Magnetic Iron Oxide Nanoparticles Research Articles

Selective Removal of Chlorophyll and Isolation of Lutein from Plant Extracts Using Magnetic Solid Phase Extraction with Iron Oxide Nanoparticles.

In recent years, there has been a growing interest in plant pigments as readily available nutraceuticals. Photosynthetic pigments, specifically chlorophylls and carotenoids, renowned for their non-toxic antioxidant properties, are increasingly finding applications beyond their health-promoting attributes. Consequently, there is an ongoing need for cost-effective methods of isolation. This study employs a co-precipitation method to synthesize magnetic iron oxide nanoparticles. Scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS) confirms that an aqueous environment and oxidizing conditions yield nanosized iron oxide with particle sizes ranging from 80 to 140 nm. X-ray photoelectron spectroscopy (XPS) spectra indicate the presence of hydrous iron oxide FeO(OH) on the surface of the nanosized iron oxide. The Brunauer-Emmett-Teller (BET) surface area of obtained nanomaterial was 151.4 m2 g-1, with total pore volumes of pores 0.25 cm3 g-1 STP. The material, designated as iron oxide nanoparticles (IONPs), serves as an adsorbent for magnetic solid phase extraction (MSPE) and isolation of photosynthetic pigments (chlorophyll a, lutein) from extracts of higher green plants (Mentha piperita L., Urtica dioica L.). Sorption of chlorophyll a onto the nanoparticles is confirmed using UV-vis spectroscopy, Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS), and high-performance liquid chromatography (HPLC). Selective sorption of chlorophyll a requires a minimum of 3 g of IONPs per 12 mg of chlorophyll a, with acetone as the solvent, and is dependent on a storage time of 48 h. Extended contact time of IONPs with the acetone extract, i.e., 72 h, ensures the elimination of remaining components except lutein, with a spectral purity of 98%, recovered with over 90% efficiency. The mechanism of chlorophyll removal using IONPs relies on the interaction of the pigment's carbonyl (C=O) groups with the adsorbent surface hydroxyl (-OH) groups. Based on molecular dynamics (MD) simulations, it has been proven that the selective adsorption of pigments is also influenced by more favorable dispersion interactions between acetone and chlorophyll in comparison with other solutes. An aqueous environment significantly promotes the removal of pigments; however, it results in a complete loss of selectivity.

The Concept of Using 2D Self-Assembly of Magnetic Nanoparticles for Bioassays

It can be observed that magnetic iron-oxide nanoparticles are increasingly used in bioassay methods. This is due to their stability in aqueous solutions, ease of functionalization, biocompatibility and very low toxicity. Here, we show that the recent discovery of the ability of magnetic nanoparticles to self-assemble into 2D structures of ordered chains may be exploited for bioassays. This would open up the possibility of controlled immobilization of proteins, enzymes, DNA or RNA and other molecular systems on spatially ordered nanostructures. In this work, fluorescein was used as an example. Also shown is the possibility of using Raman spectroscopy to analyze material accumulated on such structures. The observed formation of regularly spaced chains of magnetic nanoparticles takes place during the drying process of a thin layer of magnetic liquid placed on an appropriately prepared low-density polyethylene (LDPE) film.

Magnetic hyperthermia in tissue-like media: Finite element simulation, experimental validation, parametric variations, and calibration studies

We report the experimental characterization and finite element modeling of magnetic fluid hyperthermia (MFH) in tissue-like media using tetramethyl ammonium hydroxide coated superparamagnetic iron oxide magnetic nanoparticles (MNPs) of size ∼19.6 ± 1.2 nm, prepared using a co-precipitation technique. MFH properties are probed for the MNPs in ∼1 wt. % agar, resembling the tumor and surrounding normal tissues. The field-induced temperature rise (ΔT) is experimentally measured in real-time utilizing an infrared camera. A finite element model (FEM) is utilized to simulate the spatiotemporal variations in the thermal profiles, which are found to be in good agreement with the experimental data. FEM-based parametric studies reveal that the thermal conductivity of the medium is the most significant parameter influencing the thermal profiles. The spatiotemporal variations in the thermal profiles are numerically studied for seven different tissues, and the obtained results indicate the highest ΔT for the breast tissue in the tumor and the surrounding regions, which is due to the lowest volumetric specific heat and the highest thermal conductivity of the breast tissue, respectively. Numerical studies on the thermal profiles for sub-surface tumors with parametrically varying depths indicate a strong exponential correlation between the surface and tumor temperature, where the regression coefficients are found to be correlated with the thermo-physical properties of the tissues. The obtained findings are beneficial for developing a simplistic and easily deployable framework for a priori generation of the thermal profiles for various tissues during MFH, which is useful for appropriate planning and parameter selection for MFH-based therapy.

Evaluation of the application of suspensions of iron oxide magnetic nanoparticles functionalized with quaternized chitosan and phosphates on yellow maize and chili pepper plants

We have applied aqueous suspensions of magnetite-maghemite nanoparticles functionalized with quaternized chitosan and phosphate groups on yellow maize (Zea Mays) and chili pepper (Capsicum annuum) plants, at greenhouse conditions, to evaluate if any beneficial or adverse effects are produced by these nanocomposites in the development of these kind of plants at morphological and physiological level. Phytotoxicity assays with yellow maize seeds showed excellent germination percentages in all treatments evaluated, as well as increasing indicators of biomass and root length of germinated seeds for suspensions of nanoparticles with iron contents up to 50 ppm. Suspensions of nanoparticles with iron contents higher than 50 ppm led to decreasing indicators of biomass and root length of germinated seeds compared to lower iron contents. Iron contents of 100 ppm showed indicators lower than those of the control, suggesting phytotoxic effect of these nanocomposites for iron contents above 100 ppm. Measurements of morphological and physiological parameters of plants of both crops in greenhouse conditions, treated with suspensions of nanoparticles with iron-phosphorus contents of 25 − 3, 35 − 4 and 45 − 5 ppm, commercial fertilizer as positive control and tap water as a negative control did not evidence any phytotoxic or beneficial effect. The results suggest that, although these nanocomposites did not have a noticeable effect as vehicles of micro and macro nutrients as iron and phosphorus in the evaluated plants, they did not produce phytotoxic effects on them at the morphological and physiological level for iron contents less than 50 ppm, as they showed adequate growth and development.

Agro-Waste Sweet Pepper Extract-Magnetic Iron Oxide Nanoparticles for Antioxidant Enrichment and Sustainable Nanopackaging.

This study synthesizes magnetic iron oxide nanoparticles from agro-waste sweet pepper extract, exploring their potential as antioxidant additives and in food preservation. Iron (III) chloride hexahydrate is the precursor, with sweet pepper extract as both a reducing and capping agent at pH 7.5. Characterization techniques, including microscopy and spectroscopy, analyze the sweet pepper extract-magnetic iron oxide nanoparticles. Antioxidant capacities against 2,2-diphenyl-1-picrylhydrazyl are assessed, incorporating nanoparticles into banana-based bioplastic for grape preservation. Microscopy reveals cubic and quasi-spherical structures, and spectroscopy confirms functional groups, including Fe-O bonds. X-ray diffraction identifies cubic and monoclinic magnetite with a monoclinic hematite presence. Sweet pepper extract exhibits 100% inhibitory activity in 20 min, while sweet pepper extract-magnetic iron oxide nanoparticles show an IC50 of 128.1 µg/mL. Furthermore, these nanoparticles, stabilized with banana-based bioplastic, effectively preserve grapes, resulting in a 27.4% lower weight loss rate after 144 h compared to the control group (34.6%). This pioneering study encourages institutional research into the natural antioxidant properties of agro-waste sweet pepper combined with magnetic iron and other metal oxide nanoparticles, offering sustainable solutions for nanopackaging and food preservation. Current research focuses on refining experimental parameters and investigating diverse applications for sweet pepper extract-magnetic iron oxide nanoparticles in varied contexts.

Magnetic Metallic Nanoparticles Coated with Carbon for the Catalytic Removal of Bromate from Water

Bromate, often detected in drinking water, is associated with a significant risk of cancer. Catalytic reduction has been recognized as an effective treatment technique to remove ions by reducing them over metal catalysts in the presence of a reducing agent, usually hydrogen. This work aims to synthesize metallic magnetic nanoparticles of iron oxide (FeO) and mixed iron oxides with manganese (MnFeO), cobalt (CoFeO), and copper (CuFeO) coated with carbon via chemical vapor deposition (C-MNP) to be applied as catalysts to the reduction of bromate in water. The use of magnetic nanoparticles coated with carbon enables catalyst recovery via magnetic separation and takes advantage of the catalytic properties of the carbon materials. The iron particles proved to be the most promising catalysts for the reduction of bromate into bromide, the highest removal being obtained with the CFeO@CVD750 sample, resulting in a 99% conversion after 120 min of reaction under the conditions tested. Due to its magnetic nature, the catalytic material was easily removed after the reaction and applied in four consecutive cycles without losing its catalytic properties. These results highlight the great potential of carbon-coated magnetic nanoparticles for reducing bromate in water.

Green synthesis and characterizations of magnetic iron oxide nanoparticles using Moringa oleifera extract for improved performance in dye-sensitized solar cell

In this study, Moringa oleifera extract was used for the green synthesis of magnetic Iron Oxide (Fe3O4) nanoparticle. Natural dye from air-dried Carica papaya leaves was used as sensitizer along with commercially obtainable N719 Ruthenium dye. The optical absorptions between 350 and 650 nm confirmed the formation of the nanoparticle. After adding the nanoparticle to the TiO2 and loading it with dye, the absorbance in the visible range dramatically increased. The formation and stabilization of the nanoparticle may have been aided by the functional groups, according to the FTIR results. With an average crystallite size of 35.13 nm, the XRD patterns demonstrated the nanoparticle's crystalline nature. The morphologies of the nanoparticle demonstrated that it was well-formed and homogeneously dispersed. The presence of iron and other component elements was confirmed by the EDX spectra. The production of 40.83 nm-sized nanoparticles on average was further verified by the TEM micrograph, and the samples' crystallographic planes were identified by the SAED patterns. The photo-electrochemical performance of the DSSCs showed that the efficiencies increased significantly with percentage increase of 90.1% and 89.3% for Carica papaya and Ruthenium dyes, respectively. The green-synthesized Fe3O4 nanoparticle exhibited good properties for application in DSSC.

Synthesis of iron oxide magnetic nanoparticles and chitosan biopolymer in aqueous solutions

This study focuses on the synthesis of iron oxide magnetic nanoparticles and their coating with chitosan biopolymer in aqueous solutions. The structural properties of the synthesized nanoparticles were characterized using Fourier Transform Infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), magnetic properties analysis using Vibrating Sample Magnetometry (VSM), and thermal gravimetric analysis (TGA). The FT-IR spectra confirmed the presence of iron oxide and chitosan on the nanoparticle surface. The XRD analysis indicated the crystalline nature of the nanoparticles, and SEM images revealed the morphology and particle size. The VSM results demonstrated the superparamagnetic behavior of the nanoparticles, and TGA analysis showed the thermal stability and decomposition of the nanoparticles. Overall, this synthesis method successfully produced iron oxide magnetic nanoparticles coated with chitosan, which have potential applications in drug delivery systems.

High-affinity truncated aptamers for detection of Cronobacter spp with magnetic separation-assisted DNAzyme-driven 3D DNA walker.

Afteroptimizing the original aptamer sequence by truncation strategy, a magnetic separation-assisted DNAzyme-driven 3D DNA walker fluorescent aptasensor was developed for detecting the food-borne pathogen Cronobacter species. Iron oxide magnetic nanoparticles (MNPs) modified with a hybrid of truncated aptamer probe and DNAzyme strand (AP-E1) denoted as MNPs@AP-E1, were employed as capture probes. Simultaneously, a DNAzyme-driven 3D-DNA walker was utilized as the signal amplification element. The substrate strand (Sub) was conjugated with the gold nanoparticles (AuNPs), resulting in the formation of AuNPs@Sub, which served as a 3D walking track. In the presence of the target bacteria and Mg2+, E1-DNAzyme was activated and moved along AuNPs@Sub, continuously releasing the signal probe. Under optimized conditions, a strong linear correlation was observed for Cronobacter sakazakii (C. sakazakii) in the concentration range 101 to 106 CFU mL-1, with a low detection limit of 2 CFU mL-1. The fluorescence signal responses for different Cronobacter species exhibited insignificant differences, with a relative standard deviation of 3.6%. Moreover, the aptasensor was successfully applied to determine C. sakazakii in real samples with recoveries of 92.86%-108.33%. Therefore, the novel method could be a good candidate for ultra-sensitiveand selective detection of Cronobacter species without complex manipulation.

Magnetically Stimulated Integrin Binding Alters Cell Polarity and Affects Epithelial-Mesenchymal Plasticity in Metastatic Cancer Cells.

Inorganic nanoparticles (NPs) have been widely recognized for their stability and biocompatibility, leading to their widespread use in biomedical applications. Our study introduces a novel approach that harnesses inorganic magnetic nanoparticles (MNPs) to stimulate apical-basal polarity and induce epithelial traits in cancer cells, targeting the hybrid epithelial/mesenchymal (E/M) state often linked to metastasis. We employed mesocrystalline iron oxide MNPs to apply an external magnetic field, disrupting normal cell polarity and simulating an artificial cellular environment. These led to noticeable changes in the cell shape and function, signaling a shift toward the hybrid E/M state. Our research suggests that apical-basal stimulation in cells through MNPs can effectively modulate key cellular markers associated with both epithelial and mesenchymal states without compromising the structural properties typical of mesenchymal cells. These insights advance our understanding of how cells respond to physical cues and pave the way for novel cancer treatment strategies. We anticipate that further research and validation will be instrumental in exploring the full potential of these findings in clinical applications, ensuring their safety and efficacy.

One-dimensional assemblies of magnetic iron-oxide nanoparticles

Abstract Although high-aspect-ratio iron-oxide nanoparticles (IONPs) are known to have higher heating efficiency than spherical and cubic IONPs and focused in cancer treatment areas, their synthesis methods require high temperatures, vacuum, reduction conditions, and substantial time. In this study, we proposed and established a facile manufacturing method for one-dimensional assemblies of IONPs, expected to increase heating efficiency similar to high-aspect-ratio IONPs. We investigated how the fabrication conditions affect the length of the assemblies and found that the average length of the one-dimensional assemblies increased with the extension of magnetic-field-application time. This result demonstrates that the length could be controlled by adjusting the duration of the magnetic field application.

Iron oxide (Fe3O4) and ciprofloxacin loaded magnetic nanoparticles for magnetic drug targeting

Iron oxide (Fe3O4) pristine and ciprofloxacin loaded nanoparticles are synthesized successfully using co-precipitation method. X-ray diffraction analysis confirms the pure phase formation of the synthesized Fe3O4 particles. The grain size of the Fe3O4 calculated from the SEM images comes out to be 50 nm. UV-VIS spectrophotometric analysis indicates the accuracy of the results in which an absorption maximum of blank and ciprofloxacin containing iron oxide (Fe3O4) particle was observed at 260 and 265 nm respectively. The spectrum band shows the maximum absorption band shift of around 4-5 nm which may be explained by the drug conjugation to the Fe3O4 nanoparticles. The spectrum indicates the formation of Fe3O4 magnetic nanoparticles having black color and obtained material is found with energy band gap (E) of 2.12 eV and 2.19 eV. On the basis of the findings from dynamic light scattering (DLS) results, it can be concluded that overall particle size of magnetic iron oxide nanoparticles is observed as 765 nm. In the present study the polydispersity index (P.I.) of bare Fe3O4 magnetic nanoparticles is 0.221, which indicate the hydrodynamic property of the synthesized particles.

Magnetite nanoparticles immobilized on hydrophilic polyelectrolyte-grafted carbon nanotube as efficient organic–inorganic hybrid heterogeneous catalyst for Knoevenagel condensation in aqueous medium

In this work, a novel organic–inorganic hybrid heterogeneous catalyst was fabricated for Knoevenagel condensation. First, the surface of carbon nanotube (CNT) was covalently functionalized with poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) polyelectrolyte (i.e., organic polybase) through the surface-initiated atom transfer radical polymerization (SI-ATRP) method. Subsequently, magnetic iron oxide nanoparticles (Fe3O4 NPs) (i.e., inorganic Lewis acid) are densely and homogeneously grown on the CNT surface using the CNT-g-PDMAEMA template. The as-prepared acid–base bifunctional catalyst (i.e., CNT-g-PDMAEMA/Fe3O4NPs) was investigated in the model reaction, i.e., Knoevenagel condensation between naphthol, malononitrile and benzaldehyde. The CNT-g-PDMAEMA/Fe3O4NPs catalyst shows high catalytic activity in the Knoevenagel condensation between naphthol, malononitrile and benzaldehyde due to its unique structure and specific chemical constitution. In addition, this acid–base bifunctional catalyst can be readily recovered with an applied magnetic field and reused with negligible loss in the catalytic activity even after six cycles.

Synthesis and characterization of poly indole-iron oxide nanoparticles for biomedical applications

Iron oxide (Fe3O4) nanoparticles (NPs) were synthesized by co-precipitation method, further Fe3O4-NPs was encapsulated under inert environment with poly-indole carboxylic acid, finally the product obtained as poly-indole carboxylate iron oxide nanoparticles(PIFe3O4-NPs). Then, the both products Fe3O4-NPs and PIFe3O4-NPs were characterized and confirmed the composition of elements using X-ray diffraction pattern (XRD). The change in shape and morphology of products was confirmed by scanning electron microscopy (SEM). The functional groups and shifting of vibrational bands due to the coordination of both Fe3O4 and ligand are studied using Fourier transform infrared (FT-IR) spectra. The band gap of the products were measured using Ultraviolet–visible (UV–Vis.) spectra and also measured the direct and indirect band gap using Tauc plot. To investigate the binding nature of the sample, a molecular docking study was carried out and the results indicated that the PIFe3O4 moiety formed five hydrogen bonds with amino acid residues of Aspergillus niger ATCC9642 isopullulanase (2Z8G). The oxygen atom of Fe3O4-NPs binds well with the active sites of Staphylococcus Aureus Protein A (1BDC) and Escherichia Coli thioredoxin reductase (1TDE) with the ASN24, GLY17, ALA16, GLY14, and GLY113 residual interactions. Therefore, the results of molecular docking emphasized that the target Fe3O4-NPs nanoparticles can bind more easily to the target proteins 1BDC, 1TDE, and 2Z8G. In addition to that, antioxidant, antibacterial and antifungal activities were also examined. These findings demonstrate that PIFe3O4-NPs have antimicrobial and antioxidant properties and therefore it confirms the use of PIFe3O4-NPs in the treatment of infection against fungus, gram-positive and gram-negative bacteria.

A novel digitonin/graphene oxide/iron oxide nanocomposite: synthesis, physiochemical characterization and antioxidant activity.

In this work, iron oxide (Fe3O4) magnetic nanoparticles (MNPs) and graphene oxide (GO) nanosheets were prepared via the co-precipitation technique and the Modified Hummer method. Fe3O4 MNPs and GO nanosheets were combined to prepare Fe3O4/GO nanocomposite and subsequently conjugated with Digitonin (DIG) in order to obtain a dual-targeted delivery system based on DIG/Fe3O4/GO nanocomposite. SEM images reveal the presence of Fe3O4 MNPs at a scale of 100nm, exhibiting dispersion between the GO nanosheets. Aggregation of the DIG/Fe3O4/GO nanocomposite was observed at various size scales. The XRD structural analysis confirms the crystal structure of the prepared samples. The Fe3O4 MNPs demonstrated the main XRD-diffracted peaks. Also, GO nanosheets exhibit crystalline characteristics on the (001) and (002) planes. The predominant peaks observed in the DIG/GO/Fe3O4 nanocomposite are attributed to the crystal phases of Fe3O4 MNPs. The FT-IR vibrational modes observed in the GO/DIG/Fe3O4 nanocomposite indicate the presence of crosslinking between GO nanosheet layers and the Fe3O4 MNPs. The antioxidant activity of the prepared samples was measured and the DIG/GO/Fe3O4 nanocomposite demonstrated a significantly high antioxidant activity in both 2-diphenyl-1-picrylhydrazyl (DPPH·) and 2,2-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS·+) tests.

Plant-Polyphenol-Mediated Synthesis of Magnetic Biocompatible Iron Oxide Nanoparticles for Diagnostic Imaging and Management of Neurodegenerative Diseases

<img src=” https://s3.amazonaws.com/production.scholastica/article/92424/large/prnano_992023ga.jpg?1705765455”> Neurodegenerative diseases (NDDs), including Alzheimer’s disease (AD), Parkinson’s disease (PD), and glioblastoma tumors (GB), represent a spectrum of disorders characterized by progressive neuronal degeneration. This gradual deterioration presents significant challenges in early diagnosis and treatment. As a solution, iron oxide nanoparticles (IONPs) have emerged as promising materials due to their diminutive size and inherent biocompatibility, which facilitates bypassing the blood-brain barrier (BBB), thereby serving as effective targeted nanocarriers for neuroprotective therapeutics, offering efficient delivery to the brain. Furthermore, IONPs demonstrate efficacy as T1/T2 contrast agents (CAs), offering a novel diagnostic tool for various NDDs, emphasizing GB. Despite the expanding potential of IONPs in the management of NDDs, a clear gap exists in developing environmentally sustainable synthesis methods. Such methods must adhere to ecological standards and enable the production of nanoparticles capable of efficiently crossing the BBB. This is essential for precisely delivering and monitoring therapeutic interventions in diseases such as AD, PD, and GB. This review systematically explores the potential of green-synthesized IONPs in the context of NDD treatment. In this review, we emphasize different functionalization techniques for IONPs, tackling how these functionalized IONPs can be effective therapeutic approaches for NDDs. Moreover, we discuss biosafety and biocompatibility by covering a range of in vitro biocompatibility studies to analyze the safety of green-synthesized IONPs for the human body. Furthermore, our thorough analysis discussed the current state of green-synthesized IONPs using plant extracts polyphenols, which also act as neuroprotective agents, as proved by studies mentioned in the review.

Influence of coating on peroxidase-like activity of magnetic nanoparticles

Chitosan stabilized iron oxide magnetic nanoparticles (Chit-MNPs) were prepared with the theoretical Chit/Fe3O4 weight ratios equal to 0.5, 1, 2, 3 w/w and characterized by different techniques. The effect of various Chit/Fe3O4 weight ratios on the samples’ hydrodynamic diameter, zeta potential, and isoelectric point was studied by the dynamic light-scattering method. Using TEM analysis, the average magnetic core size was found to be ranging from 6 nm to 9 nm. The obtained results are comparable to those from magnetic measurements. The magnetic measurements confirmed successful chitosan coating on MNPs by means of the decrease in saturation magnetizations from 69.2 emu·g−1 for unmodified MNPs to 66.6, 65.9, 65.5 and 65.2 emu·g−1 for Chit-MNPs at different ratios of Chit/MNPs 0.5, 1, 2, and 3. TGA was used to quantify the amount of chitosan adsorbed on MNPs surface – the max. amount was 0.045 mg chitosan/mg MNPs. The peroxidase-like catalytic activity of unmodified MNPs and chitosan Chit-MNPs in present of a substrate such as N,N-diethyl-p-phenylenediamine sulfate salt (DPD) and hydrogen peroxide was studied. The results confirmed the peroxidase-like activity of samples, – they catalytically oxidise substrate DPD by H2O2 to produce a typical colour reaction. The chitosan coating was found to slightly decrease catalytic activity compared to MNPs at pH 7.4. Despite the fact, these findings can be useful for creating sets of MNPs and Chit-MNPs samples possessing predefined peroxidase-like activity and could be applied for chromogenic reactions in the future.

Nitrogen-rich magnetic hyper-cross-linked polymer as an efficient adsorbent for tetracycline

Antibiotic contamination remains a challenge for wastewater treatment. In this work, a hyper-cross-linked polymer (DHCP-TP3) with a dual nitrogen-rich structure was synthesized by a one-step facile Friedel-Crafts reaction, and a Fe3O4 @DHCP-TP3 composite was prepared by postmodification with the introduction of magnetic iron oxide nanoparticles (Fe3O4 NPs), which were applied to the adsorption of tetracycline (TC) from aqueous solution. The TC adsorption capacities of the DHCP-TP3 and Fe3O4 @DHCP-TP3 composites reached 519.65 and 893.85 mg·g−1, respectively, and the adsorption processes for both followed the pseudo-second-order kinetic model and the Freundlich isothermal model. Fe3O4 @DHCP-TP3 can achieve adsorption equilibrium for TC within 200 min, and also exhibits excellent regeneration and magnetic separation capabilities. Complexation, hydrogen bonding, cation exchange and π-π interactions were the main adsorption mechanisms. Moreover, Fe3O4 @DHCP-TP3 could also adsorb other pollutants, including sulfadiazine (SD), sulfamethoxazole (SMZ), methyl orange (MO), methylene blue (MB), 2,4-dichlorophenol (2,4-DCP), and iodine (I2). The brief synthesis, high adsorption capacity and easy regeneration certified that HCPs were ideal adsorbents for removing pollutants from wastewater.

Analysis of Newtonian heating in fractional hybrid nanofluid with the influence of transverse magnetic field

This article deals with the effects of Newtonian heating in second grade Hybrid nanofluid. For memory effects the problem is modeled with the help of generalized Fourier law along with generalized boundary conditions. A hybrid nanofluid model is used with nano particles of the form Magnetic Iron Oxide (Fe3O4) and Silver (Ag) nano particles with engine oil (EO) as based fluid. A uniform magnetic field perpendicular to the plate is also taken. General solutions of the problems are obtained with the help of Laplace Transform Technique. Influence of related physical parameters on the fluid flow are discussed with the help of graphical display of the solutions. It is also observed that generalized boundary conditions provides more effective and new solutions for the oscillating flow of hybrid nanofluid which produces a better way of understanding of hybrid nanofluid.

Sandpack flooding of microwave absorbent nanofluids under electromagnetic radiation: an experimental study

AbstractElectromagnetic (EM) radiation has long been recognized as an effective method for enhancing the quality and recovery of heavy and extra-heavy crude oil. The incorporation of EM absorbers, particularly nanoparticles, has demonstrated significant potential to boost efficiency and expand the stimulated reservoir volume. However, the application of simultaneous EM radiation and nanofluid injection in a natural porous medium, which is critical for the successful implementation of this approach in field-scale operations, remains an underexplored frontier. In this context, this research represents a pioneering endeavor, aiming to bridge this knowledge gap through a comprehensive statistical and optimization study. The primary objective was to unravel the intricate interplay between five distinct types of magnetic nanoparticles and their concentrations within the base fluid to improve oil production. Notably, it focused on iron oxide (Fe3O4) magnetic nanoparticles and their innovative hybridization with multi-walled carbon nanotubes (MWCNT) and nickel oxide (NiO) nanomaterial. A newly designed glass sandpack was employed as the porous medium, thus mirroring real reservoir conditions more accurately. Then, a rigorous full factorial design scrutinized the multifaceted effects of nanoparticle type and concentration when introduced into deionized water during this process. The results showed that microwave radiation, applied at 400 W, dramatically improved oil recovery, catapulting it from a baseline of 19% to an impressive 39.5% during water injection. The addition of magnetic nanoparticles to the base fluid enhances efficiency. However, the specific type of nanoparticle exerts varying effects on oil recovery rates. Notably, the synthesis of Fe3O4–MWCNT nanoparticles had a substantial impact on the ultimate oil recovery factor, achieving approximately 69%. Furthermore, the hybridization of Fe3O4 nanoparticles with MWCNT and NiO nanoparticles leads to reduced consumption (using low weight percentages) while achieving the highest oil recovery rates during the injection process. Finally, the optimization analysis demonstrated that employing 0.34 wt.% of Fe3O4–MWCNT nanoparticles under 400 W of microwave radiation represents the optimal condition for achieving the highest oil production in a sandpack porous medium. Under these conditions, the oil recovery factor can increase to 78%.