جستجوی مقالات مرتبط با کلیدواژه « magnetite » در نشریات گروه « شیمی »

Iron Oxide Magnetic nanoparticles (Fe3O4-NPs) were synthesized using a simple, fast, and environmentally green method. Extracts of thyme and rosemary were used in the green synthesis of Fe3O4-NPs. Fourier Transform InfraRed (FT-IR) technology, Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray (EDX) spectroscopy, X-Ray Diffraction (XRD), and Mössbauer Spectroscopy (MS) have been used for characterization of the prepared material. SEM images displayed that the synthesized Fe3O4-NPs were mostly in spherical shape with sizes ranging between (11 and 17 nm) and between (8 and 16 nm) when using thyme extract (0.5%) and rosemary extract (0.5%), respectively. The XRD results revealed that the prepared materials showed high purity and crystallinity of Fe3O4-NPs. The synthesized Fe3O4-NPs were also confirmed using FT-IR analysis. Mössbauer's analysis showed quadrupole splitting in compounds. properties. The synthesized Fe3O4-NPs were applied as absorbent materials to remove the 226Ra from the coproduced water with oil production successfully.

Nanotechnology is a branch of science that that has opened new research horizons, particularly in the field of ofmedicine and cancer treatment.In the present paper, magnetite nanoparticles (Fe3O4) were produced by the co-precipitating of two and three valent iron chloride salts in an alkaline medium. The surface of the nanoparticles was functionalized with (3-Aminopropyl)-trimethoxysilane(APTS), and finally the cisplatinanticancer drug was loaded onto the modified nanoparticles. Properties, structure and morphology of the nanoparticles obtained were evaluated and analyzed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Vibrating Sample Magnetometer (VSM) for measuring magnetic properties. Results showed that cisplatinwas attached to the surface of the nanoparticles confirmed by FT-IR analysis. Magnetic properties using VSM results showed that the nanocomposite is the result of superparamagnetism. Findings showed that magnetic cisplatin magnetic nanocomposites are promising for targeted magnetic drug delivery and can be used as a targeted nanoparticle suitable for delivering anticancer drugs.

Magnetic iron oxide nanoparticles (Fe3O4 NPs) were synthesized by novel precipitation method as inverse spinel (Fe2O3. FeO). They are directly prepared without calcination under oxygen gas. The Fe3O4 NPs had been prepared by combining the iron sulfate solution with the aqueous mixture including sodium hydroxide and sodium nitrate, without and with using various surfactants such as sodium dodecyl sulfate (SDS), triton X100, cetrimonium bromide (CTAB) and cetramide (CT) as templates.  The FT-IR analysis demonstrated the Fe-O octahedral and tetrahedral bending at 744 cm-1 and 598 cm-1 respectively. The XRD analysis discovered  the mean crystal size of  Fe3O4 NPs is smaller than that presence of surfactants, and its value increment from 8.5 nm for Fe3O4 NPs to 21.55 nm, 22.53 nm, 27.66 nm, and 27.72 nm for Fe3O4 + Triton X-100, Fe3O4 + CT, Fe3O4 + SDS, and Fe3O4 + CTAB, respectively. SEM revealed their samples are nanoparticles and aggregated together like broccoli.  The possibility of using Fe3O4 NPs as magnetic adsorbents to remove the eosin yellow dye from aqueous solutions was successes and economy, due to collect by magnets without need for a long time to separate with centrifuge or filter paper. The maximum chemisorption of dye was 94.48 % using Fe3O4 NPs + CT at shaking 1hour, because CT has a positive part as a hydrophilic moiety and the used dye is acidic nature so will attract and dye easy removal, and the reuse reached to five times with efficiency depressed to 75.61 %.

Magnetic nanoparticles are very effective in removing heavy metals from wastewater that can be produced by adding to mineral adsorbents, a modified adsorbent with high adsorption properties. The addition of magnetite nanoparticles to bentonite increases the cationic adsorption power of bentonite. In this paper, the adsorption of cobalt ions on metal ions is investigated using synthesized magnetite bentonite nano-absorbent (SMB) (30-40 nm). First, The nano-absorbents were produced by co-precipitation and analyzed by Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), and Fourier Transform InfraRed (FT-IR) spectroscopy, then used as adsorbent. The experiments were designed and evaluated by design expert software. Optimal conditions were obtained by CCD model for metal ion adsorption (removal). The optimum amount of adsorption of Co 2+ ion from the solution was 95%.

Sono-chemical is a fast procedure for preparing monodisperse nanoparticles. Magnetite nanoparticles were prepared via a sono-chemical reaction at a room temperature. Fe3O4 nanostructures were then added to acrylonitrile-butadiene-styrene (ABS) copolymer. Nanocomposites are very attractive due to the fact that small amount of nanostructure can lead to great improvement in many properties, such as mechanical and thermal property. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The XRD pattern of nanoparticles is indexed as a cubic phase (space group: Fd-3m). Fe3O4 nanostructures exhibit a super paramagnetic behaviour with a saturation magnetization of 54 emu/g and a coercivity of 11 Oe at room temperature. The effect of ultrasonic power on the shape and particle size was investigated and the result showed at 150W by increasing power growth stage overcome to nucleation stage and nanoparticles with bigger diameters were obtained. The flame retardancy behavior of ABS-Fe3O4 was studied by UL-94 analysis.

A mesoporous silica SBA-15/iron oxide (Fe3O4-SBA-15) nanocomposite was fabricated and employed as a magnetic solid-phase extraction (MSPE) sorbent to determine three types of organophosphorus pesticides (OPPs) in fruit samples. The fabricated nanocomposite was analysed using high-performance liquid chromatography with an ultraviolet detector (HPLC-UV). Meanwhile, the optimisation of extraction efficiency on three OPPs analyses used three different parameters, viz. desorption conditions, extraction time, and sorbent amount. The experimental results showed that the Fe3O4-SBA-15 nanocomposite achieved high analyte recoveries ranging from 89 to 118% with a relative deviation of less than 8.0%. By combining the optimised MSPE conditions with HPLC-UV, a suitable method for determining three OPPs was developed. This study revealed that the proposed method exhibits good coefficients of determination varying from 0.9942 to 0.9980, with low limit detection (LODs) ranging from 0.03 - 0.08 mgL-1 and low limit quantifications (LOQs) of 0.10 - 0.24 mgL-1. Based on these findings, the fabricated Fe3O4-SBA-15 nanocomposite is a suitable sorbent with excellent adsorption capacity for the selected OPPs from fruit matrices.

In this study, magnetite nanoparticles (Fe3O4) were synthesized as a magnetic core by chemical co-precipitation process and coated with a silica layer. The (Fe3O4@SiO2) core-shell magnetic nanoparticles were functionalized by organic-base tags to produce the MNPs-TBAN nanoparticles as a novel hybrid nanostructure. The morphology, stability, and magnetism of this hybrid nanostructure were characterized and studied by Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), vibrating sample magnetometry (VSM), X-ray powder diffraction analysis (XRD), scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The prepared hybrid nanomaterial was successfully used as a basic heterogeneous catalyst for the synthesis of pyrano[2,3-d]pyrimidine derivatives, via the condensation of an aldehyde, malononitrile and barbituric acid or thiobarbituric acid. The reaction was afforded the desired products in high purity and has advantages of excellent yields, simple workup procedure, and short reaction time. The catalyst was easily separated from the reaction mixture with the assistance of an external magnet and reused for several runs without noticeable deterioration in catalytic activity.

Plant-mediated synthesis of iron oxide nanoparticles has been increasingly drawing attention due to its eco-friendly nature and cost effectiveness. The biosynthesis technique engages plant secondary metabolites such as alkaloids, flavonoids, saponins, phenols, proteins, carbohydrates, glycosides, quinine, steroids, and tannins as reducers and/or stabilizers in the process of forming nanoparticles thereby replacing hazardous chemicals known with physical and chemical methods of nanomaterial synthesis. Biosynthesis method of nano particles has helped to a great extent to overcome some drawbacks, such as high energy and space requirement as well as high cost and hazard associated with various known physical and chemical methods. This work reviewed the biosynthesis of plant mediated iron oxide nanoparticles and their applications in water and wastewater treatment. Much work has been done to explore the effective, safe and cheap method for the dye removal in recent years. However, in future, more methods need to be explored to study and check the removal of dyes from wastewater using plant-mediated iron oxide nanoparticles for safer, cheaper and more efficient performance.

In the present work, stable ferrofluids containing oleic acid capped magnetite nanoparticles were synthesized via low temperature hydrothermal method. The physical and chemical properties of the synthesized particles were studied using TEM, XRD, AFM, VSM and PCS techniques. Mean particles size of the samples was between 4.5 and 10 nanometers, depending on experimental conditions. Effect of precursor’s medium alkalinity was investigated on particle size. Cell culture experiments performed via MTT assay demonstrated that this product was biocompatible. In addition, cellular uptakes were investigated by Prussian blue staining and also measuring Fe concentration by inductively coupled plasma spectroscopy. Finally, the synthesized particles were dispersed in the Ethiodol and the obtained suspension was used as a potential MRI contrast agent. To the best of our knowledge, the mentioned procedure of using a non-aqueous based MRI contrast agent has been done for the first time in the present work and provides good capabilities as opposed to aqueous ones including reduced synthesis process time and increased magnetic properties of the obtained contrast agent.

The surface of magnetite nanoparticles as nano-sized solid support was modified with a molybdenum-Schiff base complex to prepare an easily separable heterogeneous catalyst for the epoxidation of olefins. Characterization techniques such as Fourier transform infrared and inductively coupled plasma optical emission spectroscopies, X-ray diffraction, vibrating sample magnetometry, scanning, and transmission electron microscopies indicated the presence of molybdenum-Schiff base complex and a magnetite core in the catalyst. The magnetite nanoparticles supported Mo catalyst exhibited high catalytic activity and selectivity toward the epoxidation of olefins and was easily recovered from the reaction mixture by magnetic separation to be utilized for subsequent reactions. The catalyst showed reusability for three times without significant loss of activity.

In this work, PEI and PVC grafted Ni doped superparamagnetic iron oxide (i.e. PEI/Ni-SPIOs and PVC/Ni-SPIOs) were synthesized on steel sheet though galvanostatic (constant current) deposition mode. Structural and morphological properties of the fabricated PEI/Ni-SPIOs and PVC/Ni-SPIOs samples were studied and the results indicated the successful synthesis of polymer grafted iron oxide nanoparticles. The size of prepared particles was about 20 nm. Thermogravimetric data showed 7.2 wt % PEI and 6 wt % PVC coated onto the surface of Ni-SPIOs particles. The magnetite crystal phase of samples was proved via XRD and IR data. In addition, the obtained results from vibrating sample magnetometer analysis showed that the fabricated samples exhibit low residual magnetization values (i.e. Mr=0.95 and Mr=0.53 emu/g, respectively, for PVC and PEI grafted Ni-SPIOs), which revealed their suitability for biomedical uses.

Considering many applications of functionalized metal oxide nanoparticles in magnetic resonance imaging, drug delivery, neutron irradiation, electronics, catalysis and optics; herein, a new strategy is developed to functionalize magnetite nanoparticles to improve their performances in the delivery of acyclovir. In this study, magnetite Fe3O4 nanoparticles are synthesized by hydrothermal method. Then, the surface hydroxyl groups were extended by treating with TEOS (tetraethyl orthosilicate); Finally, TMPA (trimethoxysilyl propylamine) was anchored to the surface hydroxyl groups to produce amino-functionalized Fe3O4@SiO2-NH2 magnetic nanoparticles. The synthesized sample was characterized by UV-Vis, FESEM, FT-IR, and XRD. Afterward, the functionalized nanoparticles were examined in the delivery of acyclovir as an active antiviral drug model involving amine and hydroxyl functional groups. For this purpose, the amount of loading/release of the drug was investigated in different pHs, including mouth and stomach pH values. The screened experimental parameters in this study revealed that the prepared magnetite nanoparticles decorated with amine functional groups are successful in the controlled delivery of acyclovir.

In this research, a simple and efficient cathodic electrochemical deposition (CED) route wasdeveloped for the preparation of magnetite nanoparticles (NPs) in an aqueous media. Thesurface of magnetite NPs was also coated for the first time via an in situ procedure during theCED process. In this method, initially, the Fe3O4 NPs (with size ~10 nm) were prepared from theFe2+/Fe3+ chloride bath through CED process. Then, dextran as the coating agent was coatedon the surface of Fe3O4 NPs during the CED process. The prepared NPs were characterizedby different techniques such as XRD, FE-SEM, TEM, IR, TGA, DLS and VSM. The XRD resultsproved the pure magnetite i.e. Fe3O4 crystal phase of the prepared samples. Morphologicalobservations through FE-SEM and TEM revealed particle morphology with nano-sizes of 8nm and 12 nm for the naked and dextran coated NPs, respectively. The dextran coat on thesurfaces of NPs was confirmed by FT-IR and DSC-TGA analyses. The average hydrodynamicdiameters of 17 nm and 54 nm were measured from DLS analysis for the naked and dextrancoated NPs, respectively. The magnetic analysis by VSM revealed that prepared NPs havesuperparamagnetic behavior, i.e. Ms=82.3 emu g–1, magnetization Mr=0.71 emug–1 and Ce=2.3Oe for the naked NPs, and Ms=43.1 emu g–1, Mr=0.47 emu g–1 and Ce=0.81Oe for the dextrancoated NPs. These results implied that this electrochemical strategy can be recognized as aneffective preparation method of polymer coated Fe3O4 NPs.

In this research, the magnetite polystyrene maleic anhydride (MPSMA) was synthesized and structure and morphology characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy techniques. The obtained nano-structured inorganic material was employed as a novel magnetic nanosorbent for separation and pre-concentration of Methyl violet (10B) dye from aqueous solutions, which can be spectrophotometrically monitored at λ = 585 nm after pre-concentration by solid phase extraction (SPE). The effect of several parameters including pH of the sample solution, amount of the sorbent, extraction and desorption times, and elution conditions and sample volume were investigated and optimized. UV–Vis spectrophotometer was used for determination of MV (10B) concentration after desorption of the dye by nitric acid solution. Under the optimum experimental conditions, the limit of detection and the relative standard deviation were 0.08 µg L–1 and 1.10 %, respectively. The enrichment factor of 200 was achieved and the calibration graph using the presented solid phase extraction system was linear in the range of 0.3 – 1500 µg L–1 with a correlation coefficient of 0.9989. The method was successfully applied to pre-concentration of MV (10B) from several textile waste water effluents.

A nano-hybrid based on polystyrene derivatives and magnetite was introduced as a new sorbent for pretreatment and determine the trace amount of malachite green from aqueous solution by spectrophotometry after preconcentration by solid phase extraction (SPE). UV–Vis spectrophotometer was used for determination of MG concentration after desorption of the dye by hydrochloric acid solution in the solutions. Different variables affecting the separation/pre-concentration conditions, including pH of the sample solution, amount of the sorbent, extraction and desorption times, sample volume, and elution conditions were obtained in the range of 1–2000 ng/mL dye, with the correlation coefficient of 0.998. The enrichment factor of 133 was achieved. The limit of detection was 0.2 ng·mL−1 and the relative standard deviation for the determination of malachite was 1.4 % (n=6(. Langmuir, Freundlich, adsorption isotherm models were studied and the experimental results were addressed by Freundlich isotherm model. The maximum sorption capacity of the adsorbent for malachite green was 148.6 mg. g-1, indicating high potential of MSMA in the adsorption of malachite green. The adsorption kinetics was studied with the pseudo-first-order, pseudo-second-order models. The method was successfully applied to determine malachite green in natural waters and satisfactory recoveries were obtained >98 %.from this.

Magnetite (Fe3O4) nanoparticles have been successfully prepared by a novel one-step and surfactant-free approach utilizing ferrous ion, as a single iron source. In this manner, the reaction occurs between two aqueous solutions via the spontaneous transfer of ammonia gas from one to another in room temperature. No ferric source or oxidizing specie, oxidation controlling and capping agents are needed and the method is suited for large-scale preparation. The effects of reaction conditions on the formation of Fe3O4 were investigated using powder X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) techniques. The results have demonstrated that the pure and single phase magnetite nanoparticles were synthesized at the final pH values higher than 8. Accordingly, the formation mechanism of these nanostructures is proposed. Moreover, the vibrating sample magnetometry (VSM) measurements of the as-synthesized nanoparticles show their room temperature superparamagnetic characteristic with a typical saturation magnetization of 51 emug−1.

In this work, a new hybrid organometallic-inorganic hybrid nanomaterial was prepared by immobilization of acetyl ferrocene on the surface of magnetite nanoparticles. Covalent grafting of silica coated magnetite nanoparticles (SCMNPs) with 3-aminopropyl triethoxysilane gave aminopropyl-modified magnetite nanoparticles (AmpSCMNPs). Then, Schiff base condensation of AmpSCMNPs with acetyl ferrocene resulted in the preparation of acferro-SCMNPs hybrid nanomaterial. Characterization of the prepared nanomaterial was performed with different physicochemical methods such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). VSM analysis showed superparamagnetic properties of the prepared nanomaterial and TEM and SEM analyses indicated the relatively spherical nanoparticles with 15 nm average size.