Concentration Of Magnetic Nanoparticles Research Articles

Spatially Confined Assembly and Immobilization of Hierarchical Nanoparticle Architectures inside Microdroplets in Magnetic Fields.

Magnetic field-directed colloidal interactions offer facile tools for assembly of structures that range from linear chains to multidimensional hierarchical architectures. While the field-driven assembly of colloidal particles has commonly been investigated in unbounded media, a knowledge gap remains concerning such assembly in confined microenvironments. Here, we investigate how confinement of ferromagnetic nanoparticles in microspheres directs their magnetic assembly into hierarchical architectures. Microdroplets from polydimethylsiloxane (PDMS) liquid precursor containing dispersed iron oxide magnetic nanoparticles (MNPs) were placed in a static magnetic field leading to the formation of organized assemblies inside the host droplets. By changing the MNP concentrations, we revealed a sequence of microstructures inside the droplets, ranging from linear chains at a low MNP loading, transitioning to a combination of chains and networked bundles, to solely 3D bundles at high MNP loading. These experimental results were analyzed with the aid of COMSOL simulations where we calculated the potential energy to identify the preferred assembly conformations. The chains at high MNP loading minimized their energy by aggregating laterally to form bundles with their MNP dipoles being out-of-registry. We cured these PDMS droplets to immobilize the assemblies by forming soft microbeads. These microbeads constitute an "interaction toolbox" with different magnetic macroscale responses, which are governed by the structuring of the MNPs and their magnetic polarizability. We show that thanks to their ability to rotate by field-induced torque under a rotating field, these microbeads can be employed in applications such as optical modulators and microrollers.

Formulation and Characterization of Ferrogels Based on Agar Gum and Octenyl Succinic Anhydride (OSA) Starch

AbstractPhysicochemical and rheological analyses are carried out on ferrogels based on Agar gum in combination with octenyl succinic anhydride (OSA) starch in the presence of magnetic nanoparticles (MNPs) coated with a stabilizing agent (PNiPAAm). The objective of this work is to prepare nanocapsules of MNPs coated with OSA starch present in a rigid network of Agar to obtain a nanocomposite gel (ferrogel). It is found that the effect of MNPs on the properties of ferrogels has a direct relationship with PNiPAAm/OSA starch interactions. The results obtained show that the ferrogels have stable thermal properties and a high melting point (99.7 °C) for high concentrations of MNPs (0.1%). The rheological properties show that this concentration (0.1%) has a negative effect on the crosslinking of Agar, therefore a drop in viscosity. In addition, it is shown that each pore comprises three populations of MNPs (primary: 3–4 nm, secondary: 6–9 nm, and clusters: ≥12 nm). Moreover, it is found that MNPs are coated with OSA starch. In addition, the prepared materials possess at low concentration of MNPs an interesting stiffness and uniform surface morphology with a minimum of clusters leading to stable systems that can be used as biomaterials in nanomedecine.

Experimental and statistical investigation on the dielectric breakdown of magneto nanofluids for power applications

The insulating oil serves the dual purpose of providing insulation and cooling within transformers. This investigation aims to explore the impact of various nanoparticles on the dielectric breakdown voltage (BDV) of dielectric oils. The study examines the effect of the concentration of magnetic nanoparticles on the dielectric breakdown voltage of insulating oils. Nanoparticles such as iron (II, III) oxide (Fe3O4), cobalt (II, III) oxide (CO3O4), and ferrous phosphide (Fe3P) were utilized to create nanofluids with carrier mediums consisting of mineral oil and synthetic ester oil. BDV determination was conducted using a VDE and S–S electrode system according to IEC 60156 standards. Nanofluid were prepared using a two-step method, and their concentrations ranged from 0.01 g/L, 0.02 g/L, and 0.04 g/L in base oils. Twelve iterations were conducted for each prepared nanofluid, and breakdown voltage measurements were recorded. The results indicate a noteworthy enhancement in the breakdown voltage of nanofluids. The statistical analysis was performed on the dielectric property of nanofluid samples for better breakdown accuracy. The maximum enhancement at specific nanoparticle concentrations was shown by each nanofluid. The results show that under the S–S electrode configuration, the greatest overall enhancement was observed for Fe3P in mineral oil, with an enhancement of 70.05%, and Fe3O4 in synthetic ester oil, with an enhancement of 46.29%.

Effects of magnetic fields and nanoparticle concentration on hydro-thermal performance of a surface enhanced microchannel

This article numerically investigates fluid flow and heat transfer in plain wall (PWMC) and oblique fin (OFMC) microchannels under varying magnetic fields using water- Al2O3 nanofluid as a working fluid. Effects of magnetic flux (Hartmann number, Ha = 0–30), fluid velocity (Reynolds number, Re = 100–500), and nanoparticle volume fraction (ϕ = 0%–2%) on the overall thermo-fluid performance are analyzed. Magnetic fields can significantly improve the heat transfer in OFMC in a higher rate compared to the PWMC. Also, there is a less increment on the pressure drop in the OFMC in comparison to PWMC. In addition, individual, as well as combined effect of Joule and viscous heating on the thermo-fluid performance is investigated. Due to the combined effect of Joule and viscous heating, the Performance Evaluation Criterion (PEC) in OFMC can be improved by 21%. However, the PEC in OFMC can be enhanced by 55% without considering the combined effect. The detailed characteristics flow and heat transfer are also studied by analyzing the velocity contours, isotherms, streamlines, friction factors, and Nusselt numbers. The present study concludes the importance of consideration of Joule and viscous heating for an accurate modeling, where the viscous heating plays the dominant role. The present findings can be instrumental in enhancing the performance of micro heat sinks to optimize hydrothermal performance in high powered motors, nuclear fusion reactors etc., where magnetic field is present.

Investigating the effect of magnetic field and nanoparticles characteristics in the treatment of glioblastoma by magnetic hyperthermia method: An in silico study

This study investigated the use of magnetic fluid hyperthermia (MFH) for treating glioblastoma multiforme (GBM), a deadly and treatment-resistant tumor. It considers the effects of magnetic nanoparticle (MNP) (different sizes and materials), alternating magnetic field (AMF) characteristics (frequency and strength magnetic field), MFH duration, and injection number, using a realistic brain phantom, considering its blood circulation system, tumor, and healthy tissue properties. Results demonstrated that MFH is more sensitive to frequency, increasing frequency causing greater temperature and thermoablation than increasing strength magnetic field. The magnetic field strength can be increased at a fixed frequency to control temperature increase in mild hyperthermia treatment more reliably. The size of MNP significantly impacts temperature when exceeding 15.8 nm, while smaller particles do not significantly affect the temperature obtained. Also, the tumor's MNP concentration increases and uniformly disperses as the number of injection sites increases. The study examined the duration of hyperthermia treatment (30–60 min), it is important to optimize the duration to prevent irreparable damage in cases of temperature increase from 46 °C. In conclusion, to effectively manage the temperature generated and destruction of malignant tissue while minimizing damage to healthy tissue, multiple hyperthermia-related parameters must be adjusted simultaneously.

Research on Spatial Magnetic Field Distribution of Magnetic Fluids Based on Microstructure.

This study focuses on the spatial magnetic field distribution of magnetic fluids, an extraordinary class of fluids composed of magnetic nanoparticles (MNPs), employing the Monte Carlo method to simulate the microstructure of magnetic fluids under an external magnetic field. On that basis, a model was established through magnetic dipole theory to delve into the spatial magnetic field distribution of magnetic fluids. The findings reveal that the application of a magnetic field leads to the formation of chain-like structures within the magnetic fluids, resulting in inhomogeneous spatial magnetic field distribution. The size and concentration of MNPs are crucial determinants that significantly affect the microstructure of magnetic fluid and its spatial magnetic field distribution. Furthermore, environmental conditions such as external magnetic field strength or temperature can also regulate the positions of MNPs within magnetic fluids and the spatial magnetic field distribution of the magnetic fluids. These observations enrich the comprehension of the fundamental mechanisms of magnetic fluids and their response to diverse factors, advancing the growing comprehension on the characteristics and applications of these remarkable magnetic fluids.

Improvements of magnetic nanoparticle assays for SARS-CoV-2 detection using a mimic virus approach

Immunoassays with magnetic nanoparticles (MNPs) as markers are a promising approach for the fast and sensitive virus detection. Upon binding of antibody-functionalized MNP on virus proteins, the hydrodynamic diameter increases and a change in the Brownian relaxation time can be measured. In this study, we detect the whole SARS-CoV-2 by mimicking it with streptavidin-coated polystyrene beads with biotinylated spike proteins. Changes of the MNP dynamics are measured by alternating current susceptometry and magnetic particle spectroscopy. Due to the multiple binding sites of MNP and virus, crosslinking enlarges the change of the hydrodynamic diameter. In order to improve the sensitivity and the limit of detection of the assay, the ratio of the virus to the MNP amount RMV/MNP is investigated in detail. High RMV/MNP ratios lead to a saturation of the MNPs with viruses, so that the cluster size and therefore the sensitivity decrease again. Additionally, it is found that the smallest virus concentrations can be detected for small MNP concentrations. It is also shown that the RMV/MNP range that can be used for an unambiguous detection of viruses depends on the virus/MNP concentration; it shifts with increasing MNP concentration to smaller RMV/MNP values. For very small virus concentrations, an increase of the Brownian relaxation time is detected implying a decrease of the hydrodynamic diameter. Furthermore, the optimal antibody concentration for MNP functionalization was determined. It is also found that a washing process with a centrifuge improves the sensitivity by reliably removing unbound antibodies and eliminating small MNPs with improper functionalization.

Electric partial discharges in biodegradable oil-based ferrofluids: A study on effects of magnetic field and nanoparticle concentration

This paper presents an experimental study of partial discharge activity in ferrofluids based on biodegradable transformer oil and iron oxide nanoparticles. Three ferrofluid samples with low, medium and high nanoparticle concentrations are employed in the research. The basic ferrofluid characterization is followed by a partial discharge experiment exposing the ferrofluids to a high voltage in a needle-plate electrode configuration. The analysis confirms that the apparent charge and number of discharges decrease with increasing nanoparticle concentration. These findings are interpreted with reference to the well-recognised electro-hydrodynamic streamer model. The charge trapping by nanoparticles hinders the ionization and discharge development. The study also focuses on the partial discharge activity in the ferrofluids under the action of a static magnetic field acting perpendicularly to the electric field. A decreasing trend in the number of discharges due to the magnetic field is revealed. A qualitative explanation is provided based on the field-induced cluster formation and charge mobility reduction. The presented experiment and the discussed findings may be valuable for practical application of the ferrofluid in high voltage equipment with a special need for partial discharge suppression.

Incorporation of Magnetic Filler (Co0.2Zn0.2Cd0.6Fe2O4) in PVA Matrix and Studying the Structural, Optical and Mechanical Properties of Nanocomposite Films

AbstractThe goal of this study is to synthesize nanocomposite PVA/ Co0.2Zn0.2Cd0.6Fe2O4 films with varying contents of Co0.2Zn0.2Cd0.6Fe2O4 nanoparticles (x = 0, 0.2, 0.4, 0.6, 0.8) to improve the structural, optical, and mechanical characteristics of the examined materials. Casting technique is used to prepare PVA/ Co0.2Zn0.2Cd0.6Fe2O4 films. X-ray diffraction, FTIR, UV–Vis spectroscopy, and Vickers Hardness were used to examine the effect of magnetic nanoparticle content on the structural, optical, and mechanical characteristics of PVA nanocomposite films. The refractive index rises from 1.4967 for pure PVA to 7.6511 for PVA + 0.8Co0.2Zn0.2Cd0.6Fe2O4, allowing it to be employed in a variety of applications such as solar cell construction. Because of the presence of ferrite in the glass matrix, the average hardness values enhanced and increased from 90.7 to 114.2 MPa. The stress exponent (n) varies from 1.12 to 3.33, with grain boundary sliding as the deformation mechanism for x = 0, viscous glid for x = 0.2, 0.4, and 0.6, and dislocation climb for x = 0.8 nanocomposite thin films.

Using a New Fe3O4@CPAM Magnetic Flocculant and Microwave to Demulsify Heavy Oil-in-Water Emulsions.

In this study, cationic polyacrylamide (CPAM)-coated magnetic nanoparticles (MNPs) Fe3O4@CPAM were synthesized for treating heavy O/W emulsions. This Fe3O4@CPAM was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM) techniques, and its synergistic performances with microwaves were evaluated in detail with respect to the microwave radiation power, radiation time, and magnetic nanoparticle concentration. On this basis, the distribution of oil droplets and the wettability and chargeability of magnetic nanoparticles were measured without or with microwave radiation using biomicroscopy, contact angle measurement instrument, and a ζ-potential analyzer, thus revealing the synergistic demulsification mechanism between microwave and magnetic nanoparticles. The results showed that excessively high or low microwave radiation parameters had an inhibitory effect on the magnetic nanoparticle demulsification, and microwave promoted the magnetic nanoparticle demulsification only when the radiation parameters were in the optimal range. In addition, the water separation rate showed an increasing and then decreasing trend with the increase of magnetic nanoparticles concentration, with or without microwave action. As an example, the water separation rate of the emulsion for 1 h was 21.34% when the Fe3O4 concentration was 175 mg/L without microwave action, while it increased to 55.56% with microwave action. In contrast, when the concentration of Fe3O4@CPAM was 175 mg/L, the water separation rate was 42.86% without microwave radiation, while it was further increased to 77.38% under microwave radiation. These results indicate that magnetic nanoparticles and their complexes significantly affect the water separation process under different conditions. There is a more obvious coupling synergistic effect between Fe3O4@CPAM and microwave. This was due to the lower absolute potential of Fe3O4@CPAM and its higher hydrophobicity.

A Novel Local Magnetic Fluid Hyperthermia Based on High Gradient Field Guided by Magnetic Particle Imaging.

Magnetic Particle Imaging (MPI)-guided Magnetic Fluid Hyperthermia (MFH) has the potential for widespread utilization, as it allows for the prediction of magnetothermal dosage, real-time visualization of the thermal therapy process, and precise localization of the lesion area. However, the existing MPI-guided MFH (MPI-MFH) method is insensitive to concentration gradients of magnetic nanoparticles (MNPs) and is susceptible to causing damage to normal tissues with high MNP concentrations during MFH treatment, while inadequately heating tumor tissues with lower MNP concentrations. In this work, we established a relationship between MNP concentration and heating efficiency through simulations and phantom measurements, enabling the optimal selection of MFH parameters guided by MPI. Based on these findings, we developed a high-gradient field MPI-MFH method using a fieldfree point (FFP) approach to achieve precise local heating. Phantom experiments and in vivo glioma model experiments were conducted to validate this proposed method. The results demonstrated that the proposed method of MPIMFH can improve the MNP concentration gradient sensitivity to ±1 mg/ml, thereby enabling more effective lesion-site heating without damaging normal tissues. This method not only reduced glioma size effectively but also holds promise for application in various other types of cancers.

Analysis of variable inductor employing vegetable-based transformer oil with magnetic nanoparticles

Variable inductors using magnetorheological fluids have recently been successfully applied to power-conversion devices; however, the thermal properties of Vegetable oil-based Magnetic Nanofluids (VMNFs) have not been investigated. In this study, the temperature characteristics of a variable inductor embedded with a VMNF were analyzed by developing a multiphysics analysis method and verified experimentally. To analyze the temperature distribution efficiently, a coupled analysis of the Magnetoquasistatic (MQS) field and steady-state heat transfer field based on the finite-element method was performed. The B-H curves of the VMNF and ferrite core were obtained via magnetic property measurement experiments, and the input waveforms were measured from the current and high-frequency pulse voltages applied to the variable inductor of the DC–DC converter. To predict the temperature rise of the VMNF-gap variable inductor, the power dissipation was determined using the Steinmetz experimental equation modified by the Bertotti model in the electronic system solver and input as a heat source in the steady-state heat-transfer analysis. The temperature increase predicted by the multiphysics analysis method agreed well with the experimental data, and an increasing the concentration of magnetic nanoparticles had a cooling effect. The developed MQS–thermal field coupled analytical method and the cooling properties of VMNFs can be applied to the design of power-conversion devices operating with high-frequency power sources.

Morphology and structure of sawdust waste after adding magnetic nanoparticles

Sengon (Albizia chinensis) is a type of forest plant that grows quickly and is widely used to meet human needs. The large number of uses of Sengon wood causes sengon wood waste, such as sawdust, to increase. The study’s aim is to analyze the morphology and structure of sawdust waste after adding magnetic (Fe3O4) nanoparticles. The methods include collecting sawdust waste from wood (Sengon) was conducted by the crushing process to get smaller sawdust sizes. Alkalization was applied to sawdust and followed by a bleaching process. The powder is then immersed in a solution containing magnetic (Fe3O4) nanoparticles of 10wt%, and then dried. Sawdust composite powder the analyzed using X-ray diffraction and electron microscope instruments. The result indicates that magnetic nanoparticles deposit on sawdust powder and then make the powder become rougher. Higher content of magnetic nanoparticles causes higher agglomeration. The diffraction pattern with 2θ of 14, 16, and 22 indicates that the structure of sawdust is cellulose 1β. The degree of crystalline of sawdust powder reduces from 76.1% to 73.3% after adding magnetic nanoparticle. In the future, these composite powder results will develop as flocculants for wastewater treatment.

Comprehensive analysis of effects of magnetic nanoparticles on aerobic granulation and microbial community composition: From the perspective of acyl-homoserine lactones mediated communication

As dosing additives benefit for aerobic granular sludge (AGS) cultivation, effects of different concentrations (0, 10, 50 and 100 mg/L) of magnetic nanoparticles (Fe3O4 NPs) on aerobic granulation, contaminant removal and potential microbial community evolution related to acyl-homoserine lactones (AHLs) mediated bacterial communication were investigated with municipal wastewater. Results showed that the required time to achieve granulation ratio > 70 % was reduced by 60, 90 and 30 days in phase II with addition of 10, 50, 100 mg/L Fe3O4 NPs, respectively. 50 mg/L Fe3O4 NPs can improve contaminant removal efficiency. The promotion of relative abundance of AHLs-producing and AHLs-producing/quenching populations and AHLs-related functional genes accompanied with faster granulation. Iron-cycling-related bacteria were closely related with AHLs-related bacteria during AGS formation. Co-occurrence network analyses showed that AHLs-mediated communication may play an important role in coordinating microbial community composition and functional bacteria participating in nitrogen and polyphosphate metabolisms during aerobic granulation process.

Effects of enclosure shape on MHD nanofluid flow and irreversibility in different shaped systems under fluid volume constraint

PurposeThe purpose of this study is to investigate the influence of enclosure shape on magnetohydrodynamic (MHD) nanofluidic flow, heat transfer and irreversibility in square, trapezoidal and triangular thermal systems under fluid volume constraints, with the aim of optimizing thermal behavior in diverse applications.Design/methodology/approachThe study uses numerical simulations based on a finite element-based technique to analyze the effects of the Rayleigh number (Ra), Hartmann number (Ha), magnetic field orientation (γ) and nanoparticle concentration (ζ) on heat transfer characteristics and thermodynamic entropy production.FindingsThe key findings reveal that the geometrical design significantly influences fluid velocity, heat transfer and irreversibility. Trapezoidal thermal systems outperform square systems, while triangular systems achieve optimal enhancement. Nanoparticle concentration enhances heat transfer and flow strength at higher Rayleigh numbers. The magnetic field intensity has a significant impact on fluid flow and heat transport in natural convection, with higher Hartmann numbers resulting in reduced flow strength and heat transfer. The study also highlights the influence of various parameters on thermodynamic entropy production.Research limitations/implicationsFurther research can explore additional geometries, parameters and boundary conditions to expand the understanding of enclosure shape effects on MHD nanofluidic flow and heat transfer. Experimental validation can complement the numerical simulations presented in this study.Originality/valueThis study provides valuable insights into the impact of enclosure shape on heat transfer performance in MHD nanofluid flow systems. The findings contribute to the optimization of thermal behavior in applications such as electronics cooling and energy systems. The comparison of different enclosure shapes and the analysis of thermodynamic entropy production add novelty to the study.

Fabrication and characterization of magnesium implants coated with magnetic nanoparticles-wollastonite-hydroxyapatite for medical and sports injury applications: Finite element analysis

Recently, wollastonite nanoceramics were considered a suitable choice for the orthopedic applications in terms of the presence of silicon, and calcium ions. Using the nanoceramics for the coatings of orthopedic application was increased to facilitate the possibility of stabilization and integration with the host tissue and the regeneration of bone tissues. Using the ceramic coatings was extensively improved due to their biological properties. The present investigation delves into the utilization of innovative wollastonite nanoceramics (WS) fortified with magnetite nanoparticles (MNPs) as coatings for biomechanical implants. The study focuses on evaluating the bioactivity and mechanical attributes of electrophoretic coatings while characterizing their phase and structure through the employment of X-ray diffraction (XRD) and scanning electron microscope (SEM). The coatings are also evaluated for bioactivity and biodegradation in simulated body fluid (SBF) and phosphate-buffered saline (PBS) for 21 days. Additionally, the mechanical properties of the coatings are simulated using Finite Element Analysis (FEA) to predict porosity and elastic modulus. The presence of wollastonite with silica nanoparticles in a magnesium alloy significantly enhances bone formation, as evidenced by the highest degree of apatite formation observed in the alloy containing 10% wollastonite. This particular composition resulted in a remarkable 29% increase in apatite growth. These findings highlight the potential of incorporating wollastonite with silica nanoparticles to promote and improve bone formation processes. The results indicate that the specimen coated with a 10% concentration of magnetic nanoparticles (MNPs) exhibits favorable mechanical performance and desirable biological behavior, making it suitable for use in sports biomechanics implants. The results indicate that the specimen treated with a greater concentration of MNPs demonstrates advantageous mechanical characteristics and desirable biological responses, rendering it a promising candidate for the production of sports and orthopedic prostheses.

Impact of thermal radiations, heat generation/absorption and porosity on MHD nanofluid flow towards an inclined stretching surface: Non‐similar analysis

AbstractObjective of this investigation is to provide a novel study of the flow of a magnetohydrodynamics (MHD) nanofluid over an inclined stretching surface in a permeable medium in a 2‐dimensional boundary layer. The convection model further incorporates heat radiation and heat sources/sinks. Nanomaterials include magnesium oxide and copper oxide . Using non‐similarity transformations, the set of governing equations is transformed into a set of dimensionless partial differential equations (PDEs). Using the local non‐similarity technique, the resulting system of dimensionless PDEs is treated as a set of ordinary differential equations (ODEs), and then solved with the help of the bvp4c MATLAB tools. This comprehensive research involves a thorough investigation of the significant starting physical characteristics and their impacts on the velocity and nanofluid temperature profiles. These profiles are shown using a set of graphical representations and numerical tables. It is worth noting that changes in the magnetic and porosity parameters result in a decrease in the velocity profile, but the Grashof number exhibits a reciprocal correlation. When we account for the effects of the Eckert number and the radiation parameters in a given flow regime, we also see an increase in the nanofluid's temperature profile. It has been shown that when the magnetic number and the Eckert number are augmented, the heat transmission rate decreases. The skin friction coefficient grows on a logarithmic scale when magnetic parameters and nanoparticle concentration are increased in estimation. The numerical calculations are checked for accuracy by comparing them to previously published findings, which guarantees an exact match in a constrained setting. Scientists investigating nanomaterials and their applications in manufacturing and thermal engineering may find this research instructive.

Inclusion of CoFe2O4 ultrafine nanoparticles in 7CB liquid crystal: effects on temperature-dependent magnetic properties and insights for expanding the application of LC systems in hyperthermia treatments

ABSTRACT This work presents a comprehensive analysis of the magnetic properties of pristine and citric acid-coated cobalt ferrite ( CoF e 2 O 4 ) nanoparticles (NPs) dispersed in the host nematic 4 ′ -heptyl-4-biphenylcarbonnitrile (7CB) system. Our results shed light on the promising potential of combining liquid crystals (LC) with magnetic nanoparticles for cancer treatment. This opens up exciting avenues for further exploration and possible applications in the field of oncology. The study focuses on examining the magnetic behaviour of LC dispersed systems with two concentrations of magnetic nanoparticles (0.03 and 0.04 wt%). Notably, intriguing temperature-dependent magnetisation plots reveal a distinctive cusp, which can be attributed to the freezing phenomenon of the liquid crystal. This observation offers valuable insights into the system's magnetic properties and interactions, deepening our understanding of its behavior.

Fabrication and characterization of magnetic cobalt ferrite intercalated chitosan grafted polyaniline ternary nanocomposites for removing some heavy metals simultaneously

Chitosan grafted polyaniline (Ch-g-PANI) loaded with different concentrations of cobalt ferrite magnetic (CoFM) nanoparticles (2, 5 and 10 wt%) to form (Ch-g-PANI/CoFM) nanocomposites were fabricated. X-ray diffraction (XRD), High-Resolution Transmission Electron Microscope (HRTEM), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray (EDX), Fourier transform inferred (FT-IR), and Vibrating Sample Magnetometer (VSM) were carried out to investigate the structure, morphology, chemical composition, and magnetic properties of Ch-g-PANI and Ch-g-PANI/CoFM) nanocomposites. Adsorption performance of these prepared samples towards heavy metals (Pb2+, Cu2+, Fe3+, Cd2+, Li1+, Co2+, Al3+, Mn2+, Zn2+, Ni2+, Cr2+, and V2+) was investigated. The effects of CoFM NPs concentraion doped in grafted polymer, initial metal concentration, temperature, pH, and contact time on heavy metal removal efficiency were optimized. SEM revealed abundant pores for optimum sample that enhance the heavy metal removal efficiency. Competitive adsorption tests proved that Ch-g-PANI/CoFM5 NPs showed higher efficiency for tested heavy metals. The removal efficacy of optimum sample (Ch-g-PANI/CoFM5) reached maximum values 98, 95.3, 96, 99.2, 97, 99.9, 88, 94.4, 99.8, 93.4, 98.96, 93, and 93.9 % for Pb2+, Cu2+, Fe3+, Cd2+, Li1+, Co2+, Al3+, Mn2+, Zn2+, Ni2+, Cr2+, and V2+, respectively at 90 min(equilibrium time), the element ions concentration of 10 mg/L and pH range of 4–6 depending on the kind of metal ions. Freundlich model is the best isotherm model for the equilibrium data, suggesting the multilayer adsorption on the heterogeneous surface. The kinetic data specified that the pseudo-first-order model fitted the adsorption of heavy metal ions on Ch-g-PANI/CoFM5. Thermodynamic studies elucidated the feasible, spontaneous, random, and endothermic adsorption. From an economic viewpoint, the regeneration study implied that the optimal sample Ch-g-PANI/CoFM5 was efficiently recovered up to four successive cycles.

Evaluation of Magnetic Hyperthermia Efficiency of PEG-Coated Fe3O4 Nanoparticles

Magnetic nanoparticle hyperthermia has drawn considerable interest in cancer therapy. In this study, we report the synthesis of PEG-coated Fe3O4 nanoparticles and evaluate their suitability for magnetic hyperthermia applications. Fe3O4 nanoparticles were synthesized by the chemical coprecipitation method, which are coated with polyethylene glycol (PEG). PEG-coated Fe3O4 nanoparticles were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Synthesized nanoparticles possess inverse-spinel structural with a crystallite size of 9.1[Formula: see text]nm. From the M-H hysteresis loops, it was confirmed that the synthesized Fe3O4 nanoparticles were superparamagnetic. The physical size of bare Fe3O4 nanoparticles, as determined from the HR-TEM, is [Formula: see text][Formula: see text]nm, and the corresponding hydrodynamic size of PEG-coated Fe3O4 nanoparticles is [Formula: see text][Formula: see text]nm. Magnetic hyperthermia efficiency of PEG-coated Fe3O4 nanoparticles was determined as a function of magnetic field frequency (162–935.6[Formula: see text]kHz), field strength (5–12[Formula: see text]mT) and nanoparticle concentration (1–100[Formula: see text]mg/mL). Temperature rise in an aqueous dispersion of PEG-coated Fe3O4 nanoparticles was measured for 20[Formula: see text]min. The specific loss power (SLP) was calculated by the corrected slope method. SLP values of PEG-coated Fe3O4 nanoparticles increase with magnetic field frequency and field strength and decrease with nanoparticle concentration. The optimum hyperthermia performance of PEG-coated Fe3O4 nanoparticles was observed for 935.6[Formula: see text]kHz frequency, 10[Formula: see text]mT field strength and 25[Formula: see text]mg/mL concentration. Under these conditions, the measured SLP of PEG-coated Fe3O4 nanoparticles was 4.43[Formula: see text]W/g. These results show that the synthesized PEG-coated Fe3O4 nanoparticles could be a potential candidate for magnetic hyperthermia treatment of cancer.