Nickel Ferrite Nanoparticles Research Articles

Nanocomposites Based on Polyethylene and Nickel Ferrite: Preparation, Characterization, and Properties.

Composite materials based on NiFe2O4 nanoparticles and polyethylene matrix have been synthesized by thermal decomposition to expand the application area of high-pressure polyethylene by filling it with nanoscale particles. The synthesized compositions were obtained in the form of a dark gray powder and compressed for further study According to TEM, the average particle size in composites was 2, 3, and 4 nm in samples with a filling of 10%, 20% and 30%. The concentration dependences of the specific electrical resistivity ρV, dielectric permittivity ε, saturation magnetization MS and the parameters of reflection and attenuation of microwave power of the obtained composites were investigated. The threshold for percolation in such materials is found to be within a concentration range of 20…30%. The electronic and atomic structure of composites was studied by methods of Mössbauer spectroscopy, X-ray diffraction and X-ray absorption spectroscopy. The closest atomic environment of nickel and iron in nanoparticles is close to that of crystalline NiFe2O4. The dependence of the nanoparticles size as well as the dependence of the number of tetrahedral or octahedral iron positions in nickel ferrite nanoparticles to their content in polyethylene matrix is established. It is shown that composite materials based on NiFe2O4 nanoparticles and polyethylene matrix can be used as components of electromagnetic compatibility systems.

Amino acid functionalized metal oxide nanocomposite for the removal of fluoroquinolones

Antibiotic consumption has increased globally, and its discharge into water bodies at concentrations ranging from a few ng/L to mg/L has a detrimental effect on the ecosystems. Amino acid functionalized nickel ferrite nanoparticles were chosen to improve the stability of bare nanoparticles and prevent oxidation and leaching ions in nanoparticles thereby targeting the antibiotics in the contaminated water bodies. The removal of ciprofloxacin and lomefloxacin hydrochloride in the aqueous phase was investigated using a hydrothermally synthesized L-Leucine functionalized nickel ferrite nanocomposite (NFO@L). Various analytical techniques were used to analyze L-Leucine functionalized nickel ferrite, and the nanocomposite's average particle diameter was determined to be between 11 and 15 nm. The maximal measured zeta potential was −21.5 mV. Fourier transform infrared spectroscopy (FTIR), ninhydrin assay and X-ray diffraction (XRD) analysis confirmed the attachment of L-Leucine onto nickel ferrite. The nanocomposite's surface-to-volume ratio was calculated to be 92.916 m2/g. The S-shaped curve from the vibrating sample magnetometer analysis reflected the superparamagnetic behaviour of the nanocomposite with a saturation magnetization of 0.665 emu/g. Various parametric experiments were conducted, in which 93.549% ciprofloxacin was removed in 120 min at 303 K, pH 8 and NFO@L dosage of 100 mg in 100 mL whereas 75.192% lomefloxacin hydrochloride was removed in 140 min at 333 K, pH 9 and NFO@L dosage of 70 mg in 100 mL. The plot of experimental datum in kinetic and isotherm studies fitted well with the Pseudo second order kinetic model and Langmuir isotherm. There was no evidence of iron ions leaching from the final analyte. The recycle and regeneration studies showed good stability with a small reduction after four cycle runs. Based on these findings, the Leucine functionalized nickel ferrite nanocomposite could be a potent adsorbent for the removal of low-concentrated ciprofloxacin and lomefloxacin hydrochloride in the wastewater.

Bifunctional application of facile green-silver doped nickel ferrite nanoparticles via-combustion method

Bifunctional application of facile green-silver doped nickel ferrite nanoparticles via-combustion method

Comprehensive characterization and development of multi-core shell superparamagnetic nanoparticles for controlled delivery of drugs and their kinetic release modelling

The nanoparticles designed for application in cancer treatment should have biocompatibility, colloidal stability and triggered release at tumor sites. Magnetic nanoparticles arise as an interesting option to be used as drug nanocarriers, considering the possibility of driving nanoparticles to the correct delivery site and exploring different triggers to achieve such accomplishment. In this study, nickel ferrite nanoparticles are explored as a magnetic core for drug delivery systems, using doxorubicin and omeprazole as model drugs. The developed nickel ferrite presents a strong superparamagnetic behavior and high purity, as demonstrated by magnetometry and TGA results. The carbon-coating procedure and functionalization allowed the nanoparticle to achieve the desired characteristics for biomedical applications (i.e. stability in water, biocompatibility, and size). According to TEM results, the final carbon-coated magnetic nanoparticles have an average size of 25.09 ± 0.58 nm and multi-core shell architecture, which is suitable for biomedical applications as drug nanocarriers. In addition, DLS demonstrated that functionalized nanoparticles are monodisperse, with a hydrodynamic diameter of 167 ± 59 nm, which fits the recommended range (100–200 nm) to benefit from enhanced permeability and retention effect. Drug loading tests with doxorubicin and omeprazole revealed the versatility of the designed nanoparticles, able to load 97% of doxorubicin and 51% of omeprazole. The pH-triggered release was also confirmed for both pharmacological compounds, showing a higher cumulative drug under acidic conditions (simulating a tumor microenvironment). Finally, the kinetic analysis applied to the study of the release mechanism of both medicines showed that non-linear models fit with higher accuracy the experimental data.

Boosting the electrochemical performance of NiFe2O4/Carbon composite materials by nitrogen doping for supercapacitors application

The development of high-performance anode materials is of great importance for improving the electrochemical performance of asymmetric supercapacitors. Here, nickel ferrite/porous carbon composite is synthesized via hydrothermal approach and the electrochemical properties are improved by nitrogen doping process. As the surface nitrogen content of the porous carbon precursor increased from 2.40 at.% to 9.53 at.%, the nickel ferrite/porous carbon composite exhibited substantial improvement in specific capacitance (increased from 136.4 to 201.4 F g−1 at 1 A g−1) in an alkaline aqueous electrolyte. The energy density of the assembled asymmetric supercapacitor was increased from 17.7 W h kg−1 to 11.2 W h kg−1, and the cycle retention rate after 10,000 cycles at 2 A g−1 was increased from 16.5 % to 85.7 %. Nitrogen atoms on the carbon surface provide active sites for the growth of nickel ferrite nanoparticles and enhance the interfacial effect between nickel ferrite nanoparticles and porous carbon materials, enhancing the charge transfer and preventing particle aggregation during charge and discharge processes. The fabricated nickel ferrite/nitrogen-doped porous carbon composite exhibits excellent capacitance and cycling stability, providing a new option for asymmetric supercapacitor anode materials.

Synthesis and characterization of a novel magnetic chitosan–nickel ferrite nanocomposite for antibacterial and antioxidant properties

A novel nanomagnet modified with nickel ferrite nanoparticles (NPs) coated with hybrid chitosan (Cs–NiFe2O4) was synthesized using the co-precipitation method. The resulting nanomagnets were characterized using various techniques. The size of the nanomagnetic particles was estimated to be about 40 nm based on the transmission electron microscopy (TEM) image and X-ray diffraction analysis (XRD) pattern (using the Debye–Scherrer equation). Scanning electron microscopy (SEM) images indicated that the surface of Cs–NiFe2O4 NPs is flatter and smoother than the uncoated NiFe2O4 NPs. According to value stream mapping (VSM) analysis, the magnetization value of Cs–NiFe2O4 NPs (17.34 emu/g) was significantly lower than NiFe2O4 NPs (40.67 emu/g). The Cs–NiFe2O4 NPs indicated higher antibacterial properties than NiFe2O4 NPs and Cs. The minimum inhibitory concentrations of Cs–NiFe2O4 NPs against S. aureus and E. coli were 128 and 256 mg/mL, respectively. Antioxidant activity (evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging test) for NiFe2O4 NPs and Cs–NiFe2O4 NPs at the concentration of 100 µg/mL were 35% and 42%, respectively. Consequently, the synthesized Cs–NiFe2O4 NPs can be proposed as a viable material for biomedical applications.

The thermo-therapeutic applications of Chitosan- CTAB coated Nickel Ferrite (NiFe2O4) magnetic nanoparticles

In this study, we used a hydrothermal-assisted co-precipitation method to synthesize the nickel ferrite (FN), Chitosan coated nickel ferrite (FN-Ch) and cetyltrimethylammonium bromide coated nickel ferrite (FN-CT) nanoparticles with small sizes and good biocompatibility. These nanoparticles were then evaluated for their potential use in magnetic hyperthermia. The particles were characterized using a variety of techniques, including x-ray diffraction, transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, Thermogravimetric Analysis (TGA), Inductively coupled plasma (ICP), magnetic characterization (VSM), zeta potential analysis, and in vivo studies (blood hemolysis and MTT test). The results of the x-ray diffraction analysis showed that the nanoparticles had a spinel phase of NiFe2O4. TEM analysis revealed that all three samples contained particles with nearly quadrilateral and hexagonal shapes. FT-IR spectroscopy confirmed the presence of Chitosan and CTAB coatings on the particle surface. Magnetic hysteresis curves showed that all of the synthesized samples exhibited superparamagnetic behavior at room temperature. The findings from the ICP analysis indicated that the FN-Ch and FN-CT nanoparticles contained iron and nickel, while no substantial quantities of other trace elements were identified in either of the samples. Blood hemolysis and MTT tests were used to assess the toxicity of the nanoparticles when in contact with red blood cells, fibroblast cells, and MCF7 cancer cells. Overall, our findings suggest that FN-Ch and FN-CT nanoparticles have potential for use in cancer diagnosis and treatment as part of a new nano-carrier system. Furthermore, combining hyperthermia with other treatment methods could enhance the effectiveness of cancer therapy.

Visible light photo catalytic and optical property evolution of combustion method prepared copper doped nickel ferrite nanoparticles

By using a simple microwave combustion technique, copper-doped NiFe2O4 spinel nanoparticles were formed. The XRD patterns demonstrated that Cu doping into NiFe2O4 spinel resulted in the creation of α-Fe2O3 secondary phase in addition to the cubic structure that already existed. Using SEM, morphological investigations revealed irregular shapes and severely agglomerated different grain boundaries. In an optical analysis, it was discovered that the band gap narrowed as the Cu2+ doping percentage raised. The octahedral site (Ni-O) and tetrahedral site (Fe-O) stretching modes of the Cu-doped nanoparticle structure were linked to bands at 548, 514, and 649cm-1 from FT-IR analysis. Cu-doped nanoparticles were examined for their enhanced photocatalytic degradation of RhB in visible light irradiation under atmosphere condition. The performance of pure NiFe2O4 as a photocatalyst was discovered to be greatly impacted by the Cu-doping. Additionally, the photo-catalytic effect was optimized (efficiency rose from 88.26 percent, x = 0-99.85 percent, x = 0.4) with the rise of Cu-doping into x=0.4. An in-depth discussion was had on the potential photocatalytic mechanism. The simultaneous improvement of photocatalytic activities serves as proof that Cu-doped NiFe2O4 spinel nanoparticles will perform well in multifunctional photochromic devices in future.

Cobalt and holmium co-doped nickel ferrite nanoparticles: synthesis, characterization and photocatalytic application studies

Abstract Herein, nickel ferrite-based photocatalysts with enhanced light utilizing electrical charge transport properties have been reported for environmental remediation applications. The cobalt and holmium co-doped nickel ferrite [Ni1−x (Co) x Fe2−y (Ho) y O4] nanoparticles and bare nickel ferrite (NiFe2O4) nanoparticles have been prepared via surfactant-supported wet-chemical techniques. The as-prepared ferritic photocatalyst’s structural, morphological, and light harvesting features have been examined in detail using well-known physical, electronic, and optical methods. The co-doped ferrite photocatalyst’s tuned structural features enable it to absorb maximum wavelengths from the U.V. and visible regions. This is because the co-doped Ni1−x (Co) x Fe2−y (Ho) y O4 optical band gap is 1.73 eV; hence, the wavelength from the visible part possesses sufficient energies to trigger the electronic excitation in co-doped ferrite photocatalysts. Moreover, the co-doping-induced structural defects in the ferrite photocatalyst. These defects act as a reservoir for the charge species, mainly electrons, so the process of charge recombination is almost hampered for the Ni1−x (Co) x Fe2−y (Ho) y O4 photocatalyst. In application terms, the photomineralization capabilities of doped and bare ferrite photocatalysts have been explored using crystal violet (CV) dye. The comparative photocatalytic evaluation of both nickel ferrite-based photocatalysts shows that co-doped ferrite degraded 96.02 % of CV dye. In comparison, the undoped one only degraded 64.84 % after 80 min of W-lamp light exposure. The results demonstrated that the Ho and Co co-doped ferrite photocatalyst exhibits excellent photocatalytic activity, suggesting its potential for environmental remediation applications in textile industrial discharges.

Unveiling the multifaceted applications of magnetically responsive chitosan capped ZnS QDs for sensing and annihilation of pharmaceutical drugs

The persistence of active pharmaceutical ingredients in water bodies has lead to detrimental impacts on public health as well as deteriorated aquatic resources at breakneck pace. To address this, highly fluorescent chitosan capped ZnS QDs (CZS QDs) were integrated with nickel ferrite nanoparticles (NF NPs) through ultrasonic assisted method to yield a series of magnetically responsive CZS-xNF nanohybrids (x = 5, 10, 15 and 20 wt% of NF). The successful fabrication of nanohybrids were affirmed through various techniques such as Fourier transform infra-red spectroscopy (FT-IR), powder X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), high resolution transmission electron microscopy (HRTEM), vibrating sample magnetometer (VSM) and diffused reflectance spectroscopy (DRS). The dual applicability of CZS-xNF nanohybrid was witnessed for the detection of pharmaceutical waste by fluorescence sensing and their concomitant annihilation via visible light driven photodegradation reactions. The developed nanohybrid showed exceptional selectivity towards tetracycline antibiotics, with ultra-low limit of detection of 0.53 μM for tetracycline (TC) and 0.30 μM for minocycline (MC), respectively. The fluorescent sensor was also analysed for trace level detection of tetracyclines in real water samples that showed satisfactory recoveries of 90–106%, depicting practical applicability of sensor. Additionally, the excellent photocatalytic features of synthesized nanohybrid prompted their use in photodegradation of TC and MC and a superior photocatalytic performance was achieved in comparison to CZS QDs. The enhanced photocatalytic performance of CZS-xNF nanohybrid can be attributed to type-I charge transfer mechanism, which resulted in efficient charge separation and reduced photo-induced recombination rate of charge carriers. The nanohybrids were recyclable up to four cycles after being utilized in sensing and photocatalysis, thus offering a promising strategy for environmental remediation through synchronized sensing and extirpation of pharmaceutical waste.

Fabrication of an ultra-sensitive electrochemical DNA biosensor based on CT-DNA/NiFe2O4NPs/Au/CPE for detecting rizatriptan benzoate

A novel and first electrochemical biosensor based on Deoxyribonucleic acid (DNA) as a biological component to measure an antimigraine drug, rizatriptan benzoate (RZB) for patients under treatment in biological samples was developed. A carbon paste electrode (CPE) was modified by calf thymus (CT) double-stranded (ds)-DNA, nickel ferrite magnetic nanoparticles (NiFe2O4NPs), and gold nanoparticles (AuNPs). The morphology of the CT-DNA/NiFe2O4NPs/AuNPs/CPE was characterized by Field emission scanning electron microscope (FESEM). The presence of NiFe2O4NPs and AuNPs was confirmed by energy-dispersive X-ray spectroscopy (EDS) image of the NiFe2O4NPs/AuNPs/CPE surface. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to determine the structure and electrochemical characteristics of the CT-DNA/NiFe2O4NPs/AuNPs/CPE. Differential pulse voltammetry (DPV) was used to investigate the electrochemical behavior of RZB. Chronoamperometry (CA) was applied to study the effect of CT-DNA immobilization time on the peak oxidation current of RZB accumulated on the surface of the CT-DNA/NiFe2O4NPs/AuNPs/CPE. The results showed that, under optimum conditions, the prepared electrode responded linearly to RZB concentrations between 0.01 and 2.0 μM, with a 0.0033 μM detection limit (LOD) and 0.01 μM limit of quantification (LOQ). The parameters influencing the biosensor performance (temperature, CT-DNA immobilization time, and RZB/CT-DNA accumulation time) were optimized. DPV showed the displacement of the peak potential towards positive values and the reduction of its current, indicating that the drug could intercalate between the guanine base pairs of CT-DNA. Our biosensor was successfully applied for RZB measurement in human urine, blood serum, plasma samples, and tablets. The presented biosensor was fast response, sensitive, selective, cost-effective, and easy-to-use for RZB determination in pharmaceutical formulations and biological samples.

Synthesis, characterization, electrical, and magnetic properties of polyvinyl alcohol/carboxymethyl cellulose blend doped with nickel ferrites nanoparticles for magneto‐electronic devices

AbstractSolid polymer electrolytes are an intriguing technology in terms of magneto‐opto electronic applications due to having a high dielectric constant, a small band gap, and excellent magnetic characteristics. In order to improve structural, optical, dielectric, conductivity, and magnetic characteristics, this research seeks to prepare nickel ferrite (NiFe2O4) nanoparticles and polyvinylalcohol (PVA)/carboxymethyl cellulose (CMC) films containing NiFe2O4. Nanoparticles of NiFe2O4 are prepared using the co‐precipitation method. The CMC/PVA–NiFe2O4 nanocomposites films are prepared using casting solution. To improve their structural, optical, conductivity, dielectric, and magnetic characteristics, these films electrolytes were examined using XRD, TEM, FT‐IR, UV–vis, and VSM measurements. According to the XRD analysis, the CMC/PVA blend polymer matrix demonstrates a considerable increase in amorphous nature with the NiFe2O4 nanoparticles (NPs) content, producing a highly flexible polymer backbone, increasing ionic conductivity of the CMC/PVA–NiFe2O4 nanocomposite films. The complexation of dopant cations with the CMC/PVA polymer matrix's backbone is confirmed by the FT‐IR spectroscopy. According to the UV–visible technique, the dopant NiFe2O4 concentration considerably affects the optical energy band gap, and Urbach energy of the pure CMC/PVA. At higher loading, these effects are more pronounced. At room temperature, ac conductivity, the dielectric behavior, and electrical modulus formalism were studied. The blend's highest AC conductivity is 4.77 × 103 S/cm. After increasing the loading of NiFe2O4 to 1.5 wt%, it increased to 8.07 × 104 S/cm. There has also been research on dielectric permittivity and electric modulus to further understand conductivity relaxation and charge storage qualities. The polymer nanocomposite, generally, displayed better optical, dielectric constant, conductivity, and magnetic characteristics compared to pure CMC/PVA being useable in terms of high energy storage nanoelectronics' manufacturing.Highlights NiFe2O4 nanoparticles were prepared by using the co‐precipitation method. Nanocomposite films of CMC/PVA–NiFe2O4 were successfully prepared by casting method. XRD patterns confirmed the increase in the degree amorphousity for nanocomposites films compare pure blend. From optical energy gap results for samples prepared was enhanced after addition NiFe2O4. The dielectric and magnetic properties showed that all nanocomposites films exhibited enhanced as compared to pure CMC/PVA film.

Biosynthesis and Characterization of ZnO/NiFe2O4 Nanocatalyst via Green Route Using Anacadium occidentalelinn (cashew nut) and its photocatalytic activity for the treatment of tannery wastewater under sunlight irradiation

The Anacadium occidentalelinn (cashew nut) leaves extract have been excellently utilized as a reducing as well as capping agent for the synthesis of zincoxide and nickel ferrite nanoparticles using zinc acetate, and iron (lll) chloride, nickel chloride as precursor with a different calcined temperature at the furnace and its application in the treatment of tannery wastewater. The generation of zinc oxide was proved by various characterization techniques. XRD studies displayed that a cubic phase and the average crystallite size for the intense peak measured were about 30-56nm was exhibited by the synthesized nanoparticle SEM image showed that synthesized particle are granular around 50nm and roughly spherical in shape. EDS analysis proved the elemental composition of the synthesized sample and disclosed that oxygen as well as zinc are the dominant elements. The synthesized catalyst was used in the tannery wastewater treatment also the quality parameters of tannery wastewater after treatment with the synthesized catalyst under sunlight irradiation, significantly changed and found to be within acceptable range of quality water according to (WHO). The color, odor and appearance where changed to colorless, odorless, and clear. ph, 7.4 total organic carbon (TOC), 32(mg/dm3), turbidity, 2.5(NTU) respectively. The highest efficiency of the treatment process was attained under sunlight irradiation conditions in comparison to those which were recorded under dark conditions as revealed by the result of the analysis. This procedure is safe, environmentally friendly and viable due to its fast, low cost compared to other methods.

Synthesis, Characterization and Investigation of Optical and Electrical Properties of Polyaniline/Nickel Ferrite Composites.

Nickel ferrite nanoparticles are prepared by using a low-temperature self-propagating solution combustion method using urea as fuel. The prepared nickel ferrite nanoparticles were doped with polyaniline in the three different weight ratios of 10%, 30% and 50% by using an in situ polymerization method and by adding ammonium persulfate as an oxidizing agent. The obtained samples were characterized by using XRD, FTIR, SEM and a UV-visible spectrophotometer. XRD examined crystalline peaks of ferrites and amorphous peak of polyaniline and confirmed the formation of the composites. FTIR examined the chemical nature of samples and showed peaks due to polyaniline and the characteristic peaks that were less than 1000 cm-1 wavenumber were due to metal-oxygen bond vibrations of ferrites. AC conductivity increased with frequency in all samples and the highest AC conductivity was seen in polyaniline/nickel ferrite 50%. DC conductivity increased in all samples with the temperature showing the semiconducting nature of the samples. Activation energy was evaluated by using Arrhenius plots and there was a decrease in activation energy with the addition of ferrite content. The UV-visible absorption peaks of polyaniline showed shifting in the composites. The optical direct and indirect band gaps were evaluated by plotting Tauc plots and the values of the optical band gap decreased with addition of ferrite in polyaniline and the Urbach energy increased in the samples with 10%, 30% and 50% polyaniline/nickel ferrite composites. The optical properties of these composites with a low band gap can find applications in devices such as solar cells.

Impact of Co-doped NiFe2O4 (CoxNi1−xFe2O4) nanostructures prepared by co-precipitation route on the structural, morphological, surface, and magnetic properties

The excellent magnetic properties of spinel ferrite-based materials are preferably utilized in magnetic storage devices, and recording media. The magnetic properties of cobalt-doped nickel ferrite (Cox Ni1-xFe2O4) nanoparticles (NPs) were successfully investigated. A series of cobalt (Co)-doped nickel ferrite Cox Ni1-xFe2O4 NPs (x = 0.6, 0.7, 0.8, 0.9,1.0) were synthesized by the sol-gel method auto-combustion (SGAC) route. The crystallite sizes of the prepared CoxNi1−xFe2O4 NPs were found to be 23.5 ± 0.4, 25.3 ± 0.3, 25.0 ± 0.6, 29.5 ± 0.3, and 12.7 ± 0.3 nm for x = 0.6, 0.7, 0.8, 0.9, and 1.0, respectively, using X-ray diffraction (XRD) patterns. The random-shaped morphology with particle sizes was found to be 16.4 ± 0.8, 12.6 ± 0.1, 15.4 ± 0.7, 12.5 ± 0.2, and 11.9 ± 0.4 nm for CoxNi1−xFe2O4 (x = 0.6, 0.7, 0.8, 0.9, and 1.0), respectively, using high-resolution transmission electron microscopy (HRTEM). Tauc’s plot spectra of CoxNi1−xFe2O4 NPs showed that the direct band (2.01–2.42 eV) and indirect band gaps (0.86–1.16 eV) were tuned with Co2+ concentrations. The obtained binding energies (BEs) observed at (780–801 eV) for Co2+ and Co3+ions, (855–879 eV) for Ni2+ and Ni3+ ions, (710–760 eV) for Fe3+ and Fe2+ ions, and (529–531 eV) for O2- ions, respectively in CoxNi1−xFe2O4 NPs were confirmed by X-ray photoelectron spectroscopy (XPS). RT-dependent DC magnetization measurements exhibited saturation magnetization (45.28, 37.34, 33.32, 33.93, and 52.57 emu/g), coercivity (1090, 1160, 689, 507, and 377 Oe), retentivity (13.29, 12.86, 11.37, 8.10, and 10.18 emu/g), and magnetic anisotropy (4.834 ×106, 4.315 ×106, 4.037 ×106, 4.206 ×106, and 7.578 ×106 erg/cm3) for CoxNi1-xFe2O4 NPs (x = 0.6, 0.7, 0.8, 0.9, and 1.0), respectively. The improved magneto-crystalline anisotropy and decreased spin canting effect/ spin disorder for CoxNi1−xFe2O4 NPs indicated that the current research work can be suitable for magnetic storage devices and recording media.

Alginate functionalized MFe2O4 (MNi, Co) nanoparticles and hydrated salt incorporated flexible PVDF ternary nanocomposite fibers for magnetoelectric applications

AbstractMagnetoelectric (ME) polymer nanocomposites find a wide range of applications as ME sensors, energy storage devices, magneto‐mechano‐electric nanogenerators, tissue engineering scaffolds, and so forth. Functionalizing ferrite fillers is an effective strategy to improve the ferrite‐polymer interaction and, thereby, the functional properties. In the present work, we developed ternary nanocomposite fibers of polyvinylidene fluoride loaded with hydrated salt and alginate functionalized ferrite nanoparticles. Nanocomposites with functionalized ferrite fillers were found to have better dielectric and ME properties. The highest values of dielectric constant (14.7) and ME coupling coefficient (18.2 mV cm−1 Oe−1) were obtained for ternary nanocomposite fiber with functionalized nickel ferrite nanoparticles. The present study opens new avenues for developing flexible ME nanocomposites for realizing flexible ME nanocomposites with the required properties for developing next‐generation devices for diverse applications.

Bactericidal and Cytotoxic Study of Hybrid Films Based on NiO and NiFe2O4 Nanoparticles in Poly-3-hydroxybutyrate

This work focuses on the obtaining and the bactericidal properties study, in vitro, of hybrid films as potential coating materials to inhibit bacteria proliferation. In consequence, hybrid films from nickel oxide (NiO) and nickel ferrite (NiFe2O4) nanoparticles (NPs) embedded in poly-3-hydroxybutyrate (P3HB) were obtained by the solvent casting method. P3HB@NiO and P3HB@NiFe2O4 hybrid films and P3HB film were characterized by X-ray diffraction (XRD), Raman scattering, and scanning electron microscopy (SEM). The XRD of the hybrid films showed that NiO and NiFe2O4 NPs incorporated in the P3HB conserved their nanometric size, and by Energy-dispersive X-ray spectroscopy (EDS) were observed that NPs are homogeneously distributed in the films. The bactericidal effect of the obtained films was evaluated in vitro from the broth surface method against two opportunistic and nosocomial pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. The results showed that P3HB film, P3HB@NiO, and P3HB@NiFe2O4 hybrid films reduced 90%, 98%, and 97% of the growth of S. aureus, respectively. For P. aeruginosa, their growth was reduced by 90%, 94%, and 96%, respectively. In addition, the cytotoxic effect of NiO and NiFe2O4 NPs, as well as P3HB film, and P3HB@NiO, and P3HB@NiFe2O4 hybrid films was evaluated using human skin cells; keratinocytes and fibroblast, being the NPs less cytotoxic than films. Although P3HB is known as a biocompatible polymer, here is demonstrated that in our work conditions, their films have bactericidal properties and are cytotoxic to keratinocytes and fibroblasts, the first barrier of the human skin. However, the P3HB@NiO and P3HB@NiFe2O4 hybrid films synergize the bactericidal effect between the P3HB and the NPs. On the other hand, the NPs decrease the P3HB cytotoxicity to keratinocytes. The methodology used in this work is particularly suitable for producing hybrid films with antibacterial activity against Gram-positive and Gram-negative bacterial strains.

Nickel ferrite nanoparticles doped on hollow carbon microspheres as a novel reusable catalyst for synthesis of N-substituted pyrrole derivatives

Pyrroles are widely spread worldwide because of their critical applications, especially pharmacology. An expedition method for one-pot synthesis of N-substituted pyrrole derivatives has been presented by a reaction between 2,5-dimethoxytetrahydrofuran and various primary aromatic amines in the presence of NiFe2O4 anchored to modified carbon hollow microspheres (NiFe2O4@MCHMs) as a recoverable reactive catalyst. The Classon-Kass method has been used to synthesize the pyrroles in excellent yields and short reaction times in the same direction with green chemistry rules. This reaction was carried out by employing NiFe2O4@MCHMs as a catalyst to make a simple procedure with short activation energy in water as an accessible, non-toxic, and biodegradable solvent. This catalyst provides a promising pathway to synthesize N-substituted pyrroles several times in a row through the recyclability without remarkable loss of its catalytic activity. The NiFe2O4@MCHMs nanocatalyst was characterized by applying FT-IR, XRD, FE-SEM, TEM, EDS, BET, TGA, VSM, and elemental mapping techniques. Also, the synthesized N-substituted pyrrole derivatives were identified using melting point, FT-IR, and 1H NMR analyses.

Rapid synthesis of nickel ferrite nanoparticles by the molten salt method

It is presented a ‘shocking thermal treatment’ methodology as a modification to the molten salts process to rapidly obtain pure phase nickel ferrite nanoparticles within a high-scalable green synthesis scheme. Analysis from x-ray diffraction and electron microscopy (SEM and TEM) confirms the formation of the nanostructures, with the most frequent crystallite sizes between 55–85 nm. Room temperature magnetic characterization, from Mössbauer spectroscopy and magnetic measurements M(H), evidences their superparamagnetic distribution with a magnetic saturation of 47.9 emu g−1. An approximated stoichiometry of was proposed from Rietveld refinement, Mössbauer and energy-dispersive x-ray spectroscopies. The effect on the electronic structure due to the shocking thermal treatment was elucidated by estimating the optical band gap with values between 1.78 and 2.38 eV.

Investigating Nickel Ferrite (NiFe2O4) Nanoparticles for Magnetic Hyperthermia Applications

Many new promising therapeutic and diagnostic methods in medical science use magnetic nanoparticles (MNPs). Drug targeting, tumor detection, and magnetic hyperthermia treatment are the most common fields of interest where already clinical trials are being performed. Nickel ferrite (NiFe2O4) nanoparticles have received much attention for their potential applications in such fields. A series of samples of Nickel ferrite (NiFe2O4) nanoparticles have been synthesized using a co-precipitation route at different annealing temperatures ranging from 150 ? to 1000 ? and labeling them as S1, S2, S3, S4, and S5. The average particle size obtained from XRD data is found to lie in the range of 15 – 55 nm. The crystal structure of the prepared NiFe2O4 four samples annealed at different temperatures is FCC with a lattice constant of 8.34 Å, which agrees with the values. The magnetic properties of the samples were investigated from temperature-dependent hysteresis loops using Vibrating Sample Magnetometer (VSM). The saturation magnetization (coercivity) is found to increase (decrease) with particle size. The hyperthermia measurements are performed by applying alternating magnetic fields of various amplitudes (Oe) and frequencies (kHz). The measured heating ability of the prepared nanoparticles is obtained from the so-called specific absorption rate (SAR), which is found to increase with increasing frequency and field amplitudes. Using the experimentally obtained SAR value, we also used MATLAB code to model the heat diffusion equation to get information on the temperature rise within the tumor as a function of tumor radius and treatment time.The sample S4 annealed at a temperature of 900 ? is found to be the most suitable candidate for hyperthermia applications at the frequency of 543 kHz because of its capability to produce heat in the therapeutic range of 42-48 ? and with an SAR value of 500 W/g.