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Magnetic molecularly imprinted polymers (MMIPs) are used as artificial antibody materials. MMIPs have attracted a great deal of interest because of their low cost, wide practicality, predetermination, stability and their ability to achieve rapid separation from complex sample environments by the action of external magnetic field. MMIPs can simulate the natural recognition of entities. They are widely used because of their great advantages in terms of high selectivity. In this review article, the preparation methods of Fe3O4 NPs and a detailed summary of the commonly used methods for amination modification of Fe3O4 NPs are introduced, preparation of Ag NPs of different sizes and Au NPs of various shapes and preparation methods of magnetic molecularly imprinted plasmonic SERS composite nanoparticles such as Fe3O4@Ag NPs, Fe3O4/Ag NPs, Fe3O4@Au NPs, Fe3O4/Au NPs, Fe3O4@Au/Ag NPs and Fe3O4@Ag@Au NPs are main summarized. In addition, preparation process and the current application of MMIPs prepared from magnetic molecularly imprinted plasmonic SERS composite nanoparticles incorporating different functional monomers in a nuclear-satellite structure are also presented. Finally, the existing challenges and future prospects of MMIPs in applications are discussed. [ABSTRACT FROM AUTHOR]

AbstractThe small size, surface effect, and tunneling effect of nanomaterials enable their applications in various fields, including catalysis, sensing. Fe3O4 has been widely used in nanotechnology owing to its excellent photoelectromagnetic properties. In this study, polygonal Fe3O4 nanoparticles were prepared through a high-temperature synthesis method. Subsequently, silica coating was applied via the Stöber method to obtain a nanomaterial with uniform particles. The prepared Fe3O4 exhibited a distinct crystal structure and an ultra-high saturation magnetization, reaching up to 134.2 emu/g. Moreover, the dodecyl trimethyl ammonium bromide (DTAB) templating agent facilitated the coating of Fe3O4 with silica. The coated Fe3O4@SiO2 particles featured a well-defined core–shell structure and corrosion resistance, making them highly promising candidates for magnetic targeting medical tools, magnetic resonance imaging agents and other biological applications. [ABSTRACT FROM AUTHOR]

Standard purification systems have mainly demonstrated the inefficient removal of neonicotinoid insecticides with high persistence in the environment. In the present work, a new magnetic adsorbent composed of Fe3O4 and CuO nanoparticles impregnated with activated carbon (AC) has been used to remove imidacloprid (IMCP) as the most common neonicotinoid insecticide from the water solutions. Various techniques such as Fourier Transform infrared spectroscopy, x-ray diffraction, field emission scanning electron microscopy, energy-dispersive x-ray diffraction, and vibrating sample magnetometer were employed to characterise the fabricated composite. The main affecting parameters, including adsorbent amount, solution pH, agitating time, initial pesticide concentration, and temperature, were examined to obtain the optimised conditions. According to the obtained results from kinetic and isotherm modelling, the adsorption mechanism of IMCP on Fe3O4/CuO@AC nanocomposite (NC) is a combination of chemisorption and physisorption phenomena. The presence of heterogeneous sites for IMCP adsorption was shown by fitting the experimental data to the Freundlich isotherm model. In addition, the adsorption process was well consistent with the pseudo-second-order kinetic model, which indicates that chemisorption is the determining step in the adsorption process. Thermodynamic data showed the exothermic and spontaneous nature of the adsorption process. Under optimal conditions (initial concentration of pesticide 10 mg L−1, pH = 7, and contact time of 10 min), 99.6% of IMCP was effectively removed, indicating the excellent ability of the adsorbent to adsorb this insecticide from aqueous solutions. [ABSTRACT FROM AUTHOR]

A multicomponent reaction (MCR) for the synthesis of five novel N'-(6-chloroquinoxalin-2-yl) benzohydrazide derivatives in excellent yields at room temperature have been achieved via a reaction between 1-(6-chloroquinoxalin-2-yl) hydrazine was added 4-chloroethyl benzoyl chloride followed by the addition of Fe3O4 nanoparticles. This was applied as an efficient and recoverable nanocatalyst for the one‐pot synthesis of hydrazine Derivatives. The catalyst was magnetically recovered and reused for 4 consecutive cycles without significant loss of its activity and selectivity. Fe3O4 Nano catalyst was prepared by the co-precipitation method and characterized by X-ray diffraction (XRD), FT-IR, TEM, VSM, and analyses. This study presents an efficient multicomponent protocol, which provides several advantages, such as short reaction times, high yields, and easy working up this work. [ABSTRACT FROM AUTHOR]

Alginate is a biomaterial that is considered suitable for enzyme immobilization. The biocompatibility and characteristics of the immobilized system can be improved by combining alginate with magnetite Fe3O4 nanoparticles. Therefore, the current study investigated the effect of magnetite Fe3O4 NPs on urease immobilization using different concentrations of magnetite Fe3O4 NPs. The morphological features for alginate/magnetite Fe3O4 NPs before and after immobilization were studied using an SEM, TGA, and FTIR. The reusability, half-life, enzymatic kinetics, and storage stability of the enzyme were all enhanced. The immobilization efficiency was determined to be 91% at optimal conditions. The immobilized urease was reused 20 times and a recovery of 59% of the initial activity. The soluble and immobilized urease was stored at 4 °C for 12 weeks and preserved 13% and 49% of the initial activities, respectively. The optimum pH for soluble and immobilized urease activity was estimated to be 7. The optimum temperature for soluble and immobilized urease activity was found to be 35 °C and 40 °C, respectively. The kinetics parameters showed the Vmax of 4.4 and 3.1 μmol/ml·min and the Km of 49.5 and 54.6 mM for the soluble and immobilized urease, respectively. Immobilized urease had a half-life of 11–20 min. The activation energy (Ea) of immobilized urease was determined to be 32 kJ K−1 mol−1, indicating that a small quantity of energy is required to produce the activated complex of substrate hydrolysis. [ABSTRACT FROM AUTHOR]

Magnetite (Fe3O4) nanoparticles were synthesized by the ultrasound assisted co-precipitation method. The synthesized nanoparticles were thoroughly characterized by various analytical tools including XRD, FESEM & TEM, VSM, BET, and FTIR. It was indicated that Fe3O4 nanoparticles have cubic structure. The size of spherical-shape Fe3O4 particles ranges from 10 to 15 nm. The Fe3O4 magnetic nanoparticles were applied as a magnetic adsorbent to remove Congo red from aqueous solution. It is assumed that the adsorption process follows the pseudo-second-order kinetics equation. Equilibrium data fits well with Langmuir model. The maximum adsorption capacity is of 169.8 mg/g. This suggests that the synthesized magnetic nanoparticles could be a promising adsorbent for organic dyes removal in aqueous solutions. [ABSTRACT FROM AUTHOR]

In the present research, we introduce a simple and efficient method for the synthesis of a new heterogeneous nanocatalyst including [Fe3O4@SiO2-L-Cu(II)] via immobilizing Cu (II) on the surfaces of Fe3O4@SiO2 nanoparticles (NPs). The prepared nanocatalyst was characterized by vibration sample magnetometer (VSM), EDS, X-ray diffraction (XRD), TGA, and Field emission scanning microscopy (FE-SEM) spectroscopic methods. The obtained magnetic nanocomposite showed excellent catalytic activity for the preparation of some chromene derivatives via a three-component reaction of aldehydes, 4‐hydroxycoumarin, and 2‐hydroxynaphthalene‐1,4‐dione. This synthetic procedure provides various benefits, including cost-saving, excellent yields in short reaction times (88–98%), low catalyst loading, and catalyst reusability. [ABSTRACT FROM AUTHOR]

A special medium-density fiberboard (MDF) has been fabricated in order to electromagnetic shielding composite by adding iron oxide nanoparticles (NF) to wood fiber (WF). The aim of this work was to study the panel properties with different loadings (1, 3, 5, 7, and 10 wt %) of Fe3O4 nanoparticles. The mechanical, physical, and Electromagnetic (EM) shielding properties of the produced fiberboard were analyzed. The maximum shielding effectiveness (SE) was 13.6 dB for the NF10 in the frequency range of 8.2–12.4 GHz and the absorption had the main contribution to the SE of the panels rather than the reflection. Internal bonding (IB) of the MDF panel was increased by 8.5% by adding 1% Fe3O4 nanoparticles. After that, the IB decreased compared to the control one. The modulus of rupture (MOR) and modulus of elasticity (MOE) of the MDF panels were less than the control panel. The MOR, MOE, IB, thickness swelling (TS), and water absorption (WA) of the panel with 10% Fe3O4 nanoparticles (NF10) panel showed 21.5, 2489, 0.56 MPa, 13.4%, and 61.4%, respectively. Generally, the fiberboard fabricated with 10% Fe3O4 nanoparticles indicated the ability for Electromagnetic shielding applications because of their acceptable properties according to the EN622-5 standard and appropriate EM shielding. [ABSTRACT FROM AUTHOR]

An efficient and practical method for the synthesis of novel fused phosphorus heterocycles incorporating diethyl phosphonate by the one-pot in the presence of Fe3O4 nanoparticles as a reusable catalyst was achieved. The four-component reactions of ortho-substituted anilines, namely 2-aminophenol, 2-aminothiophenol and 1,2-phenylenediamine with salicylaldehyde, diethyl phosphite and hexaethylphosphorus triamide in the presence of Fe3O4 nanoparticles as a catalyst at 80–90 °C afforded the corresponding 1,3,2-benzo(oxaza/thiaza/diaza)phospholo[2,3-b][1,3,2]benzoxazaphosphinines 1–3 in good yields (80-84%). When the same reactions were repeated by substitution of salicylaldehyde with benzaldehyde, the 1,2-benzazaphospholo[2,1-b][1,3,2]benzo(oxaza/thiaza)phospholes 4 and 5 and 1,3,2-benzodiazaphosphole 6 derivatives were isolated in 78–83% yields. The structures of the synthesized compounds were established by elemental analysis and spectroscopic techniques (IR, MS and NMR). [ABSTRACT FROM AUTHOR]

Treatment of colored wastewater is one of the important challenges of environmental engineers. Adsorption is one of the most efficient methods in dye removal. The aim of this study was to prepare a magnetic adsorbent with Fe3O4 nanoparticles as an inexpensive adsorbent to remove basic violet 16 (BV16) dye from aqueous media. In this experimental study, the effect of parameters such as initial solution pH, adsorbent dose, initial dye concentration, and contact time on the adsorption rate was investigated. The residual dye concentration was read at 545 nm by using a spectrophotometer. Physical, surface, and magnetic properties of the adsorbent were analyzed using Brunauer–Emmett–Teller (BET), Vibrating-Sample Magnetometer (VSM), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning electron microscope (SEM) techniques. Adsorption data were described by Langmuir and Freundlich isotherms and reaction kinetics. The results showed that with increasing the contact time and increasing the adsorbent dose, the amount of dye removal by the adsorbent increased and with decreasing the initial concentration of dye, the amount of removal increased. The results also showed that with increasing pH, the removal efficiency of the process increased linearly. According to resuls, the highest BV16 dye adsorption efficiency was 99%, which was obtained at determined values of studied parameters including pH of 7, adsorbent dose: of 0.5 g/L, initial BV16 dye concentration of 25 mg/l, mixing speed of 250 rpm, and contact time of 45 min. Moreover, according to results, removal of BV16 dye using adsorption onto clinoptilolite zeolite magnetized with Fe3O4 nanoparticles obey a second-order kinetic model and Freundlich model (R2>0.99). According to SEM images, the adsorbent surface used is non-uniform and has many pores and also the morphology of the adsorbent surface is preserved after loading of Fe3O4 nanoparticles. According to VSM images, the magnetic saturation in composite is 18.11 emu/g. Results hihlighted the adsorption of BV16 dye onto clinoptilolite zeolite magnetized with Fe3O4 nanoparticles was a useful technique and could provide high efficiency in removal of studied dye from aqueous solutionsl; thus, it mabe be effective and useful in removal other similar pollutants. [ABSTRACT FROM AUTHOR]

The effect of heavy ions on the magnetic properties of Fe3O4 nanoparticles with d = 20–30 nm was studied. The magnetic properties were studied by vibrational magnetometry. It has been established that Fe3O4 nanoparticles have ferromagnetic properties under normal conditions and at room temperature. The value of the specific magnetic moment was determined: M = 33.4 emu/g. It has been established that under the influence of temperature, a decrease in the value of the specific magnetic moment in Fe3O4 nanoparticles is observed, at a temperature of TC = 655 K, a ferromagnet-paramergrite phase transition occurs, and the value M = 0 is obtained. As a result of the study, the values of the specific magnetic moment and Curie temperature in Fe3O4 nanoparticles irradiated with a stream of fast heavy 132Xe ions with an energy of 167 MeV at intensities of 4.14 × 1012 ion/cm2, 2.75 × 1013 ion/cm2 and 3.83 × 1014 ion/cm2. The mechanism of change of magnetic properties depending on radiation is determined. [ABSTRACT FROM AUTHOR]

The γ-ray irradiation method has been successfully used to prepare Fe3O4-Doped Graphene Aerogels(GA-Fe3O4-ethanol) in Ethanol-H2O solution. Electron microscopy and X-ray powder diffraction (XRD) techniques show that the graphene oxide was successfully reduced and showed a porous structure while Fe3O4 Nanoparticles are stably loaded on graphene. The material showed good adsorption stability in the process of repeatedly absorbing the organic solvent. At the same time, in the process of adsorbing organic solvents, it was noticed that the material has a certain elasticity in the organic phase, which is rarely seen in many other aerogel materials. [ABSTRACT FROM AUTHOR]

In this work, Fe3O4 nanoparticles (NPs) was synthesized by inverting microemulsion method. After that, based on the physical and chemical properties of tannic acid (TA), poly tannic acid (PTA) was coated on Fe3O4 NPs surface. Fe3O4 NPs coated with PTA, on the one hand, was used to immobilize Penicillin G acylase (PGA) by physical adsorption. On the other hand, it was modified by glutaraldehyde (GA). GA grafting rate (Gr-GA) was optimized, and the Gr-GA was 30.0% under the optimum conditions. Then, through the Schiff base reaction between the glutaraldehyde group and PGA amino group, this covalent immobilization of PGA was further realized under mild conditions. Finally, the structures of every stage of magnetic composites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibration magnetometer (VSM) and transmission electron microscopy (TEM), respectively. The results indicated that the enzyme activity (EA), enzyme activity recovery (EAR) and maximum load (ELC) of the immobilized PGA were 26843 U/g, 80.2% and 125 mg/g, respectively. Compared to the physical immobilization of PGA by only coating PTA nanoparticles, further modified nanoparticles by GA showed higher catalytic stability, reusability and storage stability. [ABSTRACT FROM AUTHOR]

The fabrication of the inorganic metal oxide nanoparticles by using extract of the different part of the plant was gaining an overwhelming response from the last few years. Magnetic iron oxide nanoparticles exhibiting verity of biomedical applications hence in the current proposed work we use an unexplored Euphorbia herita leaf extract in the green synthesis of magnetic iron oxide nanoparticles (Fe3O4 NPs). The tailored Fe3O4 NPs was structurally characterized by using advanced analytical tools like UV–visible spectroscopy, Scanning electron microscopy (SEM) analysis, Fourier transform infra-red (FT-IR) analysis and X-ray diffraction study. The fabricated nanoparticles were naturally stabilized, having cavity like structure with average particle size in the range of 25–80 nm. The phytochemicals especially polyphenols and alcoholic compound play crucial role in the fabrication of magnetic iron oxide nanoparticles. The antimicrobial activity of the fabricated iron oxide nano particles was evaluated against selected bacterial and fungal pathogen and the result of antimicrobial study was very promising. [ABSTRACT FROM AUTHOR]

A dual stimuli-responsive magnetic nanohydrogel was fabricated as a potent drug delivery system (DDS) for 'smart' treatment of cancer by chemo/hyperthermia approach. For this objective, Fe3O4 nanoparticles (NPs) were produced via a co-precipitation approach and then modified by 3-(trimethoxysilyl) propylmethacrylate (MPS) moiety. The modified NPs were copolymerized with N,N′-(dimethylamino)ethyl methacrylate (DMAEMA), and maleic anhydride (MA) monomers by a free radical polymerization approach to afford a Fe3O4@P(DMAEMA-co-MA) core-shell NPs. Afterward, the NPs were shell crosslinked by the reaction of anhydride unites with neutralized cystamine (Cys). The fabricated pH- and reduction-responsive magnetic nanohydrogel was physically loaded with methotrexate (MTX), as an anticancer drug, and its drug loading efficiency (LE) was calculated as 64 ± 2.7%. The developed nanohydrogel/MTX exhibited proper stimuli-triggered drug release behavior that qualified it as an efficient DDS according to the abnormal micro-environment of cancerous tumors. The anticancer activity investigation using chemo/hyperthermia therapy approach by MTT-assay revealed that the nanohydrogel/MTX might show better clinical outcomes than those of the free MTX. [ABSTRACT FROM AUTHOR]

This research work intended to prepare and characterize novel dendrimer-based biosensors with an improved response for the detection of glucose in saliva. The nanoparticles of Fe3O4, a core material, encapsulated in PAMAM dendrimers to immobilize glucose oxidase in the presence of cross-linking agent, glutaraldehyde. Fe3O4 nanoparticles were synthesized by oxidative reaction of ferrous chloride and potassium hydroxide. A solvent-free or green chemistry concept was used to prepare PAMAM dendrimers (G4) using Michael addition and amidation reactions where ethylene diamine and methyl methacrylate were used as reactants. The particle size of Fe3O4 nanoparticles and dendrimers were in the range of 20–30 nm and 30–40 nm, respectively. Glucose was detected by photofluorometer using Tris(1, 10-phenanthroline) ruthenium (II) chloride hydrate [TPR(II)CH] as an indicator. The biosensor showed a response in 4–6 min both in the presence and absence of artificial saliva. The behavior of biosensor showed an increase in fluorescence intensity for the concentrations of glucose (5, 10, 15, and 20 ppm). Fourier-transform infrared spectroscopy and differential scanning calorimetry studies confirmed the synthesis of Fe3O4 nanoparticle and acted as a core of PAMAM dendrimers. This potential approach is a simple, cost-effective, and reproducible for noninvasive glucose detection in saliva. [ABSTRACT FROM AUTHOR]

Iron oxide (Fe3O4) nanoparticles are synthesized using the chemical co-precipitation method. Changing factors such as surfactant, pH, and molar ratio of ferrous to ferric ions effects the size and magnetic properties of the nanoparticles significantly. The synthesized nanoparticles are characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR). The nanoparticles have inverse spinel structure. Superparamagnetic behavior is detectable for all samples. The variations of magnetic properties for different sized Fe3O4 nanoparticles can be explained with surface effects and finite size effects. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of ionic liquid (IL) supported on Fe3O4 nanoparticles and a DFT study of 1,3-dipolar cycloaddition for synthesis of isoxazolidines in the presence of IL-Fe3O4. A family of novel ionic liquid (IL) with L-alanine and choline chloride as environmentally benign materials has been synthesized and grafted on Fe3O4 nanoparticles (NPs) using easy preparation techniques. The structure of IL supported on Fe3O4 NPs (IL-Fe3O4 NPs) is characterized by various techniques such as field emission scanning electron microscopy (FE-SEM), Energy Dispersive X-Ray (EDX), XRD, Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FTIR), and vibrating sample magnetometry (VSM). A stereoselective synthesis of isoxazolidine derivatives in good yields, through a three-component 1,3-dipolar cycloaddition reaction using by IL-Fe3O4 NPs, is reported. The use of IL-Fe3O4 as a catalyst allowed us to prepare diastereoselective isoxazolidine derivatives. Conformational analysis compared with the 1H NMR data of the products obtained allowed us to determine the absolute configuration. In this paper, the density functional theory (DFT) method with 6-311G (d,p) basis set is employed for solution phase (solvent = CHCl3) of the isoxazolidine derivatives. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of ionic liquid (IL) supported on Fe3O4 nanoparticles and a DFT study of 1,3-dipolar cycloaddition for synthesis of isoxazolidines in the presence of IL-Fe3O4. A family of novel ionic liquid (IL) with L-alanine and choline chloride as environmentally benign materials has been synthesized and grafted on Fe3O4 nanoparticles (NPs) using easy preparation techniques. The structure of IL supported on Fe3O4 NPs (IL-Fe3O4 NPs) is characterized by various techniques such as field emission scanning electron microscopy (FE-SEM), Energy Dispersive X-Ray (EDX), XRD, Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FTIR), and vibrating sample magnetometry (VSM). A stereoselective synthesis of isoxazolidine derivatives in good yields, through a three-component 1,3-dipolar cycloaddition reaction using by IL-Fe3O4 NPs, is reported. The use of IL-Fe3O4 as a catalyst allowed us to prepare diastereoselective isoxazolidine derivatives. Conformational analysis compared with the 1H NMR data of the products obtained allowed us to determine the absolute configuration. In this paper, the density functional theory (DFT) method with 6-311G (d,p) basis set is employed for solution phase (solvent = CHCl3) of the isoxazolidine derivatives. [ABSTRACT FROM AUTHOR]

The aim of this research is to capsulate methadone (MTD) in polymeric layers based on layer by layer method. Fe3O4 nanoparticles (NPs) were synthesized by polyethylene glycol and modified by folic acid. MTD was conjugated to NPs and polymeric layers surrounded this nano-system. Percentage of loaded MTD, in vitro release and kinetic factors were studied. The average size of the prepared NPs was 23 nm. The surface potential of the capsule was changed from +39 to −27 mV for chitosan and alginate, respectively. In this study, a nano-system was designed to decrease methadone release rate. In vitro study indicated that MTD release was slow enough and controllable. By this designed nano-system, addicts can consume this nano-drug just two times a week. [ABSTRACT FROM AUTHOR]

The electrocoagulation (EC) of dye-polluted aqueous solutions was considered using iron electrodes. In a novel approach, the EC process was simultaneously integrated with ultrasound (US) and H2O2 on the basis of the electro-generation of magnetite nanoparticles via sacrifice anode. Direct red 31 (DR31) dye was chosen as model pollutant. During the short reaction time of 20 min, the US/H2O2/EC process led to the highest decolorization efficiency of 93.3% compared with the US/EC (65.3%) and H2O2/EC (54.1%) processes. The real textile wastewater sample was effectively treated and mineralized by the US/H2O2/EC process (COD removal: 86.7%; TOC removal: 58.7%). [ABSTRACT FROM AUTHOR]

This work was aimed at defining the suitable test for evaluating Fe3O4 NPs cytotoxicity after short-term exposure in human mesenchymal stem cells (hMSCs) using different viability tests, namely NRU, MTT and TB assays, paralleled by cell morphology analyses for cross checking. MTT and NRU data (culture medium with/without hMSCs plus Fe3O4NPs) indicated artificial/false increments in cell viability after Fe3O4NPs. These observations did not fit with the morphological analyses showing reduced cell density, loss of monolayer features, and morphological alterations at Fe3O4NPs ≥50 μg/ml. Fe3O4NPs alone induced a substantial increased absorbance at the wavelength required for MTT and NRU. A significant death (25%) of hMSC at Fe3O4NPs ≥10 μg/ml, with a maximum effect (45%) at 300 μg/ml after 24 h, exacerbated after 48 h, was observed when applying TB test. These results paralleled the effects on cell morphology. The optical properties and stability of Fe3O4NP suspension (tendency to agglomerate in a specific culture medium) represent factors that limit in vitro result interpretation. These findings suggest the non applicability of the spectrophotometric assays for hMSC culture conditions, while TB is an accurate method for determining cell viability after Fe3O4NP exposure in this model. In relation to NPs safety assessment: cell-based assays must be considered on case-by-case basis; selection of relevant cell models is also important for predictive toxicological studies; application of a testing strategy is fundamental for understanding the toxicity pathways driving cellular responses. [ABSTRACT FROM AUTHOR]

The goal of this study is to synthesize, characterize and investigate some physicochemical properties of conductive polyaniline-g-polystyrene/Fe3O4 (Fe3O4/PSt-g-PANi) nanocomposites. For this purpose, initially, Fe3O4 nanoparticles were synthesized by a co-precipitation method. Then, the desired nanocomposite was synthesized in two steps. First, the atom transfer radical polymerization (ATRP) of styrene was performed using an ATRP initiator attached to the surface of Fe3O4 nanoparticles, followed by functionalization of the Fe3O4-PSt with amine groups (–NH2). Second, surface oxidative graft copolymerization of aniline was accomplished using the –NH2 moieties on the Fe3O4/PSt-NH2 as the anchoring sites. The prepared materials were characterized by various instruments, including TEM, SEM, TGA, EDX, FT-IR, XRD and conductivity measurements. The results indicated that the synthesized conductive polymer/Fe3O4 nanocomposites had higher electrical conductivity and thermal resistance than those of the corresponding homopolymers. [ABSTRACT FROM AUTHOR]

Research on nanotechnology as an emerging discipline has advanced several branches of technology. Although iron is considered as an essential element for plant growth, its role in mitigating abiotic stresses has not been studied widely. Therefore, in this research, it has been attempted to investigate the effect of magnetic Fe3o4 nanoparticles on tomato plants under cadmium stress using 5 levels of magnetic (Fe3O4) nanoparticles (nano-Fe3O4) (0, 10, 20, 50, 100 mg/L) and 3 levels of CdCl2 (0, 100, 200 μM). Cadmium reduced growth and photosynthesis parameters as well as nutritional elements and increased the content of MDA, H2O2, and proline in tomato plants. Meanwhile 20 mg/L nano-Fe3o4 was able to improve cadmium toxicity by reduction in cadmium accumulation and increase in nutrient intake. However, 20 mg/L nano-Fe3o4 is potentially useful for plant growth and may motivate the variations of plants defense mechanisms in response to cadmium toxicity. [ABSTRACT FROM AUTHOR]

The poly(ethylenimine) functionalized magnetite particles were studied for their preconcentration efficiencies toward Cu2+, Pb2+, and Ni2+ ions. The loading capacities were found to be 26 mg g−1, 46 mg g−1, and 13 mg g−1 of Cu2+, Pb2+, and Ni2+ ions, respectively. Cu2+ ions loaded on the magnetically retrievable nanoparticles were used for Henry reaction as a representative example of a heterogeneous catalyst. These particles were characterized for their chemical, physical, thermal and magnetic properties. The Henry reaction involved reaction between m-nitro benzaldehyde and nitromethane to afford the nitroaldol adducts 1-(3-nitrophenyl)-2-nitrosoethanol with 80% yield in ethanol at room temperature. [ABSTRACT FROM AUTHOR]

Drilling fluid is a vital element and is often regarded as the "blood" in the oil industry. Although traditional oil-based drilling fluids have advantages in some harsh cases, the high cost and environmental pollution faced with them limit its application. Water-based drilling fluids (WBDFs) with environmental friendly, low cost, and high performance are important for drilling engineering to solve the problems of low efficiency and wellbore instability caused by poor rheological properties and large filtration loss in drilling operations. In this paper, Fe3O4 nanoparticles modified by poly (acrylic acid) (PAA) through 3-(trimethoxysilyl) proryl methacrylate (TMSPMA) were introduced into WBDFs for enhancing their rheological and plugging performance. Rheological tests indicated that the consistency coefficient (K) of the Fe3O4/PAA nanoparticles/WBDFs decreased at a higher concentration. Incorporated nanoparticles with a concentration of 0.05 wt %, the WBDFs will exhibit good shear-thinning behavior. The results showed that the best performance for Fe3O4/PAA nanoparticles being as a filtration additive in WBDFs was achieved at concentration as low as 0.1 wt %. These results demonstrated that Fe3O4/PAA nanoparticles are effective additives for WBDFs. [ABSTRACT FROM AUTHOR]

A novel Wells-Dawson heteropolyacid-based magnetic Inorganic-organic nanohybrid, Fe3O4@SiO2@ADMPT/H6P2W18O62, was fabricated and used as a green, efficient, eco-friendly, and highly recyclable catalyst for the one-pot and multi-component synthesis of 1,4-Dihydopyridine (1,4-DHP) derivatives from the reaction of various aromatic aldehydes with ethyl acetoacetate and ammonium acetate with good to excellent yields and in a short span of time. The nanohybrid catalyst was prepared by the chemical anchoring of Wells-Dawson heteropolyacid H6P2W18O62 onto the surface of functionalized Fe3O4 nanoparticles with 2,4-bis(3,5-dimethylpyrazol)-triazine (ADMPT) linker. These nanocatalysts were identified by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), infrared spectroscopy (IR) and vibrating sample magnetometer (VSM). This protocol is developed as a safe, cost-effective and convenient alternate method for the synthesis of 1,4-DHP derivatives utilizing an eco-friendly, and a highly reusable catalyst. [ABSTRACT FROM AUTHOR]

Advancement of an efficient and cost-effective method for heavy metal removal from contaminated water utilising Fe3O4–APTES–EDTA (FAE) nanocomposite, a productive reusable adsorbent, is explained in this study. The novel FAE nanocomposite was prepared and characterised using different techniques such as FTIR, XRD, TEM, EDS, BET, TGA, EDX and Zeta potential techniques. FAE is found to be a good adsorbent for Pb2+, Cd2+, Ni2+, Co2+and Cu2+removal with a higher adsorption capacity. The maximum adsorption capacity of Pb2+, Cd2+, Ni2+, Co2+and Cu2+are found to be 11.31, 13.88, 7.64, 4.86 and 78.67 mg/g, respectively. The adsorption and desorption cycle was studied for five cycles with minimal loss of efficiency. [ABSTRACT FROM PUBLISHER]

In this investigation, magnetite nanoparticles (Fe3O4NPs) with a diameter of 5–10 nm were synthesized by coprecipitation from an alkaline solution of ferrous/ferric mixed salt-solution in the presence of copolymers. In this process, linear–dendritic copolymers containing a linear poly (ethylene glycol) core and dendritic poly (citric acid) arms were used as the stabilizer. The Fe3O4NPs were characterized by transmission electron microscopy, energy-dispersive spectra, X-ray powder diffraction, field emission scanning electron microscopy, Fourier transform infrared spectrometer, and vibrating sample magnetometer. Compared to classical coprecipitation, the results showed that uniform, ultrafine, nearly spherical, and high purity nano-magnetite particles with better magnetic properties could be prepared by this method. [ABSTRACT FROM PUBLISHER]

Magnetic nanocomposites (Fe3O4-MPTMS-PLGA) were synthesized by single oil emulsion method and characterized by transmission electron microscopy (TEM), X-Ray diffraction (XRD), and vibrating sample magnetometer (VSM). Particle size of nanocomposites was between 117 nm and 246 nm. High performance liquid chromatography (HPLC) was used to investigate drug loading (paclitaxel, PTX) and release from Fe3O4-MPTMS-PLGA-PTX nanocomposites. The percentages of drug loading and encapsulation efficiency onto nanocomposites were found as 7.35 and 68.58, respectively. Cytotoxities of free anticancer drug and anticancer drug-loaded nanocomposites were determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay.In vitrocell culture studies indicated that Fe3O4-MPTMS-PLGA-PTX had significant toxicity on MG-63 cancer cells. [ABSTRACT FROM AUTHOR]

In this work, protease enzymatic wool was treated with citric acid and Fe3O4 nanoparticles to produce fabric with enhanced tensile strength, elongation, alkali resistance with controllable hydrophilicity/ hydrophobicity through a simple 'impregnating' method. Protease enzymatic is also one of the most important processes usually carried out in alkali condition to obtain the desirable characteristics, which enhanced the surface activity and nanoparticles adsorption. Mechanical properties such as tensile strength and elongation were reduced as a consequence of alkali enzymatic pretreatment. Here, with the help of citric acid cross-linking agent, Fe3O4 nanoparticles were stabilized on the enzymatic wool surface in a way to revenge reduction in the tensile strength, elongation, alkali resistance. In order to create optimum tensile strength, elongation, alkali resistance, lightness and hydrophilicity/hydrophobicity, the appropriate models were obtained based on Design-Expert software. Overall, the results confirmed that the enzymatic wool fabrics could be modified by citric acid and Fe3O4 nanoparticles post-treatment. The Fe3O4 nanoparticle/citric acid treatment on the protease enzymatic wool improved tensile strength and elongation along with the higher alkali resistance and controllable hydrophilicity/hydrophobicity. [ABSTRACT FROM AUTHOR]

A facile strategy for the synthesis of polystyrene/Fe3O4nanocomposite is suggested. For this purpose, styrene and 4-chloromethyl styrene monomers was copolymerized through reversible addition of fragmentation chain transfer technique [P(St-co-CMSt)] and then the chlorine groups of CMSt units were converted to diethyl malonate groups through a nucleophilic substitution reaction. Afterward, esteric groups of diethyl malonate were hydrolyzed to afford carboxylic acid-functionalized polystyrene. This polymer with carboxylic acid groups can adsorbed onto the surface of Fe3O4nanoparticles through the interaction with hydroxyl groups onto the surface of the nanoparticles. We envision that the synthesized PSt/Fe3O4nanocomposite may be find applications in electromagnetic interference shielding and environment sciences. [ABSTRACT FROM PUBLISHER]

Herein, Fe3O4nanoparticles synthesized using aqueous extract of corn ear leaves were investigated for proteasome inhibitory activity, antioxidant activity, synergistic antibacterial, and anticandidal potential. The UV-Vis spectrum displayed an absorption band at 355 nm that indicated the formation of nano-sized Fe3O4particles. Vibrating sample magnetometer analysis revealed its superparamagnetic nature. Fe3O4nanoparticles exhibited strong proteasome inhibitory potential and antioxidant activity and exerted strong synergistic antibacterial and anticandidal activity. Its significant proteasome inhibitory potential could be useful in cancer treatment and drug delivery. Furthermore, strong antioxidant, antibacterial, and anticandidal activity make them a promising candidate for biomedical and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

The novel conductive nanocomposite has been successfully prepared by emulsion polymerization. First, magnetite nanoparticles were synthesized via coprecipitation reaction. Then, poly (indole-co-thiophene)@Fe3O4nanocomposite was prepared via emulsion copolymerization of indole and thiophene monomers using sodium dodecyl sulfate as an emulsifier and ammonium persulfate as an oxidant in the presence of Fe3O4nanoparticles. Characterization of the synthesized copolymer, Poly (In-co-T), and its magnetic nanocomposite were studied by Fourier transform infrared spectra, X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis, differential scanning calorimetric, UV-vis spectrophotometer, and vibrating sample magnetometer. Also, the electrical conductivity of copolymer and nanocomposite were determined by four-probe instrument. Results showed a synergic effect in thermal stability by good interaction between polymer chain and magnetic nanoparticles. The conductivity of the nanocomposite was higher than bare copolymer, and increase of nanoparticles content caused an increment in the conductivity of the nanocomposites. The applicable properties of proposed conductive nanocomposite as a base at electrochemical biosensing have been investigated. [ABSTRACT FROM AUTHOR]

Magnetic recyclable bactericidal nanocomposites (Fe3O4@PDMC) were well-designed and prepared by coating of Fe3O4nanoparticles with quaternarized N-halamine polymers via the free radical polymerization process. In which, 5,5-dimethylhydantoinyl-(3-ethyl-methacrylamine)propyl dimethylammonium bromide (DEMPA), a new monomeric N-halamine precursor, was used as a coating material as well as the dual-functional bactericidal agent. The developed Fe3O4@PDMC nanocomposites exhibited suitable size and super-paramagnetic responsibility. The antibacterial results showed that the Fe3O4@PDMC nanocomposites had excellent biocidal abilities againstStaphylococcus aureus(gram-positive) andEscherichia coli(gram-negative). Furthermore, the TTC (Triphenyl Tetrazolium Chloride)–dehydrogenase activity assay confirmed that the reductions of the bacteria were mainly attributed to powerful biocidal effects of the coating polymer instead of bacteria capture by the cationic surface. Interestingly, due to the magnetic responsive performance of Fe3O4, the as-prepared Fe3O4@PDMC nanocomposites can be recycled by a magnet and reused for antibacterium through the quenching/rechlorination procedure. All the results presented in this study show that the proposed Fe3O4@PDMC nanocomposites could be a competitive candidate for water purification systems and household sanitation. [ABSTRACT FROM AUTHOR]

A facile route for the synthesis of high-quality Fe3O4nanoparticles (FNPs) has been successfully confirmed by employing a co-precipitation technique and then was stabilized onto wool fabric through a simple “impregnating” process. Here, the synergistic effect of BTCA and synthesized FNPs on magnetic and antifungal characteristics of the wool fabric was investigated. The FNPs was stabilized on the wool surface using BTCA cross-linking agent. The role of both FNPs and BTCA concentrations on magnetic and antifungal properties of samples was optimized using response surface methodology. The magnetization properties and uniform distribution of FNPs on the wool surface were characterized by vibrating sample magnetometry, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The saturation magnetization and antifungal activity againstCandida albicansof BTCA/FNPs-optimized wool was 7.8 emu g−1and 98.31%, respectively. Subsequently, treated wool fabric with optimum concentration of FNPs and BTCA enhanced magnetic and antifungal properties. [ABSTRACT FROM AUTHOR]

Targeted and efficient delivery of drug to tumor is one of the crucial issues in cancer therapy. In this work, we have successfully designed and prepared the pH-sensitive magnetic nanoparticles (MNPs) as targeted anticancer drug carriers, in which the MNPs were coated by poly(acrylic acid) (PAA) and the obtained PAA@MNPs exhibited a size within 100 nm, good stability, and superparamagnetic responsibility (Ms45.97 emu/g). Doxorubicin (DOX) can be successfully loaded onto MNPs via electrostatic interaction, and the drug loading content and loading efficiency are 26.4 and 88.1%, respectively. Moreover, the release studies showed that the drug-loaded carriers (MNPs-DOX) had excellent pH sensitivity, 75.6% of the loaded DOX was released at pH 4.0 within 48 h. Importantly, MTT assays in HUVEC and MCF-7 cells demonstrated that MNPs-DOX exhibited high anti-tumor activity, while the PAA@MNPs were practically nontoxic. Thus, our results revealed that PAA@MNPs would be a competitive candidate for biomedical application and MNPs-DOX could be used in targeted cancer therapy. [ABSTRACT FROM PUBLISHER]

Fe3O4 nanoparticles were synthesized via a modified coprecipitation green method under ultrasound irradiations, and were characterized with X-ray diffraction (XRD), vibrating sample magnetometer (VSM), FT-IR spectroscopy, scanning electron microscope (SEM), and transmission electron microscopy. The influences of temperatures, effect of alkali and ultrasound irradiations on the grain size and properties of Fe3O4 nanoparticles were investigated. [ABSTRACT FROM AUTHOR]

Fe3O4nanoparticles were synthesized via coprecipitation method and their dispersion properties were investigated using three types of anionic poly (ethylene glycol)-graft-acrylic comb dispersants (APADs). The Fe3O4nanoparticles have been characterized with powder X-ray diffraction, transmission electron microscopy, and dynamic laser scattering while the prepared APAD has been studied by Fourier transmission infrared and nuclear magnetic resonance spectroscopy techniques. The results revealed that Fe3O4nanoparticles could be well dispersed using APAD that PEG 2000 was grafting to the backbone of dispersant. It was also found that temperature of synthesis procedure affects a dispersion of nanoparticles more significantly than mixing time and APADs molecular weight. [ABSTRACT FROM PUBLISHER]

Magnetic solid-phase extraction was used for the preconcentration of cadmium, lead, and cobalt inMoringa Oleiferawith determination by flame atomic absorption spectrometry. Fe3O4nanoparticles were modified by oleic acid to form the sorbent for magnetic solid-phase extraction. The modified sorbent was characterized by transmission electron microscopy, infrared spectroscopy, and X-ray diffraction. The preconcentration was optimized for the mass of nanoparticles, pH, adsorption time, the presence of coexisting ions, solution volume, eluent, and reuse. The optimized limits of detection were 0.09, 0.26, and 0.54 µg/L for Cd(II), Pb(II), and Co(II) with relative standard deviations below 4.3%. The method was employed for the analysis ofMoringa oleiferaand recoveries between 90.0 and 102.0% were obtained. [ABSTRACT FROM PUBLISHER]

In the present paper, the crystallization behaviors of six different functional Fe3O4/ethylene-vinyl acetate (EVA) copolymer nanocomposite adhesives were studied. Crystal structures of the nanocomposite adhesives were characterized by wide-angle X-ray scattering, and the results showed that both functionalized and non-functionalized Fe3O4nanoparticles had only a small influence on the crystal structure of EVA. The cystallization kinetics was investigated through differential scanning calorimetry. The Ozawa and Mo methods were applied to analyze the crystallization behaviors, and the nucleating effect was estimated through the Dobreva and Gutzow method. Finally, the crystallization energy barrier was studied by the Kissinger method. [ABSTRACT FROM AUTHOR]

We study possible modification of synthesized iron oxide (Fe3O4) nanoparticles (NPs) with organic molecules of citric acid (CA) and vitamin C (ascorbic acid), and then incorporation of dicapped magnetic NPs into valuable poly(vinyl alcohol) (PVA) matrix. Biocompatible CA and ascorbic acid (AS) coupling agents can create organic functional groups on the surface of Fe3O4NPs for better interfacial compatibility with the organic polymer matrix. Magnetic PVA@Fe3O4/CA/AS nanocomposite (NC) films containing 4, 8, and 12 wt% of the modified NPs were successfully manufactured by a fast, green, and safe strategy under ultrasonic irradiation. Surface functionality groups, morphology of the modified NPs, and also the fabricated NCs were analyzed by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis, X-ray diffraction, UV–Visible spectroscopy, field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). In comparison to the pure PVA, the PVA@Fe3O4/CA/AS NCs were shown to have higher decomposition temperature. With incorporation of 4 wt% Fe3O4, the tensile strength and Young’s modulus of the NC have significantly improved compared with PVA. In addition, the surface morphology images showed that NPs were dispersed homogenously into the polymer matrix at nanoscale. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotubes were modified by Fe3O4nanoparticles with application for the preconcentration of metals. The modified materials were characterized by infrared spectroscopy, transmission electron microscopy, and X-ray diffraction. The Fe3O4nanoparticle modified multiwalled carbon nanotubes were used as sorbents for the extraction of cadmium and lead from maca prior to analysis by flame atomic absorption spectrometry. The amount of nanoparticles, pH, adsorption time, coexisting ions, eluent solution, and reuse of the material were characterized to optimize the recoveries of the analytes. Under the optimum conditions, the calibration curves were linear from 0.05 to 20 milligrams per liter for cadmium and from 0.05 to 25 milligrams per liter for lead. The limits of detection were 0.32 and 0.57 micrograms per liter while the relative standard deviations were 2.1 and 1.9 percent, respectively. The method was employed for the determination of cadmium and lead in maca and recoveries between 94.8 and 105.6 percent were obtained. [ABSTRACT FROM PUBLISHER]

A new simple magnetic electrospinning setup was devised to manufacture partially aligned nanofiber in the paper. Compared with the traditional electrospinning setup, a U-shaped permanent magnet was employed and applied with a slide rheostat. Polyvinyl alcohol (PVA) and PVA/Fe3O4fibers were prepared by the magnetic electrospinning, respectively. The morphology and alignment of the fibers were characterized by the use of scanning electron microscopy (SEM). Results showed that the magnetic field could decrease the diameter of fibers and enhance the crystal conditions of fibers, and the addition of Fe3O4nanoparticles improved the alignment of nanofibers. [ABSTRACT FROM AUTHOR]

Herein, the authors report the synthesis of electro-magnetic polyfuran/Fe3O4nanocomposites using Fe3O4magnetic nanoparticles of different content as nucleation sites viain situchemical oxidation polymerization method. Surface, structural, morphological, thermal, electrical and magnetic properties of the nanocomposites were studied by FT-IR, UV-visible spectroscopies, XRD, FESEM, TGA, four probe, and VSM, respectively. The effect of Fe3O4nanoparticles content on the electrical conductivity and magnetization of nanocomposites was studied. The obtained polyfuran and polyfuran/Fe3O4nanocomposites were analyzed for their antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. In addition, polyfuran/Fe3O4nanocomposites have been investigated for application as electrochemical biosensor. [ABSTRACT FROM AUTHOR]

The aim of this study was enhancing of stability properties of catalase enzyme by encapsulation in alginate/nanomagnetic beads. Amounts of carrier (10–100 mg) and enzyme concentrations (0.25–1.5 mg/mL) were analyzed to optimize immobilization conditions. Also, the optimum temperature (25–50°C), optimum pH (3.0–8.0), kinetic parameters, thermal stability (20–70°C), pH stability (4.0–9.0) operational stability (0–390 min), and reusability were investigated for characterization of the immobilized catalase system. The optimum pH levels of both free and immobilized catalase were 7.0. At the thermal stability studies, the magnetic catalase beads protected 90% activity, while free catalase maintained only 10% activity at 70°C. The thermal profile of magnetic catalase beads was spread over a large area. Similarly, this system indicated the improving of the pH stability. The reusability, which is especially important for industrial applications, was also determined. Thus, the activity analysis was done 50 times in succession. Catalase encapsulated magnetic alginate beads protected 83% activity after 50 cycles. [ABSTRACT FROM PUBLISHER]

The aim of the present work was to search for identification of novel reactive oxygen species (ROS) scavengers by testing new fused chromenopyrimidinethiones, which was synthesized using Fe3O4nanoparticles. The new compounds were also tested for their cytotoxic activity. The obtained results showed that the incorporated pyrimidinethione moiety significantly increase antioxidant activity. In conclusion, the study of the pharmacological properties of the new chromenopyrimidinethiones allowed establishing new structure–activity relationships for splitting antioxidant and cytotoxic activity of these compounds. [ABSTRACT FROM AUTHOR]

In this work, the Fe3O4magnetic nanoparticles (MNPs) were synthesized by a colloidal method. TEM images reveal that Fe3O4MNPs are spherical in shape with a narrow size distribution in the range of 6–7?nm. These MNPs were used in the fabrication of two types ofn-GaAs-based structures: (i) Fe3O4/n-GaAs (reference); and (ii) Fe3O4/PPF/n-GaAs. We present that carbon-based pyrolyzed polymer films (PPFs), as a buffer layer, can control the electrical characteristics of a conventional Fe3O4/n-GaAs device. The behaviour of the apparent barrier height and ideality factor with the interfacial layer due to the presence of the interface state density is discussed. PPF raises the barrier height in a Fe3O4/PPF/n-GaAs half-metallic/insulator/semiconductor (h-MIS) device as high as 0.620.002?eV. Furthermore, Fe3O4/PPF interfaces exhibit unique electronic properties including high-quality interface, low series resistance (from 17.73?k? to 85.66??) and extremely low interface state density (1.76?×?1012?eV?1?cm?2). Compared to the electrical performance for the Fe3O4/n-GaAs junction, that for the Fe3O4/PPF/n-GaAs junction was enhanced. [ABSTRACT FROM AUTHOR]

Hyperbranched polyglycerol-grafted Fe3O4nanoparticles (HPG-grafted MNPs) are newly developed MRI contrast agents with good stability, dispersibility, and biocompatibility. Their magnetic, cell uptake properties may be changed when their size varies. In this study, HPG-grafted MNPs with their size ranging from 8 to 10, 13, and 15 nm were successfully synthesized via a facile one-pot reaction using ferric oxalate pentahydrate as the precursor. With the increase of particle size, HPG-grafted MNPs show increasing trends in saturation magnetization, transverse relaxivities (R2), R2/R1ratio, and cell uptake. MTT assays indicated that nanoparticles with defferent sizes did not possess significant cytotoxicity toward mouse macrophages and 3T3 fibroblasts. Furthermore,in vivoMRI experiments were carried out with the 8-nm HPG-grafted MNPs injected into a live rabbit. Our results demonstrate that the size of HPG-grafted MNPs, which can be synthetically controlled, played an important role in tuning their magnetic and cell uptake properties. This allows HPG-grafted MNPs exhibit optional and designable properties for their application as an efficient MRI contrast agent. [ABSTRACT FROM AUTHOR]

Application of Fe3O4nanoparticles (NPs) as a robust, very efficient, and magnetically recoverable catalyst was investigated in Friedel–Crafts acylation (FCA) of ferrocene and aromatic compounds. This reaction was performed with acid chlorides in solvent-free conditions at room temperature. The catalyst was easily separated by an external magnetic field from the reaction mixture. The separated catalyst was recycled for several consecutive runs without appreciable loss of its catalytic activity. Supplemental materials are available for this article. Go to the publisher's online edition ofSynthetic Communications® to view the free supplemental file. [ABSTRACT FROM PUBLISHER]