Cobalt Ferrite Nanoparticles Research Articles

Remote Activation of Antimicrobial Properties via Magnetoeletric Stimulation of Biopolymer‐Based Nanocomposites

AbstractAntimicrobial materials are crucial for high‐touch surfaces to prevent the adhesion and proliferation of microorganisms, playing a key role in infection control measures. In this work, a magnetoelectric nanocomposite able to exert antimicrobial activity when magnetically stimulated, is obtained by solvent casting. The nanocomposites, composed of poly(hydroxybutyrate‐co‐hydroxyvalerate) (PHBV) and cobalt ferrite magnetostrictive nanoparticles (CFO NPs), respond to a variable magnetic field by mechanically stimulating the piezoelectric component of the material, thereby inducing an electrical polarization. The antimicrobial properties of the material are determined by exposing it to different frequencies (0.3 and 1 Hz) using a custom‐designed magnetic bioreactor, where the resulting electrical microenvironments are the contributing factor. The growth of Escherichia coli and Staphylococcus aureus over the nanocomposite is highly inhibited when magnetically stimulated (dynamic conditions) mainly at 0.3 Hz, in contrast to static conditions. The electric microenvironment is further measured upon magnetic stimulation, with PHBV films with 20% CFO inducing a voltage variation of ≈20 µV at the surface while the films with 10% CFO induced a voltage variation of ≈12 µV. This work demonstrated that magnetic stimulation, combined with magnetoelectric materials, can be used for remote antimicrobial control, thus preventing the spread of infections.

Development of Scaffolds with Chitosan Magnetically Activated with Cobalt Nanoferrite: A Study on Physical-Chemical, Mechanical, Cytotoxic and Antimicrobial Behavior.

Background/Objectives: This study investigates the development of 3D chitosan-x-cobalt ferrite scaffolds (x = 5, 7.5, and 10 wt%) with interconnected porosity for potential biomedical applications. The objective was to evaluate the effects of magnetic particle incorporation on the scaffolds' structural, mechanical, magnetic, and biological properties, specifically focusing on their biocompatibility and antimicrobial performance. Methods: Scaffolds were synthesized using freeze-drying, while cobalt ferrite nanoparticles were produced via a pilot-scale combustion reaction. The scaffolds were characterized for their physical and chemical properties, including porosity, swelling, and mechanical strength. Hydrophilicity was assessed through contact angle measurements. Antimicrobial efficacy was evaluated using time kill kinetics and agar diffusion assays, and biocompatibility was confirmed through cytotoxicity tests. Results: The incorporation of cobalt ferrite increased magnetic responsiveness, altered porosity profiles, and influenced swelling, biodegradation, and compressive strength, with a maximum value of 87 kPa at 7.5 wt% ferrite content. The scaffolds maintained non-toxicity and demonstrated bactericidal activity. The optimal concentration for achieving a balance between structural integrity and biological performance was found at 7.5 wt% cobalt ferrite. Conclusions: These findings suggest that magnetic chitosan-cobalt ferrite scaffolds possess significant potential for use in biomedical applications, including tissue regeneration and advanced healing therapies. The incorporation of magnetic properties enhances both the structural and biological functionalities, presenting promising opportunities for innovative therapeutic approaches in reconstructive procedures.

“Sol-gel auto combustion synthesis of Al3+-Gd3+ ions co-doped cobalt ferrite nanoparticles for nanoelectronics applications”

“Sol-gel auto combustion synthesis of Al3+-Gd3+ ions co-doped cobalt ferrite nanoparticles for nanoelectronics applications”

Targeted delivery of letrozole-loaded Mg-doped cobalt ferrite nanoparticles for breast cancer treatment

Breast cancer is the most common cancer in women globally. Letrozole is an aromatase inhibitor used as an anticancer drug. Conventional Letrozole therapies for breast cancer often cause adverse effects when administered orally or parenterally. Efforts have been made to develop an advanced drug delivery system for breast cancer treatment, aiming to improve drug release accuracy and therapeutic efficacy while minimizing side effects. This study focuses on magnesium-doped cobalt ferrite nanoparticles (Mg-doped CFNPs) as potential drug delivery carrier for breast cancer treatment. Mg-doped CFNPs with the chemical formula Co1-xMgxFe2O4 (where x = 0.0, 0.05, 0.10, 0.15, 0.20 and 0.25) were synthesized with different concentrations of 5 %, 10 %, 15 %, 20 %, and 25 % by the sol gel method with a fine size of 30–70 nm and their characteristics such as surface morphology, structural properties, chemical composition, and charge were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and zeta potential analysis respectively. After synthesis, the Mg-doped CFNPs were coated with Poly ethylene glycol (PEG) and encapsulated with Letrozole, which exhibited <10 % hemolytic activity across all concentrations, as well as minimal cytotoxic effects on non-cancerous cells (HEK-293) but exhibited significant toxicity towards breast cancer cell lines (MCF-7, MDA-MB-231).The best results were obtained at a concentration of 25 % in both the hemolytic assay and the MTT assay, which indicated that increasing the amount of magnesium in cobalt decreased the toxicity and increased the drug release efficiency of nanoparticles.

Synergy of Magnetic Nanoparticles and Sodium Alginate-Coated Lignin for Effective Pollutant Remediation, Simple Recovery, and Cost-Effective Regeneration.

In the pursuit of sustainable materials for environmental remediation, this study presents the development and comprehensive characterization of cobalt ferrite nanoparticles (CFNPs) incorporated in lignocellulosic-derived sodium alginate (CFNPs@LCG-SA) biocomposite beads. These biobased beads exhibit exceptional adsorption capabilities, particularly for methylene blue (MB) dyes, rendering them promising candidates for wastewater treatment. Using a comprehensive range of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis-derivative thermogravimetry (TGA/DTG), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), etc., we elucidated their structural, physicochemical, and thermal properties. Their multifunctional nature, derived from lignin and sodium alginate components, provides ample active sites for both physical interactions and chemical bonding with contaminants apart from the magnetic character attributed by the CFNPs. With a freeze-drying approach, the optimal adsorption capacity and removal rate of MB reached 97 mg/g and 99%, respectively, and no meaningful decline in their activity was noted even after six cycles. The CFNPs@LCG-SA biocomposite beads emerge as a cost-efficient and sustainable remedy for environmental cleanup, offering valuable perspectives in environmental preservation and advancing green energy technologies.

Effect of Zn-substitution on magnetic structure of cobalt ferrite nanoparticles.

This study investigates the effects of Zn substitution on the magnetic properties of ∼5nm cobalt ferrite nanoparticles (ZnxCo1-xFe2O4, where x = 0, 0.13, 0.34, and 0.55), demonstrating that Zn substitution induces complex changes in spin canting and prompts a redistribution of cations among the sublattices. We reconstructed the magnetic structure of these spinel ferrites by integrating the classical two-sublattice Néel model of ferrimagnetism with the data obtained from 57Fe Mössbauer spectrometry. Consequently, this research provides a comprehensive understanding of how Zn substitution tunes the magnetic properties of CoFe2O4 nanoparticles, offering valuable insights into the development of magnetic materials with tailored properties for various applications.

Synthesis and Characterization of CoFe2O4 Nanoparticles and CoFe2O4@BaTiO3 Nanocomposites for Biomedical Applications

Cobalt ferrite magnetic nanoparticles (CFO) of around 9 nm were synthesized with the solvothermal method. The CFO particles were covered with a barium titanate (BTO) shell at a 1:1 CFO:BTO ratio, via a sol-gel synthesis, to form CFO@BTO nanocomposites. X-Ray Diffraction (XRD) studies reveal the presence of only the expected CFO and BTO phases. Scanning and Transmission Electron Microscopy (SEM, TEM) images show the thorough covering with the BTO shell. Energy-Dispersive X-ray spectroscopy (EDX) mapping was used to analyze the elemental composition of the nanocomposites. Magnetic characterization shows high saturation magnetization and low coercive field at 300 K, suitable for biomedical applications.

Efficient degradation of tetracycline by cobalt ferrite modified alkaline solution nanofibrous Ti3C2Tx MXene activated peroxymonosulfate system: Mechanism analysis and pathway

Magnetic CoFe2O4 nanoparticles have received considerable attention as an activator for peroxymonosulfate (PMS) in the degradation of tetracycline. However, it is still challenging to construct CoFe2O4 composites with good dispersion and highly exposed reactive sites. Herein, the KOH fiber-functionalized MXene matrix decorated by cobalt ferrite nanoparticles (denoted as CoFe2O4@Alk-MXene) was developed by electrostatic self-assembly method. The layered fibrotic structure effectively disperses and fixes cobalt ferrite nanoparticles, increasing the exposure of reactive sites. The as-prepared CoFe2O4@Alk-MXene material exhibited rapid removal of 100% tetracycline hydrochloride (TC-HCl) within 10 minutes by activating PMS, leveraging the excellent conductivity of alkalized MXene and the efficient activation of transition metal atoms. The experimental and theoretical analysis revealed that the electron transfer process of Ti2+/Ti4+, Co2+/Co3+ and Fe3+/Fe2+, as well as the free radical and non-free radical attack behaviors produced by the adsorption of PMS by the composite, are the primary mechanisms for achieving rapid removal of pollutants. A comprehensive degradation mechanism and potential pathways were proposed based on these findings. Overall, CoFe2O4@Alk-MXene/PMS emerges as a promising catalytic system for TC removal.

Structural, magnetic and electrical properties of gadolinium doped cobalt ferrite nanoparticles: Role of Gd doping level

In this communication, effect of Gd doping for CoFe2–xGdxO4 (CFGO) nanoparticles has been investigated for structural, magnetic and electrical properties. X–ray diffraction (XRD) patterns reveal the presence of matrix like CFGO phase fraction with coexisting GdFeO3 (GFO) smaller crystallites and α–Fe2O3 (FO) phase fraction. Variation in crystallite size (D) for all three phases has been explored from the analysis on XRD patterns. Magnetic nature has been understood on the basis of lattice disorder, magnetic linkages between different ions of CFGO lattices that conduces magnetic characteristic of three different phases coexist within the CFGO nanoparticle lattices. Influence of frequency, temperature and Gd doping level on different electrical behaviors has been understood on the bases of various relaxation processes, charge conduction mechanism, correlated barrier hopping (CBH) mechanism, maximum barrier height, activation energy and structure–property correlations.

Colloidal dispersions of cobalt ferrite nanoparticles in EMIM TFSI, propylene carbonate and their mixtures

Liquid thermocells are promising devices for the recovery of low-grade waste heat and its conversion into electricity. The present study proposes dispersing charged magnetic nanoparticles in liquids to improve thermoelectric conversion, due to their thermodiffusive and magnetic properties. Core@shell cobalt ferrite@maghemite nanoparticles (NPs) of various sizes with three different kinds of coatings are tested for dispersion in EMIM TFSI (ethyl-methylimidazolium bistriflimide), an ionic liquid (IL) of high electrical conductivity. Among the tested ligands, PAC6MIM±Br− (1-(6-hexylphosphonate) 3-methyl imidazolium bromide) emerges as the most efficient due to its phosphonic group. This ligand leads to dispersions of clusters of a few dozen NPs in water and a few NPs in EMIM TFSI. For improving both the viscosity and the electrical conductivity, dispersions in binary mixtures of propylene carbonate (PC), a polar medium, and EMIM-TFSI are further investigated with the sample based on NPs of ∼ 9 nm diameter. Through a pumping and heating procedure, stable dispersions are obtained with a subsequent reduction of the size of the NP clusters, down to 1 to 2 NPs in EMIM TFSI and a few NPs in PC and their binary mixtures. The mixture with an IL mole fraction ∼0.2–0.3 and maximal electrical conductivity is a promising candidate for further thermoelectric investigations.

Effect of SiO2 on structural, magnetic, and nonlinear optical behavior of cobalt ferrite nanoparticles

CoFe2O4 and CoFe2O4/SiO2 were synthesized by sol-gel method. The studies carried out using XRD, FT-IR, SEM, TEM, VSM, UV–Vis DRS, and Z-scan techniques. The CoFe2O4 has the inverse cubic spinal structure. TEM and SEM confirmed the less crystallite size of CoFe2O4/SiO2 nanocomposite than CoFe2O4. The results show that two samples have a pure single phase cobalt ferrite with face-centred cubic spinel phase. SiO2 matrix in CoFe2O4 nanocomposite results in reduction particle size and magnetic properties as well as enhancement band gap. The band-gap energy of CoFe2O4 and CoFe2O4/SiO2 calculated 1.76 and 1.92 eV, respectively. Our findings in nonlinear optical aspects suggest that the distinctive characteristics of CoFe2O4/SiO2 present opportunities for advancements in telecommunications and other related fields.

Improvement of photocatalytic ammonia production of cobalt ferrite nanoparticles utilizing microporous ZSM-5 type ferrisilicate zeolite

The development of decarbonized synthesis approaches is a critical step in the fabrication of ammonia, an indispensable chemical and a potential carbon–neutral energy carrier. In this regard, the photocatalytic production technology has gained ample attention as a sustainable alternative to energy-intensive and environmentally detrimental Haber–Bosch process. Here, we present cobalt ferrite nanoparticles supported on microporous ZSM-5 type ferrisilicate zeolite as a desirable novel photocatalyst for the ammonia generation. The zeolite introduced as a microporous support increasing the catalytically active sites. A straightforward one-pot sol–gel method was used to synthesize cobalt ferrite (CoFe2O4) and CoFe2O4/ferrisilicate (CF/FS) nanocomposites with various weight percentages (10, 25 and 50%) of CoFe2O4. The photocatalytic performances of the samples in the production of ammonia were investigated under visible light irradiation. The highest rate of NH4+ production (484.74 µmol L−1 h−1) was achieved using the CF50%/FS photocatalyst. The distribution of < 50 nm-sized CoFe2O4 nanoparticles on the surface of the zeolite, as demonstrated by TEM images, and extensive BET surface areas are presented as convincing evidences for the improved photocatalytic activity paticularly in CF50%/FS photocatalyst.

Structural, morphological, optical, and antimicrobial study of Mikania micrantha (leaf) extract treated zinc doped cobalt ferrite nanoparticles and antibacterial clothing applications

To manage pathogenic diseases, different applications of nanotechnology have been harnessed to improve the antimicrobial and self-cleaning attributes of materials. The objective of this study is to examine the anti-microbial activity of silk thread; coated (ultra-sonication method) with Zn doped cobalt ferrite nanoparticles with future prospects of developing interlayer of surgical facemask or producing antibacterial wearing. The nanoparticles were synthesized following the co-precipitation method by using Mikania micrantha leaf extract. The potential antibacterial activity (against E. coli and S. aureus) of the thread as well as the nanoparticles was recorded using the Zone of Inhibition (ZOI) test result. XRD results showed the cubic crystal structure and the lattice parameter change due to Zn doping. SEM findings revealed particle agglomeration, though the particles retained an approximately spherical shape of around 52.498 nm for undoped and 32.13 nm for doped materials. FT-IR analysis confirmed that flavonoids from the leaf extract stabilized the nanoparticles. This research investigated the antibacterial capabilities of threads coated with nanoparticles; using the agar well diffusion method, the study established the robust antibacterial capabilities of the nanoparticles-coated thread. Notably, the CoFe2O4 NPs exhibited strong antimicrobial activity against specific bacterial strains, and Zn doping enhances this characteristic.

Single-domain configuration tune high coercive field in Co-precipitated monazite-decorated cobalt ferrite nanoparticles

Single-domain configuration is one of the important key in the applied current- technology especially information technology. In order to address this issue, a magnetic modification of cobalt ferrite nanoparticles (CFO-NPs) by decorating the monazite-natural-mineral (Ce) is presented. Monazite-decorated CFO-NPs are successfully synthesized by the co-precipitation method. The obtained nanoparticle samples are annealed at 200 °C, 300 °C, and 400 °C for 5 hours. XRD results confirms the successful decoration of the monazite sand with CFO-NPs, as demonstrated by the distinctive peaks of CFO-NPs, as well as the major peaks of the monazite-sand. The presence of monazite in the CFO-NPs sample was confirmed by the EDS results. With increasing annealing temperature, the crystallite size increases, respectively. FTIR results show that the monazite-decorated CFO-NPs outcome absorption peaks at kt ∼590/cm and ko ∼390/cm, which are the original absorptions of CFO-NPs. VSM results showed that the single-domain configuration realized owing high the HC (supported by K1 and Kσ) for samples without and annealed at 200 °C, whereas the multi-domain configuration appears to have a small HC (supported only by K1) for samples annealed at 300 °C and 400 °C. The largest HC of the monazite-decorated CFO-NPs was obtained with the annealing temperature at 200 °C, i.e., 3.02 kOe, suggesting that it be supported by both the K1 and Kσ. The magnetic properties obtained also indicate the potential for developing permanent magnets.

Nano-priming of Phaseolus vulgaris OTI cultivar with cobalt ferrite nanoparticles enhances the mineral composition of progeny seeds

Nano-priming of Phaseolus vulgaris OTI cultivar with cobalt ferrite nanoparticles enhances the mineral composition of progeny seeds

Research and Improvement in Magnetic Field Sensors Using Mach–Zehnder Interferometer with Cobalt Ferrite Nanoparticles

Research and Improvement in Magnetic Field Sensors Using Mach–Zehnder Interferometer with Cobalt Ferrite Nanoparticles

Structural, micro-structural and physico-chemical studies of Polyvinylpyroledene (PVP) added Cobalt ferrite (CoFe2O4) nanoparticles

To understand the structural and physico-chemical behavior of magnetic nanoparticle (CoFe2O4) is necessary for the selection of materials for various technological applications. The structural parameters derived from X-Ray diffraction (XRD) such as hopping length of site A (LA) and site B (LB), bond length between two A sites (dLA), two B sites (dLB), A and B (dLAB) and some related lengths. The micro-structural and magnetic studies from Fourier transform infrared spectroscopy (FTIR) and vibration sample magnetometer (VSM) analysis such as force constant, bond lengths between cation – anion (p, q, r, s) and cation - cation (b, c, d, e, f), and the angles between the bonds (θ1, θ2, θ3, θ4, θ5) values and trends were studied and it is merely suitable for 7.5 and 12.5 %. In addition some mechanical behavior obtained through their stiff constant C11 and C12 such as Young's modulus, bulk modulus, rigidity modulus and etc., The dielectric and electrochemical behavior of CoFe2O4 measured through AC conductivity (σAC), resistivity (ρAC) and electric modulus (M’, M’’ and M*) electrochemical parameters (V/I, impedance) through LCR and Cyclic voltameter measurements. The obtained results were interpreted and discussed extensively.

Entropy optimization in ternary hybrid nanofluid flow over a convectively heated bidirectional stretching sheet with Lorentz forces and viscous dissipation: A Cattaneo–Christov heat flux model

Bidirectional stretching sheet models can represent surfaces in heat exchangers where fluids flow under continuous deformation. Ternary hybrid nanofluids could be employed in these systems to increase heat transfer rates between fluids in heat exchangers and improve the efficiency of energy conversion processes. In this work, we explore the novel application of a ternary hybrid nanofluid (water with titanium dioxide, cobalt ferrite, and magnesium oxide nanoparticles) for enhanced heat transfer in heat exchangers modeled by a bidirectional stretching sheet. This approach offers a potential advancement over traditional nanofluids (with one or two nanoparticles). Furthermore, we present a comprehensive analysis that incorporates ohmic heating, Cattaneo–Christov heat flux, thermal radiation, viscous dissipation, and irreversibility. The governing equations are transformed into a system of nonlinear ordinary differential equations using appropriate similarity transformations and then solved using the bvp4c solver, a MATLAB built-in function. This study's findings reveal that the Eckert number and radiation parameter increase fluid temperature, while the thermal relaxation parameter leads to a reduction in the temperature of the fluid. It is detected that an increase in magnetic field parameter and volume fraction of [Formula: see text] results in a decline of the skin friction factors in both directions. It is revealed that there is a reduction in the Nusselt number with the rise in Eckert number ([Formula: see text]), and the same number declines at a rate of 0.8252 when [Formula: see text]. It is noticed that the skin friction coefficient declines at a rate of 0.62179204 (in case of x-direction) and 0.621791816 (in case of y-direction), respectively, when the values of magnetic field parameter lie between 0 and 3.5. Furthermore, it is noticed that an upsurge in thermal relaxation parameter results in a fall in the temperature of the fluid.

Structural, Morphological, Optical and Dielectric Studies of RE3+ Doped CoFe2O4

Cobalt ferrite nanoparticles, both undoped and Eu³⁺-doped, with the formula CoEuxFe2-xO4 (where x = 0.00 and 0.10), were produced using the citrate gel auto-combustion technique. X-ray diffraction confirmed the successful formation of the phase and the purity of the synthesized nanoparticles. The morphological analysis was conducted using scanning electron microscopy (SEM). The optical properties of cobalt ferrite were analyzed using UV-Vis spectrometer. Dielectric properties, such as the real part of the dielectric constant and loss tangent, were evaluated using an LCR meter. Doping cobalt ferrite nanoparticles with europium resulted in a significant improvement in charge storage and transport characteristics.

Non-Stoichiometric Cobalt Ferrite Nanoparticles by Green Hydrothermal Synthesis and their Potential for Hyperthermia Applications

Non-Stoichiometric Cobalt Ferrite Nanoparticles by Green Hydrothermal Synthesis and their Potential for Hyperthermia Applications