Magnetic Response Research Articles

Magnetite Nanoparticles with High Affinity Toward Target Protein for Efficient and Facile Bio-Separation.

Magnetite nanoparticles (Fe3O4 NPs) with molecular recognition capabilities offer significant potential for biomedical applications, yet existing surface protein imprinting methods often suffer from low efficiency. Herein, a surface enzyme-mediated polymerization strategy is exploited for surface imprinting of bovine serum albumin (BSA) onto Fe3O4 NPs. This method, compatible with all vinyl monomers and operable under mild conditions, enables imprinting at high monomer concentrations while preventing nanoparticle agglomeration. Notably, increasing the pre-polymerization solution concentration enhances the pre-assembly of functional monomers and template molecules, thereby improving imprinting efficiency. Furthermore, replacing conventional crosslinkers with a polyglutamic acid-based peptide crosslinker introduces a pH-responsive helix-coil transition, allowing complete template removal under mild conditions and increasing the adsorption capacity and imprinting factor to 139.8mg g⁻¹ and 10.36, respectively. The resulting BSA-imprinted Fe₃O₄ NPs exhibits high selectivity, robustness, and rapid adsorption kinetics while maintaining strong magnetic responsiveness for easy separation. These features allows for the selective extraction of BSA from bovine fetal serum, demonstrating the potential of this approach for biomedical applications, particularly in bioseparations.

Magnetic-responsive shape memory performance of 4D-printed acoustic metamaterials

Abstract To address the limitations of traditional acoustic metamaterials in sound absorption selectivity as well as their inadequate flexibility and adaptability for noise reduction, a honeycomb-thin-film acoustic absorbing metamaterial was developed via 4D printing. By incorporating soft magnetic particles, the structure was enabled to obtain a remote magnetic response, thereby facilitating adaptive sound absorption capabilities. We evaluated the mechanical properties, shape memory characteristics, and sound absorption performance of both the matrix material and the printed structure independently. The results indicated that the shape memory polymer containing 10 wt% Fe3O4 exhibited exceptional properties, with a shape fixation rate of 100% and a shape recovery rate of 97%; the honeycomb-thin-film structure could revert to its original shape within 120 s. The tuning ranges for the two absorption frequencies—sound insulation and sound absorption—were determined to be 68 Hz and 53 Hz, respectively. This study introduces a novel approach to the development of smart acoustic materials with adaptive sound absorption properties.

Magnetic Ionic Liquid-Assisted Alignment: Morphology and Orientation Control in Amorphous-Amorphous Diblock Copolymer

Abstract This study proposes using magnetic ionic liquids, 1-butyl-3-methylimidazolium tetrachloroferrate (bmimFeCl₄), to achieve alignment in amorphous polymers without inherent magnetic anisotropy. Selective doping into the polar phase of polystyrene-polymethyl methacrylate diblock copolymer promotes magnetic responsiveness. SAXS analysis revealed that adding bmimFeCl₄ transitions microphase separation morphologies from cylindrical to lamellar due to volume fraction changes. 13C CP/MAS spectroscopy confirmed bmimFeCl₄ localization in the polymethyl methacrylate phase. Thermal treatment within a magnetic field aligned interfaces parallel to the field direction, demonstrating control over morphology and orientation through magnetic ionic liquid doping.

On-Chip Planar Metasurfaces for Magnetic Sensors with Greatly Enhanced Sensitivity.

Metamaterials with engineered structures have been extensively investigated for their capability to manipulate optical, acoustic, or thermal waves. In particular, magnetic metamaterials with precise geometry, shape, size and arrangement of their elemental blocks may be used to concentrate, focus, or guide magnetic fields. In this work, we show the potential of using soft-magnetic permalloy (Py) metasurfaces to tailor the physical properties of other magnetic structures at the local scale. As an illustration, the magnetic response of a Cobalt (Co) sensor bar placed at the core of a Py metasurface is investigated as a function of in-plane magnetic fields through the planar Hall effect. Our findings reveal that by appropriately selecting the metasurface geometrical parameters, we can adjust the Co bar's coercive field and susceptibility, leading to a huge enhancement in sensor sensitivity of over 2 orders of magnitude. Micromagnetic simulations, coupled with magneto-transport equations and X-ray photoemission electron measurements (XPEEM) with contrast from magnetic circular dichroism (XMCD), accurately capture this effect and provide insights into the underlying physical mechanisms. These findings can potentially enhance the performance and versatility of magnetic functional devices by using specifically designed structural magnetic materials.

Chirality-Dependent Magnetization of Colloidal Squares with Offset Magnetic Dipoles.

Colloidal particles with anisotropic geometries and interactions display rich phase behavior and hence have the potential to serve as the basis of functional materials, which can tunably and reversibly self-assemble into different configurations. External fields are one design parameter that can be used to manipulate how systems of colloidal particles assemble with one another. One challenge in designing new materials using anisotropic colloidal particles is understanding how an individual particle's various anisotropic features, like geometry, affect their overall self-assembly. Here, we present the results of simulation studies that explore the self-assembly of 2D colloidal squares with offset magnetic dipoles in the presence of an external field. Annealing simulations are used to measure the equilibrium-phase behavior of systems of these particles in the ground state, when the magnetic interactions dominate over the thermal forces of the system. We find that the magnetic properties of these systems are strongly influenced by the relative number of squares with opposite "handedness", or chirality, that are present within the system. Systems of squares that contain equal numbers of either chirality are extremely responsive to the external field; a relatively weak external field is required to magnetize them. In contrast, systems that contain only one chirality of squares are significantly less responsive to the external field; a significantly stronger external field is required to elicit the same magnetic response. Ultimately, the differing macroscopic magnetic properties of these systems are related to their microscopic self-assembly in an external field. Simulation snapshots and ground state phase diagrams illustrate how the absence of opposite chirality squares prevents systems of these particles from leaving an energetically favorable antiparallel configuration in the presence of an external field. When opposite chirality squares are present, these magnetic particles assemble into a head-to-tail configuration, therefore inducing a magnetic state.

The Role of Brain Derived Neurotrophic Factor Polymorphism in Transcranial Magnetic Stimulation Response for Major Depressive Disorder.

Repetitive transcranial magnetic stimulation (rTMS) is a safe and effective therapy for treatment-resistant depression (TRD). A crucial next step in improving rTMS therapy is to identify response predictors to inform patient selection criteria. Brain-derived neurotrophic factor (BDNF) exerts influence over TRD treatment modalities. BDNF polymorphism, Val66Met, has shown altered cortical plasticity after single-session rTMS in healthy subjects and clinical response in noninvasive brain stimulation methods in major depressive disorder, stroke, Alzheimer's, and cerebral palsy. We sought to evaluate the effect of this BDNF polymorphism on clinical response in a standard course of rTMS therapy for TRD. In this naturalistic study, 75 patients with TRD completed a standard course of rTMS with weekly clinical assessments via the Inventory of Depressive Symptomatology Self-Report (IDS-SR). BDNF polymorphisms were retrospectively compared in respect to treatment response and remission, baseline and final scores, percent change scores, and scores across the 6-week treatment course. As expected, rTMS significantly decreased depressive symptoms as measured by IDS-SR scores. No difference was found in baseline, final, or percent change IDS-SR scores between polymorphism types. There was no difference between polymorphisms in IDS-SR scores across the treatment course. Response and remission rates did not differ between genotypes. In contrast to previous research highlighting differential response between BDNF polymorphisms to motor plasticity and clinical rTMS outcomes, our data suggest that BDNF polymorphism status may not influence the response to a standard course of 10-Hz rTMS for major depressive disorder. Differences in TMS protocol, target, or BDNF serum levels may underlie our results.

Facile Synthesis of Silicone Oil-Based Ferrofluid: Toward Smart Materials and Soft Robots.

Ferrofluids are stable colloidal dispersions of magnetic nanoparticles in carrier liquids. Their combination of magnetic and fluidic characteristics not only inspires fundamental inquiries into forms and functions of matter but also enables diverse applications ranging from sealants and coolants in mechanical devices to active components in smart materials and soft robots. Spurred by such fundamental and applied interests, a growing need for easy-to-synthesize, high-quality ferrofluid exists. Here, we report the facile synthesis and comprehensive characterization of a silicone oil-based ferrofluid that displays the characteristic surface instability of high-quality ferrofluids and demonstrate its functions in smart interfacial materials and soft robots. Silicone's chemical immiscibility with polar solvents and its biological inertness, when coupled with magnetic responsiveness and fluidic deformability, enable the manipulation of solid particles, gas bubbles, simple and complex liquids, as well as micro-organisms. We envision that the silicone oil-based ferrofluid will find applications in diverse areas, including magnetic digital microfluidics, multifunctional materials, and small-scale robotics.

Cellulose nanofiber-created air barrier enabling closed-cell foams prepared via oven-drying

Cellulose nanofiber-created air barrier enabling closed-cell foams prepared via oven-drying

Construction of magnetic response nanocellulose particles to realize smart antibacterial of Pickering emulsion.

Construction of magnetic response nanocellulose particles to realize smart antibacterial of Pickering emulsion.

A Review on Formulation of Polyester Resin From Recycled PET and Its Composite With the Incorporation of Metallic Fillers: Utilization of Recycled PET Products

ABSTRACTThe review paper explores the innovative utilization of recycled polyethylene terephthalate (PET) waste in synthesizing advanced polyester resin‐based composites, particularly through integrating metallic nanofillers. PET, a highly durable and versatile polymer, poses significant environmental challenges due to its non‐biodegradable nature and extensive use, especially in consumer packaging. The paper examines chemical recycling methods such as glycolysis, methanolysis, hydrolysis, and aminolysis, which depolymerize PET into monomers that can be repolymerized into unsaturated polyester resins (UPRs). These UPRs, reinforced with metallic fillers like iron oxide, alumina, nickel, and copper, exhibit enhanced mechanical, thermal, and magnetic properties. The incorporation of these nanofillers significantly improves composite matrices, increasing tensile strength, thermal stability, conductivity, and magnetic responsiveness, thus making them suitable for applications in electronics, automotive, and structural industries. This study highlights the synergistic effects of multi‐filler systems, which provide superior reinforcement by altering thermal conductivity and electromagnetic absorption properties. Furthermore, this review promotes the circular economy, demonstrating how PET waste can be transformed into high‐performance, sustainable composites, thereby reducing environmental impact and conserving resources. Future research is directed toward optimizing nanoparticle dispersion and developing multi‐functional composites tailored for specific high‐performance applications. This paper contributes valuable insights into sustainable materials science by advancing Recycling Technologies and Hybrid Nanocomposites Development.

Advancing the design of conductive composite cryogels based on hydroxypropyl cellulose derivatives for improving the compressibility and anti-freezing properties.

Advancing the design of conductive composite cryogels based on hydroxypropyl cellulose derivatives for improving the compressibility and anti-freezing properties.

Tb diffusion induced microstructural evolution and magnetic responses of multi-main-phase Nd-Dy-Fe-Ga-B magnet

Tb diffusion induced microstructural evolution and magnetic responses of multi-main-phase Nd-Dy-Fe-Ga-B magnet

Magnetic Properties of Bilayer Penta-Graphene-Like Nanostructures: A Monte Carlo Study

This study explores the magnetic properties of bilayer Penta-graphene-like nanostructures using Monte Carlo simulations, focusing on the effects of temperature, exchange interactions, crystal field anisotropy, and external magnetic fields. The analysis reveals how these factors govern magnetic phases, transitions, and overall stability. Furthermore, it examines spin alignment dynamics and phase boundaries, highlighting the potential of these nanostructures for advanced spintronic devices, high-density magnetic memory, and precision sensors, owing to their highly tunable magnetic responses.

Efficient removal of direct dyes and heavy metal ion by sodium alginate-based hydrogel microspheres: Equilibrium isotherms, kinetics and regeneration performance study.

Efficient removal of direct dyes and heavy metal ion by sodium alginate-based hydrogel microspheres: Equilibrium isotherms, kinetics and regeneration performance study.

Deep eutectic solvent and styrene copolymer-shelled magnetic microspheres for the capture of Ovomucoid in foods and their interactions.

Deep eutectic solvent and styrene copolymer-shelled magnetic microspheres for the capture of Ovomucoid in foods and their interactions.

Dynamic magnetic response of multicore particles: The role of grain magnetic anisotropy and intergrain interactions

Dynamic magnetic response of multicore particles: The role of grain magnetic anisotropy and intergrain interactions

Remanent magnetic response of hard magnetorheological elastomer foams: Fabrication, microstructure characterization and modeling

Remanent magnetic response of hard magnetorheological elastomer foams: Fabrication, microstructure characterization and modeling

Aharonov–Bohm magnetism and Landau diamagnetism in semimetals

Abstract We compute the magnetic response of hollow semimetal cylinders and rings to the presence of an axial Aharonov-Bohm magnetic flux, in the absence of interactions. We predict nullification of the Aharonov-Bohm effect for a class of dispersion laws that includes "non-relativistic" dispersion and demonstrate that at zero flux the ground-state of a very short "armchair" graphene tube will exhibit a ferromagnetic broken symmetry. We also compute the diamagnetic response of bulk semimetals to the presence of a uniform magnetic field, specifically predicting that the susceptibility has a logarithmic dependence on the size of the sample.

Osteogenesis induced by magnetic responsive composite scaffolds under a static magnetic field

Currently, traditional osteogenesis methods face significant challenges in terms of therapeutic efficiency and biocompatibility, particularly in the context of bone repair where higher precision and efficacy are required. In this study, we fabricated a novel composite scaffold composed of polycaprolactone (PCL), polydopamine (PDA), and iron oxide nanoparticles (IONPs) and investigated its osteogenic potential. The incorporation of IONPs imparts magnetic responsiveness to the scaffold, thereby enabling the application of an external magnetic field to stimulate osteogenesis. Characterization of the scaffold confirmed its structural integrity, porosity, and biocompatibility, whereas the inclusion of PDA improved its hydrophilicity and cell adhesion properties. In vitro studies demonstrated that an external magnetic field significantly enhanced cell proliferation, osteogenic differentiation, and mineral deposition of osteoprogenitor cells cultured on the scaffolds. Furthermore, in vivo evaluation revealed that when the scaffold was exposed to magnetic stimulation, bone regeneration was accelerated, and integration of the defect site was improved. The magnetic-field-mediated approach proposed in this study effectively enhanced the osteogenic rate by augmenting the magnetic responsiveness of IONPs and combining the biocompatibility and cell-adhesion-promoting functions of PCL/PDA. This method offers a more controllable and biologically responsive alternative strategy for bone tissue regeneration with considerable potential for clinical applications.

Confining Magnetic Response by the Surface Reorganization of Buckling Permalloy Microspheres for Boosting Microwave Absorption.

Sharp corners and edges with high surface curvature provide low-dimensional nanosized materials with special static magnetic properties. However, the surface engineering of their high-frequency magnetic response remains challenging, and the underlying mechanism requires further clarification. In this study, we propose a template-aided surface reorganization strategy for integrating surfaces with different curvatures into one permalloy architecture. The high-curvature surface demonstrates a dramatic variation in localized magnetic moments and confines the coupling of magnetic flux lines owing to high anisotropy, which helps concentrate magnetic energy absorption and dissipation. In addition, the magnetic resonances of multiple surfaces were superimposed by the spin-wave interaction for enhancing magnetic loss capacity, which cooperates with amorphous/crystalline interfacial polarization to achieve a satisfactory dielectric-magnetic synergistic electromagnetic wave (EMW) absorption performance. The reflectance loss values increased from -13.4 dB for microspheres to -49.7 dB for surface-restructured ones. Remarkably, the effective absorption bandwidth can be extended to 7.68 GHz with a matching thickness of 2.0 mm. This advancement presents new possibilities for an elaborate design of magnetic EMW absorbers and establishes a basis for comprehending a complex magnetic response mechanism.