Search Results (295)

In the last decade, magnetic nanoparticles (MNPs) have attracted much attention for the implementation of non-invasive approaches suitable for the diagnosis and treatment of vascular diseases. In this work, the optimization of novel vascular grafts loaded with Nickel-based nanoparticles via electrospinning is proposed. Two different polycarbonate urethanes—i.e., Corethane A80 (COT) and Chronoflex AL80 (CHF)—were used to fabricate 3D electrospun nanocomposite grafts. SEM analysis showed a homogeneous distribution of fibers, with slight differences in terms of average diameters as a function of the polymer used—(1.14 ± 0.18) µm for COT, and (1.33 ± 0.23) µm for CHF—that tend to disappear in the presence of MNPs—(1.26 ± 0.19) µm and (1.26 ± 0.213) µm for COT/NPs and CHF/NPs, respectively. TGA analyses confirmed the higher ability of CHF to entrap MNPs in the fibers—18.25% with respect to 14.63% for COT—while DSC analyses suggested an effect of MNPs on short-range rearrangements of hard/soft micro-domains of CHF. Accordingly, mechanical tests confirmed a decay of mechanical strength in the presence of MNPs with some differences depending on the matrix—from (6.16 ± 0.33) MPa to (4.55 ± 0.2) MPa (COT), and from (3.67 ± 0.18) MPa to (2.97 ± 0.22) MPa (CNF). The in vitro response revealed that the presence of MNPs did not negatively affect cell viability after 7 days in in vitro culture, suggesting a promising use of these materials as smart vascular grafts able to support the actuation function of vessel wall muscles. Full article

In the pursuit of environmental sustainability, reduced emissions, and alignment with circular economy principles, bio-epoxy resin nanocomposites have emerged as a promising alternative to traditional petroleum-based resins. This study investigates the development of novel bio-epoxy nanocomposites incorporating iron-oxide nanoparticles (Fe₂O₃, MnP) as multifunctional fillers at loadings of 0.5 wt.% and 3.0 wt.%. MnP nanoparticles were synthesized and subsequently functionalized with citric acid (MnP-CA) to enhance their surface properties. Comprehensive characterization of MnP and MnP-CA was performed using X-ray diffraction (XRD) to determine the crystalline structure, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), and zeta potential measurements to confirm surface functionalization. The bio-epoxy resins matrix (bio-EP), optimized for compatibility with MnP and MnP-CA, was thoroughly analyzed in terms of chemical structure, thermal stability, curing behavior, dynamic–mechanical properties, and surface characteristics. Non-isothermal differential scanning calorimetry (DSC) was employed to evaluate the curing kinetics of both the neat (bio-EP) and the MnP/MnP-CA-reinforced composites, offering insights into the influence of nanoparticle functionalization on the resin system. Surface zeta potential measurements further elucidated the effect of filler content on the surface charge and hydrophilicity. Magnetic characterization revealed superparamagnetic behavior in all MnP- and MnP-CA-reinforced (bio-EP) composites. This research provides a foundational framework for the design of green bio-epoxy nanocomposites, demonstrating their potential as environmentally friendly materials and representing an emerging class of sustainable alternatives. The results underscore the viability of bio-epoxy systems as a transformative solution for advancing sustainable resin technologies across eco-conscious industries. Full article

This study focused on composites of magnetite magnetic nanoparticles (MNP) and poly(lactic acid) (PLA) prepared via sonochemical synthesis. The evaluation of MNP loadings (2, 5, 10, 15, and 20 wt.%) provided insights into the structural and reactivity properties of the materials. Methods used included XRD, FT-IR and Raman spectroscopy, SEM and TEM microscopy, textural and thermal analysis (TG and DTA), and magnetic property measurements. The agreement between theoretical and experimental MNP loadings was good. XRD patterns showed predominantly MNP and semicrystalline phases, with a minor maghemite phase detected by FT-Raman and magnetic measurements. FT-IR analysis revealed interactions between MNP and PLA, confirmed by thermal analysis showing higher transition temperatures for the composites (145 °C) compared to pure PLA (139 °C). FT-Raman spectra also indicated that PLA helps prevent iron oxide oxidation, enhancing nanoparticle stability. SEM and TEM micrographs showed well-dispersed, spherical nanoparticles with minimal agglomeration, dependent on MNP loading. The nanocomposites exhibited low N₂ adsorption, resulting in low surface area (~2.1 m²/g) and porosity (~0.03 cm³/g). Magnetic analysis indicated that in the 2MNP/PLA sample, MNP were in a superparamagnetic-like regime at 300 K, suggesting good dispersion of 2 wt.% MNP in the PLA matrix. Full article

Aerogels have gained much interest in the last decades due to their specific properties, such as high porosity, high surface area, and low density, which have caused them to be used in multiple and varied fields. As the applicability of aerogels is tightly correlated to their morpho-structural features, special consideration must be allocated to the fabrication method. An emerging technique for producing nanostructured materials with tailored morphology and dimensions is represented by continuous-flow microfluidics. In this context, this work explores the synergic combination of aerogel-based materials with microfluidic synthesis platforms to generate advanced nanocomposite adsorbents for water decontamination. Specifically, this study presents the novel synthesis of a magnetic silica-based aerogel using a custom-designed 3D microfluidic platform, offering enhanced control over nanoparticle incorporation and gelation compared to conventional sol–gel techniques. The resulting gel was further dried via supercritical CO₂ extraction to preserve its unique nanostructure. The multi-faceted physicochemical investigations (XRD, DLS, FT-IR, RAMAN, SEM, and TEM) confirmed the material’s uniform morphology, high porosity, and surface functionalization. The HR-MS FT-ICR analysis has also demonstrated the advanced material’s adsorption capacity for various pesticides, suggesting its adequacy for further environmental applications. An exceptional 93.7% extraction efficiency was registered for triazophos, underscoring the potential of microfluidic synthesis approaches in engineering advanced, eco-friendly adsorbent materials for water decontamination of relevant organic pollutants. Full article

Magnetic zeolite nanocomposites (NCs) have emerged as a promising class of hybrid materials that combine the high surface area, porosity, and ion exchange capacity of zeolites with the magnetic properties of nanoparticles (NPs), particularly iron oxide-based nanomaterials. This review provides a comprehensive overview of the synthesis, characterization, and diverse applications of magnetic zeolite NCs. We begin by introducing the fundamental properties of zeolites and magnetic nanoparticles (MNPs), highlighting their synergistic integration into multifunctional composites. The structural features of various zeolite frameworks and their influence on composite performance are discussed, along with different interaction modes between MNPs and zeolite matrices. The evolution of research on magnetic zeolite NCs is traced chronologically from its early stages in the 1990s to current advancements. Synthesis methods such as co-precipitation, sol–gel, hydrothermal, microwave-assisted, and sonochemical approaches are systematically compared, emphasizing their advantages and limitations. Key characterization techniques—including X-Ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning and Transmission Electron Microscopy (SEM, TEM), Thermogravimetric Analysis (TGA), Nitrogen Adsorption/Desorption (BET analysis), Vibrating Sample Magnetometry (VSM), Zeta potential analysis, Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and X-Ray Photoelectron Spectroscopy (XPS)—are described, with attention to the specific insights they provide into the physicochemical, magnetic, and structural properties of the NCs. Finally, the review explores current and potential applications of these materials in environmental and biomedical fields, focusing on adsorption, catalysis, magnetic resonance imaging (MRI), drug delivery, ion exchange, and polymer modification. This article aims to provide a foundation for future research directions and inspire innovative applications of magnetic zeolite NCs. Full article

Nanotechnology has emerged as a highly focused field of research due to the unique properties of nanometric materials, particularly their large specific surface areas and excellent adsorption capabilities. This study investigated the synthesis of materials based on graphene oxide (GO) functionalized with different metal oxides (MnO₂, Fe₃O₄, CuO, NiO), with potential applications in water decontamination. The morphological, structural, and compositional properties of these nanocomposites were extensively characterized using different experimental techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM) for magnetic property evaluation. Preliminary adsorption tests were performed for the removal of pesticides and drugs from aqueous solutions. The synthesized materials demonstrated a higher affinity for selected pesticides compared to drugs. The best removal efficiencies were 98.59% for cymoxanil, 97.93% for triadimefon, 63.33% for sulfamethoxazole, and 99.59% for diclofenac. The results indicate that the functionalization of GO with metal oxides modifies the material’s structure, increasing its potential for environmental applications such as water purification. Full article

This paper presents the synthesis and characterization of Ni-TiN@CN nanocomposites fabricated via arc discharge, followed by dopamine polymerization and pyrolysis. The cubic morphology of the Ni-TiN cores and uniform CN encapsulation were confirmed by structural analyses. Electromagnetic evaluations revealed that the CN shell thickness critically influenced the dielectric dispersion, polarization relaxation and conductive loss. The optimal sample (Ni-TiN@CN-3) achieved a minimum reflection loss of −42.05 dB at 4.06 GHz. The incorporation of magnetic Ni particles introduced a magnetic loss mechanism, while the multiple intrinsic defects within the heterogeneous structure synergistically generated defect dipole polarization and conductive loss. The strategic addition of Ni facilitated the construction of heterogeneous interfaces, which achieved enhanced interface polarization effects. The effective absorption bandwidth (≤−10 dB) reached 14.9 GHz, while the effective absorption bandwidth (≤−20 dB) achieved 6.5 GHz. The optimized CN layer facilitated a synergistic interplay between the dielectric loss and magnetic loss, which ensured balanced impedance matching and attenuation, as well as enhanced electromagnetic wave dissipation. This integrated optimization ultimately endowed the material with exceptional microwave absorption performance through an effective electromagnetic energy conversion. This work highlights Ni-TiN@CN nanocomposites as promising candidates for high-performance microwave absorbers in extreme environments. Full article

In this review work, the different routes and methods for preparing hybrid materials based on nanostructured block copolymers (BCPs) and magnetic nanoparticles (MNPs) are analyzed, as they can be potentially employed in different sectors like biomedicine, electronic or optoelectronic devices, data storing devices, etc. The first procedure for their preparation consists of the nanostructuring of BCPs in the presence of previously synthesized NPs by modifying their surface for increasing compatibility with the matrix or employing magnetic fields for NP orientation, which can also promote the orientation of nanodomains. Surface modification with surfactants led to the selective confinement of NPs depending on the interaction (mainly hydrogen bonding) degree and their intensity. Surface modification with brushes can be performed by three methods, including grafting from, grafting to, or grafting through. Those methods are compared in terms of success for the positioning and confinement of NPs in the desired domains, showing the crucial importance of brush length and grafting density, as well as of NP amount and modification degree in the self-assembled morphology. Regarding the use of external magnetic fields, the importance of relative amounts of MNPs and BCPs employed and that of the magnetic field intensity for the orientation of the NPs and the nearby BCP domains is shown. The second procedure, consisting of the in situ synthesis of NPs inside the nanodomains by a reduction in the respective metallic ions or employing metal-containing BCPs for the generation of MNP patterns or arrays, is also shown. In all cases, the transference of magnetic properties to the nanocomposite was successful. Finally, a brief summary of some aspects about the use of BCPs for the synthesis, encapsulation, and release of MNPs is shown, as they present potential biomedical applications such as cancer treatment, among others. Full article

Magnetoelectric composites enable strain-mediated coupling between magnetic and electric fields, supporting applications in sensors, actuators, and tunable devices. This study presents a finite element modeling framework for simulating the direct magnetoelectric effect in core–shell and layered nanocomposites fabricated by material jetting (inkjet printing). The model incorporates nonlinear magnetostrictive behavior of cobalt ferrite nanoparticles and size-dependent piezoelectric properties of barium titanate, allowing efficient simulation of complex interfacial strain transfer. Results show a strong dependence of coupling on field orientation, particle arrangement, and interfacial geometry. Simulations of printed droplet geometries, including coffee ring droplet morphologies, reveal enhanced performance through increased surface area and directional alignment. These findings highlight the potential of material jetting for customizable, high-performance magnetoelectric devices and provide a foundation for simulation-guided design. Full article

Glucose detection is critical in addressing health and medical issues related to irregular blood levels. Colorimetry, a simple, cost-effective, and visually straightforward method, is often employed. Traditional enzymatic detection methods face drawbacks such as high costs, limited stability, and operational challenges. To overcome these, enzyme mimics or artificial nano-enzymes based on inorganic nanomaterials have garnered attention, but their cost and susceptibility to inactivation limit applications. This study presents a ZnFe₂O₄/GQDs nanocomposite as an innovative enzyme mimic, addressing key requirements like low cost, high stability, biocompatibility, and wide operational range. Synthesized using a simple and inexpensive method, the composite benefits from the synergistic interaction between ZnFe₂O₄ nanoparticles and graphene quantum dots (GQDs), resulting in excellent magnetic properties, high surface area, and functional versatility. The material demonstrated remarkable sensitivity with a detection limit of 7.0 μM across a range of 5–500 μM and achieved efficient peroxidase-like activity with Km values of 0.072 and 0.068 mM and Vmax of 4.58 × 10⁻⁸ and 8.29 × 10⁻⁸ M/s for TMB and H₂O₂, respectively. The nanocomposite also exhibited robust recyclability, retaining performance over six reuse cycles. Full article

The primary resonance responses of high-performance nanocomposite materials used in spacecraft components in complex electromagnetic field environments were investigated. Simultaneously considering the interfacial effect, agglomeration effect, and percolation threshold, a theoretical model that can predict Young’s modulus and electrical conductivity of graphene nanocomposites is developed by the effective medium theory (EMT), shear lag theory, and the Mori-Tanaka method. The magnetoelastic vibration equation for an axially moving graphene nanocomposite current-carrying beam was derived via the Hamilton principle. The amplitude-frequency response equations were obtained for different external loading conditions. The study reveals the significant role of graphene concentration, external force, and magnetic field on the system’s primary resonance, highlighting how electromagnetic forces play a critical role similar to external excitation forces. It is shown that the increase in graphene content could lead the system from period-doubling motion into chaotic behavior. Moreover, an enhanced magnetic field strength may lower the minimum graphene concentration needed for period-doubling motion. This work provides new insights into controlling nonlinear vibrations of such systems through applied electromagnetic fields, emphasizing the importance of designing multifunctional nanocomposites in multi-physics coupled environments. The concentration of graphene filler would significantly affect the primary resonance and bifurcation and chaos behaviors of the system. Full article

As the global plastic pollution crisis intensifies, the development of sustainable food packaging materials has become a priority. Starch-based films present a viable, biodegradable alternative to petroleum-derived plastics but face challenges such as poor moisture resistance and mechanical fragility. This review comprehensively examines state-of-the-art advancements in starch-based packaging, including polymer modifications, bio-nanocomposite incorporation, and innovative processing techniques that enhance functionality. Furthermore, the role of advanced analytical tools in elucidating the structure–performance relationships of starch films is highlighted. In particular, we provide an in-depth exploration of advanced characterization techniques, not only to assess starch-based food packaging but also to monitor starch retrogradation, including Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), and iodine binding (Blue Value). We also explore cutting-edge developments in active and intelligent packaging, where starch films are functionalized with bioactive compounds for antimicrobial protection and freshness monitoring. While substantial progress has been made, critical challenges remain in upscaling these technologies for industrial production. This review provides a roadmap for future research and the industrial adoption of starch-derived packaging solutions. Full article

Based on modern concepts of the nonlinear percolation mechanisms of electrical and magnetic properties in granular metal–dielectric nanocomposites, the authors present for the first time a comparative analysis of their own results of a comprehensive study of nonlinear electromagnetic properties in two nanocomposite systems: metal–dielectric Co_x(MgF₂)_100−x and alloy–dielectric (CoFeZr)_x(MgF₂)_100−x, obtained by ion-beam sputtering of composite targets in a wide range of different compositions. For the first time, the features of the influence of atomic composition and structural-phase transitions on nonlinear magnetoresistive, magnetic, and magneto-optical properties in two systems are presented in comparison, one of which, Co_x(MgF₂)_100−x, showed soft magnetic properties, and the second, (CoFeZr)_x(MgF₂)_100−x, hard magnetic properties, during the transition from the superparamagnetic to the ferromagnetic state. Moreover, for the first time, the concentration dependences of the oscillating fine structure of XANES K-absorption edges of Co atoms in the first system and Co and Fe atoms in the second system are presented, which undergo changes at the percolation thresholds in each of the two systems and thus confirm the nonlinear nature of the electromagnetic properties changes in each of the two systems at the atomic level. Full article

The significance of hydrogen sulfide (H₂S) release in vivo is multifaceted. It functions as a crucial gaseous signaling molecule with extensive physiological and pathological impacts within organisms. To create novel H₂S-releasing materials, we synthesized Fe₇S₈@Lip, a slow-release gas nanocomposite, which exhibits stable and sustained H₂S-release properties. Our gas releaser possesses selective H₂S-release capabilities, and, notably, it can achieve effective H₂S release under magnetic force with the assistance of a magnetic field. In conclusion, our findings indicate that Fe₇S₈@Lip can serve as an H₂S slow-release nanocomposite, offering a potentially innovative approach for programmed H₂S release in vivo. Full article

The printing of composite magnetic filaments using additive manufacturing techniques has emerged as a promising approach for biomedical applications, particularly in bone tissue engineering and magnetic hyperthermia treatments. This study focuses on the synthesis of nanocomposite ferromagnetic filaments and the fabrication of bone tissue scaffolds with time-dependent properties. Three classes of polylactic acid-based biocompatible polymers—EasyFil, Tough and Premium—were combined with magnetite nanoparticles (Fe₃O₄) at concentrations of 10 wt% and 20 wt%. Extruded filaments were evaluated for microstructural integrity, printed dog-bone-shaped specimens were tested for elongation and mechanical properties, and cylindrical scaffolds were analyzed for magnetic hyperthermia performance. The tensile strength of EasyFil polylactic acid decreased from 1834 MPa (0 wt% Fe₃O₄) to 1130 MPa (−38%) at 20 wt% Fe₃O₄, while Premium polylactic acid showed a more moderate reduction from 1800 MPa to 1567 MPa (−13%). The elongation at break was reduced across all samples, with the highest decrease observed in EasyFil polylactic acid (from 42% to 26%, −38%). Magnetic hyperthermia performance, measured by the specific absorption rate, demonstrated that the 20 wt% Fe₃O₄ scaffolds achieved specific absorption rate values of 2–7.5 W/g, depending on polymer type. Our results show that by carefully selecting the right thermoplastic material, we can balance both mechanical integrity and thermal efficiency. Among the tested materials, Tough polylactic acid composites demonstrated the most promising potential for magnetic hyperthermia applications, providing optimal heating performance without significantly compromising scaffold strength. These findings offer critical insights into designing magnetic scaffolds optimized for tissue regeneration and hyperthermia-based therapies. Full article