Papers by Keyword: Iron Oxide Nanoparticles

Abstract: In this study, we synthesize the nanocomposites of Fe₃O₄/graphene using an electrochemical exfoliation followed by thermal treatment. The morphology and bonding structure of the prepared samples have been characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The photo-characteristic aspects of the prepared samples have been indicated by ultraviolet-visible diffuse reflection spectroscopy (DRS). The photocatalytic performance of Fe₃O₄/graphene demonstrated that it is an effective photocatalyst for methylene blue (MB) dye decomposition through illumination by a solar simulator. The results showed that after 10 minutes of electrooxidation/photocatalytic treatment in the presence of 1000 mg/L of the nanocomposite, dye degradation exceeded 70%, compared to only 29% with electrooxidation alone. Furthermore, after 60 minutes, degradation reached over 95% with the nanocomposite, compared to 75% for electrooxidation alone. Different MB concentrations and percentage photocatalyst loadings have been investigated. Furthermore, the results showed that as the amount of catalyst increased, the decomposition of MB enhanced. The results showed that the prepared nanocomposites had good photocatalytic activity towards water splitting and photodecomposition of MB.

Abstract: A magnetic resonance imaging contrast agent is proposed using iron oxide nanoparticles (IONPs) synthesized by a pulsed laser ablation technique. Experimentally, an Nd: YAG laser (1064 nm, 7 ns, 30 mJ) was directed and focused on a high-purity iron plate immersed in a liquid solution of deionized water and polyvinylpyrrolidone (PVP). After a few minutes of laser bombardment, iron oxide nanoparticles dispersed in the liquid were homogeneously produced. A reddish yellow color-colloidal IONPs are produced in the water, while its color changes to dark brown for the PVP solution. The characterization results demonstrated that IONPs in the form of Fe₂O₃ and Fe₃O₄ made in the PVP have an excellent dispersibility with a spherical shape that is significantly smaller than that of IONPs made in the deionized water at the same laser repetition rate. The produced IONPs are further applied as a contrast agent for the magnetic resonance imaging (MRI) modality by varying concentrations from 0.05 mM to 2.31 mM. The results demonstrated that images of the IONPs sample with a concentration of 2.31 mM showed the highest contrast enhancement (Cenh), with an enhancement factor of 221.875 % for T₁-weighted images and 91.227 % for T₂-weighted images. IONPs with a concentration of 2.31 mM had the highest signal-to-noise ratio (SNR) for a T₁-weighted picture of 52.92, while IONPs with a concentration of 0.05 mM had the highest SNR for a T₂-weighted image of 179.117.

Abstract: The synthesized iron oxide nanoparticles by green synthesis method have been widely favored because of highly bio-degradable, ecofriendly, environmentally, low toxicity and highly reactive surfaces. The aim of this study, the magnetite iron nanoparticles (Fe/NPs) were preparing by waste natural materials such as banana, orange, and pomegranate peels, that’s consider as reducing agent. In this study, evaluate of the magnetite nanoparticles for removal of pollutants from wastewater, and determined of efficiency, yield, size, shape and morphology of the synthesized iron nanoparticle. The synthesized nanoparticle was characterized by Fourier Transform Infrared spectrometer (FT-IR), X-ray diffraction (XRD), X-ray fluorescence (XRF), Energy disperse X-ray (EDX), and UV spectroscopy (UV-vis). The characterization of synthesized magnetite NPs was also done through-ray diffraction (XRD), X-ray fluorescence (XRF), Energy disperses X-ray (EDX), and UV spectroscopy (UV-vis). The FT-IR spectra confirmed the association of biological molecules from waste materials. The EDX and XRD data presented the elemental configuration matched with the iron element. Finally, the synthesized iron nanoparticles with pomegranate more efficiency than banana, and orange for removal of pollutants from wastewater.

Abstract: In this study Fe₃O₄-polyethersulfone (PES) membranes were prepared in the present of a magnetic field or without a magnetic field by using the phase inversion process. A comparison of membrane properties was investigated. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) were used to determine the morphology and chemical composition of the prepared membranes. Furthermore, the fouling analysis of the non-magnetized and magnetized Fe₃O₄-PES membranes were also conducted through the filtration study. The pure water flux of membranes increased from 158.49±11.96 L/m^2·hr (neat PES) to 187.06±6.54 L/m^2·hr (magnetized Fe₃O₄-PES). These results showed that the magnetized Fe₃O₄-PES membrane not only had the high pure water flux but also had a high humic acid (HA) rejection and good antifouling ability. As such, magnetized Fe₃O₄-PES membrane had excellent comprehensive properties which could use for water remediation.

Abstract: Ethylene vinyl-acetate copolymer (EVA) composite materials containing multiwall carbon nanotubes (MWCNT), graphene (Gr) and iron (III, IV) oxide (Fe₃O₄) nanoparticles where processed by melt blending. Film specimens were prepared by using compression moulding method. All nanoparticles content in samples was chosen equal to 20 wt.%. The material dielectric spectroscopy was used in a range of 10^-2 Hz to 10⁷ Hz to investigate nanoparticle effect on the dielectric active (ε’) and passive components (ε’’), specific electrical conductivity (σ’) and dielectric loss (tg) for the characterization of the dissipation of electromagnetic energy.

Abstract: Phosphate buffer saline (PBS) is commonly applied as an electrolyte for glucose sensor application because ion concentration and osmolality of PBS are similar to the human body. Therefore, it is important to study the effect of concentration and pH of PBS to the electrocatalytic performance of the modified electrode in glucose detection. In this study, the modification of indium tin oxide (ITO) glass electrode by utilizing iron oxide nanoparticles (IONP) coated with citric acid (CA), glucose oxidase (GOx) enzyme and Nafion layer (Nafion/Gox/IONP-CA/ITO) were performed. IONP was prepared by using the precipitation technique through formation of colloidal stable IONP in water at physiological pH. The size of IONP-CA precipitates was ~19 nm with maghemite (γ-Fe₂O₃) phase characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. Increasing the PBS concentration increased the electrocatalytic performance of the bioelectrode whereas pH of PBS buffer solution affected the GOx bioactivity. The modified electrode Nafion/Gox/IONP-CA/ITO displayed good electrochemical and electrocatalytic performance in glucose detection.

Abstract: The magnetic particles of iron oxides are promising materials for the purification of water from ions of heavy metals and radionuclides. Their advantage compared to other sorbents is the ability to extract by applied magnetic field, which greatly simplifies the task of extraction, separation and processing in cleaning technologies. The aim of this work is investigation of temperature and concentration of iron in the solution effect on the phase composition, nanoparticle size and their magnetization. Phase magnetite in the sample increases with increasing temperature and the magnetization decreases slightly with increasing the initial concentration of iron in solution. We found that regardless of the conditions of deposition formed spherical particles whose average size ranges from 7 to 15 nm. The sorptive capacity of the particles is virtually independent of the phase composition and for cobalt is about 18 mg/g. For sorption-based material magnetic particles Fe3O4 recommended to carry out the deposition process at a temperature not lower than 80°C. The concentration of iron in solution must be within 0,15–0,3M. The particles obtained contain in their composition at least 90 wt.% of magnetite phase and are characterized by a magnetization in the range of 65–70 A·m2/kg. Also in the paper is comparing efficiency of extraction and sorption capacity for cobalt particles by different phase of magnetite and hematite.

Abstract: In this work, iron oxide were derived from millscale has been used as a potential scavenging agent in wastewater treatment due to its high adsorption capacity and its shorter sedimentation time during wastewater treatment. Iron oxide obtained from the magnetic separation technique was subjected to high energy ball milling (HEBM) at different milling time to produce different size of nanoparticles of iron oxide. X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and Scanning Trasmission Electron microscopy (STEM) were performed to study the morphological properties of the iron oxide nanoparticles. After HEBM, iron oxide nanoparticles was modified with Hexadecyltrimethylammonium Bromide (CTAB) to study the adsorption possibility of iron oxide nanoparticle modified with CTAB (Iron oxide– CTAB nanoparticles) in dye wastewater. The variation effect of particle size of derived Iron oxide– CTAB were studied. Permanent magnet was used to separate iron oxide nanoparticles from the solution. The clear part of the solution (treated wastewater) was filtered out and adsorption efficiency of Iron oxide– CTAB nanoparticles was measured using UV – Visible spectroscopy. Efficiency adsorption of iron oxide nanoparticles modified with CTAB greatly achieved above 99 % and the size of iron oxide nanoparticles affected its performance in dye wastewater treatment.

Abstract: We report the effects of exposure to alkylated silicon nanocrystals (‘alkyl-SiNCs’ at concentration ~ 7.2 mg/L) and -Fe₂O₃ nanoparticles coated with ultra-thin silica (‘SiO₂-coated IONPs’ at concentration ~ 150 mg/L) on sea urchins Paracentrotus lividus and Arbacia lixula, respectively, studied with X-ray fluorescence (XRF) and Fourier transform infrared (FTIR) spectroscpoies using excitation from a synchrotron light source. A remarkably low mortality and low incidence of skeletal deformation is observed for exposure to both types of nanoparticles studied, despite the high concentrations employed in this work. XRF mapping demonstrates that both types of nanoparticle are found to agglomerate in the body of the sea urchins. FTIR spectra indicates that alkyl-SiNCs remain intact after ingestion and corresponding XRF maps show increased an oxygen throughout the organisms, possibly related to oxidation products arising from reactive oxygen species generated in the presence of the nanoparticles. Exposure to SiO₂-coated IONPs is found to produce sulphur-containing species, which may be the result of a biological response in order to reduce the toxicity of the nanomaterial.

Abstract: Superparamagnetic Iron oxide nanoparticles (SPIONs) have fascinated researchers due to their vast applications in biomedical fields such as magnetic resonance imaging, cell sorting, hyperthermia, drug delivery etc. The special properties of SPIONs depend on the method of synthesis and surface modification. Among various synthetic protocols, hydrothermal method has attracted much attention due to simplicity, uniformity and excellent magnetic properties of iron oxide nanoparticles. Magnetic properties of SPIONs could be tuned by controlling the size and shape of the particles as well as by the surface modification. Low colloidal stability and high hydrophobic nature of SPIONs result in aggregation of the particles which could be avoided by surface modification of the SPIONs using various capping agents. The size, shape and surface environment of SPIONs can also be controlled by the surface coating. SPIONs are promising contrast agents due to their non-poisonous nature, biocompatibility and large surface area. The biocompatibility of SPIONs is enhanced by the surface coating/modification. The present review focuses on the hydrothermal synthesis of SPIONs and their characterization using various techniques and the applications of SPIONs in the MRI.Table of Contents