Papers by Keyword: Iron Oxide

Abstract: Carboxylic (COOH) functionalized zinc oxide and iron oxide (COOH-ZnO@Fe₃O₄) composites were used in this study to modify polyamide thin film composite membranes. The resultant membranes exhibit improved water permeability, greater antifouling qualities, robust stability for repeated usage, and enhanced rejection of Pb²⁺ metal ions compared to the unmodified membrane. In contrast to the unmodified PA-TFC membrane, which had an 82.36±0.01% Pb²⁺ removal efficiency, a contact angle of 82.36°±0.01, a flux recovery ratio of 33.6%, and a water permeation flux of 3.3 L·m⁻²·h⁻¹, the membrane containing 1.5% of the COOH-ZnOFe₃O₄ composite, for instance, achieved a 97.6±0.35% Pb²⁺ removal efficiency, a lower contact angle of 58°±1.86, a higher flux recovery ratio of 86.3%, and a higher water permeation flux of 10.23 L·m⁻²·h⁻¹. Additionally, by combining ZnO, Fe₃O₄ nanoparticles, and COOH groups from sodium polyacrylate as additives to the PA layer, the modified membranes demonstrated improved performance relative to the other membranes.

Abstract: Nanoparticles' unique properties, such as their huge surface area, higher thermal conductivity, and increased dielectric strength, make them appealing candidates for high voltage insulation applications. The choice of a suitable surfactant is critical in the creation of nanofluids. The ratio of hydrophilic to lipophilic (HLB) values, which ratio up the hydrophilic and lipophilic structure of the surfactant, is normally considered in the selection of suitable surfactant for the nanofluid. Surfactant with HLB value less than 6 is said to be more suitable for oil base nanofluids. Recent research, however, indicated that the sediment generated by high and low HLB value surfactants is not significantly different. Tween 20 surfactant, while rarely used in this context due to its high HLB value, is an intriguing option due to its affordable cost and excellent properties. Its distinct features, such as low toxicity, and strong emulsification capacity, make it an appealing candidate for stabilizing and dispersing nanoparticles in nanofluid compositions. In this research, tween 20 was used in the preparation of palm oil (PO) and palm fatty acid ester oil (PFAE) based nanofluids. Iron (II,III) Oxide (Fe₃O₄) nanoparticle was introduced to the nanofluids at high, medium and low concentrations. The nanofluids were evaluated in terms of its breakdown strength and dielectric properties. The alternating current (AC) breakdown and dielectric properties were conducted based on the IEC 60156 and ASTM D924 Standard respectively. Tween 20 has positive impact on shortening down the sonication period by 10 % and 33.3 % for PO and PFAE based nanofluids, respectively, while elongating the sedimentation period for PO nanofluids. The breakdown voltage improved by 40% and 18% for PO based nanofluid and PFAE based nanofluid, respectively. Even at low concentrations, the inclusion of Fe₃O₄ nanoparticles improved breakdown strength, and breakdown voltage distributions offered useful information. The addition of nanoparticles slightly increases the relative permittivity of the base oils. Fe₃O₄ nanoparticle and tween 20 surfactant has successfully improved the dielectric loss of the base oil with the lowest value recorded at 0.05 g/L, with 72.4 % and 36.8 % improvement for PO and PFAE based nanofluids, respectively. These results proved that tween 20 is suitable for oil-based nanofluids applications.

Abstract: Iron oxide was produced from lathe waste using green tea leaf extracts. Green tea leaves contain catechins, has been produced as a possible reducing, precipitating, stabilizing, and capping agent. Another advantage of applying green tea leaves to synthesize iron oxide is reducing toxicity. Various temperatures of synthesis utilizing the precipitation method proved successful in the formation of hematite. X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscope (SEM) were used to characterize the synthesis product. According to the XRD results, the magnetite transition phase was obtained after precipitation, while hematite formed after calcination. The crystallite sizes were 50.5 nm, 45.4 nm, and 39 nm, respectively. According to FTIR identification, the iron oxide was generated before and after calcination in the presence of a specific Fe-O group at the wavenumbers 553 cm^-1 and 451 cm^-1. The SEM results revealed that the particle size ranges from 4.61 nm – 20.74 nm, and the shape was not uniform, and aggregation.

Abstract: In this study, synthesis of reduced graphene oxide-iron oxide-silica dioxide (rGO/Fe₃O₄/SiO₂) was done through a facile chemical process. Physical characterization was carried out as such Fourier transform infrared spectroscopy (FTIR) which confirmed the presence of silica peak in the spectrum of rGO/Fe₃O₄/SiO₂, while RAMAN displayed the vibrational bands of carbon materials studied. Results of SEM-EDX and TEM confirmed the unification of SiO₂ on rGO/Fe₃O₄ nanocomposite with difference in morphologic structure. X-ray diffraction (XRD) analysis exhibited that addition of SiO₂ increased the crystalline size of the nanocomposite. Nitrogen adsorption isotherm analysis describes the nanocomposites fall in the mesopore region. The nanocomposite was then drop-casted on the surface of glassy carbon electrode (GCE) for fabrication of the electrode which denoted as rGO/Fe₃O₄/SiO₂/GCE. Electrochemical characterization of modified electrode was studied using electron impedance spectroscopy (EIS), which showed the minimal resistance charge transfer. Oxygen reduction reaction analysis shows that electrocatalytic reduction of oxygen was excellent with four-electron transfer when calculated using Randles-Sevcik equation. All the analysis was compared to the nanocomposites without the addition of silica oxide (rGO/Fe₃O₄)_. This work proves that addition of nanoparticle in a compound as a matrix improves the oxygen reduction potential of rGO/Fe₃O₄/SiO₂/GCE composite.

Abstract: Disposing of dyes without proper treatment can cause water pollution because disposable dyes have a complex composition and are inert, so they must be adequately treated before being discharged into the waters. Using carbon from sugar palm (Arenga pinnata) fiber waste modified with iron oxide can be an alternative functional adsorbent for dye waste. The production of this practical adsorbent starts with carbonation of palm sugar fiber, chemical activation using H₂SO_4, incipient wetness impregnation with Fe(NO₃)₃.9H₂O and ends with calcination at various temperatures of 200 °C, 300 °C; and 400 °C for 2 hours. The resulting carbon adsorbent material is characterized using FTIR (Fourier Transform Infrared), XRD (X-Ray Diffraction), and SEM (Structural Equation Modeling) analysis. In addition, the absorption capacity of the adsorbent for the dye waste is tested using the UV-VIS (Ultraviolet-Visible) instruments.

Abstract: Iron is a ubiquitous element found on Earth's crust, existing in various forms, such as Magnetite (Fe₃O₄) and Hematite (α-Fe₂O₃). Magnetic iron oxide nanoparticles (MIONPs) have become increasingly popular because they possess unique properties such as high surface area to volume ratio, super-paramagnetic properties, photocatalytic properties, and economical synthesis methods. This study produced MIONPs using the co-precipitation method, stabilized by a molybdenum magnet. Two soluble iron salts (FeCl₃.6H₂O and FeSO₄.7H₂O) were reacted with 5N NH₄OH solution at 80 °C in a nitrogen atmosphere. The MIONPs had a high saturation magnetization of 74.2emu/g, good crystallinity with crystalline spinel structured magnetite phase of iron oxide, high thermal stability depicted by 2.09 wt. % weight loss, and small particle sizes (6-25 nm). FTIR revealed a high-intensity peak at 546.28 cm^-1, attributed to the Fe-O stretching bond. Furthermore, the study showed that the co-precipitation method could be used to produce nanoparticles with a wide range of properties that could be used for various applications. It is a promising solution for producing stabilized magnetic nanoparticles since it uses non-toxic reagents and a straightforward, secure technique. Therefore, it may be used to synthesize nanoparticles for targeted treatment, magnetic resonance imaging, drug delivery, water treatment purposes and environmental remediation.

Abstract: In this research, a homemade autoclave reactor was used for preparing iron oxide nanoparticles by hydrothermal technique at different reaction times by using ferric chloride, ferrous sulfate, and ammonium hydroxide as raw materials. The XRD characterization showed that the nanoparticles of the samples have high crystallinity with the crystal phase of magnetite, furthermore, the crystal phase of hematite appears clearly as the reaction time increased. The SEM results showed when the time of reaction increased the average particle size increased too from 28.1 to 49.2 nm. That means the reaction time is an effective parameter for the nanoparticle's growth, The EDX spectrum verified the confirmation of iron oxide nanoparticles by the appearance of Iron and Oxygen peaks. The FT-IR results showed that all samples have an absorption peak at about 578 cm^-1 corresponding to the Fe-O bond stretching modes of the in magnetite and the peak of hematite appeared as the reaction time increased above 2 hours which was confirmed with XRD results. Finally, the reaction time is a powerful tool for controlling in size and phase of nanoparticle preparation. Keywords: Hydrothermal, Iron Oxide, Reaction time, magnetite, and hematite.

Abstract: This study was carried out to determine the possibility of reducing the iron oxide ratio in silica sand from Ardhumah, an area, (18) km west of Rutba, a city in Al-Anbar Governorate, to obtain sand specifications appropriate for making colorless glasses (not exceeding 0.02 % iron oxide ratio). The reduction process of iron oxide includes three stages; the first stage is magnetic separation to reduce Fe₂O₃ from 0.092% to 0.040%, the second stage is re-floatation which has reduced Fe₂O₃ to 0.024%, finally treatment of the sand output from the first and second stage with diluted HCl or H₂SO₄, this study showed the possibility of obtaining silica sand with a ratio of Fe₂O₃ up to 0.016%.

Abstract: In this research, iron oxide nanoparticles were prepared by a new hydrothermal pyrolysis technique at different reaction times. X-ray diffractometer (XRD) characterization showed that the nanoparticles have high crystallinity with a combination of two crystal phases maghemite and magnetite, as the reaction time increase the ratio of magnetite phase to maghemite phase increased. The morphological properties of the samples showed an increase in the particle size from 58 to 108 nm due to the single domain–multidomain transition as showed by scanning electron microscope (SEM). Electron Dispersive X-ray (EDX) spectra showed only peaks of oxygen and iron that verified the formation of iron oxide nanoparticles. The Fourier transform infrared spectroscopy (FT-IR) showed that the absorption peaks at about 578 cm^-1 and 630 cm^-1 correspond to the stretching modes of the Fe-O in magnetite, as the reaction time increased the peak around 630 cm^-1 decreased due to the magnetite phase only. Finally, all the results showed the formation of iron oxide nanoparticles by this new technique that merges spray pyrolysis and hydrothermal techniques with many advantages such as spraying successive parameters in a short time, high-speed, good homogeneity, and pure material with small particle size.

Abstract: The need to recycle and develop valuable materials from waste, and use them in various applications have become increasingly important in recent decades. Printer toner waste is one of the most polluting electronic waste due to the toxic nature of the material content in it. Despite the toxicity of the material in the toner powder, it contains iron oxide that can be extracted and recycled to make a beneficial material. Therefore, this study aims to investigate a facile and effective method to extract iron oxide from printer toner waste powder. Magnetic separation and oxidation processes were used as a method for extraction and phase conversion. The structural transformation was investigated using X-ray diffraction, microstructural observation using scanning electron microscope whereas static magnetic characteristics were investigates using vibrating sample magnetometer. The results from XRD spectra show that printer toner wastes that have been subjected to magnetic separation process and chemical treatment, even without any heat treatment process, have produced a single phase magnetite. Through the process of heat treatment on the sample, phase transformation from magnetite to hematite occurs, in which a single phase of hematite is obtained at a temperature of 1400 °C. The saturation magnetization of the sample also showed a reduction where the sample before undergoing the heat treatment process had a saturated magnetization value of 18.81 emu/g. Meanwhile, after heat treatment, the saturation magnetization value decreased to 0.42 emu/g. These results are in line with the phase transformation shown where magnetite has high ferrimagnetic characteristics, whereas hematite is basically antiferromagnetic at room temperature. However, the saturation magnetization that has been obtained in hematite shows a little difference to that of commercially sold hematite. This proves that iron oxide extracted from printer toner waste has a high potential as an alternative to existing commercial iron oxide in producing high performance magnetic materials.