Zirconium Concentrations Research Articles

Chemical and Physical Characterization of Three Oxidic Lithological Materials for Water Treatment

Water treatment necessitates the sustainable use of natural resources. This paper focuses on the characterization of three oxidic lithological materials (OLMs) with the aim of utilizing them to prepare calcined adsorbent substrates for ionic adsorption. The three materials have pH levels of 7.66, 4.63, and 6.57, respectively, and organic matter contents less than 0.5%. All of the materials are sandy loam or loamy sand. Their electric conductivities (0.18, 0.07, and 0.23 dS/m) show low levels of salinity and solubility. Their CEC (13.40, 13.77, and 6.76 cmol(+)kg) values are low, similar to those of amphoteric oxides and kaolin clays. Their aluminum contents range from 7% up to 12%, their iron contents range from 3% up to 7%, their titanium contents range from 0.3% to 0.63%, and their manganese contents range from 0.007% up to 0.033%. The amphoteric oxides of these metals are responsible for their ionic adsorption reactions due to their variable charge surfaces. Their zirconium concentrations range from 100 to 600 mg/g, giving these materials the refractory properties necessary for the preparation of calcined adsorbent substrates. Our XRD analysis shows they share a common mineralogical composition, with quartz as the principal component, as well as albite, which leads to their thermal properties and mechanical resistance against abrasion. The TDA and IR spectra show the presence of kaolinite, which is lost during thermal treatments. The results show that the OLMs might have potential as raw materials to prepare calcined adsorbent substrates for further applications and as granular media in the sustainable treatment of both natural water and wastewater.

Surface Morphology of Various Matrixes with Zirconium Oxide Coatings Synthetized by Alternating Pulsing of Zirconium(IV) <i>tert</i>-Butoxide and Water Vapors Treatment of the Surface

Zirconium oxide coatings of various thicknesses were synthesized on the surface of plates of monocrystalline silicon and borosilicate glass by alternating pulsing of zirconium(IV) tert-butoxide and water vapors treatment. The effect of the matrix type and the coating thickness on surface morphology of the samples was investigated using atomic force microscopy. The concentrations of zirconium in the synthesis products were determined by X-ray spectral microanalysis and the growth constant of the zirconium oxide film on silicon was evaluated. Assumptions are made about the influence of the type of the matrix on the structure of the surface of the zirconium oxide layer.

Cassiterite trace element discrimination diagrams to facilitate critical mineral exploration

Cassiterite is a weathering-resistant mineral, which can incorporate a variety of trace elements. Trace elements in cassiterite samples collected from twelve deposits in the Herberton Mineral Field, Australia, were measured with the use of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The results were combined with published data from other tin fields, including the Andean Sn belt in South America; the Karagwe Ankole belt in Rwanda; and, from China, the Kangxiwa-Dahongliutan pegmatite field, the Youjiang basin, the Nanling belt and the Da Hinggan Range belt. Tin deposits in the dataset can be subdivided into four deposit types: 1) greisen and veins; 2) skarns; 3) Li-Cs-Ta pegmatites; and 4) polymetallic veins. The cassiterite dataset was analyzed using basic descriptive statistics, principal component analysis (PCA), and cluster analysis. Cassiterite grains from greisen and vein deposits are characterized by high concentrations of Ti (avg. 1751 ppm) and moderate concentrations of Al (avg. 97 ppm), whereas cassiterite grains from skarn deposits generally contain lower concentrations of Ti and Al. Chemical compositional boundaries in cassiterite from different deposits were recognized with cluster analysis. The relative enrichment of Al and Ti in cassiterite grains from greisen and vein deposits is likely due to greisenization reactions. The Ti vs. Al diagram can be used to differentiate between cassiterite grains derived from greisen and vein deposits, as compared to cassiterite grains derived from skarn deposits, whereas Sb vs. V diagram can be used to differentiate between cassiterite grains from polymetallic vein deposits. Zirconium and Nb concentrations are useful in identifying cassiterite grains sourced from LCT pegmatite deposits. The discrimination diagrams developed in this study through cluster analysis indicate that cassiterite grains sourced from different deposit types can be differentiated based on their trace element geochemistry and this can be a useful tool in critical mineral exploration. Therefore, these diagrams can be used effectively to understand metal association and deposit types in a region with detrital cassiterite from stream sediments, till and heavy mineral placer deposits.

Experimental and computational approach of zirconium and chitosan doped NiCo2O4 nanorods served as dye degrader and bactericidal action

Different concentrations of zirconium with a fixed quantity (4 wt%) of chitosan (CS) doped nickel cobaltite (NiCo2O4) nanorods were synthesized using a co-precipitation approach. This cutting-edge research explores the cooperative effect of Zr-doped CS-NiCo2O4 to degrade the Eriochrome black T (EBT) and investigates potent antibacterial activity against Staphylococcus aureus (S. aureus). Advanced characterization techniques were conducted to analyze structural textures, morphological analysis, and optical characteristics of synthesized materials. XRD pattern unveiled the spinal cubic structure of NiCo2O4, incorporating Zr and CS peak shifted to a lower 2θ value. UV–Vis spectroscopy revealed the absorption range increased with CS and the same trend was observed upon Zr, showing a decrease in bandgap energy (Eg) from 2.55 to 2.4 eV. The optimal photocatalytic efficacy of doped NiCo2O4 within the basic medium was around 96.26 %, and bactericidal efficacy was examined against S. aureus, revealing a remarkable inhibition zone (5.95 mm).

Tattoo Pigment Biokinetics in vivo in a 28-Day Porcine Model: Elements Undergo Fast Distribution to Lymph Nodes and Reach Steady State after 7 Days

Introduction: Pigments of tattoo inks may over time migrate to other parts of the body. Inks kinetics are still poorly understood and little studied. The aim of this first study was to investigate the kinetics of tattoo inks pigment in tattooed porcine skin, which is closer to human skin than mouse skin studied in the past. Methods: Three animals were tattooed on the inner thigh and one animal served as untreated control. Skin biopsies were taken on days 7, 14, and 28 after tattooing. Animals were sacrificed on day 28 and homogenate samples of the liver, spleen, kidney, and brain, as well the local lymph nodes were prepared. All samples were analyzed for ink components using inductively coupled plasma-mass spectrometry. The ink itself was characterized by dynamic light scattering and matrix-assisted laser desorption-ionization mass analysis. Results: Titanium (212 g/kg), copper (6 g/kg), aluminum (1 mg/kg), zirconium (1 mg/kg), and chromium (3 mg/kg) were found in the ink. Significant deposits of ink elements were detected in the tattooed skin when compared to non-tattooed skin from the same animal (mean ± standard deviation: titanium 240 ± 81 mg/kg, copper 95 ± 39 mg/kg, aluminum 115 ± 63 mg/kg, zirconium 23 ± 12 mg/kg, and chromium 1.0 ± 0.2 mg/kg; p < 0.05). Lymph node concentrations of titanium, copper, aluminum, zirconium, and chromium were 42 ± 2 mg/kg, 69 ± 25 mg/kg, 49 ± 18 mg/kg, 0.3 ± 0.2 mg/kg, 0.5 ± 0.2 mg/kg, respectively. Conclusion: Deposits in skin were unchanged from days 7–28 indicating no redistribution or elimination. No significant deposits of ink elements were found in the liver, spleen, kidney, and brain. In conclusion, our findings confirmed distribution of elements from tattoos to regional lymph nodes, but neither to excretory organs, e.g., liver and kidney, nor to spleen and brain. Thus systemic internal organ exposure was not found.

Effect of cooling rate during solidification on structure and mechanical properties of Cu45Zr48Al7 glass-forming alloy

The CuZr-based bulk metallic glass matrix composites have attracted great attention in recent years owing to their unique mechanical properties compared to bulk glassy samples. The vital effect of B2 CuZr phase on mechanical properties was previously confirmed in CuZr-based alloys with equiatomic concentrations of copper and zirconium. In this paper, the structures and mechanical properties of the Cu45Zr48Al7 alloy, which has hypereutectoid composition with respect to stoichiometric B2 CuZr phase, were studied. This alloy exhibits high glass-forming ability, but low tendency to form the B2 CuZr phase during solidification. However, we demonstrated that depending on the cooling rate during solidification, governed by sample diameter, either bulk metallic glass or bulk metallic glass matrix composite can be produced. In order to allow partial crystallization of the B2 phase during solidification with the volume fraction allowing to observe the strain hardening effect, the minimum cooling rate should be lower than 40 K/s. The composite consisting of a glassy outer layer and a crystalline core composed of the B2 phase exhibits fracture strength of the same level as the bulk glassy sample (above 1800 MPa) obvious work-hardening with a plastic deformation of about 6%.

Spectral sensor fusion for prediction of Li and Zr in rocks: Neural network and PLS methods

Integrating information from multiple sensors, known as sensor fusion, is particularly challenging for small datasets where selecting from the plethora of available methods poses a significant challenge in chemometric analysis. This study compares several sensor fusion methods (spanning data-level, feature-level, and decision-level fusion) based on partial least squares (PLS) and convolutional neural network (CNN) models. This study is the first to compare simple sensor fusion methods to the latest multiblock PLS models and parallel-input CNNs, to the best of our knowledge. We demonstrate sensor fusion using a small dataset of 177 rock samples on two prediction tasks: predicting lithium (Li) concentrations and zirconium (Zr) concentrations using three types of spectra, namely X-ray fluorescence (XRF), visible to short-wave infrared (Vis-NIR-SWIR), and laser-induced breakdown spectroscopy (LIBS). The best-performing Li model was PLS using XRF (mean RMSEP: 0.078%) and the best sensor fusion model was ROSA (mean RMSEP: 0.087%). The best Zr model was a high-level fusion of PLS models (mean RMSEP: 0.042%).

A rutile and titanite record of subduction fluids: Integrated oxygen isotope and trace element analyses in Franciscan high‐pressure rocks

AbstractIn situ oxygen analysis of garnet in eclogite and related rocks is increasingly being used to probe the composition of subduction fluids. However, in many cases, these samples contain textural signs of both fluid flow and retrograde metamorphism, some of which may take place outside the garnet stability field. In order to test the connection between polymetamorphism and fluid infiltration, rutile rimmed by titanite from high‐grade tectonic blocks of the Franciscan Formation (California, USA) was analysed for oxygen isotope ratios and trace element concentrations. Zirconium concentrations in rutile yield temperatures of ~600°C for eclogite and hornblende eclogite from three well‐studied localities (Junction School, Tiburon and Ward Creek). Rutile trace element concentrations are generally low and consistent with a mafic protolith. Titanite surrounding rutile has inherited much of its trace element content from rutile, and Zr‐in‐titanite temperatures are spuriously high. Titanite in rutile‐free samples (blueschist and eclogite from Jenner beach) have similar compositions suggesting that they were formed at the expense of rutile as well. Oxygen isotope ratios from rutile and titanite in the same sample are fortuitously similar, indicating disequilibrium between these minerals, which formed at different times and temperatures but in equilibrium with the same oxygen reservoir. Rutile in blocks with garnets zoned in oxygen isotopes are generally in equilibrium with the rims rather than the cores. Slow oxygen diffusion in rutile and the low temperatures of formation require that rutile recrystallized after fluid interaction and before blueschist facies metamorphism. External fluid interaction of Franciscan eclogites took place near the peak of metamorphism.

Tailoring the Structural, Optical and Electrical Properties of Zinc Oxide Nanostructures by Zirconium Doping

Owing to its low resistivity, high transmittance, and tunable optical band gap, ZnO is of great interest for optoelectronic applications. Herein, the sol–gel technique was used to synthesize un-doped and zirconium-doped zinc oxide (ZZO) nanostructures with different concentrations of Zirconium (Zr). X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, and photoluminescence (PL) measurements were used to investigate the influence of Zr doping on the structural, optical, and electrical properties of developed nanostructures. XRD and SEM confirmed the increase in crystallite size with increasing concentrations of Zr. Raman analysis indicated the presence of oxygen vacancies in synthesized nanostructures. UV-Vis spectroscopy illustrated the blue shift of band gap and red shift of the absorption edge for ZZO nanostructures with increasing concentrations of Zr. For the measurement of electrical properties, the spin-coating technique was used to deposit un-doped and Zr-doped ZnO layers of ~165 nm thickness. The four-probe-point (4PP) method illustrated that the doping of Zr caused a reduction in electrical resistance. Hall Effect measurements showed a high value, 3.78 × 1020 cm−3, of the carrier concentration and a low value, 10.2 cm2/Vs, of the carrier mobility for the Zr-doped layer. The high optical transmittance of ~80%, wide band gap of 3.51 eV, low electrical resistivity of 1.35 × 10−3 Ω·cm, and maximum carrier concentration of 3.78 × 1020 cm−3 make ZZO nanostructures one of the most promising candidates for the application of transparent conductive oxide (TCO) in optoelectronic devices.

Ruthenium-Zirconium Oxides As Highly Stable Oxygen Evolution Electrocatalysts

The further development and utilization of proton exchange membrane water electrolyzers (PEMWEs) is hindered by the cost, activity, and stability of the oxygen evolution reaction (OER) electrocatalyst. Iridium oxide (IrOx) is currently the go-to OER electrocatalyst, as it has been shown to have relative high activity and stability when compared to other OER active catalysts. However, iridium is one of the rarest elements in the Earth’s crust and therefore cost is a major limitation of iridium-based electrocatalysts. Ruthenium oxide (RuO2) is a highly active OER catalyst; although, it is highly unstable in acidic media and undergoes catalyst degradation over time. We investigated modifying RuO2 by substituting zirconium, which is highly stable in acidic conditions, to provide an electrocatalyst with increased stability. Our study explored the effect of low and moderate zirconium concentrations within RuO2 (Ru1-xZrxO2) on the structure, morphology, OER activity, and stability. The structure and morphology were characterized by X-ray diffraction and scanning electron microscopy. Preliminary results from XRD showed no observable phase separation at low Zr concentrations, and peak shifts were indicative of the incorporation of the larger Zr ion into the crystal structure of rutile RuO2. The OER activities and stabilities of Ru1-xZrxO2 were measured using a rotating disk electrode configuration and compared with RuO2. Our preliminary results show that the OER activity and stability are strongly affected by the addition of Zr and there may be an optimal concentration range for obtaining a balance between OER activity and stability. Our work furthers the understanding of how to develop OER electrocatalysts with increased stability while maintaining a high OER activity, which is crucial to the large-scale adoption of PEMWE’s.

Anomalous Behavior of Zirconium and Hafnium in Volcanic Fumarolic Fluids

AbstractThe Zirconium and Hafnium concentrations in worldwide fumaroles fed by magmatic fluids reveal that the Zr/Hf ratio is inversely related to the temperature of emission. Lower Zr/Hf ratio values below the chondritic signature are found in fluids having the highest temperature while super‐chondritic Zr/Hf ratio values are found in lower temperatures. Sub‐chondritic values of the Zr/Hf ratio may be related to larger volatility of Hf‐chloride gas species with respect to Zr‐Cl gas species, while super‐chondritic ratios may correspond to fluid‐rock processes resulting from cooling of uprising magmatic fluids. We propose that sub‐chondritic Zr/Hf ratio values in fumaroles associated with high temperature may be an appropriate marker of fast magmatic rising representing a new sensitive tool for volcanic risks strategies.

Structural, morphological, optical properties of Zr- doped Co3O4 nanoparticles

Cobalt oxide nanoparticles are of great interest in recent years due to their potential applications. As very less work on synthesizing nanoparticles by microwave-assisted method, an attempt is made to synthesize cobalt oxide nanoparticles with zirconium doped at various weight % by the microwave-assisted method. The effect of doping on the Physico-chemical properties is reported. The result of P-XRD confirms the crystalline nature and the calculated average crystallite sizes were 12.29 nm, 11.95 nm, 11.06 nm, and 7.65 nm for 5, 10, 15, and 20 wt% of Zr doped Co3O4 nanoparticles respectively. The decrease in crystallite size is due to the occupation of the zirconium atoms at the vacant sites. The functional groups were identified by the FTIR spectrum. The UV-DRS spectra show the good optical transmission property of the samples and also indicate the decrease in bandgap with an increase in the concentrations of zirconium. The SEM pictures depict the morphological changes due to the agglomeration of zirconium particles. The SAED pattern in TEM images confirms the occupation of zirconium in cobalt oxide. The result of antibacterial activities indicates that the 20 wt% zirconium doped cobalt oxide nanoparticles display better activity.

UiO-66-NH-(AO) MOFs with a New Ligand BDC-NH-(CN) for Efficient Extraction of Uranium from Seawater.

Metal-organic frameworks (MOFs) with a high surface area and excellent stability are potential candidates for uranium (U) adsorption. Amidoxime (AO) is the most widely used functional group to extract U, which is usually introduced into MOFs by two-step post-synthetic methods (PSMs). Herein, MOF UiO-66-NH-(AO) was obtained by a one-step PSM with amidoximation from UiO-66-NH-(CN), which was synthesized by a new organic ligand of 2-cyano-terephthalic acid and whose morphology was octahedron and could be well controlled with the new ligand. The one-step PSM can greatly maintain the octahedron of the MOFs. What is more, UiO-66-NH-(AO) showed good adsorption performance for U, the adsorption equilibrium was obtained within 1500 min, and the adsorption capacity of U was calculated to be 134.1 mg/g according to the Langmuir model. It also had excellent selectivity for U in the presence of high concentrations of vanadium (V), ferrum (Fe), magnesium (Mg), calcium (Ca), and zirconium (Zr). The adsorption capacity of U in natural seawater was determined to be 5.2 mg/g within 8 days. The recyclability of UiO-66-NH-(AO) in simulated seawater was demonstrated for at least four adsorption/desorption cycles. The binding mechanism was investigated by the extended X-ray absorption fine structure spectroscopy, revealing that U binding occurs in a fashion η2 motif. This study provides a reliable idea for the modification of MOFs and the potential for MOF-based materials to extract U from seawater.

The structure, segregation and microhardness of the structural components of the Al – Ni – Zr alloys synthesized from nickel oxide NiO and brazilite concentrate by means of SHS metallurgy

Intermetallide Al &ndash; Ni alloys can potentially be used to create materials with unique properties. Alloying with refractory transition metals plays an important role in building a strong combination of physico-mechanical and performance properties in alloys. Such alloys serve as an innovative material in various fields of technology. Aluminothermic reduction of oxides of various metals (including mineral concentrates such as scheelite, brazilite and other concentrates) and the use of SHS metallurgy help obtain complex alloyed aluminides of nickel. Thus, the production process becomes much simpler and the cost of producing new high-temperature materials decreases. The authors applied the technique of ladle aluminothermic reduction to nickel oxide NiO and brazilite concentrate to obtain zirconium alloys with the following concentrations of zirconium: 0.47, 1.05, 1.67 and 3.52 wt %. Optical and scanning electron microscopes were used to study the microstructure of the alloys. It was found that the addition of 0.47 wt % Zr leads to a dramatic refining of the structural components of nickel aluminides Al3Ni2 and Al3Ni. Nickel aluminide AlNi is quite rare to be found. A further increase in the addition of zirconium to 3.52 wt % resulted in slightly coarser structural components of the Al &ndash; Ni &ndash; Zr alloys. With the help of scanning electron microscopy and electron probe microanalysis, a multiphase structure was established and the structural components of the Al &ndash; Ni &ndash; Zr alloys were identified. It was established how the distribution of elements (segregation processes) and the microhardness of the structural components tend to change in the Al &ndash; Ni &ndash; Zr alloys.1. Apart from nickel aluminide AlNi, which solidifies primarily as small compact inclusions, Al3Ni2 and Al3Ni form in the initial Al &ndash; Ni alloy. The crystals of Al3Ni envelope the grains of Al3Ni2.2. The conducted research helped establish how elements tend to distribute in the structural components, and the structural components were identified &ndash; nickel aluminides AlNi, Al3Ni2 and Al3Ni with strengthening phases &ndash; alloyed with nickel aluminides with Zr, Si and others, as well as with aluminium zirconides.3. A relationship was established between the changing microhardness and the distribution of elements in the structural components of the Al &ndash; Ni &ndash; Zr alloys.This research was funded by the Ministry of Education and Science of the Russian Federation under the Governmental Assignment No. FEME-2020-0010 &ldquo;Physico-chemical and process basis of metallothermic synthesis of metals in ion melts of alkaline metals and complex alloyed nickel aluminides by SHS metallurgy&rdquo;. The research was carried out as part of research and development covered by the Scholarship of the President of the Russian Federation: SP-1904.2019.1 (2019&ndash;2021) using the equipment of the Shared Knowledge Centre &ldquo;Applied Materials Science&rdquo;, a part of the Pacific National University.

Effect of hydrothermal aging on dental multilayered zirconia for monolithic restorations: An in vitro study

The aim of this in vitro study was to investigate the changes in mechanical, optical, and surface properties of multilayered zirconia during hydrothermal aging.One conventional block (Katana Zirconia HT) and three multilayered blocks (Katana Zirconia ML, STML, and UTML) of monolithic zirconia were examined. Bar-shaped specimens were autoclaved at 134°C and 0.2MPa for 0, 5, and 10 h. The Young's modulus, three-point flexural strength, and nanoindentation hardness were measured to evaluate the mechanical properties. The surface roughness, phase distribution, surface microstructure, and elemental composition were measured to analyze the surface properties. The contrast ratio and total transmittance were measured via spectrophotometry to evaluate the optical properties. Statistical differences were analyzed using appropriate ANOVA, Tukey HSD post hoc tests, and independent and paired sample t-tests (α = .05).The monoclinic phase increased gradually after hydrothermal aging. The yttrium and zirconium concentrations decreased, and the oxygen concentration and the surface roughness increased in all specimens (P<.05) after the aging process. All specimens showed significant grain push-out and microcracks. The total transmittance increased, and the contrast ratio and Young's modulus decreased in all specimens (P<.05) after the aging process. The nanoindentation hardness and three-point flexural strength exhibited a decreasing tendency after the aging process. However, there were no statistical differences (P>.05) between the materials. Significant interactions between material grades and hydrothermal aging were found for all the properties studied (P<.001).Microstructural alterations and significant phase transformations were detected on the surface of the multilayered zirconia after hydrothermal aging. The hydrothermal aging led to increased surface roughness, opaqueness, and elasticity of multilayered zirconia. The optical, mechanical, and surface properties of multilayered zirconia were influenced by the grade of the material after hydrothermal aging. Careful consideration of the grade of materials is necessary for the appropriate selection of multilayered zirconia ceramics for monolithic restorations.

In-situ phenylhydrazine chemical detection based on facile Zr-doped MoS2 nanocomposites (NCs) for environmental safety

ABSTRACT Various concentrations (2.5, 5, 7.5, 10 wt%) of zirconium were doped onto MoS2 using hydrothermal method. X-ray diffraction affirmed existence of hexagonal phase and increased crystallite size upon doping. Synthesized nanosheets appeared agglomerated after doping. Raman analysis provided evidence about defect density, layered structure of S-Mo-S planes as well as electronic band configuration of Zr-doped MoS2. Furthermore, Zr-doped MoS2 nanosheets were applied on a glassy carbon electrode as a layer of sensor film using nafion adhesive to fabricate the working electrode of the proposed phenylhydrazine (PHyd) electrochemical sensor probe. A calibration curve based on concentration of PHyd versus current plot was recorded to be linear over the full concentration range of 0.1 nM to 1.0 mM. The concentration linear range (0.1 nM–0.1 mM) was denoted as the large dynamic range (LDR) for PHyd detection based on the measurement of calibration plot. The slope of LDR with active surface area (0.0316 cm2) of GCE was used to determine analytical parameters of the sensor such as sensitivity (13.4652 µA µM−1 cm−2), linearity, and detection limit (91.54 ± 4.58 pM). Besides these, the PHyd sensor performance was investigated in terms of reproducibility, long-term stability, response time, and validity with regard to its capability for effective analysis of real environmental samples in this field. All parameters exhibited satisfactory and acceptable results.

Evaluation of microstructure and mechanical properties of PMMA Matrix composites reinforced with residual YSZ from CAD/CAM Milling process

Background: Reinforcement of dental acrylics with fillers has yielded positive results. Different proportions of fillers have been added to strengthen the dental acrylics, but no consensus has been reached. Aim: The purpose of this study was to investigate the effects of the addition of different concentrations of yttria-stabilized zirconium (YSZ) obtained from the residues generated from the CAD-CAM milling of YSZ on the microstructure and mechanical properties of poly-methyl-methacrylate (PMMA)-YSZ composites. Materials and methods: Composite materials with different amounts (0.0 to 70.0% by weight) of recycled YSZ reinforced PMMA resin matrix were produced. Scanning electron microscope (SEM), energy dispersive electron spectrometer (EDS) and Fourier Transform Infrared Spectrometer (FTIR) were used for microstructural analysis. Among the mechanical properties, the Vickers microhardness test method for hardness, 2D profilometer for surface roughness and composite densities were evaluated by Archimedes method. Data were analyzed using a one-way analysis of variance (ANOVA) at a pre-set alpha of 0.05. Results: Microhardness and density increased until 60% by weight YSZ addition, while surface roughness remained unchanged but increased after 60% by weight YSZ addition. The addition of more than 60% by weight of YSZ caused agglomeration in the microstructures. The mechanical properties of poly-methyl-methacrylate decreased with more than 60% YSZ by weight. Conclusion: Reinforcement of PMMA with residue zirconia powder will increase the usage chance of residue YSZ powder and provide a safer use of PMMA.

Bactericidal behavior of chemically exfoliated boron nitride nanosheets doped with zirconium.

In this work, boron nitride nanosheets (BNNS) were produced through chemical exfoliation of bulk boron nitride (BN). Furthermore, hydrothermal technique was used to incorporate various concentrations (2.5, 5, 7.5, and 10 wt%) of zirconium (Zr) as a dopant. The prepared undoped and doped BN samples were evaluated for its antimicrobial activity against E. coli and S. aureus. Structural analysis was undertaken using x-ray diffraction which identified the presence of hexagonal BN. FTIR and Raman spectroscopy were utilized to outline IR fingerprint and electronic properties of the synthesized material. Morphological information was obtained through micrographs extracted using field emission scanning electron spectroscope (FESEM) and high resolution transmission electron microscope (HRTEM), while d-spacing was also calculated through HRTEM analysis. Optical properties and emission spectra were examined by applying UV–vis and photoluminescence spectroscope (PL); whereas, band gap analysis was carried out via Tauc plot. Zr-doped BN nanosheets at increasing concentrations (0.5, 1.0 mg/50 μl) revealed enhanced antibacterial activity against E. coli compared to S. aureus (p < 0.05).

A thermodynamic model for reactive extraction of macro amounts of zirconium and hafnium with TBP

Pure component thermodynamic models are developed for solvent extraction involving ionic reaction equilibrium for distribution of macro concentrations of zirconium and hafnium between an aqueous phase containing HNO3 and an organic solvent phase containing diluted TBP. The concentration range considered is 10−03 to 100 M. A framework based on chemical speciation calculation is used for the purpose. Experimental procedures adopted to obtain the required solvent extraction data for modeling and validating these models are detailed. Measured equilibrium concentrations of total zirconium, total HNO3, total nitrate in the aqueous phase and total zirconium in the organic phase are used to obtain the thermodynamic parameters such as equilibrium constants and activity coefficient model parameters for zirconium and hafnium extraction systems.The novel framework is useful for computing equilibrium concentrations of all the species present in the respective systems. It is also demonstrated that the pure component models developed for extraction of zirconium and hafnium are effective over a wide range of concentrations. These pure component models can be used to simulate and optimize industrial scale zirconium – hafnium separation process.

Promising performance of chemically exfoliated Zr-doped MoS2 nanosheets for catalytic and antibacterial applications.

Nanostructured materials incorporated with biological reducing agents have shown significant potential for use in bactericidal applications. Such materials have also demonstrated considerable efficacy to counter effects of chemical toxicity. In this study, nanostructured molybdenum disulfide (MoS2) was doped with various concentrations (2.5, 5, 7.5, 10 wt%) of zirconium (Zr) using a hydrothermal route in order to assess its antimicrobial and catalytic potential. Doped and control samples were characterized with various techniques. X-ray diffraction (XRD) analysis confirmed the presence of the hexagonal phase of MoS2 and identification of various functional groups and characteristic peaks (Mo bonding) was carried out using FTIR spectra. Micrographs obtained from FESEM and HR-TEM showed a sheet-like surface morphology, while agglomeration of nanosheets was observed upon doping with nanoparticles. To seek further clarity regarding the layered features of S–Mo–S planes, the defect densities and electronic band structure of pure MoS2 and doped MoS2 samples were investigated through Raman analysis. Optical properties of Zr-doped MoS2 nanosheets were assessed using a UV-vis spectrophotometer and the results indicated a red-shift, i.e., movement of peaks towards longer wavelengths, of the material. Dynamics of migration and recombination of excited electron–hole pairs were investigated using PL spectroscopy, which was also used to confirm the presence of exfoliated nanosheets. In addition, the synthetic dye degradation potential of pure and doped samples was investigated in the presence of a reducing agent (NaBH4). It was noted that doped MoS2 showed superior catalytic activity compared to undoped MoS2. The nanocatalyst synthesized in this study exhibited enhanced antibacterial activity against E. coli and S. aureus at high concentrations (0.5, 1.0 mg/50 μl). The present study suggests a cost-effective and environmentally friendly material that can be used to remove toxins such as synthetic dyes and tannery pollutants from industrial wastewater.