Papers by Keyword: Magnetite

Abstract: Magnetite nanoparticles are synthesized in an environmentally friendly way by utilizing natural ingredients found in citrus limon juice. The acid in citrus limon juice serves as a fuel for the sol-gel process, producing magnetite nanoparticles. Annealing treatment (400°C, 500°C, and 600°C) is used to change the structural and magnetic properties of the magnetite nanoparticles. All samples magnetite phase was verified by X-Ray Diffraction (XRD) examination. Increasing the annealing temperature causes an increase in crystallite size from 10.81 to 27.30 nm. Furthermore, the results of infrared spectroscopy revealed the presence of oxide bonds (M-O) in the range 558–567 cm^-1 and 408–437 cm^-1, which are Fe-O bonds. Magnetic properties also change as a result of the annealing treatment, which is characterized by increased saturation magnetization and changes in other magnetic parameters. Furthermore, green synthesis of magnetite nanoparticles is effective against gram-negative bacteria (E. Coli) with enhanced antibacterial performance.

Abstract: The magnetic properties of magnetite nanoparticles (Fe₃O₄ NPs) are being investigated. Fe₃O₄ NPs were prepared using the co-precipitation method and oven dried. The magnetic properties are influenced by the electron environments of the Fe³⁺ ions within the iron oxide structure. XPS spectra of Fe³⁺ (2p_3/2) and (2p_1/2) show peaks around 706.45 eV and 720.76 eV, respectively. Furthermore, magnetite NPs dried at 60 °C exhibited the largest hysteresis loop at 50K and less at 300K. In addition, the values of Ms and Mr indicate ferromagnetic behavior in Fe₃O₄ NPs. The result of this material shows high Ms (~38.638 emu/g) at 50K with Hc of 3.094K (near ferromagnetism) and ~33.843 emu/g at 300K with Hc of 0.000K (superparamagnetic). However, these magnetic properties are utilized for biomaterial applications such as separating biomolecules or coating core shells for nanoparticles, which presents an option for future biomedical technology.

Abstract: Magnetite (Fe₃O₄) nanoparticles have garnered significant attention in biomedicine due to their distinctive magnetic properties, biocompatibility, and ease of functionalization for diverse applications. In this study, Fe₃O₄ nanoparticles were synthesized via the co-precipitation method, followed by the synthesis of a SiO₂ coating on Fe₃O₄ (Fe₃O₄@SiO₂) and an amino group coating on Fe₃O₄@SiO₂ (Fe₃O₄@SiO₂_NH₂) before chitosan coating. Chitosan concentration was varied at 1% and 5% to improve their stability and biocompatibility. Characterization of the nanoparticles was conducted using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDXS). XRD analysis confirmed that the synthesized nanoparticles were magnetite (Fe₃O₄), while FTIR confirmed the presence of -OH and -NH₂ functional groups, which increased after coating with a chitosan layer on the magnetite surface. SEM/EDX analysis revealed that the average diameter of the uncoated Fe₃O₄ nanoparticles was approximately 12 nm, and EDX analysis indicated the presence of sodium after coating with chitosan. Using chitosan as a coating material enhanced the biocompatibility, stability, and functional versatility of the nanoparticles. The results demonstrated the successful coating of chitosan on the Fe₃O₄ nanoparticles, which retained their superparamagnetic properties, making them promising candidates for drug delivery applications.

Abstract: Recently, magnetic nanocomposites have demonstrated considerable potential for applications using magnetic fluid hyperthermia (MFH). The synthesis of hybrid nanocomposites of carbon nanotubes-iron oxide (CNT-Fe₃O­₄) for radio-frequency hyperthermia therapy and the investigation of their heating efficiency at varying frequencies and field amplitudes of an alternating magnetic field (AMF) are reported. XRD, SEM, EDS, FTIR and SQUID techniques have been employed to fully characterize the as-synthesized samples. XRD and FTIR results confirmed the successful fabrication of the nanocomposites. Magnetization (M) versus magnetic field strength (H) loops at room temperature revealed superparamagnetic behavior with saturation of 17 emu/g. Zero-field-cooled and field-cooled (ZFC-FC) curves showed that the blocking temperature (T_B) was around 282 K. Heating abilities and SAR values as functions of frequency, field amplitude of AMF and concentration of nanoparticles were systematically investigated. Hyperthermia temperatures range can be attained in relatively short times for different concentrations of the nanocomposite. An enhancement in SAR was observed with decreasing concentrations and rising frequency and amplitude. Interestingly, the lowest dose of the nanocomposite (2.5 mg/ml) showed the greatest SAR (113W/g) and intrinsic loss power (ILP) of 1.86 nHm²/kg. This elevated ILP value falls into the range achieved by commercial ferrofluids (0.2−3.1 nHm²/kg). Lastly, according to linear response theory (LRT), SAR values depend on field amplitude. Overall, the obtained nanocomposites have a significant potential for use in cancer therapies involving hyperthermia, as indicated by their generally good heating efficiencies.

Abstract: The article presents the results of studies of the chemical stability of solidified radioactive waste with alkali cement through long-term leaching. Efficiency of application of alkaline slag Portland cement type LCEM IV as a matrix for reliable chemical and physical binding of caesium ions in the compound for long-term burial we confirmed. Modification of alkaline cement by additions of magnetite from 5 to 8.3% and zeolite in the amount from 4.2 to 5% promotes additional sorption of caesium ions in solidification products of alkaline matrix at maximum content of radioactive waste up to 17.5%. It they noted that the maximum values of sorption capacity of compounds (from 42000 to 68000 ml/g) we observed on the 14th day of the leaching process. They are characteristic for compounds containing magnetite from 5 to 8.3%, zeolite - from 4.2 to 7.5% and radioactive waste from 10 to 15%. It is shown that on the first day of leaching the highest rate (8.35E-02 g/сm²day) is characterised by compositions containing magnetite from 5 to 8.3%, zeolite from 4.2 to 5% and radioactive waste from 15 to 17.5%. At 56 days of the test, the leaching rate decreases exponentially to values of 3.45E-05 to 9.62E-06 g/сm²day. Characteristic of compounds, magnetite and zeolite up to 5% and radioactive waste 17.5%.

Abstract: The interfacial solar steam generator presents a viable and environmentally conscious solution for generating fresh water from seawater. The interfacial solar steam generator is accomplished through the integration of a photothermal material with a supporting material, resulting in a bilayer structure. In general, the efficiency of achieving a bilayer structure by the coating of a photothermal material on the surface of a substrate is limited. This is due to the potential for separation and variations in coating thickness, which can result in a drop in the rate of evaporation. In this study, a bilayer structure was successfully obtained through the implementation of a co-gelation technique utilizing a biomass-derived substrate, aerogel cellulose, and magnetite (Fe₃O₄) as photothermal materials. Additionally, we investigate the impact of magnetic fields on the evaporation rate of photothermal materials. The bilayer solar steam generator obtained demonstrates a notable evaporation rate of 1.87 kg.m^-2h^-1, which is sufficient to meet the daily water requirements of individuals.

Abstract: For the purpose of synthesizing 2D-Material–Magnetic nanocomposites, several new modifications of existing 2D-materials synthesis methods by exfoliation and chemical synthesis from liquid charge are developed. Using them, graphene (G), graphene oxide (GO), reduced graphene oxide (rGO) and hexagonal boron nitride (h-BN) matrix magnetic nanocomposites for the first time are obtained by coating or intercalation their nanoparticles with ferromagnetic iron (Fe) or ferrimagnetic iron oxide – magnetite (Fe₃O₄). These materials are prospective for variety of high tech applications. In particular, h-BN–Fe₃O₄ composite nanoparticles can serve for neutron-capturing boron isotope ¹⁰B effective delivery agents in BNCT (Boron Neutron Capture Therapy) of cancer as they allow the controlling by an external magnetic field targeting to tumor tissue.

Abstract: The article provides information about the initial elements in the waste and tailings of the copper processing plant of the Almalyk Mining and Metallurgical Combine and theoretical solutions for the extraction of metals. According to chemical data, the amount of iron in the waste is high (52.6%), and the most effective solution for extracting iron from the waste is the reduction process. An increase in the amount of iron to 88.9% was formed using coal and lime as reducing agents.

Abstract: The application of an external electric field to the surface plasmon resonance (SPR) system of green-synthesized magnetite (Fe₃O₄) nanoparticles (MNPs) is very promising for increasing the SPR detection signal. Electro-optic surface plasmon resonance (EOSPR) behavior of MNPs has been successfully carried out. The EOSPR system was investigated using the Kretschmann configuration with the prism/Au thin film/MNPs/air layer arrangement and applying an electric voltage of 0 V, 2 V, 4 V, and 6 V. In this study, we synthesized MNPs using the green synthesis approach from moringa oleifera extract. The benefits of green synthesis include being safe, affordable, clean, and ecologically friendly processes. X-ray diffraction results obtained crystal size of the MNPs is about 9.2 nm with inverse spinel face-centered cubic crystal structure. Fourier transforms infrared characterization showed the presence of Fe-O bonds at wave numbers 569 cm^-1 and 629 cm^-1, indicating that MNPs were successfully formed. The saturation magnetization of the samples is 55.3 emu/g. The SPR angle of the SPR system Prism/Au thin film/air without the addition of MNPs is 44.66°. After being deposited by MNPs and induced by a voltage of 0 V, 2 V, 4 V, and 6 V, the SPR angles changed to 44.87°, 44.90°, 44.95° and 45.12°. The addition of MNPs and an external electric field causes the SPR angle to increase. The results of this study can provide new insights into the development of optical devices that can be manipulated electrically and have the potential for future biosensor applications.

Abstract: The aim of this research is to identify the crystal structure, surface area, and magnetic properties of The Mn_0.25Fe_2.75O₄-rGO (reduced Graphene Oxide) nanocomposites (NCs). The synthesis of Mn_0.25Fe_2.75O₄-rGO nanocomposites used the co-precipitation method. The rGO was obtained from the chemical reduction of GO by hydrazine hydrate as the reduction agent. The ratio between Mn_0.25Fe_2.75O₄ nanoparticles and rGO was 1:1 that ultrasonicated at 200 Hz for an hour. The IR spectra of NCs from the FTIR instrument showed that the absorption band around 580 cm^-1 and 1622 cm^-1 corresponds to the stretching mode of Fe-O and C=C respectively. According to X-Ray Diffraction (XRD) pattern analysis, peak of Mn_0.25Fe_2.75O₄ was detected on 2θ at 30.1°, 35.5°, 53.5°, 57.1°, 62.7° and the peak of rGO phases was amorphous that detected on 2θ between 17º and 30º. The XRD pattern analysis and FTIR spectra have proved the completion of NC’s synthesis. The crystallite size was between 10.3 nm by Scherer's formula. The Specific Surface Area showed that the surface area of the nanocomposites was 100.61 m²/g and the Molecular cross-sectional area was 0.162 nm² by BET Theory. The Magnetic properties show that the NCs were Superparamagnetic material that has a saturation magnetization of 9.34 emu/g. The material has many potentials to be explored by the researcher around the world.