Vibrating Sample Magnetometer Research Articles

A comparative study of sericin and gluten for magnetic nanoparticle-mediated drug delivery to breast cancer cell lines

With breast cancer emerging as a pressing global health challenge, characterized by escalating incidence rates and geographical disparities, there is a critical need for innovative therapeutic strategies. This comprehensive research navigates the landscape of nanomedicine, specifically focusing on the potential of magnetic nanoparticles (MNPs), with magnetite (Fe3O4) taking center stage. MNPs, encapsulated in biocompatible polymers like silica known as magnetic silica nanoparticles (MSN), are augmented with phosphotungstate (PTA) for enhanced chemodynamic therapy (CDT). PTA is recognized for its dual role as a natural chelator and electron shuttle, expediting electron transfer from ferric (Fe3+) to ferrous (Fe2+) ions within nanoparticles. Additionally, protein-based charge-reversal nanocarriers like silk sericin and gluten are introduced to encapsulate (MSN-PTA) nanoparticles, offering a dynamic facet to drug delivery systems for potential revolutionization of breast cancer therapy. This study successfully formulates and characterizes protein-coated nanocapsules, specifically MSN-PTA-SER, and MSN-PTA-GLU, with optimal physicochemical attributes for drug delivery applications. The careful optimization of sericin and gluten concentrations results in finely tuned nanoparticles, showcasing uniform size, enhanced negative zeta potential, and remarkable stability. Various analyses, from Dynamic Light Scattering (DLS) and scanning electron microscopy (SEM) to transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction analysis (XRD), and Thermogravimetric analysis (TGA), provide insights into structural integrity and surface modifications. Vibrating Sample Magnetometer (VSM) analysis underscores superparamagnetic behavior, positioning these nanocapsules as promising candidates for targeted drug delivery. In vitro evaluations demonstrate dose-dependent inhibition of cell viability in MCF-7 and Zr-75–1 breast cancer cells, emphasizing the therapeutic potential of MSN-PTA-SER and MSN-PTA-GLU. The interplay of surface charge and pH-dependent cellular uptake highlights the robust stability and versatility of these nanocarriers in tumor microenvironment, paving the way for advancements in targeted drug delivery and personalized nanomedicine. This comparative analysis explores the suitability of silk sericin and gluten, unraveling a promising avenue for the development of advanced, targeted, and efficient breast cancer treatments.

Structural, optical and magnetic properties of chemically grown copper oxide nanoparticles: An insight into anticancer activities

Self-assembling nanorods like copper oxide (CuO) nanoparticles (NPs) have been successfully synthesized using two different copper cationic precursors to investigate their structural, optical, and magnetic properties. These NPs are employed in anticancer applications. Both the CuO-NPs have been tested for their toxicity on human cells. The XRD patterns confirm the formation of monoclinic crystal structures for both the systems. The FESEM microstructural surface morphology shows high agglomeration and a typical elemental composition is evaluated from EDAX analysis. The HRTEM analysis reveals high crystalline CuO nanorods with diameters in the range of 60 ∼ 94 nm and 09∼ 22 nm for two different nanoparticles named CuO-NPs1 and CuO-NPs2, respectively. The optical band gap of CuO-NPs has been calculated from UV–visible absorption spectra and is found to be 2.18 eV and 2.55 eV for CuO-NPs1 and CuO-NPs2, respectively. FTIR analysis provides insights into the chemical compositions of both the CuO-NPs. Magnetization study using vibrating sample magnetometer (VSM) indicates antiferromagnetic-like properties associated with weak ferromagnetic behaviour. Cytotoxicity tests on MCF-7 cell lines show that CuO-NPs2 exhibit more pronounced effect with IC50 of 22.95 μg/mL. The toxicity of both the CuO-NPs are also assessed using human lymphocytes, suggesting that CuO-NPs could be promoted as anticancer agents while remaining non-toxic to biological systems.

Modified nanomagnetite silica core shell with new Cu (II) N,N‐ chelating complex as an efficient and reusable catalyst in the C‐N bond formation

In this article, initially, the TCTCl (DiPrAEA)2 ligand was synthesized and characterized by Fourier transform infrared (FT‐IR), X‐ray crystallography, 1H‐ and 13C‐NMR spectroscopy, and elemental analysis. The crystallographic structure data for the ligand has been deposited at the Cambridge Crystallographic Data Centre (CCDC No. 2282732). Then, using of this novel multidentate ligand, a novel and stable copper (II) nanocatalyst complex was synthesized by anchoring copper (II) acetate onto the core‐shell surface (Fe3O4@SiO2) via the novel multidentate ligand TCTCl (DiPrAEA)2. The successful synthesis of the Fe3O4@SiO2‐NH‐TCT (DiPrAEA)2‐Cu (II) nanocatalyst was confirmed by employing physicochemical techniques such as FT‐IR, X‐ray diffraction, ultraviolet‐visible, thermogravimetric analysis, X‐ray photoelectron spectroscopy, Brunauer–Emmett–Teller, energy‐dispersive X‐ray, dynamic light scattering, inductively coupled plasma, transmission electron microscopy, field emission scanning electron microscopy, and vibrating sample magnetometer. Subsequently, this novel copper (II) nanomagnetic complex was evaluated as an efficient, reusable, and novel catalyst for the formation of C‐N bonds via the Ullmann coupling reaction of aryl halides and nitrogen‐containing compounds. The influence of this novel TCTCl (DiPrAEA)2 ligand on the reactivity and stability of the nanomagnetic copper complex was visible in the Ullmann reaction, which resulted in rapid reaction times and excellent yields, and seven times reusability.

Development of MnWO4:Ag Nanodilute Magnetic Semiconductors with Tunable Magnetic and Optoelectronic Properties

The bandgap engineered MnWO4 nanoparticles doped with Ag were developed using a facile one-pot synthesis method. The impurity doping concentration of Ag was varied from 1 to 5 weight percentages to tune the interactions between manganese tungstate and silver ions to obtain desirable magnetic and optoelectronic properties. The structural properties of the MnWO4 particles with various concentrations of Ag were investigated using X-ray diffraction. The optical properties of the pristine and Ag-doped MnWO4 particles were determined using UV‒Vis and photoluminescence spectroscopy. The impurity concentration-dependent structural transformations and changes in the vibrational modes, lattice dynamics, electronic transitions and optoelectronic properties of the prepared materials were analyzed using Raman spectroscopy. The topology, morphology and elemental analysis of the synthesized nanoparticles were elucidated using TEM, SEM, SEM and EDX techniques. The magnetic properties of the MnWO4:Ag nanoparticles were measured using a vibrating sample magnetometer (VSM). The obtained results suggested that Ag-doped MnWO4 nanosystems show enhanced and tunable magnetic properties suitable for nanodilute magnetic semiconductor (nDMS) applications. The presented work opens a range of possibilities for the development of advanced materials with applications in optoelctronics, nanomedicine, energy-efficient electronic devices and energy conversion.

Pennisteum glaucum-derived carbon dots, synthesized through green approach to degrade Rose Bengal and Methylene Blue dyes photocatalytically

In the present study, carbon dots (C-dots) were synthesized using a simple and uncomplicated pyrolysis method at 250 °C with varying duration of 1 h, 2 h, and 3 h, utilizing Pennisetum glaucum as the biomass precursor to break down methylene blue (MB) and Rose Bengal (RB) dyes under UV light exposure. Various analytical techniques, including X-ray diffraction (XRD), UV–visible spectroscopy, high-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared spectroscopy (FT-IR), and vibrating-sample magnetometer (VSM), were utilized to investigate the chemical, optical, electronic, surface morphological, and magnetic characteristics of the C-dots produced. These C-dots are crystalline, nearly spherical, and have particle sizes ranging from 4.73 nm to 12.44 nm. FTIR analysis identified the functional groups present on the surface of the C-dots. Additionally, the band gap energy of the C-dots reduced from 2.82 eV to 2.40 eV with an increase in pyrolysis time. They are effective for cleaning dye-polluted wastewater and demonstrate high photocatalytic performance. When exposed to UV light, the synthesized particles achieved impressive photocatalytic degradation of 94.80 % for MB and 91.80 % for RB dyes.

Physical properties of La3+ ion doped Ni[sbnd]Zn based spinel ferrite nanomaterials for technological applications

Spinel ferrite nanoparticles are extensively utilized in various everyday applications due to their exceptional capabilities. They are highly effective and efficient for various applications such as energy storage devices, microwave, electrode design, fuel cells, and recording media. Based on these applications, five samples of lanthanum doped nickel‑zinc spinel ferrite Ni0.5Zn0.5LaxFe2-xO4 nanoparticles were synthesized using the sol-gel auto-combustion technique. The lanthanum concentrations varied as x = 0.00, 0.05, 0.10, 0.15 and 0.20. X-ray diffraction (XRD) analysis revealed the formation of single phase cubic spinel structure of the prepared samples. The crystallite size was determined using the Scherrer formula and the values lies in the range of 9.22 to 20.09 nm. The chemical composition of the prepared samples was confirmed using Fourier transform infrared spectroscopy (FTIR) analysis. Transmission electron microscopy (TEM) confirmed the agglomeration and spherical shape morphology of the nanoparticles with an average particle size of 40 nm. Magnetic properties along with La3+ ion concentrations were investigated using the vibrating sample magnetometer (VSM). The dielectric properties of the prepared samples were carried out using impedance analyzer with an applied frequency ranging from 1 MHz to 3 GHz. Furthermore, the polarization mechanism in the applied frequency range was discussed with relaxation behavior at high frequency. The impact of La3+ concentrations on different parameters such as dielectric constant, impedance, electric modulus, tangent loss, and Ac conductivity were also investigated. The investigation of dielectric parameters. The relaxation mechanism at high frequency provided a significant impact of such type of materials to store energy due lake of hopping between the tetra and octahedral sites by addition of La3+ doping. The prepared samples exhibit excellent magnetic as well dielectric properties which makes suitable for microwave devices and soft magnetic applications.

Preparation and Study Some Properties of Ferrite Nanoparticles(CuxAl0.3-xNi0.7Fe2O4)

The current study includes the preparation of CuxAl0.3-xNi0.7Fe2O4 ferrite nanoparticles where: x = 0, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 using the auto combustion method (sol-gel). The citric acid was used as fuel for auto combustion. The X-ray diffraction (XRD) test showed an increase in the crystal lattice constant, which is of face-centered cubic (FCC) structure. Field Emission Scanning Electron Microscopy (FE-SEM) showed that the compound has apparent porosity; its grains are spherical or semi-spherical and within the nanoscale. The Energy-Dispersive X-ray spectroscopy (EDX) proved the presence of all the elements involved in the preparation of the compound, and there are no other elements, which means that it is of high purity. The vibrating sample magnetometer (VSM) showed that the hysteresis loop is small and narrow, meaning the wasted energy is as little as possible. In addition, it was found that the compound has good sensitivity to NO2 gas.

Investigating the structural and magnetic properties of Fe3Se4 nanoparticles and it's photocatalytic application

This study explores the potential of synthesized Fe3Se4 nanoparticles by solid-state reaction method and it's photocatalytic application. The structural parameters validated by X-ray diffraction (XRD) demonstrate a monoclinic structure. The particle size of the prepared material was estimated at approximately 95 nm, as observed by field emission scanning electron microscopy (FE-SEM) and it's composition was verified by energy dispersive spectroscopy (EDS). Strong Raman modes were observed at 225 cm−1 which is responsible for lattice vibration in Fe3Se4. Both Fe2+ and Fe3+ oxidation states were present in Fe3Se4, as characterized by X-ray photoelectron spectroscopy (XPS). From the thermal gravimetric analysis (TGA) curves, the Fe3Se4 was confirmed to be stable up to 295 °C. vibrating sample magnetometer (VSM) tests revealed that the coercivity was 151 Oe at ambient temperature and increased 20 times to 2425 Oe at 15 K. Tauc's plot indicated an optical band gap value of 1.12 eV. Fe3Se4 nanoparticles achieved an 80.79 % dye degradation efficiency and exhibited photocatalytic activity against methylene blue dye. In photocatalysis, the apparent pseudo-first-order k1 and pseudo-second-order k2 rate constants are 0.018 min−1 and 0.058 min−1.

Influence of GO content on the optical, magnetic and dielectric properties of the BaFe12O19/GO nanocomposites

Abstract In this research, BaFe12O19/GO (GO:10%, 20%, 40%, 50%) nanocomposites were synthesized by sol-gel auto combustion method and their structural, optical, magnetic and dielectric properties were investigated. The X-ray diffraction results for all nanocomposites validate the formation of a hexagonal phase of Ba hexaferrite. Measurements of the magnetic hysteresis loop for all composites were conducted at room temperature using a vibrating sample magnetometer. By increasing the percentage of GO, a decrease in the saturation magnetization was observed for the samples. The band gap also decreased with an increase in the percentage of GO. The dielectric constant, loss function and conductivity were also measured for the samples. The nanocomposite sample of BFO-40GO exhibited the highest observed value for real part Modulus.

Green auto-combustion synthesis of SrNiO3/NiO/SrCO3 ferromagnetic-nanocomposites in the presence carbohydrate sugars and their application as photocatalyst for degradation of water-soluble organic-pollutants

This study utilized an environmentally-friendly method to synthesize SrNiO3/NiO/SrCO3 nanocomposites using glucose and lactose as fuels. A variety of fuel concentrations were investigated in order to determine their effects on SrNiO3/NiO/SrCO3 nanocomposites from both a pure and a morphological perspective. Various physiochemical techniques were employed to examine the crystal structure, morphology, optical, magnetic, and surface properties of the synthesized nanoparticles. These techniques included X-ray diffract, scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR), vibrating sample magnetometers, and Brunauer-Emmett-Tellers. The band gap of the as-synthesized nanoparticles was determined to be 2.5eV, suggesting that they are capable of acting as a photocatalyst under sunlight-like conditions. The photocatalytic activity of SrNiO3/NiO/SrCO3 nanocomposites was evaluated against Methyl orange (MO) and Methyl violet (MV), and the mechanism of the photocatalyst was investigated using EDTA, benzoic acid, and benzoquinone as scavengers. A comparison of photocatalytic activity in UV and sun-like light showed that maximum degradation (92%) and (84.8%) were related to degradation of MO (20 ppm) and MV in 60min, respectively. The results indicate that SrNiO3/NiO/SrCO3 nanocomposites synthesized using the auto combustion method may serve as a promising photocatalyst for the degradation of organic pollutants in the environment within a short period of time.

Innovative approach against cancer: Thymoquinone-loaded PHEMA-based magnetic nanoparticles and their effects on MCF-7 breast cancer

Breast cancer is most common cancer among women in the World. Thymoquinone (TQ) exhibits a wide range of biological activities such as anticancer, antidiabetic, antimicrobial, analgesic, antioxidant, and anti-inflammatory effects. However, its effectiveness in cancer treatment is hindered by its poor bioavailability, attributed to its limited solubility in water. Hence, novel strategies are required to enhance the bioavailability of TQ, which possesses remarkable anticancer characteristics. The aim of this study is to prepare pHEMA-based magnetic nanoparticles carrying TQ (TQ-MNPs) to improve bioavailability, and therapeutic efficacy against breast cancer. For this purpose, TQ-MNPs were synthesized and characterized with Fourier transform infrared spectrophotometer (FTIR), scanning electron microscopy (SEM), dynamic light scattering (DLS), magnetic field using a vibrating sample magnetometer (VSM). The loading capabilities of synthesized magentic nanostructures were evaluated, and release investigations were conducted under experimental conditions that mimic the cellular environment. The findings of the studies indicated that the TQ carrying capacity of MNPs was deemed satisfactory, and the release efficiency was adequate. MNPs and TQ-MNPs showed biocompatibility against HDFa cells. TQ-MNPs showed stronger anti-proliferative activity against MCF-7 breast cancer cells compared to free TQ (p < 0.05). TQ-MNPs induced apoptosis in MCF-7 breast cancer cells.

Facile sol–gel synthesis of trivalent Al3+-Gd3+ ions co-doped nanoscale cobalt spinel ferrite for magneto-electronic applications

The magnetic spinel ferrites nanomaterials simultaneously doped with multivalent cations have gained a lot of interest from many researchers during the last decade. Also, the doping of trivalent rare-earth ions in spinel ferrites is promising for many technological applications. Considering these facts, in this work we investigated the trivalent Al3+-Gd3+ ions co-doped cobalt ferrite nanoparticles with nominal composition as CoFe2-2xAlxGdxO4 (x = 0.00, 0.03, 0.05, 0.07, 0.10). The sol–gel auto ignition route assisted by citric acid as a chelating agent was utilized to synthesize the series of nanoparticles. The Rietveld refined X-ray diffraction (XRD) patterns were analyzed to ensure the single-phase formation of nanoparticles with spinel cubic structure. The spherical-shaped grain morphology of the nanoparticles was indicated by scanning electron microscopy (SEM) images. The elemental analysis obtained by energy dispersive X-ray analysis (EDAX) revealed stoichiometric formation of the samples along with high purity. The two prominent frequency modes analogous to the spinel ferrite structure were noted in the infrared spectra assuring the successful formation of all the samples. The soft magnetic behaviour with a lower coercivity of the prepared nanoparticles was confirmed by the vibrating sample magnetometer (VSM) technique. The DC electrical resistivity plots indicated that resistivity decreases with an increase in Al3+-Gd3+ co-doping. The dielectric studies of all the samples showed increasing behaviour with an increase in Al3+-Gd3+ co-doping. All the results suggest that the Al3+-Gd3+ co-doped cobalt ferrite nanoparticles can be useful for real-world applications, specifically in nanoelectronics devices.

Superparamagnetic Fe3O4 nanoparticles capped with silver induce apoptosis of colon cancer cells via damaging DNA@increasing ROS

A sol-gel approach was used to create magnetite nanoparticles (Fe3O4 NPs) as a core and silver (Ag) as a shell. Ag-Fe3O4 NPs were identified by x-ray diffraction (XRD) and energy dispersive x-ray (EDX), scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, and vibrating sample magnetometer (VSM) techniques. The capabilities of Ag-Fe3O4 NPs to induce apoptosis were investigated utilizing the Acridine orange/Ethidium bromide stain. The activity of NPs against (HT-29) cancer cells was further evaluated in and out of the existence of near-infrared (NIR) laser beam and alternating magnetic field (AMF). The exposed laser enhanced the cytotoxicity effect against (HT-29) cells. However, greatly elevated cytotoxic activity was seen with using the AMF.

Magnetic curcumin–copper graphene oxide as facile and recyclable heterogeneous nanocatalyst for preparation of polyhydroquinolines and sulfoxides

In this research project, a versatile procedure has been designed for the preparation of supported copper@curcumin on magnetic graphene oxide nanoparticles (GO@Fe3O4@Cur–Cu). The structure of prepared nanocatalyst was characterized by several techniques including; Fourier transform infrared, powder X-ray diffraction, thermal gravimetric analysis, energy dispersive X-ray analysis, inductively coupled plasma optical emission spectroscopy, vibrating sample magnetometer, transmission electron microscopy, and scanning electron microscopy analyses. The catalytic properties of GO@Fe3O4@Cur–Cu were examined for the efficient synthesis of polyhydroquinolines as well as the preparation of sulfoxides through selective oxidation of sulfides in the presence of hydrogen peroxide.

Geometry and Surface Area Optimization in Iron Oxide Nanoparticles for Enhanced Magnetic Properties.

Iron oxide nanoparticles (IONPs) are recognized for their potential in biomedical applications due to their distinctive physicochemical properties. This study investigates the synthesis of IONPs with various geometric morphologies-cubic, star-like, truncated icosahedron, and spherical-via thermal decomposition to enhance their utility in magnetic resonance imaging (MRI) and targeted drug delivery. X-ray diffraction analysis verified the Fe3O4 phase in all nanoparticles, illustrating the synthesis's efficacy. Particle morphologies were well-defined, with sizes ranging from 10 to 150 nm, as determined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Magnetic evaluations using a vibrating sample magnetometer (VSM-PPMs) demonstrated their superparamagnetic behavior, with larger particles exhibiting greater saturation magnetization. Notably, truncated icosahedron and cubic IONPs showed superior transverse relaxation rates, with r2 values of 56.77 s1 mM1 and 42.67 s1 mM1, respectively. These results highlight the potential of customizing IONP geometries to optimize their magnetic properties and increase surface area available for functionalization, thereby improving their efficacy for biomedical applications.

Visible light-boosted photodegradation activity of Ag–AgVO3/Zn0.5Mn0.5Fe2O4 supported heterojunctions for effective degradation of organic contaminates

Abstract One of the most important concerns in developing efficient heterojunction photocatalysts for the photodegradation of environmental contaminants is the enhancement and acceleration of photocarrier separation. In this study, novel nanocomposite photocatalysts of Ag–AgVO3 nanorods grafted with Zn0.5Mn0.5Fe2O4 metal ferrites nanoparticles were developed by using facial hydrothermal and coprecipitation techniques for the effective photodegradation of Rhodamine B (Rh B) under visible light exposure. The fabricated materials were analyzed in detail using scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS), nitrogen adsorption/desorption, transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), vibrating sample magnetometer, and ultraviolet–visible diffuse reflectance spectroscopy (DRS). The results showed an efficient contribution when compared to the earlier research. The TEM showed a hybrid of nanorods of supported composite with metal ferrite and Ag attached on the surface, consistent with field emission scanning electron microscopy and EDS results. The DRS expressed a lower band gap for supported nanocomposites (1.5 eV), which, arranged with PL, showed a lower recombination rate of supported nanocomposites. The surface properties showed that the supported hybrid might be as small as 45.42 nm or as large as 20.33 nm compared with others. When comparing the photocatalytic activity of pure AgVO3, Ag/AgVO3, and Zn0.5Mn0.5Fe2O4 photocatalysts, the performance of Ag–AgVO3/Zn0.5Mn0.5Fe2O4 nanocomposite photocatalyst was clearly superior (more than 99.9% degradation efficiency was achieved). The boosted activity the Ag–AgVO3/Zn0.5Mn0.5Fe2O4 photocatalyst system was justified by Z-system heterojunction induced by the plasmonic effect, and the suggested mechanism was investigated by quenching of reactive species by scavengers. The degradation performance was achieved under optimum conditions (pH = 2, 20 ppm of pollutant concentration, 120 mM of hydrogen peroxide, 1 g/L of catalysts dose). The results showed that after 240 min of visible irradiation resulted in the high (chemical oxygen demand) and (total organic carbon) reductions with a removal efficiency of (85) to (90%) for Rh B dye. The fabricated Ag–AgVO3/Zn0.5Mn0.5Fe2O4 nanocomposites were effective in the degradation of organic pollutants in wastewater treatment.

Synthesis and characterization of cerium doped NiZn nano ferrites as substrate material for multi band MIMO antenna.

In addressing issues related to electromagnetic interference, the demand for ferrite materials with exceptional magnetic and dielectric properties has escalated recently. In this research, sol-gel auto combustion technique prepared Nickel zinc ferrites substituted with cerium, denoted as Ni0.5Zn0.5Ce0.02Fe1.98O4.X-ray diffraction (XRD), Vibrating Sample Magnetometer (VSM), and Field Emissions Scanning Electron Microscope (FESEM) were used to investigate the structure, magnetic properties, and morphology of Cerium doped NiZn Nano ferrites, respectively. The magnetic and dielectric properties of the sample was examined within a frequency range of 2.5-5.5 GHz. Sample exhibits low permittivity (2.2), high permeability (1.4), low dielectric (0.35) and magnetic loss tangent (-0.5) and highest saturation magnetization measuring 30.28 emu/g. A Novel Double-band, 4x4 MIMO window grill-modeled antennas operating on 3.5 GHz and 4.8 GHz frequency bands for 5G smartphones is designed using the CST microwave studio suite. The performance of window grilled 4x4 MIMO antenna model with Cerium doped NiZn nano ferrites as substrate, is investigated and found the return loss of -35 and -32 dB, with the bandwidth of 200MHz, gain (1.89 & 4.38dBi), envelope correlation coefficient (0.00185), channel capacity loss (0.2bps/Hz), and interterminal isolation of (22& 19dB).The results show that the antenna size is reduced with improved bandwidth, higher isolation and better diversity gain performance using Cerium doped NiZn nano ferrite substrate compared to conventional dielectric substrates.

Magnetic yolk-shell structured periodic mesoporous organosilica supported palladium as a powerful and highly recoverable nanocatalyst for the reduction of nitrobenzenes

A novel palladium-loaded yolk-shell structured nanomaterial with magnetite core and phenylene-based periodic mesoporous organosilica (PMO) shell (Fe3O4@YS-Ph-PMO/Pd) nanocatalyst was synthesized for the reduction of nitrobenzenes. The Fe3O4@YS-Ph-PMO/Pd was prepared through cetyltrimethylammonium bromide (CTAB) directed condensation of 1,4-bis(triethoxysilyl)benzene (BTEB) around Fe3O4@silica nanoparticles followed by treatment with palladium acetate. This nanocatalyst was characterized by using Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetric analysis (TGA), low-angle and wide-angle powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) analyses. These analyses showed a magnetic nanomaterial with high chemical and thermal stability for the designed composite. The Fe3O4@YS-Ph-PMO/Pd nanocomposite was employed as a powerful and highly recoverable catalyst in the green reduction of nitroarenes in H2O at room temperature. A variety of nitroarene derivatives were applied as substrate in the presence of 0.9 mol% of Fe3O4@YS-Ph-PMO/Pd catalyst. All nitroarenes were selectively converted to their corresponding amines with high to excellent yields (92–96%) within short reaction times (10–18 min). This catalyst was recovered and reused at least 11 times without significant decrease in efficiency and stability.

Magnetic covalent organic framework with ionic tags as an efficient catalyst in the preparation of 2,3-disubstituted thiazolidine-4-ones and N‑amino-2-pyridones

The functionalization of magnetic nanoparticles with covalent organic frameworks (COFs) will endow them inspiring characteristics. Herein, a new magnetic covalent organic framework (MCOF) decorated with trifluoroacetate as ionic sections (Fe3O4@COF-TFA) was designed and constructed. To confirm the successful synthesis of this hybrid material, several techniques including Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy(EDS), elemental mapping, transmission electron microscopy (TEM), vibrating-sample magnetometer (VSM) and X-ray diffraction analysis (XRD) were applied. TG/DTG analyses show that Fe3O4@COF-TFA has an excellent thermal stability up to 450 ℃. The FE-SEM analysis revealed that catalyst has the island-like morphology and according to TEM analysis, it has spherical geometry with nanometer scale particle size. Also, surface area of Fe3O4@COF and Fe3O4@COF-TFA are 74 and 12 m2.g−1, respectively. Fe3O4@COF-TFA was applied as a recoverable heterogeneous catalyst for construction of 2,3-disubstituted thiazolidine-4-ones and N‑amino-2-pyridones via a multi-component synthetic strategy. It is worth mentioning that synthesized derivatives have a good yield and short reaction times.

Physical properties of Pr3+ substituted zinc spinel (ZnPrxFe2−xO4) nanoferrites synthesized via sol–gel auto-combustion route

Spinel ferrites, a group of metal oxides, have garnered significant attention in the recent decade due to their high demand for numerous applications, including data storage and microwave device applications. In this context, we studied the effect of different doping concentrations of large Pr ions on the physicochemical properties of spinel lattice, such as dielectric and magnetic properties. In this research, we successfully fabricated a series of praseodymium ion-doped zinc spinel ferrites ZnPrxFe2-xO4 nanoparticles 0.00≤x≤0.20 via a simple and economical sol–gel auto-combustion approach. XRD (X-ray Diffraction Analysis) and FTIR investigations validate the presence of a cubical phase, with the crystallite size varying between 11 nm to 19 nm depending on the amount of Pr present. The Scherrer method, Williamson-Hall analysis (WH), and size-strain plot method (SSP) were investigated the correlation of crystalize size. The SSP approach has a better correlation coefficient than the WH method. Transmission electron microscopy TEM shows that the prepared material possessed the cubic and spherical symmetry. The significant variation in electrical parameters was discussed at an applied frequency ranging from 1 MHz to 3 GHz. The dielectric constant is approximately constant in low-frequency regions then relaxation peaks were observed at nearly 1.4 GHz and 2.2 GHz. The dielectric constant and complex dielectric constant of these samples dropped as the praseodymium content increased. Investigations regarding the magnetic properties were carried out using a vibrating sample magnetometer (VSM) at −23 k Oe to +23 k Oe. Low coercivity and relaxation peaks at high frequencies suggest that this material may be suitable for core materials, microwave technologies and recording media.