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The conventionally synthesized nano-ferrite materials do not possess bulk properties, generally required for their use in mainstream industry. To make ferrite nanoparticles clinically applicable materials, it is important to have good control over morphology and optical properties of these materials. In this study, low-pressure microwave plasma was used to tailor the structural properties and surface chemistry of manganese ferrite nanoparticles. A facile sol-gel method was used to prepare cubic spinal structures of manganese ferrite nanoparticles. These nanoparticles were exposed to oxygen plasma sustained with a microwave source for improving their magnetic and photocatalytic activities. The techniques like XRD, SEM, PL, UV-Vis DRS, transient photocurrent response and EIS were used to characterize the samples. The plasma treated nanoparticles were used to degraded methyl blue (MB) dye in the solution. The photocatalytic activity showed 85% degradation of MB after 100 min of exposure of visible light. The second part of the paper studied the magnetic properties of the nanoparticles. The saturation magnetization decreased from 0.78 emu/g to 0.68 emu/g after plasma treatment of nanoparticles.

Manganese ferrite (MnFe2O4) nanoparticles were synthesized through a coprecipitation method using manganese (II) chloride tetrahydrate (MnCl2·4H2O) and ferric chloride hexahydrate (FeCl3·6H2O) as precursors. The scanning electron microscopy images showed that the as-synthesized particles were granular and about 20 nm. The X-ray diffraction patterns revealed that the manganese ferrite phase was completely decomposed into ferric oxide (Fe2O3) and manganese (III) oxide (Mn2O3) after annealing above 800°C in air. In contrast, its crystalline quality significantly improved when it was annealed in argon. By using the vibrating-sample magnetometry technique, it was demonstrated that the saturation magnetization (M s) of the as-prepared sample (~36.6 emu/g) decreased sharply up to ~5 emu/g after annealing at 1000°C in air and significantly increased to ~77.6 emu/g when it was annealed at 1000°C in argon. Under sunlight radiation, a higher efficiency was observed for manganese ferrite particles annealed in argon in the presence of hydrogen peroxide (H2O2), mainly due to the Fenton reaction between manganese ferrite and hydrogen peroxide. The authors suggest that the presence of hydrogen peroxide and the enhancement of the crystalline quality of the manganese ferrite phase are the two leading factors in improving methylene blue degradation efficiency.

Manganese ferrite (MnFe2O4) was prepared via hydrothermal route and characterized by advanced techniques. The photocatalytic activity (PCA) was evaluated by degrading methylene blue (MB) dye under UV irradiation. The effect of process variables such as catalyst dose, UV exposure time and pH was studied for maximum degradation of dye at optimum conditions. The MnFe2O4 showed face centered cubic structure and average particle size of 23.98 nm. The lattice constant, lattice strain, ionic radii (rA & rB), bonding angles and hoping lengths of MnFe2O4 were recorded to be 0.8467 nm, 0.08, 1.66, 0.766, 1.833 and 2.116 Å, respectively. The MnFe2O4 showed promising PCA and at optimum conditions of process variable, up to 99% MB dye degradation was achieved. The PCA was found dependent to catalyst dose, UV exposure time and pH. Results revealed that the hydrothermal rout is feasible route for the preparation of MnFe2O4 ferrite in nano size and the PCA revealed the potential application of MnFe2O4 ferrite to degrade dye in textile wastewater.

Nanomaterials properties are deeply dependent on several features, being easily tuned according to its composition, shape, and dimensionality. Graphene, a two-dimensional (2D) material has outstand...

Cadmium-substituted manganese ferrite nanoparticles with the general formula Mn1‒xCdxFe2O4(x = 0.0, 0.2, 0.4, 0.6, 0.8) were synthesised by the citrate‒gel auto combustion method. X-ray diffraction...

This paper discusses the results of the research carried out to study the structure, optical properties and thermophysical properties of a sample (nanopowder with a true density of 4.96 g/cm3, a particle size of 60 nm and a purity of 98.5%, SkySpring Nanomaterials, USA) with high purity. Based on the results of X-ray diffraction, the crystalline phase of MnFe2O4 ferrite nanoparticles was completely obtained and the values of the lattice parameters were determined. The results of the MID-IR analysis showed that the absorption coefficient [Formula: see text] reaches its maximum value at 748 cm[Formula: see text] wave number. The optical properties of the as-prepared nanostructures were also investigated by VERTEX 70 V diffuse reflectance spectroscopy (DRS). As can be seen from the results of the DSC analysis, the effects occurring in the temperature range up to [Formula: see text]C clearly reflect the nature of the phase transitions and the amount of energy generated in the ferrite samples.

In the presented study, manganese ferrite MnFe2O4 nanoparticles were synthesized by applying a modified co-precipitation method based on the decomposition of metallic precursors in a liquid phase environment in the presence of surfactant oleic acid. The synthesized sample was then characterized with X-ray Diffraction XRD , standard and high resolution Transmission Electron Microscopy TEM and Fourier Transform Infrared Spectroscopy FTIR , which revealed that the as-prepared MnFe2O4 particles are monodispersed nanocrystals with an average size of 4.7 nm and well surrounded with dimeric oleic acid coating. The magnetic properties of nanoparticles were first investigated by means of Superconducting Quantum Interference Device SQUID magnetometry. The temperature and field dependent magnetization measurements showed that the MnFe2O4 nanoparticles exhibit superparamagnetic property with zero coercivity at room temperature and thermal irreversibility. The superparamagnetic behavior of MnFe2O4nanoparticles was further confirmed by conducting zero field Mössbauer Spectroscopy measurements on nanoparticle powders. As to fulfill all the requirements like crystallinity, small size and superparamagnetism, the prepared oleic acid coated MnFe2O4 nanoparticles has the potential to be used in biomedical applications like targeted drug delivery, MRI and hyperthermia

Single-domain manganese ferrite nanoparticles were synthesized through one-step chemical co-precipitation technique using diethanolamine which acted simultaneously as precipitating and capping agent. The synthesized nanoparticles were characterized by XRD, FTIR, TGA, EDX, FESEM and VSM. XRD pattern showed the presence of peaks corresponding to the single-phase inverse spinel structure with an average crystallite size of 59.6 nm. The average particle size determined by FESEM was 46.8 nm. In addition, the magnetic properties of the nanoparticles analyzed by VSM exhibited nearly superparamagnetic property with a high saturation magnetization of 77.31 emu/g with little coercivity (10.53 emu/g) and remanence (9.32 emu/g) at 300 K temperature. TGA and FTIR results confirmed the binding of diethanolamine onto the surface of manganese ferrite nanoparticles. The synthesized nanoparticles exhibited single crystalline phase with improved magnetic properties.

Manganese ferrite nanoparticles are superparamagnetic and have very high saturation magnetization, which makes them candidates for application as MRI contrast agents. Because these nanoparticles are very effective enhancers of transverse relaxation, they are particularly suitable as negative (T2-weighted) contrast agents. The magnitude of the relaxivity of nanoparticulate Mn ferrites seems to be determined mainly by the method of preparation, their dimensions, and their saturation magnetization.

Manganese ferrite (MnFe2O4) and calcium-doped manganese ferrite (Ca-MnFe2O4) were synthesized, characterized, and tested for oxidation of hydrocarbons (CH) in a self-designed gas blow rotating (GBR) reactor. The uniformly sized and thermally stable MnFe2O4 nanoparticles (molar ratio, 1/284.5) showed a reasonable catalytic activity (productivity: 366.17 mmolg&minus, 1h&minus, 1) with 60% selectivity at 80 &deg, C, which was further enhanced by calcium doping (productivity: 379.38 mmolg&minus, 1). The suspicious behavior of Ca-MnFe2O4 was disclosed experimentally and theoretically as well.

Two types of manganese ferrite nanoparticles, namely MF-SA and MF-CHI, have been synthesized solvothermally from the synthesis systems containing sodium alginate and chitosan, respectively. Both MF-SA and MF-CHI showed well crystalline nature based on the XRD and TEM measuremants. The larger saturation magnetization value of MF-SA should be ascribed to its slightly larger crystallite size than that of MF-CHI. Results from N adsorption-desorption isotherms and Raman spectra confirmed the structural difference in MF-SA and MF-CHI. The electrocapacitive behavior of manganese ferrite-based supercapacitors has been studied and MF-SA displayed a specific capacitance of around 60.4 F•g at 0.25 A•g in aqueous symmetric supercapacitors, larger than that of MF-CHI about 45.1 F•g at the same condition. MF-SA based supercapacitor also showed better capacitance maintenance of around 82% of the initial value at 1 A•g after 2000 cycle test than that of MF-CHI based cells. Based on the experimental data, the structure-property relationship of two types of MnFeO nanoparticles have been discussed and analyzed.

Nanosized manganese ferrite (MnFe2O4) particles were prepared by sol–gel method using natural polymers like wheat flour (WF) and potato flour (PF) as surfactants and its structural, morphological, optical and magnetic characteristics were studied by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), scanning electron microscope (SEM), photoluminescence spectroscopy (PL) and vibration sample magnetometer (VSM). Brunauer–Emmett–Teller (BET) surface area test also performed and the results obtained were discussed. The average crystallite size was found to be 23 and 16 nm for WF/MnFe2O4 and PF/MnFe2O4 samples, respectively. Magnetic hysteresis loops confirmed the super-paramagnetic behavior for both the samples. For oxidation of benzyl alcohol to benzaldehyde, the catalytic activity of MnFe2O4 nanoparticles (NPs) was carried out. Antimicrobial and antifungal activity of WF/MnFe2O4 and PF/MnFe2O4 samples were investigated against two Gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumoniae), two Gram-negative bacteria (Pseudomonas aeruginosa, Salmonella paratyphi) and fungus (Candida albicans) using inhibition zone method. Minimum Inhibitory Concentration (MIC) values also calculated to determine susceptibilities of bacteria to drugs and also to evaluate the activity of new antimicrobial agents. The in vitro cytotoxicity of newly synthesized samples were analyzed by MTT assay against MCF-7, A549 and HaCaT cell lines in a dose-dependent fashion. Among these two samples, sample B (using potato flour) shows better response than sample A (using wheat flour) and both the samples were non-toxic to normal cell line. The concentration required to kill 50% of the cell (IC50) was also calculated. MnFe2O4 nanoparticles were synthesized by sol–gel method using natural polymers, wheat flour and potato flour, as surfactant. The as-prepared MnFe2O4 was characterized by XRD, FT-IR, SEM, EDX, PL and VSM analysis. The average crystallite size was found to be 23 and 16 nm for WF/MnFe2O4 and PF/MnFe2O4 samples, respectively. Magnetic hysteresis loops confirmed the super-paramagnetic behavior for both the samples. The catalytic activity of MnFe2O4 nanoparticles (NPs) were carried out for oxidation of benzyl alcohol to benzaldehyde. Biological activities like antimicrobial, antifungal and anticancer activities of the samples were investigated. Among these two samples, PF/MnFe2O4 shows better response than WF/MnFe2O4 and both the samples were non-toxic to normal cell line. IC50 values of WF/MnFe2O4 (a) and PF/MnFe2O4 (b) against A549 and MCF-7 cell lines

Manganese-doped magnetite nanoparticles as magnetic resonance imaging (MRI) contrast agents have been well developed in recent years due to their higher saturation magnetization and stronger transverse (T2) contrast ability compared to parent magnetite. However, the underlying role that manganese doping plays in altering the contrast ability of magnetite is still not thoroughly understood. Herein, we investigate the effects of manganese doping on changes of ferrite crystal structures, magnetic properties, and contrast abilities. We developed a successful one-pot synthesis of uniform manganese-doped magnetite (MnxFe3–xO4) nanoparticles with different manganese contents (x = 0–1.06). The saturation magnetization and T2 contrast ability of ferrite nanoparticles increase along with rising manganese proportion, peak when the doping level of MnxFe3–xO4 reaches x = 0.43, and decrease dramatically as the manganese percentage continues to augment. At high manganese doping level, the manganese ferrite nanoparticles...

Annealing is an essential step used in processing of ferrites. As-synthesized magnetic nanoparticles are subject to annealing to improve specific characteristics like hardness or magnetization. Co-precipitation is a popular and easy technique to synthesize manganese ferrite nanoparticles. Effect of annealing on the structural and magnetic properties of manganese ferrite nanoparticles synthesized by co-precipitation method is not well understood. In this article, effect of annealing on structural and magnetic properties of manganese ferrite nanoparticles has been studied. When sintered at 400 °C, as-synthesized MnFe2O4 nanoparticles decompose into γ-Fe2O3 and Mn3O4. Upon further heating at 600 °C, γ-Fe2O3 gets transformed into α-Fe2O3. When MnFe2O4 is annealed at 900 °C, it decomposes into three crystallographic phases, i.e. α- Fe2O3, Mn3O4 and Fe3O4. The corresponding changes in the magnetic properties are in good agreement with the observed changes in the structural properties of the MnFe2O4.

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Manganese ferrite nanoparticles (MnFe2O4) were synthesized via surfactant-assisted co-precipitation, where sodium dodecyl sulfate (SDS) was used as the template to control particle size at various SDS concentrations. The substitutions of iron (II) (Fe2+) into the MnFe2O4 ferrite nanoparticles were carried out to obtain Fe(1–x)MnxFe2O4, with various Mn2+: Fe2+ molar ratios. The synthesized ferrite nanoparticles were characterized by the Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analyzer (TGA), X-ray diffractometer (XRD), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM), two-point probe, and vibrating sample magnetometer (VSM) techniques. The experimental Mn:Fe mole ratios of the Fe(1−x)MnxFe2O4 ferrite nanoparticles were verified to be in agreement with the theoretical values. The synthesized MnFe2O4 and Fe(1−x)MnxFe2O4 ferrite nanoparticles were of mixed spinel structures, with average spherical particle sizes between 17–22 nm, whereas the magnetite ferrite nanoparticles (Fe3O4) were of the inverse spinel structure. They showed soft ferromagnetic behavior. The synthesized Fe0.8Mn0.2Fe2O4 ferrite nanoparticle possessed the highest saturation magnetization of 88 emu/g relative to previously reported work to date.

A simulation of magnetic properties of nanosized manganese ferrite particles is performed. In the simulations, the Metropolis Monte Carlo algorithm is used. The particle parameters are selected taking into account true values of the exchange integrals and anisotropy constants, as well as particle size distribution in nanostructured manganese ferrite powder produced by the mechanochemical synthesis.

A facile hydrothermal method is used to synthesize manganese ferrite nanoparticles with the addition of polyacrylic acid (PAA). PAA addition does not largely decrease the magnetic performance of MnFe2O4 nanoparticles, but highly enhance the adsorption properties for methylene blue (MB) dye. It demonstrates that the concentration of negative –COO− groups in the solution determines the adsorption capacity of MnFe2O4 nanoparticles for MB. The maximum MB adsorption capacity was 44.9 mg/g, and the adsorption kinetics of MB match well with the pseudo-second-order model. To reveal the influence mechanism of PAA addition on the properties of manganese ferrite nanoparticles, two different synthetic routes are designed by changing the adding method of PAA with the different mass ratio of PAA to MnFe2O4. Here, the second synthetic route is easier and simpler to operate than the first one. Moreover, with the PAA addition, the adsorption capacity for the samples synthesized by synthetic route 2 increases by 43.4%, which is much higher than that (28.6%) of the samples synthesized by synthetic route 1. Synthetic route 1 reveals that PAA acting as a reducing agent participates in the reaction on the formation of MnFe2O4 ferrites. Herein, the Fe3 + ions bound by PAA chains are reduced to Fe2 + ions. This work clearly points out that the PAA addition contributes to enhancing the adsorption properties of ferrite nanoparticles for organic dye, which provides guidance to the adsorption study on the similar adsorbents for the removal of organic contaminant from the wastewater.

Recently, potential applications of the magnetic heating for heterogeneous catalysis or organic synthesis have been reported. As these new applications are not limited by biocompatibility requirements, a wide range of possibilities for non-aqueous colloidal nanoparticles with enhanced magnetic properties is open. In this work, manganese and cobalt ferrite nanoparticles are synthesized by co-precipitation method with average particle size around 12 nm. The particles are either coated with tetramethylammonium hydroxide (TMAOH) and dispersed in water or with oleic acid (OA) and dispersed in hexane to produce aggregated or disaggregated nanoparticles, respectively. It is observed that the particle disaggregation improves significantly the heating efficiency from 12 to 96 W/g in the case of cobalt ferrite, and from 120 to 413 W/g for the manganese ferrite. The main responsible for this improvement is the reduction of hydrodynamic volume that allows a faster Brownian relaxation. This work also discusses the relevance of the size distribution., This work was supported by grants from the Spanish Ministry of Science and Innovation (MAT2012-37109-C02-01), and Fundación Mutua Madrileña (Spain).

Semiconductor photocatalysis has recently emerged as an effective and eco-friendly approach that could meet the stringent requirements for sustainable environmental remediation. To this end, the fabrication of novel photocatalysts with unique electrochemical properties and high catalytic efficiency is of utmost importance and requires adequate attention. In this work, dual component mesoporous frameworks of spinel ferrite ZnFe2O4 (ZFO) and MnFe2O4 (MFO) nanoparticles are reported as efficient photocatalysts for detoxification of hexavalent chromium (Cr(VI)) and organic pollutants. The as-prepared materials, which are synthesized via a polymer-templated aggregating self-assembly method, consist of a continuous network of linked nanoparticles (ca. 6–7 nm) and exhibit large surface area (up to 91 m2 g−1) arising from interstitial voids between the nanoparticles, according to electron microscopy and N2 physisorption measurements. By tuning the composition, MFO-ZFO composite catalyst containing 6 wt.% MFO attains excellent photocatalytic Cr(VI) reduction activity in the presence of phenol. In-depth studies with UV-visible absorption, electrochemical and photoelectrochemical measurements show that the performance enhancement of this catalyst predominantly arises from the suitable band edge positions of constituent nanoparticles that efficiently separates and transports the charge carriers through the interface of the ZFO/MFO junctions. Besides, the open pore structure and large surface area of these ensembled networks also boost the reaction kinetics. The remarkable activity and durability of the MFO-ZFO heterostructures implies the great possibility of implementing these new nanocomposite catalysts into a realistic Cr(VI) detoxification of contaminated wastewater.

We synthesized manganese ferrite (MnFe2O4) nanoparticles of different sizes by varying pH during chemical co-precipitation procedure and modified their surfaces with polysaccharide chitosan (CS) to investigate characteristics of hyperthermia and magnetic resonance imaging (MRI). Structural features were analyzed by X-ray diffraction (XRD), high-resolution transmission electron microscopy (TEM), selected area diffraction (SAED) patterns, and M&ouml, ssbauer spectroscopy to confirm the formation of superparamagnetic MnFe2O4 nanoparticles with a size range of 5&ndash, 15 nm for pH of 9&ndash, 12. The hydrodynamic sizes of nanoparticles were less than 250 nm with a polydispersity index of 0.3, whereas the zeta potentials were higher than 30 mV to ensure electrostatic repulsion for stable colloidal suspension. MRI properties at 7T demonstrated that transverse relaxation (T2) doubled as the size of CS-coated MnFe2O4 nanoparticles tripled in vitro. However, longitudinal relaxation (T1) was strongest for the smallest CS-coated MnFe2O4 nanoparticles, as revealed by in vivo positive contrast MRI angiography. Cytotoxicity assay on HeLa cells showed CS-coated MnFe2O4 nanoparticles is viable regardless of ambient pH, whereas hyperthermia studies revealed that both the maximum temperature and specific loss power obtained by alternating magnetic field exposure depended on nanoparticle size and concentration. Overall, these results reveal the exciting potential of CS-coated MnFe2O4 nanoparticles in MRI and hyperthermia studies for biomedical research.

The use of metal oxide nanoparticles for the development of cost-effective glucose biosensors has been receiving increased attention. Enzymatic and non-enzymatic glucose sensor using polyethylene glycol (PEG) grafted manganese ferrite (PEG-MnFe2O4) nanoparticles (NPs) modified onto a glassy carbon electrode (GCE) is reported in the present study. XRD and Raman studies confirmed the cubic spinel structure of MnFe2O4. The immobilization of glucose oxidase (GOx) on PEG-MnFe2O4 (GOx@PEG-MnFe2O4) was validated using FTIR and TGA. Sensing electrodes exhibited well-defined redox peaks in 0.1 M phosphate buffered saline (PBS) solution at pH 7.4 against the reference electrode Ag/AgCl. GOx@PEG-MnFe2O4/GCE displayed a sensitivity of 1.985 μA mM−1 cm−2 in the linear range of 1 to 20 mM with a limit of detection (LOD) of 0.132 mM whereas non-enzymatic sensor exhibited a sensitivity of 1.044 μA mM−1 cm−2 in the linear range of 1 to 10 mM with a LOD of 0.099 mM. The lower Michaelis constant ( K m a p p ) value indicates greater affinity towards glucose for the enzymatic sensor. GOx@PEG-MnFe2O4 revealed selectivity specifically for glucose over various interferants such as fructose, lactic acid, sucrose, uric acid and ascorbic acid. In addition, this enzymatic sensor demonstrated better reproducibility and lifetime.

The original version of this article unfortunately contains an incorrect project number in Acknowledgment section. The correct acknowledgement text is given below.

Multifunctional liposomes containing manganese ferrite/gold core/shell nanoparticles were developed. These magnetic/plasmonic nanoparticles were covered by a lipid bilayer or entrapped in liposomes, which form solid or aqueous magnetoliposomes as nanocarriers for simultaneous chemotherapy and phototherapy. The core/shell nanoparticles were characterized by UV/Visible absorption, X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Superconducting Quantum Interference Device (SQUID). The magnetoliposomes were characterized by Dynamic Light Scattering (DLS) and TEM. Fluorescence-based techniques (FRET, steady-state emission, and anisotropy) investigated the incorporation of a potential anti-tumor drug (a thienopyridine derivative) in these nanosystems. The core/shell nanoparticles exhibit sizes of 25 &plusmn, 2 nm (from TEM), a plasmonic absorption band (&lambda, max = 550 nm), and keep magnetic character. XRD measurements allowed for the estimation of 13.3 nm diameter for manganese ferrite core and 11.7 nm due to the gold shell. Aqueous magnetoliposomes, with hydrodynamic diameters of 152 &plusmn, 18 nm, interact with model membranes by fusion and are able to transport the anti-tumor compound in the lipid membrane, with a high encapsulation efficiency (EE (%) = 98.4 &plusmn, 0.8). Solid magnetoliposomes exhibit hydrodynamic diameters around 140 nm and also carry successfully the anticancer drug (with EE (%) = 91.2 &plusmn, 5.2), while also being promising as agents for phototherapy. The developed multifunctional liposomes can be promising as therapeutic agents for combined chemo/phototherapy.

Nanoparticles of manganese ferrite were obtained by the impregnation of highly ordered mesoporous MCM-41 silica support. The investigated sample contained 20% wt. Fe. The obtained nanocrystallites were strongly dispersed in silica matrix and their size was about 2 nm. The sample annealing at 500°C led to increase of particle size to about 5 nm. The Mössbauer spectroscopy investigations performed at room temperature show on occurrence of MnFe2O4 nanoparticle in superparamagnetic state for the sample annealed in all temperatures. The coexistence of superparamagnetic and ferromagnetic phase was observed at liquid nitrogen temperature. The sample annealed at 400°C and 500°C has bigger manganese ferrite particle and better crystallized structure. One can assign them the discrete hyperfine magnetic field components.

Laccase was immobilized onto manganese ferrite nanoparticle (MFN) and dye decolorization from single and binary systems was studied. The characteristics of laccase immobilized manganese ferrite nanoparticle (LIMFN) were investigated using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). Direct red 31 (DR31), Acid blue 92 (AB92) and Direct green 6 (DG6) were used. A least square support vector machine (LSSVM) was developed to predict the decolorization efficiency of various single and binary systems based on the obtained laboratory data under different experimental conditions. Statistical and graphical quality measures were also employed to evaluate the performance and accuracy of the developed intelligent models. It is shown that the predictions of the designed LSSVM models are in close agreement with the experimental data. The effects of LIMFN dosage, pH and dye concentration on dye decolorization from single and binary systems were evaluated. Decolorization kinetics followed Michaelis–Menten Model.

In this paper, uniform and superparamagnetic nanoparticles have been prepared using one-step polyol synthesis method. Structural, morphological and magnetic properties of obtained MnFe2O4 nanoparticles have been investigated by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA) techniques. Structural investigation showed that the average crystallite size of obtained nanoparticles was about 10[Formula: see text]nm. Magnetic study revealed that the nanoparticles were superparamagnetic at room temperature with magnetization 67[Formula: see text]emu/g at room temperature. The self-heating characteristics of synthesized MnFe2O4 nanoparticles were studied by applying external AC magnetic field of 167.6 to 335.2[Formula: see text]Oe at a fixed frequency of 265[Formula: see text]kHz. The SAR values of MnFe2O4 nanoparticles were calculated for 2, 5, 10[Formula: see text]mg[Formula: see text]mL[Formula: see text] concentrations and it is observed that the threshold hyperthermia temperature is achieved for all concentrations.

An environmentally benign and efficient method for the synthesis of spirooxindoles has been developed via a one-pot and three-component reaction of isatins, malononitrile, and anilinolactones in the presence of a catalytic amount of manganese ferrite nanoparticles in PEG-400, as a nontoxic, green, and reusable solvent. The significant advantages of this protocol are; the use of a magnetically recoverable and reusable catalyst, high to excellent product yields, operational simplicity and the use of PEG-400 as an environmentally-friendly solvent.

A one-pot and three-component reaction for the efficient, green and economical synthesis of novel spiro-furo-pyrido-pyrimidine-indolines using 2,6-diaminopyrimidine-4(3H)-one or uraciles, isatins and tetronic acid or anilinolactones in the presence of manganese ferrite nanoparticles as a magnetic catalyst in water is described. The present synthesis shows attractive characteristics such as; the use of magnetically recoverable and reusable catalyst, convenient one-pot operation, short reaction periods, good to high yields and the use of water as a green reaction medium and is considered to be relatively environmentally benign.

Reducing ferromagnetic particle size is an important strategy to improve their positive effect on imaging through the suppression of their negative effect, demonstrated by ultrasmall manganese ferrite nanoparticles prepared from an environmentally-friendly aqueous route. These ultrasmall particles exhibit pronounced paramagnetic characteristics and nontoxicity, making them efficient T1-positive contrast agent and manganese contrast agents for manganese enhanced MRI.

In this work, Manganese ferrite nanoparticles of various compositions were reproducibly synthesized via coprecipitation route. Variation in structural and dielectric properties was studied by varying the sintering temperature, sintering time and manganese to iron ratio. Structural, compositional and phase properties were investigated by X-ray diffraction (XRD) technique which confirmed the pure normal spinel structure with no other phase/impurity. Particle size, Lattice constant, measured bulk density, X-ray density, Specific Surface Area and Porosity were determined by the standard formulae. Responses of Capacitance and Dielectric constant were studied at room temperature in the frequency range of 600Hz to 1MHz by LCR meter which both showed the exponential decay at low frequency while both became nearly independent of frequency in higher frequency ranges.

Well-crystallized manganese ferrite nanoparticles with mean size of 20 nm were synthesized at low temperature (≤100 °C) by ultrasound wave-assisted solid–liquid reaction ball milling technique without subsequent calcination. MnO2 were used as the raw material and iron milling balls with diameter of 1.0–1.5 mm were used. As a comparison, solid–liquid reaction ball milling without ultrasonic wave assistance and the effects of different milling balls were also investigated. The results showed that, this technique is simple, environmentally friendly and energy-saving for nanocrystal synthesis.

Manganese ferrite (MnFe2O4) magnetic nanoparticles were successfully prepared by a sol-gel self-combustion technique using iron nitrate and manganese nitrate, followed by calcination at 150 °C for 24 h. Calcined sample was systematically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and vibrational sample magnetometry (VSM) in order to identify the crystalline phase, functional group, morphology, particle size, shape and magnetic behavior. It was observed that the resultant spinal ferrites obtained at low temperature exhibit single phase, nanoparticle size and good magnetic behavior. The study results have revealed the existence of a potent dose dependent cytotoxic effect of MnFe2O4 nanoparticles against 4T1 cell lines at varying concentrations with IC50 values of 210, 198 and 171 μg/mL after 24 h, 48 h and 72 h of incubation, respectively. Cells exposed to higher concentrations of nanoparticles showed a progressive increase of apoptotic and necrotic activity. Below 125 μg/mL concentration the nanoparticles were biocompatible with 4T1 cells.

A novel one-pot three-component reaction of isatins, anilinolactones, and malonitrile furnishes spirooxindoles with potential biological activity.

Nanoparticles that are formed in the course of additional heat treatment in borate glasses containing iron and manganese oxide additives at low concentrations are directly observed for the first time using electron microscopy. The size, the shape, and the structure of nanoparticles and their volume distribution in the glass matrix are determined. Correlations between the nanoparticle parameters and the magnetic and magneto-optical properties of the glasses containing these particles are revealed.

The Association between nanotechnology and biomagnetic diagnostic techniques unwrapped a whole new research field that allows us to noninvasively study physiological parameters, such as dynamic perfusion and retention in organs and tissues. By associating the AC Biosusceptometry (ACB) system to magnetic iron oxide nanoparticles doped with manganese, we analyzed circulation time and biodistribution patterns for these particles after 20 minutes of infusion. We found a circulation time of 181±49 s, with major biodistribution to liver, lungs and spleen, given the particles features and the organs morphology. Our results showed the ACB system efficiency on particles dynamic tracing and bloodstream patterns assessments, and suggest the use of less reactive nanoparticles with a higher circulation time in the body.

0000-0002-3081-0691 WOS: 000418383300001 The microstructure, composition and magnetism of CoFe2O4, MnFe2O4 and NiFe2O4 nanoparticles of comparable sizes (similar to 20 nm) and interparticle spacings (similar to 20 nm) have been characterized from 10 to 400 K. The cation distributions of the tetrahedral and octahedral sites of the particles, that have cubic spinel structures, have a high degree of inversion, similar to 0.98 for CoFe2O4, similar to 0.80 for MnFe2O4 and NiFe2O4 nanoparticles. The blocking temperatures were similar to 300 K for the MnFe2O4 and NiFe2O4 nanoparticles, while the CoFe2O4 nanoparticles, due to their higher intrinsic anisotropy had a significantly higher blocking temperature above 400 K. Specifically, the magnetocrystalline anisotropy of the CoFe2O4 nanoparticles was K = ( 2.96 +/- 0.03) x 10(6) ergs cm(-3), while for the MnFe2O4 nanoparticles, K = ( 0.04 +/- 0.01) x 10(6) ergs cm(-3), and for the NiFe2O4 nanoparticles, K = ( 0.07 +/- 0.01) x 10(6) ergs cm(-3). The magnetism of these three ferrite systems are discussed in detail with regards to their microstructures and cation distributions. Mugla Sitki Kocman UniversityMugla Sitki Kocman University [14/066] The authors thank the Scientific and Technological Research Council of Turkey (TUBITAK) and Natural Sciences and Engineering Research Council of Canada (NSERC). This paper has been granted by the Mugla Sitki Kocman University Scientific Research Project Coordination through Project Grant Number: (14/066).

Manganese ferrite (MnFe2O4) hollow microspheres were synthesized through a sacrificial template approach using manganese carbonate (MnCO3) microspheres as sacrificial templates. Different from the literatures, the synthesis of MnFe2O4 hollow spheres was achieved through a one-pot hydrothermal process without subsequent calcination process. The temperature and reaction time of the hydrothermal process were set to be 180 °C and 8 h. The formation mechanism of the MnFe2O4 hollow microspheres was also investigated. Results indicate that the average diameter of the as-synthesized MnFe2O4 hollow microspheres is 1.2 μm. The shells of the hollow microspheres are composed of nanoparticles. During hydrothermal process, Mn2+ ions diffused outward and resulted in shell materials of MnFe2O4, thus MnCO3 templates were consumed and MnFe2O4 hollow microspheres were obtained.