Magnetic Oxide Research Articles

Magnetic graphene oxide functionalized dimercaptosuccinic acid/putrescine as a selective and stable solid-phase extraction adsorbent for preconcentration and speciation of arsenic (III) in water samples

ABSTRACT It is challenging for environmental scientists to identify the trace value of arsenite (As(III)) as an essential hazardous material in the presence of arsenate (As(V)) and other metal ions. This paper proposes a method of magnetic solid-phase extraction (MSPE) for the trace analysis of As(III) using magnetite graphene oxide (MGO) covalently functionalised with dimercaptosuccinic acid (DMSA) and putrescine (PUT). The hydrothermally synthesised MGO/DMSA-PUT adsorbent was carefully characterised by using energy-dispersive X-ray spectroscopy analysis, Fourier transform infrared, dynamic light scattering, scanning electron microscopy, zeta potential analyser, X-ray diffraction, and vibrating sample magnetometer techniques in detail. Maximum adsorption capacity of MGO/DMSA-PUT for As(III) was determined 144 mg g−1 which considerably improved vs. graphene oxide with the adsorption capacity of 54.8 mg g−1. Sample pH of 6 with a volume of 50 mL, contact time of 5 minutes, initial concentration of 50 μg L−1, adsorbent dosage of 0.1 g and volume of eluent 3 mL were obtained as the optimised parameters for the developed MSPE procedure. According to experimental data obtained with hydride generation atomic absorption spectroscopy, the linear range and detection limit of the proposed method for As(III) measurement was found to be 0.4–5000 µg L−1 and 9.914 ng L−1, respectively. According to experimental results, a preconcentration limit (PL) of 1.72 µg L−1 was achieved for As(III), corresponding to a preconcentration factor of 965. Statistical analysis of standard reference materials confirmed the accuracy of the method against systematic and constant errors (>95% recovery with <5% RSD). Because of the selectivity of MGO/DMSA-PUT towards the As(III), the developed MSPE procedure is capable for successful speciation and determination of As(III) in water samples with satisfactory analytical results.

Magnetic graphene oxide and vertically-ordered mesoporous silica film for universal and sensitive homogeneous electrochemiluminescence aptasensor platform

Herein, we demonstrated a convenient and highly sensitive homogeneous electrochemiluminescence (ECL) aptasensor platform by combination of magnetic composite probe and vertically-ordered mesoporous silica films (VMSF). Magnetic composite probe composed of biorecognition element (target-specific aptamer), ECL signal reporter (Ru(bpy)32+) and large-scale magnetic graphene oxide (M−GO), can be prepared by simple incubation, magnetic separation and redispersion prior to use. High-affinity and specific binding between target and aptamer can detach aptamer from M−GO and simultaneously release the slight amount of Ru(bpy)32+ into a solution, which can be sensitively detected by VMSF modified indium tin oxide (VMSF/ITO) due to the excellent electrostatic preconcentration capacity of VMSF. In this sensing system, detectable signal of Ru(bpy)32+ can be remarkably amplified by VMSF/ITO and meanwhile background signal can be reduced by the adsorption capacity of M−GO and size exclusion property of VMSF/ITO, effectively promoting the analytical performance of the present homogeneous ECL aptasensor. The applicability and universality of this sensing platform was confirmed by employing alpha fetoprotein (AFP) and prostate specific antigen (PSA) as the target models and their detection limits were 0.08 pg/mL and 9.6 pg/mL, respectively. Furthermore, the designed homogeneous ECL aptasensor platform is label-free, immobilization-free, low-cost, and free of additional electrode modification and sample pretreatment procedures, rendering a simple sensing strategy for quantitative determination of various biomarkers in clinical diagnosis by adapting the specific aptamer.

Comprehensive life cycle assessment of NH2-functionalized magnetic graphene oxide for mercury removal: Carbon emissions and economic evaluation

Heavy metals contamination critically affects human health and ecosystems, necessitating pioneering approaches to diminish their adverse impacts. Hence, this study synthesized aminated magnetic graphene oxide (mGO-NH2) for the removal of mercury (Hg) from aqueous solutions. Although functionalized GO is an emerging technology at the early stages of development, its synthesis and application require special attention to the eco-environmental assessment. Therefore, the life cycle assessment and life cycle cost of mGO-NH2 were investigated from the cradle-to-gate approach for the removal of 1 kg Hg. The adsorption process was optimized based on pH, Hg concentration, adsorbent dose, and contact time at 6.48, 40 mg/l, 150 mg/l, and 35 min, respectively, resulting in an adsorption capacity of 184.17 mg/g. Human carcinogenic toxicity with a 40.42% contribution was the main environmental impact, relating to electricity (35.76%) and ethylenediamine (31.07%) usage. The endpoint method also revealed the pivotal effect of the mGO-NH2 synthesis on human health (90.52%). The most energy demand was supplied by natural gas and crude oil accounting for 70.8% and 22.1%, respectively. A 99.02% CO2 emission originated from fossil fuels consumption based on the greenhouse gas protocol (GGP). The cost of mGO-NH2 was about $143.7/kg with a net present value of $21064.8 per kg Hg removal for a 20-year lifetime. Considering the significant role of material cost (>70%), the utilization of industrial-grade raw materials is recommended to achieve a low-cost adsorbent. This study demonstrated that besides the appropriate performance of mGO-NH2 for Hg removal, it is essential that further studies evaluate eco-friendly approaches to decrease the adverse impacts of this emerging product.

The effect of intrinsic magnetic order on electrochemical water splitting

To reach a long term viable green hydrogen economy, rational design of active oxygen evolution reaction (OER) catalysts is critical. An important hurdle in this reaction originates from the fact that the reactants are singlet molecules, whereas the oxygen molecule has a triplet ground state with parallel spin alignment, implying that magnetic order in the catalyst is essential. Accordingly, multiple experimentalists reported a positive effect of external magnetic fields on OER activity of ferromagnetic catalysts. However, it remains a challenge to investigate the influence of the intrinsic magnetic order on catalytic activity. Here, we tuned the intrinsic magnetic order of epitaxial La0.67Sr0.33MnO3 thin film model catalysts from ferro- to paramagnetic by changing the temperature in situ during water electrolysis. Using this strategy, we show that ferromagnetic ordering below the Curie temperature enhances OER activity. Moreover, we show a slight current density enhancement upon application of an external magnetic field and find that the dependence of magnetic field direction correlates with the magnetic anisotropy in the catalyst film. Our work, thus, suggests that both the intrinsic magnetic order in La0.67Sr0.33MnO3 films and magnetic domain alignment increase their catalytic activity. We observe no long-range magnetic order at the catalytic surface, implying that the OER enhancement is connected to the magnetic order of the bulk catalyst. Combining the effects found with existing literature, we propose a unifying picture for the spin-polarized enhancement in magnetic oxide catalysts.

Self‐assembly of thiourea intercalated graphene oxide based dual IIP for the SPE coupled FAAS method development of Cu(II) and Pb(II) determination

AbstractA new dual‐template surface imprinted polymer for Cu(II) and Pb(II) was synthesized in one pot. Magnetic graphene oxide was self‐assembled with low cost and environmentally benign thiourea. Presence of sulfur and nitrogen donor atoms provide hooks for coordination and partial reduction of graphene oxide matrix. It was used as an solid‐phase extraction adsorbent for extraction, preconcentration, and coupled with flame atomic absorption spectrometry to manifest performance comparable with inductively coupled plasma atomic emission spectrometry (ICPAES) both in terms of quantification limit as well as interference. The critical experimental parameters such as pH; 4.6, contact time of 15 min and initial concentration of 777 (Qe; 227 mg g−1) and 800 μg L−1 (Qe; 273 mg g−1) for Cu(II) and Pb(II), respectively, were optimized using RSM‐CCD and artificial neural network. The adsorption process was kinetically faster (50% adsorption in 5 min), following fractal‐like‐pseudo‐second‐order (FLPSO) kinetics and Brouers–Sotolongo isotherm model owing to the heterogenous energy landscape. The imprinting factors were in the range of 4–7 in the presence of all coexisting ions. The proposed method was robust in the determination and removal of Cu(II) and Pb(II) from food, ground water, and industry effluents with low limit of detection (Cu(II); 1.03 μg L−1 &amp; Pb(II); 1.79 μgL−1). Spiking and recovery tests were used to assess the method's accuracy. Cu(II)/Pb(II) loaded dual template IIP (DIIP) was utilized to remove anionic dyes with &gt;95% efficiency. Thorough examination of the method and material selectivity (in binary, ternary, and multielement system), multi fold applications of determination, removal of Cu(II), Pb(II), and removal of anionic dyes makes DIIP a promising candidate for environmental remediation.

Removal of selective serotonin reuptake inhibitor using magnetic graphene oxide derivatives: Adsorption study in low drug concentration using HPLC quantification, in vitro safety, and phytotoxicity

Citalopram (CIT) is a drug widely used around the world in the treatment of depression. Due to the high toxicity of CIT and the failure of the methods used in treatment plants to purify water, the removal of this pollutant from the environment is very necessary. In this study, the removal of CIT was performed using graphene oxide (GO) and magnetic graphene oxide (GO·Fe3O4 1:1, 1:5, and 1:10). Moreover, the adsorption of CIT was accomplished at low drug concentrations, and the safety of biological and phytological adsorbents was investigated. The characteristics of the adsorbents were analyzed through SEM and TEM images, XRD, EDS, XPS, FTIR, Raman, VSM and the analysis revealed the spectra and signal characteristics of GO and GO·Fe3O4. The GO·Fe3O4 1:1 showed the highest adsorption capacity of 97.92 mg g−1 and removal percentage (98%). The pH, initial concentration, and glucose natural organic matter did not significantly affect the adsorption. The ionic strength and high dosages of GO·Fe3O4 1:1 disfavors the adsorption. Pseudo-second-order (PSO) and Liu models suggest that adsorption occurs at heterogeneous surfaces. The thermodynamic study confirms that CIT adsorption onto GO·Fe3O4 was spontaneous and exothermic. The in vitro assays evidenced that the complex, after adsorption, decreases the genotoxicity and the oxidative stress caused by CIT. Finally, the complex after adsorption does not show phytotoxic for L. sativa seeds. These findings have significant relevance for the safe use of GO·Fe3O4 1:1, allowing the employ in water remediation processes and their biocompatibility for biological applications.

The effect of thiol ligands on the adsorption behavior of silver ions on functionalized nanomagnetic graphene oxides

The magnetic graphene oxides (MGO) were modified with l-cysteine (Cys), glutathione (GSH), and thioglycolic acid (TGA) as the thiol ligands. using field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry, and Brunauer Emmett Teller (BET) surface area analysis, the structural and magnetic properties of the as-prepared samples have been studied. The results affirmed the successful synthesis of functionalized adsorbents. The adsorbents presented here have been reported for the first time to remove Ag ions from dilute aqueous solutions. The influence of the adsorption conditions (pH, contact time, and initial concentration) was investigated. The experimental data were consistent with both the pseudo-second-order kinetic model and the Langmuir isotherm model indicating chemisorption monolayer adsorption with the fast kinetics. The maximum adsorption capacity for MGO-TGA, MGO-Cys, and MGO-GSH based on the Langmuir isotherm model was found to be qm = 67.16, 53.42, and 43.73 mg/g, respectively. The calculated separation factors (0 < RL < 1) revealed that the adsorption process was favorable for three adsorbents. The large surface area of the adsorbents (57.244, 37.006, and 15.676 m2/g, for MGO-TGA, MGO-Cys, and MGO-GSH, respectively), along with the presence of thiol ligands on them, significantly affects the adsorption behavior. Therefore, these adsorbents offer an effective and rapid process for adsorbing silver ions from low concentration aqueous solutions.

Characterization of a recombinant Aspergillus niger GZUF36 lipase immobilized by ionic liquid modification strategy

Enzyme immobilized on magnetic nanomaterials is a promising biocatalyst with efficient recovery under applied magnets. In this study, a recombinant extracellular lipase from Aspergillus niger GZUF36 (PEXANL1) expressed in Pichia pastoris GS115 was immobilized on ionic liquid-modified magnetic nano ferric oxide (Fe3O4@SiO2@ILs) via electrostatic and hydrophobic interaction. The morphology, structure, and properties of Fe3O4@SiO2@ILs and immobilized PEXANL1 were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, vibration sample magnetometer, and zeta potential analysis. Under optimized conditions, the immobilization efficiency and activity recovery of immobilized PEXANL1 were 52 ± 2% and 122 ± 2%, respectively. The enzymatic properties of immobilized PEXANL1 were also investigated. The results showed that immobilized PEXANL1 achieved the maximum activity at pH 5.0 and 45 °C, and the lipolytic activity of immobilized PEXANL1 was more than twice that of PEXANL1. Compared to PEXANL1, immobilized PEXANL1 exhibited enhanced tolerance to temperature, metal ions, surfactants, and organic solvents. The operation stability experiments revealed that immobilized PEXANL1 maintained 86 ± 3% of its activity after 6 reaction cycles. The enhanced catalytic performance in enzyme immobilization on Fe3O4@SiO2@ILs made nanobiocatalysts a compelling choice for bio-industrial applications. Furthermore, Fe3O4@SiO2@ILs could also benefit various industrial enzymes and their practical uses.Key points• Immobilized PEXANL1 was confirmed by SEM, FT-IR, and XRD.• The specific activity of immobilized PEXANL1 was more than twice that of PEXANL1.• Immobilized PEXANL1 had improved properties with good operational stability.Graphical abstract

Comparison of extraction processes, characterization and intestinal protection activity of Bletilla striata polysaccharides

We optimized the extraction process of Bletilla striata polysaccharides using orthogonal design, Box-Behnken design (BBD), and genetic algorithm-back propagation (GA-BP), then compared and evaluated them to confirm that the combination of BBD and GA-BP neural networks was capable of increasing polysaccharide yields and antioxidant activity. The optimal extraction parameters were as follows: liquid-to-solid ratio of 15 mL/g, extraction power of 450 W, and extraction time of 34 min. Under these conditions, the polysaccharide yield and antioxidant activity were 8.29 ± 0.50 % and 26.20 ± 0.28 (mM FE/mg). Subsequently, the polysaccharide was purified to obtain purified Bletilla striata polysaccharides 1 (pBSP1) with a Mw of 255.172 kDa. Scanning electron microscope (SEM), ultraviolet-visible detector (UV), fourier transform infrared spectrometer (FTIR), high performance liquid chromatography (HPLC), X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and periodate oxidation were used to analyze the structure of pBSP1. The results showed pBSP1 had a smooth surface and a rough interior, with a composition of α-D conformation glucose (18.23 %) and β-D conformation mannose (53.77 %), and an amorphous crystal structure. According to the results of thermogravimetric and rheological tests, pBSP1 exhibits good thermal stability and viscoelastic behavior. Furthermore, pBSP1 protected lipopolysaccharide (LPS)-induced GES − 1 and Caco2 cells, the results showed pBSP1(400 μg/mL) lowered TEER synthesis in Caco2 cells as well as apoptosis and reactive oxygen species (ROS) production in both cells, indicating that pBSP1 may have an intestine protective effect.

Assessment of Electromagnetic Shielding Efficacy of Magnetic Metal Oxide Nanoparticles and their Application in Electromagnetic Shielding Paints

AbstractPeople are continuously exposed to electromagnetic waves emitted by mobile phones, base stations, computers, household electrical appliances, and nearby devices. Shielding against electromagnetic radiation is of great importance to avoid potential adverse effects on human health. This study addresses the development of electromagnetic shielding paints containing magnetic metal oxide nanoparticles. Magnetic metal oxide nanoparticles with a spinel ferrite structure, namely Fe3O4, CoFe2O4, and SnFe2O4, were synthesized using the co‐precipitation method. Their structural, morphological, and magnetic properties were characterized through FTIR, XRD, TEM, and VSM measurements. Electromagnetic shielding efficacy was assessed within the 3.5–12.5 GHz frequency range using waveguide measurements. Notably, pure magnetic metal oxide nanoparticles exhibited limited shielding efficiency, but incorporating conductive materials like multi‐walled carbon nanotubes improved the efficacy. Optimization studies, involved adjusting the nanoparticle‐to‐carbon nanotube ratios and coating thickness, demonstrated the best shielding to be with 50 : 10 [MFe2O4:PEG]:mwcnt ratio (M : Fe, Co, Sn) and 0.720 mm thickness, achieving up to 99 % of radiation shielding. The subsequent incorporation of the optimized magnetic composites into a water‐based wall paint at a 1 : 2 weight ratio demonstrated their effectiveness in shielding, successfully blocking 84 % of incoming radiation.

Greatly Improved the Tunable Amplitude of Ferromagnetism Based on Interface Effect of Flexible Pt/YIG Heterojunctions.

Flexible quantum spin electronic devices based on ferromagnetic insulators have attracted wide attention due to their outstanding advantages of low-power dissipation and noncontact sensing. However, ferromagnetic insulators, such as monocrystalline yttrium iron garnet (Y3Fe5O12, YIG), hve weak stress effects with a small magnetostrictive coefficient (λ110, 10 ppm), making it difficult to achieve a large magnetic tunable amplitude. In this paper, large-scale (with a diameter of 40 mm), flexible Pt/YIG heterojunctions were obtained by double-cavity magnetron sputtering technology, indicating typical soft magnetism and good bending fatigue characteristics. Here, the 3 nm thickness of the Pt layer triggers an obvious magnetic proximity effect, in which the in-plane ferromagnetic resonance field is decreased by 70 Oe compared to flexible Cu/YIG heterojunctions. Meanwhile, it shows a wide tunable amplitude of 110 Oe under the flexible bending stresses, which is induced by the sensitive interface effect of Pt (3 nm)/YIG heterojunctions. The saturation magnetization of Pt/YIG heterojunctions is negatively correlated with Pt thickness rather than the relative stability of Cu/YIG heterojunctions, depending on the magnetic proximity effect. It brings greater application possibilities for flexible stress-sensitive magnetic oxides in spin logic electronic devices.

Magnetic graphene oxide supported tin oxide (SnO) nanocomposite as a heterogeneous catalyst for biodiesel production from soybean oil

In this study, the MGO@SnO as a new nanocatalyst with diverse chemical/physical properties was generated by the combination of graphene oxide covered with magnetic iron oxide (MGO) and tin oxide (SnO(x)) nanoparticles used for biodiesel production from soybean oil. Before GC-FID analysis, the nanostructured MGO@SnO was successfully employed to transesterify soybean oil to FAMEs (biodiesel). The proposed material was characterized using Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). Given the acidic-alkaline nature of the proposed catalyst, it has a strong probability of creating carbocation ions to attack with methanol and subsequently converting the triglycerides to methyl ester (FAMEs). In further experiments, it was found that the ideal reaction parameters were a ratio of MGO to SnO of 1:0.5, a molar ratio of soybean oil to methanol (MeOH) of 1:10, a reaction period of 180 min, and a reaction temperature of 120 °C. Furthermore, the MGO@SnO catalyst demonstrated adequate catalytic performance (>88 %) for transforming the triglycerides of soybean oil to FAMEs (biodiesel) as compared to pure SnO NPs (74 %) and plain MGO (69 %) at similar conditions.

Adsorption of Crystal Violet with Magnetic Graphene Oxide Nano Adsorbent Synthesized from &lt;i&gt;Schima wallichii&lt;/i&gt; Wood

The textile industry continues to experience production developments to reach a target for the country's economic development. The increase in production leads to an increase in the amount of waste generated. Dyes such as crystal violet (CV) in textile wastewater are toxic and difficult to remove by conventional treatment. Adsorption with nano adsorbent has been widely researched and developed to remove dyes in the environment because it has various advantages. Magnetic graphene oxide (GO-Fe3O4) as a006E adsorbent has been widely studied because it has a large surface area, strong chemical bonds and is easily separated from the aqueous phase. Puspa (Schima wallichii) wood has the potential to be used as a natural source of graphite. The characterization of the adsorbent was tested with FTIR, SEM-EDS, and BET. The equilibrium time for the adsorption process was 20 min, while the optimum adsorbent dose was 0.04 g. Adsorption isotherm and kinetics analysis showed that CV adsorption using MGO followed Langmuir and pseudo-second-order models, respectively. Thermodynamic studies displayed that the CV adsorption was endothermic and spontaneous. The results of this study suggested that the adsorption of CV using GO-Fe3O4 nano adsorbent from S. wallichii wood proceeds by chemisorption and physisorption.

Interaction of Fe2O3 and Fe3O4 Nanoparticle with Pathogenic Bacteria: A In-silico Molecular Mechanism Study

Background:: Magnetic materials like iron, nickel, and cobalt have been a subject of interest among the scientific and research community for centuries. Owing to their unique properties, they are prevalent in the mechanical and electronic industries. In recent times, magnetic materials have undeniable applications in biotechnology and nanomedicine. Bacteria like Salmonella enterica, Clostridium botulinum, Bacillus subtilis, etc, pose a hazard to human health and livestock. This ultimately leads to huge yields and economic losses on a global scale. Antimicrobial resistance has become a significant public health concern in recent years, with the increasing prevalence of drugresistant infections posing a significant threat to global health. Many coherent studies have successfully reported magnetic metal oxide nanoparticles to be highly selective, specific, and effective in neutralizing pathogens through various mechanisms like cell membrane disruption, direct contact-mediated killing, or by generating Reactive Oxygen Species (ROS) and numerous costimulatory and inflammatory cytokines. Therefore, we explored the inhibitory effects of iron oxide nanoparticles (NPs) on various pathogenic bacteria via an in-silico approach. This method helped us to understand the active sites where the iron oxide NPs bind with the bacterial proteins. Methods:: The 3D crystal structures of all the pathogenic proteins of Streptococcus pneumoniae, Pseudomonas aeruginosa, Vibrio cholerae, Salmonella enterica, Shigella flexneri, Clostridium botulinum and nanoparticles (Fe2O3 and Fe3O4) under study were downloaded from RCSB PDB and ChemSpider official websites respectively. It was followed by the in-silico molecular Docking using PyRx and AutoDock Vina and analyzed on LigPlot. Results:: This study interprets the efficacy of the Fe2O3 and Fe3O4 nanoparticles against all the test bacteria. At the same time, Fe2O3 and Fe3O4 formed the most stable complexes with cholera enterotoxin subunit B and lectin II (PA-IIL) mutant S23A of Pseudomonas aeruginosa, respectively. Conclusion:: As in this era of AMR, researchers have been exploring alternative strategies to combat bacterial infections, including using magnetic nanoparticles as a potential treatment. They possess unique physical and chemical properties that make them attractive candidates for antimicrobial therapy, including their ability to penetrate bacterial biofilms and selectively target pathogenic bacteria while leaving healthy cells unharmed. This study examined the inhibitory effects of iron oxide (magnetic) nanoparticles, namely Fe2O3 and Fe3O4, on various bacterial proteins involved in cell-to-cell interactions and pathogenesis.

WITHDRAWN: Removal of 2, 4 dichlorophenol as herbicide’s by-product using graphene oxide + CYPHOS® IL 103 ionic liquid entrapped in Fe3O4 magnetic poly-sulfone adsorbent

2,4-Dichlorophenoxyacetic acid (2,4-D), a phenoxy alkanoic acid herbicide, is among the most widely distributed pollutants in the environment. 2,4-Dichlorophenol (2,4-DCP), as the main metabolite of 2,4-D, always accompanies 2,4 dichloro nitrophenol and is also frequently detected in the environment. The toxicity of 2,4 dichloro phenol is more severe than that of its parent 2,4- DCP at any concentration level. In this study, the removal of 2,4 dichloro phenol from an aqueous environment using graphene oxide + CYPHOS® IL 103 ionic liquid entrapped in Fe3O4 magnetic poly-sulfone was studied. Phase separation method was used to make CYPHOS® IL 103 ionic liquid entrapped in magnetic poly-sulfone facilitated to graphene oxide (Fe3O4/PSF@GO) adsorbent. Immobilization of Trihexyl (tetradecyl) phosphonium decanoate (CYPHOS® IL 103) ionic liquid in magnetic polysulfone-assisted graphene oxide was ascertained to be 85.6 % respectively. Furthermore, the obtained magnetic adsorbents were analyzed by the Langmuir, Freundlich, and Redlich-Peterson isotherms. The equilibrium data were best represented by the Redlich-Peterson model (R2 = 0.9926), with a maximum experimental adsorption capacity of 424.50 mg.g-1at room temperature. The adsorption kinetics was well described by the pseudo-second-order kinetic model, whereas intraparticle diffusion is the limiting step for the Weber-Morris model. Interestingly, graphene oxide + CYPHOS® IL 103 ionic liquid entrapped in poly-sulfone adsorbent was shown to be a promising material for adsorption of 2,4- Dichlorophenol (DCP) from aqueous solutions.

Preparation and investigation of catalytic activity of a magnetic Cu-complex immobilized on the histidine modified starch biopolymer

In the present study, at first a magnetic starch oxide support that functionalized with histidine methyl ester was prepared. Then, histidine segments were alkylated with ethyl bromide to form imidazolium salts on this magnetic biopolymer hybrid. The successful synthesis of the prepared nanocomposite was proved by various analysis contain EDX, FE-SEM, FT-IR, VSM, ICP and XRD. The catalytic amount of this nanocomposite was accelerated coupling reaction of aryl boronic acids, NaN3 and phenylacetylene for the synthesis of different 1,4-diaryl-1,2,3-triazoles with high yields at proper reaction times under mild reaction conditions.

Dual-functional metal-organic frameworks-based hydrogel micromotor for uranium detection and removal

Self-propelled micro/nanomotors have attracted great attention for environmental remediation, however, their use for radioactive waste detection and removal has not been addressed. Engineered micromotors that are able to combine fast detection and highly adsorptive capability are promising tools for radioactive waste management but remain challenging. Herein, we design self-propelled micromotors based on zeolite imidazolate framework (ZIF-8)-hydrogel composites via inverse emulsion polymerization and show their potential for efficient uranium detection and removal. The incorporation of magnetic ferroferric oxide nanoparticles enables the magnetic recycling and actuation of the single micromotors as well as formation of swarms of worm-like or tank-treading structure. Benefited from the enhanced motion, the micromotors show fast and high-capacity uranium adsorption (747.3 mg g−1), as well as fast uranium detection based on fluorescence quenching. DFT calculation confirms the strong binding between carboxyl groups and uranyl ions. The combination of poly(acrylic acid-co-acrylamide) with ZIF-8 greatly enhances the fluorescence of the micromotor, facilitating the high-resolution fluorescence detection. A low detection limit of 250 ppb is reached by the micromotors. Such self-propelled micromotors provide a new strategy for the design of smart materials in remediation of radioactive wastewater.

Unlocking the Potential of Garnet Ferrites: A Comprehensive Review on Properties, Preparation Methods, and Applications

Abstract This review paper provides a comprehensive overview of the recent advances in garnet ferrites, a class of complex magnetic oxides with promising properties for various applications. The paper covers the crystal structure and different properties of garnet ferrites as well as their synthesis methods, including sol-gel auto-combustion, low-temperature liquid phase epitaxy, pulsed laser deposition, coprecipitation method, sol-gel, hydrothermal, ball billing method, and low-temperature solid-state reactions. The functional properties of garnet ferrites, such as permeability, hysteresis loop, loss mechanics, and saturation magnetization, are also discussed in detail, along with their potential applications in microwave devices, antennas, Faraday lasers, and cancer treatment. Finally, the challenges and future directions for the development of garnet ferrites are outlined, highlighting the need for further research to optimize their properties and improve their performance in real-world applications.

Exploring the Oil/Water Separation Efficiency of PU Foam Modified with Magnetic Graphene Oxide

Exploring the Oil/Water Separation Efficiency of PU Foam Modified with Magnetic Graphene Oxide

Design and development of folic acid engineered magnetic graphene oxide nanosheets for selective synergistic chemophotothermal inhibition of lung cancer cell

Selective tumor targeting is considered as most advanced approach in nanomedicine. Targeted therapeutics will be useful for providing better therapeutic outcome in the cancer management. Surface engineering of carbon backbone based material is simplest approach compared to other polymeric substrate. The 2 dimensional backbone (2DC) like graphene oxide (GO) promote multifactorial surface architecture for design and delivery of multiple therapeutic agents. The present research explores the surface engineering of magnetic graphene oxide (GO@IO) using folic acid (FA) for selectivity towards folate receptor for the active delivery of Gefitinib (GF). The presence of oxygen embedded groups on the surface of GO promotes multi-payload with high loading efficiency. The advance analytical characterization reveals successful surface grafting of FA on the surface of GO@IOG with smooth textural characteristics. The surface grafting of FA protects the premature release of GF and release the content at targeted site. The in-vitro release characteristics reveals the prompt release of GF in physiological environment with 80 % release observed in 12h. The surface encapsulation improves the heacompatibility of anticancer drug thereby increase blood circulation time. The cytotoxicity assay performed on A549 cells shows 20-fold increase in inhibition compared to pure anticancer agent. The multifunctionalized strategy also improve the photothermal effect which further improve 9 % inhibition post FA grafting. The fabricated magnetic GO nanocarrier can be useful for contrast imaging and targeted drug delivery applications. Material engineering along with photothermal effect can relatively accomplish the development of standard protocol for complete eradication of cancer cell.