaces. It is also shown that this chemistry is mineralogy-specific.

Aqueous rechargeable batteries (ARBs) are generally safer than non-aqueous analogues, they are also less-expensive, and more friendly to the environment. However, the inherent disadvantage of the narrow electrochemical window of H2O seriously restricts the energy density and output voltage of ARBs, especially aqueous rechargeable Fe-based batteries. Herein, we introduce a new battery system: the anode contains C@Fe/Fe2O3 composite, which is interfaced with an alkaline electrolyte; the cathode contains LiMn2O4 in contact with a neutral electrolyte. A Li+-conducting membrane is carefully selected to decouple the electrode-electrolyte, which effectively widens the electrochemical window to above 2.65 V, thereby enables an aqueous rechargeable iron battery. Its average output voltage is 1.83 V and its energy density is 235.3 Wh/kg at 549 W/kg. In this work, we propose the energy storage mechanism with the aid of density functional theory (DFT). The calculated reduction potential of the anode agrees with the experimental value. Furthermore, this battery system demonstrates long cycle lifespan of approximately 2500 cycles at 2 A/g, corresponding to a capacity retention of 82.1%. These results are very far superior than those of mainstream aqueous rechargeable Fe-based batteries, which guarantee future investigation for storing electricity energy. [ABSTRACT FROM AUTHOR]

The demand for a facile approach for synthesizing multifunctional nanocomposites is increasingly vital across diverse applications. In this study, a polymerizable sol–gel synthesis has been reported to obtain nanocomposites of magnetic iron oxide deposited over alumina nanopowder. The synthesis is mediated by the deposition of a calculated amount of iron(III) methacrylate, along with ethylene glycol dimethacrylate crosslinker, over alumina nanopowder, followed by thermally-inducing free radical polymerization at 125 °C for 30 min. The powder thus obtained has been subjected to calcination at 400 °C for 150 min and the resultant nanocomposites were characterized using wide-angle x-ray scattering, attenuated total reflectance—Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, field-emission scanning electron microscopy, ultraviolet-diffuse reflectance spectroscopy, vibrating sample magnetometer and Brunauer–Emmett–Teller surface area measurements. The nanocomposites containing 15 and 20 wt% of iron oxide have been found to exhibit a saturation magnetization (M s) value ranging from 12 to 14 emu g−1. To the nanocomposite containing 20 wt% of iron oxide, 5 wt% of AgBr was loaded through thoroughly mixing a surfactant-based precursor, silver-tetraoctyl ammonium bromide (Ag-TOAB), followed by thermolysis. All the nanocomposites have been studied for their antibacterial activity against a representative gram-negative bacterium, Escherichia coli, under dark and visible light conditions. While a 3 mg ml−1 loading of the AgBr-loaded nanocomposite has exhibited complete clearance of the bacterial growth by 90 min in the dark, a similar activity has been observed in 60 min under light. The study has revealed the multifunctionality and high potential of the AgBr-loaded iron oxide/alumina nanocomposite as a promising dual-mode antibacterial and magnetically recoverable photocatalyst material. [ABSTRACT FROM AUTHOR]

Nickel isotope fractionation during continental weathering is not well constrained due to the limited research on Ni isotopes during weathering of mafic rocks such as basalt. This study investigated two weathering profiles (strongly and extremely weathered) derived on basalts in tropical China. The strongly weathered profile was dominated by kaolinite and divided into three layers with depth (soil, saprolite and rock). The extremely weathered profile was mainly composed of Fe- and Al-(oxyhydr)oxides and kaolinite, and included a special ferricrust layer, iron-rich duricrust with ferruginous nodules, between the soil and saprolite. We analysed the Ni speciation (e.g. Fe-oxide phases and residual phase) and isotopic composition of soil, ferricrust, saprolite, rock and water samples in the weathering profiles. Pore water and groundwater were collected underlying the extremely weathered profile, and the size-distribution of particulate Ni (1 kDa–450 nm) in water samples was analysed. Nickel in both profiles was mainly hosted in the residual phase (>71% of total Ni) which included primarily secondary silicates and Al-(oxyhydr)oxides. Weathering intensity controlled the mineral compositions and physico-chemical properties of the weathering profiles as well as Ni isotopic variations. Nickel redistribution (∼30%) and isotope fractionation (Δ60Ni regolith-rock = −0.08‰ to 0.07‰) were slight in the strongly weathered profile due to the dominance of secondary silicates in Ni speciation. For the extremely weathered profile, significant Ni depletion (∼67%) and isotope fractionation (Δ60Ni regolith-rock = −0.25‰ to 0.32‰) were related to the transformation of secondary silicates into Fe- and Al-(oxyhydr)oxides during lateritic weathering. The positive correlation of δ60Ni and Ni concentrations indicated that Ni isotope fractionation was controlled by Ni adsorption and incorporation of secondary minerals. In the lower saprolite, the calculated isotope fractionation between Ni remaining in the profile and leaching to the solution (Δ60Ni solid-solution = −0.47‰) indicated that Ni isotope fractionation was mainly controlled by the preferential adsorption of isotopically light Ni on Fe- and Al-(oxyhydr)oxides. However, in the soil and ferricrust, acidic pH (∼5.0) might reduce Δ60Ni solid-solution to −0.28‰ by releasing the isotopically light adsorbed Ni, leading to the predominance of incorporated Ni in Fe- and Al-(oxyhydr)oxides. Specifically, the highest δ60Ni value (0.27 ± 0.05‰) and Ni concentration in the upper saprolite indicated that the isotopically heavy Ni leached from the soil and ferricrust was scavenged by precipitating secondary silicates. Finally, the estimated isotopic composition of Ni leached from the extremely weathered profile (δ60Ni output = 0.02 ± 0.15‰) was close to that of pore water (0.06 ± 0.01‰) where Ni was mainly present in the particulate phase. Compared with groundwater (δ60Ni = 0.33 ± 0.04‰) dominated by dissolved Ni, Ni output from the profile likely consisted of isotopically heavy dissolved Ni and light particulate Ni. Overall, this study provides a comprehensive understanding of Ni redistribution and speciation in basalt weathering profiles, highlighting the significance of weathering intensity in controlling Ni isotope fractionation and its implications for Ni outputs from continental weathering. [ABSTRACT FROM AUTHOR]

This work designed a mesoscale method of multi-step reduction of Fe 2 O 3 with H 2 based on Lattice Gas Cellular Automata (LGCA). Particles in the LGCA were marked to distinguish all the reactants, intermediates, products, and inert. A self-organized evolutionary mechanism is designed. The hydrogen reduction of Fe 2 O 3 in the temperature range of 460–550 °C and 650–800 °C was simulated. Results show that the intermediate product Fe 3 O 4 was found in both conditions, and its mass fraction quickly reach a peak at ∼0.8 and gradually decrease thereafter. An "induction period" can be identified in the initial stage of the reaction at 650–800 °C, where the reduction rate is slow due to the hindered formation of FeO. The porosity inside the Fe 2 O 3 particles increases continuously through the reduction process, resulting in significant changes in the flow field around the particles. Consequently, the wake vortex gradually decreases and disappears eventually. • The multiple step reduction of Fe 2 O 3 by hydrogen is investigated in mesoscale. • A mesoscale method with self-organized evolutionary mechanism is developed. • Three obvious reaction rate transitions can be identified at 650–800 °C by the method. • The flow field is altered from internal structural of Fe 2 O 3 changes during reduction. [ABSTRACT FROM AUTHOR]

Organometallic complexes of transition metals with inorganic anions are considered as promising precursors for the synthesis of nanoscale materials used in various applications including chemical catalysis. In this work, organometallic complexes of nickel, iron, and copper with imidazole as an organic ligand and the nitrate anion as an inorganic ligand were synthesized and characterized. The kinetic parameters of thermal decomposition of the synthesized organometallic complexes were determined by low heating-rate thermogravimetric analysis and high-speed dynamic mass spectrometric thermal analysis. The main gaseous products of thermal decomposition of the complexes under high-speed heating were identified. The chemical and phase compositions of condensed combustion products of the organometallic complexes in air were studied. [ABSTRACT FROM AUTHOR]

The establishment of a new metallurgical complex in Bellara, located in El-Milia in the Jijel region, is geographically advantageous due to its proximity to the Sidi Maarouf deposit (Algeria). This proximity has been a fundamental motivation for the completion of the current study. The object of research is the quality of iron products from Sidi Maarouf. The research is aimed at developing a treatment process aimed at improving the quality of iron products from Sidi Maarouf, while reducing the impurities of quartz and clay present in this ore. This approach will be based on an approved technological treatment scheme, implemented through an experimental approach to ensure reliable results that meet the requirements of the steel industry. The problem issue revolves around the difficulties encountered in the production of steels due to the natural characteristics of the raw material. In the absence of a physico-chemical characterization of the Sidi Maarouf iron ore deposit, samples taken undergo a series of thorough analyses, including microscopic examinations, X-ray diffraction (XRD), as well as additional chemical analyses using X-ray fluorescence (XRF). The identified minerals are predominantly composed of hematite in terms of iron. As for the gangue, it is mainly composed of calcite and quartz. Through to the pretreatment process involving washing, we have successfully removed lightweight particles, resulting in a concentrate containing dense particles. This approach was crucial in achieving satisfactory results during the high-intensity dry magnetic separation. As a result of the research it is shown that the enrichment of the Sidi Maarouf iron ore through high-intensity dry magnetic separation, a final concentrate was obtained with a Fe2O3 content exceeding 67 %, along with a significant reduction in silica impurities to 0.92 % and alumina to 0.77 %. It was concluded that this concentrate, derived from the –1+0.5 mm fraction and obtained under a current intensity of 12 A, meets the requirements of the steel industry. Following the work carried out, it is found that the methods of valorization of iron ore through mineralogical processes consistently require a high level of efficiency and performance in terms of equipment and characterization of the products obtained. In the future, iron ore processing will be conducted using innovative methods, integrating advanced technologies to enhance its characteristics while adopting environmentally friendly practices. [ABSTRACT FROM AUTHOR]

Magnetite quantum dots were synthesized by solvothermal method in a conventional reflux setup, in an inert environment, at different reaction temperatures and times. Powder X-ray diffraction patterns of the as-prepared iron oxide confirmed magnetite crystalline phases irrespective of the reaction conditions. TEM micrographs revealed that the iron oxides obtained at 200, 180 and 165 °C are spherical in shapes with mean particle sizes of 3.25, 3.3 and 3.90 nm respectively, showing an increase in particle size with decreasing temperature. TEM micrographs revealed that particles obtained at 6 and 3 h have a mean particle size of 3.25 nm while particles obtained at 4.5-h has a bigger mean particle size of 7.5 nm. The results show that irrespective of the synthetic parameters, the average particle sizes of the magnetite are in the range 3–8 nm and could be described as quantum dots. Optical absorption spectra of the as-prepared magnetite quantum dots exhibited maximum absorption in the range of 200–210 nm. Fe3O4-1, Fe3O4-2 and Fe3O4-3 synthesized at 200, 180 and 165 °C have energy band gaps of 5.49, 5.13 and 5.01 eV respectively, showing a decrease in band gap with decreasing temperature. Fe3O4-4 and Fe3O4-6 synthesized at 6 and 3 h have optical band gap of 5.44 eV while Fe3O4-5 synthesized at 4.5 h has a band gap of 3.75 eV. FTIR spectra confirmed the passivation of the surface of the as-prepared magnetite quantum dots by oleate. [ABSTRACT FROM AUTHOR]

Atomic force microscopy (AFM) and spectral induced polarization (SIP) are widely used to investigate the electrical properties of mineral surfaces at vastly different scales of measurement. We compare AFM and SIP measurements made on two different materials (glass beads and silica gel) subjected to etching, deposition of iron oxide particles, and inclusion of calcite grains. We found that the treatments produced qualitatively consistent behaviors in the AFM and SIP data. Direct AFM measurements of surface charge density for silica and calcite surfaces were quantitatively compared to values estimated from the SIP results using a grain polarization model. No statistically significant difference (at a 95% confidence level) was found between the surface charge density of silica estimated by AFM (2.3 ± 6.6 mC/m2 for glass beads and 1.6 ± 0.1 mC/m2 for silica gel) versus SIP (5.4 ± 4.4 mC/m2 for glass beads and 1.6 ± 0.5 mC/m2 for silica gel). The surface charge density for calcite determined by AFM (43.5 ± 12.9 mC/m2) was approximately 19 times higher than that found for silica. While the charge density of calcite surfaces determined by SIP was also generally higher than that found for silica, different treatments produced significantly different values between 4.7 and 258 mC/m2 (with a maximum 95% CI of ±8.7 mC/m2). Several possible explanations exist for the range of the observed SIP measurements, including aging of the calcite surfaces. Overall, this study suggests the potential for the complementary use of AFM and SIP measurements to constrain future investigations of polarization mechanisms in porous media. Plain Language Summary: The electrical properties of rock and mineral surfaces are sensitive to their physical and chemical environment and are therefore important for earth applications ranging from detecting minerals to monitoring microbial growth. In most environmental settings, these properties are controlled by ions that move through the open pore spaces between grains and along mineral surfaces, where they are more tightly bound to charged surfaces. Atomic force microscopy (AFM) provides a way to directly measure the charge present on a mineral surface, but makes measurements at a microscopic scale and is not practical for field investigations or monitoring real‐time experiments in porous media. In contrast, spectral induced polarization (SIP) can measure electrical properties averaged over volumes of earth in the lab or field, but it is not always clear what exactly is being measured by this geophysical measurement. We therefore compare AFM and SIP measurements for glass beads and silica gel subjected to different treatments (etching, iron oxide deposition, and calcite formation) to assess whether these two distinct measurements provide consistent responses to the modifications. We found that the two measurements qualitatively provide consistent measurement responses and quantitatively determine similar amounts of charge present on mineral surfaces for both silica and calcite. The study suggests the combined use of AFM and SIP could improve our understanding of electrical process in porous media across measurement scales. Key Points: Atomic force microscopy (AFM) and spectral induced polarization (SIP) provide consistent information on the electrical properties of mineral surfaces despite having vastly different scales of measurementA grain polarization model was used to obtain consistent estimates of the surface charge density from SIP and AFM measurements for silica and calciteThe surface charge of calcite is an important contributor to the electrical response of porous media [ABSTRACT FROM AUTHOR]

Nanoparticles have been shown to inhibit major life cycle stages of ticks, indicative of the promising application of nanomaterials against hard ticks. The study thus probed into one of the alternative options to curtail Hyalomma by employing nanocomposites consisting of pyrethroids (cypermethrin and deltamethrin) coated nanoparticles of iron oxides and iron sulfides keeping alongside the evaluation of their toxicity through plant and mammalian cell lines. The nanoparticles used in this study were roughly spherical in morphology and exhibited various size dimensions upon characterization using SEM, EDX, and FTIR. The application of nanomaterials on female ovipositioning tick showed a decline up to 15% (females ovipositioned) in deltamethrin-coated FeO NPs, whereas this decline was up to 18% in Cyp-FeS NPs and up to 5% in Cyp-FeO NPs. Similarly, the larval hatching was also impacted, leading to a hatching percentage of 5% and only 1% by application of Cyp-FeS NPs and Cyp-FeO NPs, respectively. Similarly, the larval groups had LC90 of 4.1 and 4.73 mg/L for the Cyp-FeO NPs and Cyp-FeS NPs groups. The delta-FeO NPs and delta-FeS NPs demonstrated a promising effect against adult ticks, showing LC50= 3.5 mg/L, LC90= 6.7 mg/L and LC50= 3.8 mg/L, LC90= 7.9 mg/L, respectively. MTT assay revealed that the pyrethroids coupled with iron oxide nanoparticles showed the least cytotoxicity even at the highest concentration (10–1 µL) among other nanomaterials. The study thus concluded a safer spectrum of non-target effects of pyrethroids-coated nanomaterials in addition to their significant anti-tick activity. [ABSTRACT FROM AUTHOR]

[Display omitted] Macrophages are known to depict two major phenotypes: classically activated macrophages (M1), associated with high production of pro-inflammatory cytokines, and alternatively activated macrophages (M2), which present an anti-inflammatory function. A precise control over M1-M2 polarization is a promising strategy in therapeutics to modulate both tissue regeneration and tumor progression processes. However, this is not a simple task as macrophages behave differently depending on the microenvironment. In agreement with this, non-consistent data have been reported regarding macrophages response to magnetic iron oxide nanoparticles (MNPs). To investigate the impact of both tissue microenvironment and MNPs properties on the obtained macrophage responses, single-core (SC) and multi-core (MC) citrate coated MNPs, are synthesized and, afterwards, loaded with a macrophage polarization trigger, IL-4. The developed MNPs are then tested in macrophages subjected to different stimuli. We demonstrate that macrophages treated with low concentrations of MNPs behave differently depending on the polarization stage independently of the concentration of iron. Moreover, we find out that MNPs size and morphology determines the effect of the IL-4 loaded MNPs on M1 macrophages, since IL-4 loaded SC MNPs favor the polarization of M1 macrophages towards M2 phenotype, while IL-4 loaded MC MNPs further stimulate the secretion of pro-inflammatory cytokines. [ABSTRACT FROM AUTHOR]

Herein we synthesized biochar/iron oxide composite (C/α‐Fe2O3/γ‐Fe2O3) by two‐step calcination method. The prepared C/α‐Fe2O3/γ‐Fe2O3 had a highly pure and a concentration ratio of α‐Fe2O3 and γ‐Fe2O3 about 1 : 1. The optical properties of as‐synthesized C/α‐Fe2O3/γ‐Fe2O3 show a lower bandgap energy (1.90 eV) than that of pure C/α‐Fe2O3 (2.02 eV). The effects of different biochar composite catalysts on the removal of amino black were investigated. Upon illumination, the total removal rate of amino black dye by C/α‐Fe2O3/γ‐Fe2O3 catalyst reached 98 %, which was about 1.7 times that of C/α‐Fe2O3. In addition, the coercivity and the remanence intensity of C/α‐Fe2O3/γ‐Fe2O3 is respectively 1.81 times and 7.17 times that of C/α‐Fe2O3. The catalyst could be magnetically separated and reused for five times with a slight loss of its reactivity. The study of biochar composite provides a new direction for the removal of toxic organic dye in wastewater. [ABSTRACT FROM AUTHOR]

The utilization of nanoparticles to enhance bacterial activity and boost hydrogen production in fermentation processes has gained significant attention due to their unique properties such as high specific surface area and quantum size. This research aimed to improve the biohydrogen yield from food waste by adding iron oxide nanoparticles (Fe 3 O 4) at various concentrations (50, 75, 100, 150, and 200 mg/l) and titanium dioxide (TiO 2) at different amounts (25–150 mg/l) to a single-stage hybrid (dark/photo) fermentation reactor. After obtaining the optimal amount of these two nanoparticles, the effect of synergic addition of nanoparticles on hydrogen production yield, was investigated at ratios of Fe 3 O 4 /TiO 2 = 50/50 and 100/50 mg/mg. At the ratio of Fe 3 O 4 /TiO 2 = 100/50, the cumulative hydrogen production and yield of hydrogen have increased from 1613 to 3392 ml and 101.60 to 213.66 mlH 2 /gVS, respectively, compared to the control experiment. We also found that the COD removal rate has enhanced from 28% to 40.1%. In the optimal value, the bacterial growth lag phase has also remarkably decreased from 8.19 to 4.81 h. • Synergic application of TiO 2 and Fe 3 O 4 significantly increased biohydrogen purity and production yield. • TiO 2 played an important role in the activity of bacteria in the photo fermentation process. • Fe 3 O 4 played an important role in the dark fermentation system. • Nanoparticles may act as a scaffold for enzyme and substrate binding. • Optimal nanoparticle concentration may differ for different bioreactors. [ABSTRACT FROM AUTHOR]

Fluorine magnetic resonance imaging (19F MRI) has emerged as an attractive alternative to conventional 1H MRI due to enhanced specificity deriving from negligible background signal in this modality. We report a dual nanoparticle conjugate (DNC) platform as an aptamer‐based sensor for use in 19F MRI. DNC consists of core–shell nanoparticles with a liquid perfluorocarbon core and a mesoporous silica shell (19F‐MSNs), which give a robust 19F MR signal, and superparamagnetic iron oxide nanoparticles (SPIONs) as magnetic quenchers. Due to the strong magnetic quenching effects of SPIONs, this platform is uniquely sensitive and functions with a low concentration of SPIONs (4 equivalents) relative to 19F‐MSNs. The probe functions as a "turn‐on" sensor using target‐induced dissociation of DNA aptamers. The thrombin binding aptamer was incorporated as a proof‐of‐concept (DNCThr), and we demonstrate a significant increase in 19F MR signal intensity when DNCThr is incubated with human α‐thrombin. This proof‐of‐concept probe is highly versatile and can be adapted to sense ATP and kanamycin as well. Importantly, DNCThr generates a robust 19F MRI "hot‐spot" signal in response to thrombin in live mice, establishing this platform as a practical, versatile, and biologically relevant molecular imaging probe. [ABSTRACT FROM AUTHOR]

This article presents a literature review of the iron oxide nanoparticles synthesis routes with applications as nanocatalysts in the synthesis of carbon nanostructures using the plastic pyrolysis method. Through pyrolysis, it is possible to synthesize structures such as single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), multi-walled carbon nanotubes (MWCNTs), and carbon nanofibers (CNFs). The morphological and chemical properties of the nanocatalysts ensure the majority production with minimal defects of these nanostructures. Regarding the iron oxide nanocatalyst, this review emphasizes the importance of parameters such as its shape and size, properties that are controlled during the synthesis process, and the significance of the interaction between nanoparticles and the support material used. These factors directly influence the nanocatalyst's performance in terms of catalytic activity, selectivity, and durability. [ABSTRACT FROM AUTHOR]

Herein, we propose a comprehensive chemical experiment that include the preparation, characterization and lithium storage performance evaluation of mesoporous carbon-coated iron oxide nanoparticles. Students are guided to acquaint themselves with the characterization methods of material structure, the operation of battery assembly and battery testing technique. This experiment will disclose the interrelationship between material structure and performance to students, and cultivate their experiment skills, scientific literacy, and practical innovation ability. Furthermore, this experiment serves as a gateway for students to explore the frontier in new energy, and stimulate their scientific interest. Therefore, this experiment is recommended as a comprehensive chemical experiment course for senior undergraduates majoring in materials chemistry or applied chemistry. [ABSTRACT FROM AUTHOR]