Autocombustion Route Derived Zinc Ferrite Nanoparticles as Chemiresistive Sensor for Detection of Alcohol Vapors.

Prolonged exposure to alcohol vapors can have detrimental effects on human health, potentially leading to eye irritation, dizziness, and in some cases, damage to the nervous system. The present article aims to provide a comprehensive understanding on the synthesis and characterization of zinc ferrite (ZnFe2O4) nanoparticles, as well as their interactions with a range of alcohol vapors, including methanol, ethanol, n-propanol, and isopropanol. These alcohols differ in their molecular weight, boiling points, diffusivity, and other properties. The study reveals the semiconducting ZnFe2O4 nanoparticulate sensor's capability for reversible, repeatable, and sensitive detection of alcohol vapors. The sensor exhibits the highest response to ethanol within operating temperature range (225-300 °C). An attempt is made to establish a correlation between the properties of the target analytes and the observed sensing signals. Additionally, the response conductance transients of ZnFe2O4 under the exposure to the studied alcohol vapors are modeled based on the Langmuir-Hinshelwood adsorption mechanism. The characteristic time constants obtained from this modeling are justified with respect to the properties of the analytes.

Comparative evaluation of antimicrobial activity of spinel structured transition metal ferrites supported on reduced graphene oxide against pathogenic strains of bacteria and fungi.

One of the global challenges for living things is to provide pollution and harmful microbes-free environment. In this study, magnetically retrievable spinel-structured manganese zinc ferrite (Mn0.5Zn0.5Fe2O4) (MZF) was synthesized by a facile solvothermal method. Further, the MZF with different weight percentages (10 wt%, 50 wt%, and 80 wt%) were supported on reduced graphene oxide (rGO). The phase purity and morphology of MZF and MZF/rGO nanocomposite were confirmed by x-ray diffraction technique and scanning electron microscopy, respectively. The Fourier transform infrared spectroscopy, Raman, UV-visible spectroscopy, and thermogravimetric analyses of the as-synthesized nanocomposites were examined for the detection of various chemical groups, band gap, and thermal properties, respectively. The MZF/rGO nanocomposite exhibited significant antibacterial and antifungal activity againstEggerthella lenta, Enterococcus faecalis, Klebsiella pneumonia, Pseudomonas aeruginosa,andCandida albicanscompared to bare MZF and rGO. The high surface area of rGO plays a crucible role in antimicrobial analysis. Additionally, the antibacterial and antifungal activity is compared by synthesizing various metal ferrites such as MnFe2O4, ZnFe2O4, and Fe3O4. The 50 wt% MZF/rGO nanocomposite exhibits significantly high antibacterial activity. However, 10 wt% MZF/rGO nanocomposite shows good antifungal activity than Fe3O4, MnFe2O4, ZnFe2O4, MnZnFe2O4, 50 wt%, and 80 wt% MZF/rGO nanocomposites. These findings suggest that the prepared ferrite nanocomposites hold promise for microbial inhibition.

Efficient removal of crystal violet dye from water using zinc ferrite-polyaniline nanocomposites.

Nanomaterials are widely employed in wastewater treatment, among which nanoferrites and their composites hold significant prominence. This study adopts a green approach to synthesize zinc ferrite nanoparticles, subsequently integrating them with polyaniline (PANI) to fabricate the ZnFe2O4-PANI nanocomposite. Characterization of the prepared ZnFe2O4-PANI nanocomposite was conducted using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. Using Scherrer's equation, the crystallite size of the synthesized zinc ferrite nanoparticles was found to be 17.67 nm. SEM micrographs of the ZnFe2O4-PANI nanocomposite revealed that in situ polymerization of ZnFe2O4 with polyaniline transforms the amorphous surface morphology of the polymer into a homogeneous nanoparticle structure. The adsorption of crystal violet (CV) dye onto the surface of the ZnFe2O4-PANI nanocomposite depends on pH, adsorbent dosage, temperature, concentration levels and duration. The Langmuir adsorption model fitted the data well, indicating adherence to a pseudo-second-order kinetic pattern. Thermodynamic values ΔG°, ΔH° and ΔS° indicated that the adsorption process occurred spontaneously. Advantages and disadvantages of the technique have also been highlighted. Mechanism of adsorption is discussed. From the obtained results, it is evident that the ZnFe2O4-PANI nanocomposite holds promise as a sorbent for the removal of dye from wastewater.

PEGylated Manganese-Zinc Ferrite Nanocrystals Combined with Intratumoral Implantation of Micromagnets Enabled Synergetic Prostate Cancer Therapy via Ferroptotic and Immunogenic Cell Death.

Therapeutic efficacy for prostate cancer is highly restricted by insufficient drug accumulation and the resistance to apoptosis and immunogenic cell death (ICD). Although enhanced permeability and retention (EPR) effect of magnetic nanomaterials could benefit from external magnetic field, it falls off rapidly with increased distance from magnet surface. Considering the deep location of prostate in pelvis, the improvement of EPR effect by external magnetic field is limited. In addition, apoptosis resistance and cGAS-STING pathway inhibition-related immunotherapy resistance are major obstacles to conventional therapy. Herein, the magnetic PEGylated manganese-zinc ferrite nanocrystals (PMZFNs) are designed. Instead of providing external magnet, micromagnets into tumor tissues are intratumorally implanted to actively attract and retain intravenously-injected PMZFNs. As a result, PMZFNs accumulate in prostate cancer with high efficacy, depending on the established internal magnetic field, which subsequently elicit potent ferroptosis and the activation of cGAS-STING pathway. Ferroptosis not only directly suppresses prostate cancer but also triggers burst release of cancer-associated antigens and consequently initiates ICD against prostate cancer, where activated cGAS-STING pathway further amplifies the efficacy of ICD by generating interferon-ß. Collectively, the intratumorally implanted micromagnets confer a durable EPR effect of PMZFNs, which eventually achieve the synergetic tumoricidal efficacy with negligible systemic toxicity.

Development of zinc ferrite nanoparticles with enhanced photocatalytic performance for remediation of environmentally toxic pharmaceutical waste diclofenac sodium from wastewater.

Diclofenac sodium is an anti-inflammatory drug commonly used to cure pain in various treatments. The remarkable potential of this pain-killer leads to its excessive use and, therefore, a persistent water contaminant. Its presence in aqueous bodies is hazardous for both humans and the environment because it causes the growth of harmful drug-resistant bacteria in water. Herein, we present a comparative study of the ZnO and ZnFe2O4 as photocatalysts for the degradation of diclofenac sodium, along with their structural and morphological studies. A simple co-precipitation method was used for the synthesis of ZnO and ZnFe2O4 and characterized by various analytical techniques. For instance, the UV-Vis study revealed the absorption maxima of ZnO at 320 nm, which was shifted to a longer wavelength region at 365 nm for zinc ferrite. The optical band gaps obtained from the Tauc plot indicated that the incorporation of iron has led to a decreased band gap of zinc ferrite (2.89 eV) than pure ZnO (3.14 eV). The metal-oxygen linkages shown by FTIR indicated the formation of desired ZnO and ZnFe2O4, which was further confirmed by XRD. It elucidated the typical hexagonal structure for ZnO and spinel cubic structure for ZnFe2O4 with an average crystallite of 31 nm and 44 nm for ZnO and ZnFe2O4, respectively. The micrographs obtained by SEM showed rough spherical particles of ZnO, whereas for ZnFe2O4 flower-like clustered particles were observed. The photocatalytic investigation against diclofenac sodium revealed the higher degradation efficiency of ZnFe2O4 (61.4%) in only 120 min, whereas ZnO degraded only 48.9% of the drug. Moreover, zinc ferrite has shown good recyclability and was stable up to five runs of photodegradation with a small loss (3.9%) of photocatalytic activity. The comparison of two catalysts has suggested the promising role of zinc ferrite in wastewater remediation to eliminate hazardous pharmaceuticals.

Green Synthesis of Genistein-Fortified Zinc Ferrite Nanoparticles as a Potent Hepatic Cancer Inhibitor: Validation through Experimental and Computational Studies.

In hepatic cancer, precancerous nodules account for damage and inflammation in liver cells. Studies have proved that phyto-compounds based on biosynthetic metallic nanoparticles display superior action against hepatic tumors. This study targeted the synthesis of genistein-fortified zinc ferrite nanoparticles (GENP) trailed by anticancer activity assessment against diethylnitrosamine and N-acetyl-2-aminofluorene induced hepatic cancer. The process of nucleation was confirmed by UV/VIS spectrophotometry, X-ray beam diffraction, field-emission scanning electron microscopy, and FT-IR. An in vitro antioxidant assay illustrated that the leaves of Pterocarpus mildbraedii have strong tendency as a reductant and, in the nanoformulation synthesis, as a natural capping agent. A MTT assay confirmed that GENP have a strong selective cytotoxic potential against HepG2 cancer cells. In silico studies of genistein exemplified the binding tendency towards human matrix metalloproteinase comparative to the standard drug marimastat. An in vivo anticancer evaluation showed that GENP effectively inhibit the growth of hepatic cancer by interfering with hepatic and non-hepatic biochemical markers.

A Comparative and Critical Analysis for In Vitro Cytotoxic Evaluation of Magneto-Crystalline Zinc Ferrite Nanoparticles Using MTT, Crystal Violet, LDH, and Apoptosis Assay.

Zinc ferrite nanoparticles (ZFO NPs) are a promising magneto-crystalline platform for nanomedicine-based cancer theranostics. ZFO NPs synthesized using co-precipitation method are characterized using different techniques. UV-visible spectroscopy exhibits absorption peaks specific for ZFO. Raman spectroscopy identifies Raman active, infrared active, and silent vibrational modes while Fourier transforms infrared spectroscopic (FTIR) spectra display IR active modes that confirm the presence of ZFO. X-ray diffraction pattern (XRD) exhibits the crystalline planes of single-phase ZFO with a face-centered cubic structure that coincides with the selected area electron diffraction pattern (SAED). The average particle size according to high-resolution transmission electron microscopy (HR-TEM) is 5.6 nm. X-ray photoelectron spectroscopy (XPS) signals confirm the chemical states of Fe, Zn, and O. A superconducting quantum interference device (SQUID) displays the magnetic response of ZFO NPs, showing a magnetic moment of 45.5 emu/gm at 70 kOe. These ZFO NPs were then employed for comparative cytotoxicity evaluation using MTT, crystal violet, and LDH assays on breast adenocarcinoma epithelial cell (MCF-7), triple-negative breast cancer lines (MDA-MB 231), and human embryonic kidney cell lines (HEK-293). Flow cytometric analysis of all the three cell lines were performed in various concentrations of ZFO NPs for automated cell counting and sorting based on live cells, cells entering in early or late apoptotic phase, as well as in the necrotic phase. This analysis confirmed that ZFO NPs are more cytotoxic towards triple-negative breast cancer cells (MDA-MB-231) as compared to breast adenocarcinoma cells (MCF-7) and normal cell lines (HEK-293), thus corroborating that ZFO can be exploited for cancer therapeutics.

Utilization of ZnFe2O4-Polyaniline (PANI), ZnFe2O4-Polystyrene (PST), and ZnFe2O4-Polypyrrole (PPy) nanocomposites for removal of Red X-GRL and Direct Sky Blue dyes from wastewater: Equilibrium, kinetic and thermodynamic studies.

In this study, ZnFe2O4-Polyaniline (PANI), ZnFe2O4-Polystyrene (PST), and ZnFe2O4-Polypyrrole (Ppy) nanocomposites were synthesized by the adsorption method and characterized by field emission scanning electron microscopy and Fourier transform infrared spectrometer. Batch adsorption experiments were conducted for removing two types of hazardous dyes Red X-GRL and Direct Sky Blue 51 from an aqueous solution and the effect of pH, adsorbent dosage, contact time, and initial concentration of dyes were investigated. Meanwhile, kinetic, isotherm, and thermodynamic parameters were also determined. The electrolyte and surfactant effect was also tested for the prepared nanocomposites. To test the reusability desorption study was also conducted.

Synthesizing nanoparticles of zinc and copper ferrites and examining their potential to remove various organic dyes through comparative studies of kinetics, isotherms, and thermodynamics.

Nanoparticles of zinc ferrite (ZnFe2O4) and copper ferrite (CuFe2O4) were synthesized, and characterized, and these materials were applied for removal of organic dyes of alizarin yellow R (AYR), thiazole yellow G (TYG), Congo red (CR), and methyl orange (MO) from industrial wastewater through adsorption technique. Synthesis of ZnFe2O4 and CuFe2O4 was achieved through chemical co-precipitation method. These nanomaterials were characterized for physicochemical properties using XRD, FTIR, BET, VSM, DLS, Zeta-potential, and FESEM-EDX analytical instruments. BET surface areas of ZnFe2O4 and CuFe2O4 were 85.88 m2/g and 41.81 m2/g, respectively. Adsorption-influencing parameters including effect of solution pH, adsorbent quantity, initial concentration of dye pollutant, and contact time were examined. Acidic medium of the solution favored higher percentage of removal of dyes in wastewater. Out of different isotherms, Langmuir equilibrium isotherm showed the best fit with experimental data, indicating monolayer adsorption in the treatment process. The maximum monolayer adsorption capacities were found as 54.58, 37.01, 29.81, and 26.83 mg/g with ZnFe2O4, and 46.38, 30.06, 21.94, and 20.83 mg/g with CuFe2O4 for AYR, TYG, CR, and MO dyes, respectively. From kinetics analysis of the results, it was inferred that pseudo-second-order kinetics were fitting well with better values of coefficient of determination (R2). The removal of four organic dyes from wastewater through adsorption technique using nanoparticles of ZnFe2O4 and CuFe2O4 was observed to be spontaneous and exothermic. From this experimental investigation, it has been inferred that magnetically separable ZnFe2O4 and CuFe2O4 could be a viable option in removal of organic dyes from industrial wastewater.

A zinc ferrite nanodrug carrier for delivery of docetaxel: synthesis, characterization, and in vitro tests on C6 glioma cells.

AIM: Docetaxel (DTX) loaded bio-compatible PLGA-PEG encapsulated zinc ferrite nanoparticles (ZFNP) formulation was developed and evaluated against C6 glioma cells. METHODS: The ZFNP were characterised using XRD, FE-SEM, TEM, etc. A series of drug formulations were fabricated by conjugating hydrothermally synthesised ZFNP with DTX in a PLGA-PEG matrix and optimised for drug loading. FTIR and DLS analysis of the formulation along with in vitro drug release, cytotoxicity, cellular uptake, and haemolytic effect were evaluated. RESULTS: Spherical, monodisperse, crystalline ZFNP with an average size of ∼28 nm were formed. The optimised formulation showed a hydrodynamic diameter of ∼147 nm, a surface charge of -34.8 mV, a drug loading of 6.9% (w/w) with prolonged drug release properties, and higher toxicity in C6 glioma cells compared to free DTX along with good internalisation and negligible haemolysis. CONCLUSION: The results indicate ZFNP could be effectively used as nanodrug carrier for delivery of docetaxel to glioma cells.

Rare earth metal (Sm) doped zinc ferrite (ZnFe2O4) for improved photocatalytic elimination of toxic dye from aquatic system.

Wastewater remediation is the serious topic that must be taken into concern which would be a most crucial problem that destroys the natural properties as well as it has some worse effect on living organisms. By doing better wastewater management, the scarcity of water for domestic purposes can be eventually managed. Dyes are main organic pollutant that must be removed from wastewater. Pristine, 1% Sm doped and 2% Sm doped ZnFe2O4 were prepared through simple co-precipitation method. The materials were further analyzed for its structure, optical properties, rotational properties and morphology studies. These analyses were investigated with respect to X-ray diffraction, UV-vis spectroscopy, photoluminescence and scanning electron microscopic studies. XRD pattern of Pristine, 1% Sm doped and 2% Sm doped ZnFe2O4 was matched with JCPDS Card #89-1012 with cubic phase. Bandgap energy of prepared samples were 1.7 eV, 1.65 eV and 1.47 eV. The prepared cationic dye was degraded with help of visible light irradiation. 2% Sm doped ZnFe2O4 nanoparticles easily removed 65% of dye within 1 h duration. 2% Sm doped ZnFe2O4 was tested for its reusability and efficiency was stable for more than three cycles. This shows the stability of the sample towards degrading the cationic dye. By the doping of Samarium, ZnFe2O4 nanoparticles enthusiastically removed cationic dye and it proves to be an efficient candidate in removing dyes and can help in wastewater treatment in upcoming era.

Purification of the leaching solution of recycling zinc from the hazardous electric arc furnace dust through an as-bearing jarosite.

Leaching of the hazardous electric arc furnace (EAF) dust containing mainly zinc ferrite and zinc oxide, accompanied by minor concentrations of arsenic compounds, was investigated using sulfuric acid. In order to reach the maximum recovery of zinc, the leaching solution was adjusted to recover both iron and zinc at their maximum possible values. To obtain a high recovery value of zinc and iron, analyzed by AAS, the optimum leaching condition was found to be the temperature of 90 °C, the sulfuric acid concentration of 3 M, the particle size of 75 µm, the S/L ratio of 1:10 g/mL and the leaching time of 2 h. The percentages of the zinc and iron recovery under the optimum condition were ca. 98.6% and 99.1% respectively, which were verified by a confirmation test and were very close to the predicted values of 100% based on the optimized model, obtained through the software. From the thermodynamics' point of view, it has been found that Zn2+ is the predominant species (90%) under the leaching condition applied. Moreover, the predominant species of iron are FeSO4+, FeHSO42+, Fe(SO4)2- and Fe3+ in the magnitudes of 65.8%, 25.6%, 4.4% and 4.0%, respectively. According to the kinetic results, the controlling step in the leaching was the chemical reaction at the most of the operating temperatures and times. In order to purify the zinc solution for electrowinning, iron and arsenic were removed through the jarosite formation process as confirmed by the XRD results. The speciation of arsenic in the precipitated jarosite was explored by XPS. Finally, the low concentrations of arsenic (less than 0.1 ppm) and iron (less than 50 ppm) were determined by the ICP analysis.

Utilizing a nanocomposite consisting of zinc ferrite, copper oxide, and gold nanoparticles in the fabrication of a metformin electrochemical sensor supported on a glassy carbon electrode.

The conception and development of a new electrochemical sensor is reported for the detection of metformin (MET). Zinc ferrite and copper oxide nanostructure (ZnFe2O4-CuO) and gold nanoparticles (AuNPs) have been used to prepare a nanocomposite in modifying a glassy carbon electrode (GCE). The unique ZnFe2O4-CuO/Au nanocomposite was applied as a sensor for the determination of traces of MET by some electroanalytical techniques. Experimental parameters affecting the results were investigated and optimized. Under the optimum conditions and at a working potential of 0.85 V (vs. Ag/AgCl/3.0 M KCl), the sensor response is linear in the MET range of 1.0 nmol L-1 to 1.0 µmol L-1 MET. The limit of detection (LOD) is 0.3 nmol L-1 (at an S/N ratio of 3) and the sensitivity is 1.13 µA µmol L-1 cm-2. The sensor was applied to the determination of MET in real samples where it gave acceptable results. Graphical abstract.

Selective Recovery of Zinc from Metallurgical Waste Materials from Processing Zinc and Lead Ores.

A method for processing of metallurgical waste materials (chemically defined as sulfur-bearing zinc-ferric materials) produced by plants processing zinc ores and their concentrates is proposed. The method proposed is a combination of pyro- and hydrometallurgical treatments of the waste material. The crucial steps in the developed method include: roasting the material at 450 °C to generate sulfur dioxide (SO2), absorption of SO2 in an aqueous system to form sulfuric acid (IV), carbothermic decomposition of zinc ferrite compounds, and leaching of zinc from the roasted material using sulfuric (IV) acid. The method allows one to extract up to 40% of zinc from the waste material and, consequently, to generate a fraction of material with substantially higher content of iron oxides. The proposed method takes advantage of the presence of sulfur in the processed material which upon roasting is converted to sulfuric acid (IV)-a leaching agent for selective extraction of zinc. The properly adjusted pH of the aqueous medium in which the leaching process is carried out is the key factor determining the quantitative and selective separation of zinc. If the amount of sulfur in the processed material is insufficient, it may be supplemented by adding sulfuric acid (VI) to adjust the pH. The method proposed was tested at a laboratory scale and quarter industrial scale using the real samples taken from stockpiles in the vicinity of the plant processing zinc and lead ores in Poland. It may also work for any zinc-ferric materials from various sources.

Enhanced adsorption of arsenate by spinel zinc ferrite nano particles: Effect of zinc content and site occupation.

In this work, zinc ferrite spinel with different zinc contents (ZnxFe3-xO4) was synthesized by a hydrothermal method and used for removing As(V) in aqueous solution. X-ray diffraction (XRD) results indicated that in the crystal structure of ZnxFe3-xO4, the zinc atoms tended to occupy the octahedral sites for x < 0.6 and diffused into the tetrahedral sites gradually with x > 0.6. The size of ZnxFe3-xO4 crystallites increased with the increasing zinc content. Batch adsorption experiments showed that the adsorption isotherms could be well described by the Langmuir model, while the adsorption kinetics followed the pseudo-second-order kinetic model. Zinc ferrite exhibited the highest adsorption capacity towards As(V) when x = 0.6. Study of the mechanism indicated that doping with zinc increased the number of surface hydroxyl groups on ferrite spinel, and thus enhanced the adsorption capacity when x = 0.6. This work revealed the effects of doping site and content of metal atoms on the adsorption ability of ferrite spinel towards As(V).

Solvent-Mediated Preparation of Zinc Ferrite-Reduced Graphene Oxide Nanocomposites and Its Application in Removal of Methylene Blue.

Zinc ferrite-reduced graphene oxide composites, which could effectively remove the methylene blue from aqueous solution, were prepared via a facile solvothermal process. These as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, vibration sample magnetometer and UV-vis diffuse reflectance spectroscopy. Experimental results showed that solvents played an important role in the electron structure of the final samples. Moreover, they influenced the photocatalytic performance as well. Among all the samples prepared in different solvents, those composites prepared in N-N-dimethylformamide showed the greatest performance. They could effectively remove more than 90% of the methylene blue from the solution in about 180 min. The efficient removal of target dye turned out to be the result of the combination of physical adsorption and photocatalytic degradation under visible light irritation. These catalysts showed remarkable stability, which could be effectively reused for three times. In addition, all these samples showed a certain magnetic response, which was beneficial to recycle.

Electroplating sludge derived zinc-ferrite catalyst for the efficient photo-Fenton degradation of dye.

A zinc-dominant ferrite catalyst for efficient degradation of organic dye was prepared by the calcination of electroplating sludge (ES). Characterizations indicated that zinc ferrite (ZnFe2O4) coexisted with Fe2O3 structure was the predominant phase in the calcined electroplating sludge (CES). CES displayed a high decolorization ratio (88.3%) of methylene blue (MB) in the presence of H2O2 combined with UV irradiation. The high efficiency could be ascribed to the photocatalytic process induced by ZnFe2O4 and the photo-Fenton dye degradation by ferrous content, and a small amount of Al and Mg in the sludge might also contribute to the catalysis. Moreover, the degradation capability of dye by CES was supported by the synthetic ZnFe2O4 with different Zn to Fe molar ratio (n(Zn): n(Fe)), as 84.81%-86.83% of dye was removed with n(Zn): n(Fe) ranged from 1:0.5 to 1:3. All synthetic ferrite samples in the simulation achieved adjacent equilibrium decolorization ratio, the flexible proportioning of divalent metal ions (M2+) to trivalent metal ions (M3+) applied in the synthesis indicated that the catalyst has a high availability. Therefore, an efficacious catalyst for the degradation of dye can potentially be derived from heavy metal-containing ES, it's a novel approach for the reutilization of ES.

Polypyrrole-Coated Zinc Ferrite Hollow Spheres with Improved Cycling Stability for Lithium-Ion Batteries.

Here, ZnFe2 O4 double-shell hollow microspheres are designed to accommodate the large volume expansion during lithiation. A facile and efficient vapor-phase polymerization method has been developed to coat the ZnFe2 O4 hollow spheres with polypyrrole (PPY). The thin PPY coating improves not only the electronic conductivity but also the structural integrity, and thus the cycling stability of the ZnFe2 O4 hollow spheres. Our work sheds light on how to enhance the electrochemical performance of transition metal oxide-based anode materials by designing delicate nanostructures.

Synthesis and characterization of ZnFe2O4 nanoparticles and its biomedical applications.

Biomedical applications of ZnFe2O4 nanoparticle are preferable among all kinds of ferrites due to the compatibility of Zn2+ ions for human bodies. We have followed the soft chemical route to synthesize chitosan and PEG coated ZnFe2O4 nanoparticles and also the chitosan-coated-nanoparticles encapsulated with liposome. X-ray diffraction studies by the Mo Kα target, showed the formation of single phase spinel structure. The lattice parameter turned out to be 8.48Å and grain size ~ 4.8 nm (± 0.1 nm). Similar particle size was observed by transmission electron microscope analysis. HRTEM studies showed the distinct lattice fringes thus confirming the good crystallinity of the synthesized nanoparticles. M-H curve at room temperature showed the prepared sample was superparamagnetic in nature, which is also confirmed by the doublets of Mössbauer spectroscopy. Relaxivity values (r2) of Chitosan and PEG coated ZnFe2O4 nanoparticles are 68 and 76 mM-1s-1 respectively. In order to achieve further biocompatibility the chitosan-coated-nanoparticles were encapsulated with liposome. The r2 relaxivity was found as 54mM-1s-1. MR images obtained from the in vitro experiments based on phantoms demonstrated good contrast enhancement. Induction heating of bare and coated particles was investigated to reveal the self heating temperature rising properties of ZnFe2O4 nanoparticles.

Reduction behavior of zinc ferrite in EAF-dust recycling with CO gas as a reducing agent.

EAF-dust containing metal oxides can be regarded as an important source for zinc and iron. In this study, the reduction behavior of zinc ferrite with CO gas as a reducing agent under different temperatures was investigated to develop a new process for the recovery of zinc and iron from EAF-dust. The results of the phase studies with synthetic franklinite show that zinc substituted wustite, and spinel with low zinc content formed at lower temperatures from 450 to 850 °C due to incomplete zinc-iron-separation. Zinc ferrite was completely reduced to metallic zinc and iron at 950 °C. After evaporation and condensation, metallic zinc was collected in the form of zinc powder while iron, the reduction residue, was obtained in the form of direct reduced iron (DRI). The mass balance indicates a high zinc recovery ratio of over 99%. The new treatment process by thermal reduction with CO gas as a reducing agent achieved higher recovery and metallization grade of both zinc and iron from EAF-dust at lower temperatures than other commercial processes. The metallic products can be used directly as semi-products or as raw materials for refinery.