Dispersion Of Magnetic Nanoparticles Research Articles

Hierarchical Magnetic Carbon Nanoflowers for Ultra-Efficient Electromagnetic Wave Absorption.

Porous carbon nanomaterials are widely applied in the electromagnetic wave absorption (EMWA) field. Among them, an emerging flower-like carbon nanomaterial, termed carbon nanoflowers (CNFs), has attracted tremendous research attention due to their unique hierarchical flower-like structure. However, the design of flower-like carbon nanomaterials with different magnetic cores for EMWA has rarely been reported. Herein, a general template method is proposed to achieve a set of high-quality magnetic CNFs, namely Co@Void@CNFs, CoNi@CNFs, and Ni@CNFs. The prepared magnetic CNFs have highly accessible surface area and internal space, rich heteroatom content, multi-scale pore system, and uniform and highly dispersed magnetic nanoparticles, as a result, deliver superior EMWA performance. Specifically, when the thickness is 2.6mm, the Co@Void@CNFs exhibit a maximum refection loss (RLmax) of -56.6dB and an effective absorption bandwidth (EAB) from 8.0 to 12.1GHz covering the whole X band. The CoNi@CNFs have an RLmax of up to -57.6dB and a wide EAB of 5.6GHz at just 1.9mm. For the Ni@CNFs, possess an ultra-broad EAB of 6.1GHz, covering the entire Ku band at 2.0mm. Overall, the hierarchical magnetic carbon nanoflowers proposed here offer new insights toward realizing multifunctional integrated carbon nanomaterials for EMWA.

Adsorption of cationic dyes in wastewater with magnetic κ-carrageenan nanoparticles

The application of innovative adsorbents with high adsorption capacity and easy recovery in wastewater treatment has always been of great concern. This study employed κ-carrageenan to enhance the dispersion of magnetic nanoparticles and improve their stability through Ca2+ and Na+ crosslinkinelg. XRD, FTIR, SEM and EDS revealed that the magnetic nanoparticles were coated with κ-carrageenan. The synthesized MΚC@Fe3O4MNPs exhibited a stable structure and multiple adsorption sites, which was beneficial for the treatment of cationic dyes in wastewater. The absorption results indicated that abundant active sites on the surface of the adsorbent efficiently adsorbed the three cationic dyes. Through optimization experiments, the MΚC@Fe3O4MNPs demonstrated maximum adsorption capacities of 729.9 mg/g, 184.1 mg/g, and 311.0 mg/g for methylene blue, malachite green, and safranin T, respectively. The adsorbent could maintain excellent adsorption efficiency even after 5 cycles of use. The adsorption mechanisms for the three cationic dyes included electrostatic interactions, n-π interactions, and hydrogen bonding. Therefore, the MΚC@Fe3O4MNPs showed highly efficient adsorption and separation of cationic dyes and are suitable candidates for dye wastewater treatment.

Carbon nanotubes-encapsulated Co/Co7Fe3 nanocomposites: Achieving wideband electromagnetic wave absorption at ultrathin-thickness by regulating magnetic phase ratio

Nowadays, through various strategies such as composition regulation and structural design, the electromagnetic wave (EMW) attenuation ability of composites has been significantly improved. Nevertheless, at ultra-thin sample matching thicknesses, it is still a challenge for absorbing materials to possess high-intensity and wide bandwidth simultaneously. In this work, the cobalt/iron nitrilotriacetic acid chelates (Co/Fe-NAC) were fabricated by a one-step hydrothermal self-assembly strategy. Then, a series of carbon nanotubes-encapsulated Co/Co7Fe3 (Co/Co7Fe3@CNTs) nanocomposites were constructed by coating glucose hydrothermal carbon on Co/Fe-NAC precursors and subsequent calcination process. By controlling the Co/Fe ion content, the magnetic phase ratio in the product can be efficiently regulated to comprehensively optimize microwave absorption (MA) performance. The minimum reflection loss (RL) of the optimized sample is −42.6 dB at only 1.1 mm thickness, and the effective absorption bandwidth (EAB) reaches up to 10.1 GHz (7.9–18 GHz). Surprisingly, for all samples, the widest EAB can exceed 8.2 GHz at the ultra-thin thickness (thinner than 1.3 mm) and the strongest RL values are all below −30 dB (99.9 % EMW can be absorbed). Such excellent MA performance is attributed to the strong magnetic loss of highly dispersed magnetic nanoparticles, the strong dielectric properties of carbon nanotubes and shells, optimized impedance matching, as well as the synergistic effect of multi-dimensional heterogeneous components and structures. Moreover, the high-frequency structure simulator (HFSS) was used to further analyze the multi-polarization behaviors and heterogeneous magnetic coupling effect. This work may provide a new direction to the fabrication of efficient and ultra-thin absorbers, and Co/Co7Fe3@CNTs nanocomposites may become a promising candidate for practical application in the MA field.

Magnetochromic Elastomer With Instant Color Changes: A Study of the Influence of Material Composition

AbstractMagnetochromic materials change color upon variation in an external magnetic field. A magnetochromic elastomer resulting from the dispersion of magnetic nanoparticles (MNPs) in a liquid and subsequent emulsification in a crosslinkable polydimethylsiloxane (PDMS) is presented. The MNPs form rod‐like structures under an external magnetic field, aligning with the field and allowing light to pass through the elastomer. The elastomer thus changes from dark grey to transparent/light grey. Polyethylene glycol 200 (PEG200) is selected as carrier liquid due to the faster movement of MNPs herein than in glycerol, leading to more rapid color changes in the films. The influence of magnetic particle types (commercial, superparamagnetic, and surfactant‐coated) on the magnetochromic effects is investigated. All films exhibit optical density changes upon exposure to a magnetic field. Moreover, the films retain their color‐changing ability after cycles of 40 times exposure to a magnetic field. Compared to the synthesized superparamagnetic particles, the films with commercial particles display superior optical density change abilities, suggesting commercial MNPs are more suitable for magnetochromic films. The obtained films have promising applications as magnetical field sensors due to their simple storage requirements, rapid response, and excellent repeatability.

Dispersions of magnetic nanoparticles in water/ionic liquid mixtures.

Nanoparticles (NPs) of iron oxide are dispersed in mixtures of water and ionic liquid, here ethylammonium nitrate (EAN), and the NP/NP and NP/solvent interactions are studied. They are analysed via small-angle X-ray scattering and dynamic light scattering coupled to forced Rayleigh scattering, from 22 °C to 80 °C. The NPs are well-dispersed as individual objects in the whole range of compositions and temperatures thanks to sufficient repulsion due to the organization of the solvents at the interface. The surface changes from hydrophilic to hydrophobic around a proportion of 50 vol% water : 50 vol% EAN, following the evolution of the bulk mixtures, which remain heterogeneous in the whole range of compositions.

Numerical study on permanent magnetic heat transfer inside a dual semicircle enclosure: Controlling by magnet position

Cooling is vital in electronic devices from which excess heat should be removed. Heat transfer can be controlled in this context through the dispersion of magnetic nanoparticles in the working fluid and subjecting it to an external magnetic field. Such a field can be obtained effectively and passively with permanent magnets. The resulting phenomenon is called thermomagnetic convection. The present study is dedicated to the numerical analysis of the heat transfer of a ferrofluid in a compact circular cavity subjected to two permanent magnets to assess the impact of the magnets' location and magnetic convection properties on the heat transfer behavior of the ferrofluid. The various equations governing the thermomagnetic in the enclosure are developed and presented in the non-dimensional form. The finite element method using Comsol Multiphysics is employed to model the problem. The effects of magnetic Rayleigh number, temperature factor, thermomagnetic number, and the position of the permanent magnets on the thermal and hydrodynamic response of the ferrofluid are investigated. It is found that the magnetic Rayleigh number and the temperature factor are the main parameters affecting the intensity of the heat transfer in the enclosure. The magnets' orientation affects the ferrofluid's thermal behavior mainly when the magnetic Rayleigh number is high. In that case, up to 64% rise in the average Nusselt number is reached when the inclination angle of the magnetic field is reduced from 75° to 15°. The impact of raising the magnetic Rayleigh number is also more important for lower inclination angle. Increasing this number from 5e3 to 5e7 leads to an augmentation of 91% and 11%, for the angles 15° and 75°, respectively Finally, multiplying the temperature ratio by 5 can increase the average Nusselt number by 2.

Analyte‐Driven Clustering of Bio‐Conjugated Magnetic Nanoparticles

AbstractThe dynamics of bio‐conjugated magnetic nanoparticles suspended in buffer‐saline solutions containing target proteins (i.e., analytes) is investigated numerically on a mesoscopic level. To simulate the dispersion of magnetic nanoparticles the dissipative particle dynamics is employed, which allows to study rather large systems, while still retaining important microscopic nanoparticle properties. In addition, the method is coupled to the Landau–Lifshitz–Gilbert equation, describing the dynamics of the magnetic nanocrystals within the macrospin approximation. The binding of multivalent analytes to the recognition ligands of the nanoparticles leads to the formation of clusters of magnetic nanoparticles, which in turn drastically changes the macroscopic magnetic response of the solution. Such colloidal changes are experimentally observable, allowing to explore new approaches to quantify the analyte amount. The ratio of the concentrations between the analytes (biomarkers) and the recognition ligands on the nanoparticles is found to play an important role in the formation and hydrodynamic size of the clusters. The proposed computational framework has great potential to be integrated with experimental efforts to advance the development of nanoparticle‐based biosensors for disease diagnostics and other biomedical applications.

Magnetic field enabled in situ control over the structure and dynamics of colloids interacting via SALR potentials.

Colloidal suspensions are an ideal model for studying crystallization, nucleation, and glass transition mechanisms, due to the precise control of interparticle interactions by changing the shape, charge, or volume fraction of particles. However, these tuning parameters offer insufficient active control over interparticle interactions and reconfigurability of assembled structures. Dynamic control over the interparticle interactions can be obtained through the application of external magnetic fields that are contactless and chemically inert. In this work, we demonstrate the dual nature of magnetic nanoparticle dispersions to program interactions between suspended nonmagnetic microspheres using an external magnetic field. The nanoparticle dispersion simultaneously behaves as a continuous magnetic medium at the microscale and a discrete medium composed of individual particles at the nanoscale. This enables control over a depletion attractive potential and the introduction of a magnetic repulsive potential, allowing a reversible transition of colloidal structures within a rich phase diagram by applying an external magnetic field. Active control over competing interactions allows us to create a model system encompassing a range of states, from large fractal clusters to low-density Wigner glass states. Monitoring the dynamics of colloidal particles reveals dynamic heterogeneity and a marked slowdown associated with approaching the Wigner glass state.

Checkerboard-like nickel nanoislands/defect graphene aerogel with enhanced surface plasmon resonance for superior microwave absorption

To solve the problem of dispersion of magnetic nanoparticles in ultralight electromagnetic absorption field, checkerboard-like nickel nanoislands/defect graphene aerogel (NIDG) with enhanced surface plasmon resonance was designed and prepared through electrostatic self-assembly method. This special structure successfully overcame the aggregation phenomenon of magnetic metals and built high-density gap regions to enhance surface plasmon resonance. And the NIDG has achieved excellent electromagnetic wave absorption performance in C band. Specially, NIDG is superior in ultra-lightness with only 6.2 wt%, compared to some recently reported magnetic electromagnetic wave absorbers. Such great performance can be attributed to the enhanced surface plasmon resonance and improved impedance matching. This work is significant for achieving effective dielectric loss and designing lightweight low-frequency EMW absorbing materials.

Dual nature of magnetic nanoparticle dispersions enables control over short-range attraction and long-range repulsion interactions

Competition between attractive and repulsive interactions drives the formation of complex phases in colloidal suspensions. A major experimental challenge lies in decoupling independent roles of attractive and repulsive forces in governing the equilibrium morphology and long-range spatial distribution of assemblies. Here, we uncover the ‘dual nature’ of magnetic nanoparticle dispersions, particulate and continuous, enabling control of the short-range attraction and long-range repulsion (SALR) between suspended microparticles. We show that non-magnetic microparticles suspended in an aqueous magnetic nanoparticle dispersion simultaneously experience a short-range depletion attraction due to the particulate nature of the fluid in competition with an in situ tunable long-range magnetic dipolar repulsion attributed to the continuous nature of the fluid. The study presents an experimental platform for achieving in situ control over SALR between colloids leading to the formation of reconfigurable structures of unusual morphologies, which are not obtained using external fields or depletion interactions alone.

Impedance amelioration of coaxial-electrospun TiO2@Fe/C@TiO2 vesicular carbon microtubes with dielectric-magnetic synergy toward highly efficient microwave absorption

An impedance-optimized hierarchical TiO 2 @Fe/C@TiO 2 vesicular carbon microtube is constructed for the first time via coaxial electrospinning and solvothermal method. Benefit from the integration of cavities, highly dispersed magnetic nanoparticles, and dielectric coating, the impedance is effectively improved by dielectric-magnetic synergy. The unique structure simultaneously fulfills a dual-network of micron-scale magnetic interaction and charge transfer, embedding the composite with enhanced magnetic and dielectric loss. The interfacial polarization and multiple reflections further promote microwave absorption. • 1D vesicular structure was successfully constructed via coaxial electrospinning. • Structural and compositional integration progressively improved impedance. • Strong magnetic-dielectric synergy of quaternary components in this absorber. • Electron holography confirmed magnetic coupling and charge transfer dual-network. Impedance matching ( Z ) is a key issue requested by high-efficient microwave absorption materials, which remains a major challenge. Lacking magnetic loss capacity and electromagnetic impedance balance, the microwave attenuation capacity of carbon-based absorbers urgently needs to be improved. Herein, a TiO 2 @Fe/C@TiO 2 vesicular carbon microtube was reasonably constructed by coaxial electrospinning. The characteristic impedance was gradually improved by introducing cavities, magnetic Fe particles and dielectric TiO 2 coating. The composite achieves an enhanced microwave performance with a maximum reflection loss of as strong as − 60.98 dB and a broad absorption bandwidth of 4.8 GHz at only 2.0 mm thickness. Such a well-integrated hierarchically vesicular carbon microtube with a tubular porous structure endows the assembly with high magnetic anisotropy and multiple interfaces, further offers the composites: i) the dual-networks of micron-scale 1D anisotropic magnetic coupling and charge conduction, ii) dielectric-magnetic synergy of quaternary components, iii) progressively matched impedance, proved by micromagnetic simulation and electron holography. This finding might have great significance in the impedance matching control of high-performance microwave absorbents.

Constructing two-dimensional lamellar monometallic carbon nanocomposites by sodium chloride hard template for lightweight microwave scattering and absorption

Low-dimensional carbon matrix nanocomposites are promising for lightweight and efficient electromagnetic wave absorption considering their large specific surface area and the multi-interface interaction. However, it remains a challenge to maintain the uniform dispersion of magnetic nanoparticles, which plays a vital role in regulating both dielectric and magnetic loss abilities. In this paper, by sodium chloride (NaCl) hard template, two-dimensional (2D) lamellar Co/C (NCC) and Fe/C (NFC) nanocomposites with well dispersed magnetic nanocomposites are prepared consecutively. An in-depth study of the construction of 2D lamellar structure on the electromagnetic dissipation and impedance matching has been carried out. The result shows that the 2D lamellar NCC and NFC prepared by NaCl hard template own the higher degree of graphitization and dielectric loss than those three-dimensional (3D) bulk composites without the addition of NaCl. Furthermore, the series of 2D lamellar nanocomposites exhibit excellent microwave absorption properties. The minimum reflection loss (RL) value of NCC and NFC can reach −52.2 and −46.7 dB, respectively. Particularly, accompanied by the thin thickness of only 2.0 mm, the effective absorption bandwidth (EAB, RL ≤ −10 dB) of NFC can reach 5.4 GHz (11.5–16.9 GHz). Furthermore, the smallest RCS value of only −8.098 dBm2 for NFC under vertical incidence can be obtained for excellent electromagnetic wave scattering and absorption.

Improvement of multiple attenuation characteristics of two-dimensional lamellar ferrocobalt@carbon nanocomposites as excellent electromagnetic wave absorbers.

The lightweight carbon skeleton compounded with magnetic nanoparticles as excellent electromagnetic wave absorbers has attracted much attention considering their strong dielectric loss and magnetic loss, as well as the optimized impedance matching. However, the conventional method of compounding magnetic metals with carbon materials usually leads to the inevitable aggregation of magnetic nanoparticles, resulting in poor microwave attenuation characteristics. In this study, two-dimensional (2D) lamellar carbon matrix ferrocobalt (CoxFe1-x/C) nanocomposites are prepared using sodium chloride (NaCl) as a hard-template. By regulating the relative contents of Co and Fe in the nanocomposites, the 2D lamellar carbon skeleton with uniformly dispersed magnetic nanoparticles can be obtained successfully. Furthermore, the existence of a variety of metal and alloy phases promotes the generation of multiple attenuation characteristics. As a result, the Co0.9Fe0.1/C exhibits a broad effective absorption bandwidth of about 5.4 GHz at a thin thickness of only 1.65 mm. The excellent electromagnetic wave absorption can be attributed to the formation of a 2D lamellar structure and the uniform distribution of magnetic nanoparticles being conducive to the enhancement of polarization loss including dipole polarization loss and interfacial polarization loss. Considering that, the 2D lamellar Co0.9Fe0.1/C nanocomposite is promising to be a candidate for excellent electromagnetic wave absorbers.

Investigation of the physicochemical properties of magnetic nanoparticles: size, magnetic properties, concentration

This work presents the results of studies of a series of samples of aqueous dispersions of magnetic nanoparticles. The particle sizes were measured for these samples by the dynamic scattering method. Using the method of ultramicroscopy, the number concentration of particles in the samples and the concentration of particles remaining in the volume of the samples after exposure to a magnetic field at various time intervals were measured.

Facile Synthesis, Static, and Dynamic Magnetic Characteristics of Varying Size Double-Surfactant-Coated Mesoscopic Magnetic Nanoparticles Dispersed Stable Aqueous Magnetic Fluids.

The present work reports the synthesis of a stable aqueous magnetic fluid (AMF) by dispersing double-surfactant-coated Fe3O4 magnetic nanoparticles (MNPs) in water using a facile ambient scalable wet chemical route. MNPs do not disperse well in water, resulting in low stability. This was improved by dispersing double-surfactant (oleic acid and sodium oleate)-coated MNPs in water, where cross-linking between the surfactants improves the stability of the AMFs. The stability was probed by rheological measurements and all the AMF samples showed a good long-term stability and stability against a gradient magnetic field. Further, the microwave spin resonance behavior of AMFs was studied in detail by corroborating the experimental results obtained from the ferromagnetic resonance (FMR) technique to theoretical predictions by appropriate fittings. A broad spectrum was perceived for AMFs which indicates strong ferromagnetic characteristics. The resonance field shifted to higher magnetic field values with the decrease in particle size as larger-size MNPs magnetize and demagnetize more easily since their magnetic spins can align in the field direction more definitely. The FMR spectra was fitted to obtain various spin resonance parameters. The asymmetric shapes of the FMR spectra were observed with a decrease in particle sizes, which indicates an increase in relaxation time. The relaxation time increased with a decrease in particle sizes (sample A to D) from 37.2779 ps to 42.8301 ps. Further, a detailed investigation of the structural, morphological, and dc magnetic properties of the AMF samples was performed. Room temperature dc magnetic measurements confirmed the superparamagnetic (SPM) characteristics of the AMF and the M-H plot for each sample was fitted with a Langevin function to obtain the domain magnetization, permeability, and hydrodynamic diameter of the MNPs. The saturation magnetization and coercivity of the AMF samples increased with the increase in dispersed MNPs’ size of the samples. The improvement in the stability and magnetic characteristics makes AMFs suitable candidates for various biomedical applications such as drug delivery, magnetic fluid hyperthermia, and biomedicines.

Enhanced magnetic nanoparticles dispersion effect on the behaviour of ultrasonication-assisted compounding processing of PLA/LNR/NiZn nanocomposites

In this study, magnetic polymer nanocomposite comprising of polylactide, liquified natural rubber and different loadings of NiZn ferrite nanoparticles was prepared using ultrasonication-assisted melt compounding method. The fabrication process has involved the ultrasonication treatment of the nanocomposite for 1 and 2 h. The influence of ultrasonication on the dispersion degree of the nanoparticles and its reflection on the behaviour of PLA/LNR/NiZn nanocomposites was evaluated. The tensile properties showed an improvement when the nanocomposites were treated for 1 and 2 h, with optimum values obtained at 4 wt% of nanofiller loading. Similarly, the optimum values of Tg, Tc and Tm obtained from DSC analysis were found for sample ultrasonically treated for 1 h with highest crystallinity increment of 55.16% as compared to untreated sample of the same nanofiller loading. Moreover, the statistical analysis based on TGA and SEM results revealed that the nanocomposite treated ultrasonically for 1 h had better nanofiller dispersion as compared to its counterparts with 0 and 2 h treatment periods. These findings, as confirmed by magnetic testing, formed a solid evidence that the optimal behaviour of PLA/LNR/NiZn nanocomposites was attained with ultrasonication treatment of 1 h with potential applications in areas served by soft magnetic materials.

Self-Limitations of Heat Release in Coupled Core-Shell Spinel Ferrite Nanoparticles: Frequency, Time, and Temperature Dependencies.

We explored a series of highly uniform magnetic nanoparticles (MNPs) with a core-shell nanoarchitecture prepared by an efficient solvothermal approach. In our study, we focused on the water dispersion of MNPs based on two different CoFe2O4 core sizes and the chemical nature of the shell (MnFe2O4 and spinel iron oxide). We performed an uncommon systematic investigation of the time and temperature evolution of the adiabatic heat release at different frequencies of the alternating magnetic field (AMF). Our systematic study elucidates the nontrivial variations in the heating efficiency of core-shell MNPs concerning their structural, magnetic, and morphological properties. In addition, we identified anomalies in the temperature and frequency dependencies of the specific power absorption (SPA). We conclude that after the initial heating phase, the heat release is governed by the competition of the Brown and Néel mechanism. In addition, we demonstrated that a rational parameter sufficiently mirroring the heating ability is the mean magnetic moment per MNP. Our study, thus, paves the road to fine control of the AMF-induced heating by MNPs with fine-tuned structural, chemical, and magnetic parameters. Importantly, we claim that the nontrivial variations of the SPA with the temperature must be considered, e.g., in the emerging concept of MF-assisted catalysis, where the temperature profile influences the undergoing chemical reactions.

Preparation and characterization of ferrite/carbon aerogel composites for electromagnetic wave absorbing materials

Ferrite/carbon aerogel composites have been fabricated via vacuum impregnation and coprecipitation of iron ions. The resultant Fe3O4/carbon aerogels possess high specific surface area, electronic conductive interconnected network and uniformly dispersed magnetic nanoparticles, showing an excellent electromagnetic wave absorption performance, which can be tactfully regulated by the pyrolysis temperature and incorporated Fe3O4 content. The minimum reflection loss of −57 dB is achieved with a filler loading of 10 wt%, and the effective absorption bandwidth can cover 5.2 GHz with a thickness of 1.8 mm. Furthermore, the electromagnetic energy dissipation mechanism has been discussed to provide a new route for preparing electromagnetic wave absorption materials.

Nanostructure, compositional and magnetic studies of Poly(aniline)–CoFe[formula omitted]O[formula omitted] nanocomposites

Magnetic and conducting composites of cobalt ferrite nanoparticles and poly(aniline) have been synthesized in acid media by the oxidative polymerization of aniline in the presence of a dispersion of magnetic nanoparticles, using Fe(III) ions as an oxidizing agent. The materials have been characterized by X-ray diffraction studies, X-ray fluorescence, energy dispersive X-ray spectroscopy, thermogravimetric analysis, transmission electron microscopy, spectrum-imaging electron energy loss spectroscopy, conductivity and DC magnetization measurements. The composite composition and morphology depend on the aniline/magnetic nanoparticle molar ratio used during the synthesis; for composites with a low polymer content, poly(aniline) (PANI), growth occurs preferably in the vicinity of the magnetic nanoparticles, while for composites with a higher polymer content, the magnetic nanoparticles are embedded in the PANI matrix. It was also observed that iron is incorporated in the composites during their preparation. The electrical conductivities of all the synthesized materials have values in the range 1–100 S cm−1, i.e., in the metallic regime. Also, the composites feature good magnetic properties, with ferrimagnetic behavior for CoFe2O4 and the composites. The coercivity decreases as the PANI/ferrite ratio increases, indicating that poly(aniline) affects the magnetic anisotropy. All these results suggest that the morphology and the composition affect the magnetic behavior.

Assessing the combination of magnetic field stimulation, iron oxide nanoparticles, and aligned electrospun fibers for promoting neurite outgrowth from dorsal root ganglia in vitro

Magnetic fiber composites combining superparamagnetic iron oxide nanoparticles (SPIONs) and electrospun fibers have shown promise in tissue engineering fields. Controlled grafting of SPIONs to the fibers post-electrospinning generates biocompatible magnetic composites without altering desired fiber morphology. Here, for the first time, we assess the potential of SPION-grafted scaffolds combined with magnetic fields to promote neurite outgrowth by providing contact guidance from the aligned fibers and mechanical stimulation from the SPIONs in the magnetic field. Neurite outgrowth from primary rat dorsal root ganglia (DRG) was assessed from explants cultured on aligned control and SPION-grafted electrospun fibers as well as on non-grafted fibers with SPIONs dispersed in the culture media. To determine the optimal magnetic field stimulation to promote neurite outgrowth, we generated a static, alternating, and linearly moving magnet and simulated the magnetic flux density at different areas of the scaffold over time. The alternating magnetic field increased neurite length by 40% on control fibers compared to a static magnetic field. Additionally, stimulation with an alternating magnetic field resulted in a 30% increase in neurite length and 62% increase in neurite area on SPION-grafted fibers compared to DRG cultured on PLLA fibers with untethered SPIONs added to the culture media. These findings demonstrate that SPION-grafted fiber composites in combination with magnetic fields are more beneficial for stimulating neurite outgrowth on electrospun fibers than dispersed SPIONs. Statement of significanceAligned electrospun fibers improve axonal regeneration by acting as a passive guidance cue but do not actively interact with cells, while magnetic nanoparticles can be remotely manipulated to interact with neurons and elicit neurite outgrowth. Here, for the first time, we examine the combination of magnetic fields, magnetic nanoparticles, and aligned electrospun fibers to enhance neurite outgrowth. We show an alternating magnetic field alone increases neurite outgrowth on aligned electrospun fibers. However, combining the alternating field with magnetic nanoparticle-grafted fibers does not affect neurite outgrowth compared to control fibers but improves outgrowth compared to freely dispersed magnetic nanoparticles. This study provides the groundwork for utilizing magnetic electrospun fibers and magnetic fields as a method for promoting axonal growth.