Zirconium Nitrate Research Articles

Effect of Xerogel and Powder Synthesis Conditions on the Properties of Ceramics Based on t-ZrO2 in the ZrO2–СeO2–Al2O3 System

Xerogels and powders of a solid solution based on zirconium dioxide are synthesized by the method of coprecipitation of hydroxides from aqueous solutions of salts of zirconium nitrate ZrO(NO3)2⋅2H2O, aluminum Al(NO3)3⋅9H2O, and cerium Ce(NO3)3⋅9H2O with an aqueous 1 M solution of ammonia NH4OH. A dense ceramic with low porosity and water absorption is obtained. The effect of the ultrasonic treatment of the precipitate and mechanical treatment of the xerogel on the physicochemical properties of the obtained materials is evaluated.

A blue emission of zirconium (IV) complex based on 2, 6-pyridinedicarboxylic acid ligand: Syntheses, crystal structure, and luminescence sensing

A novel blue emission of zirconium complex, formulated as [Zr(pydc)3]·[(CH3)2NH2]2 (1), has been synthesized by using a mixture of zirconium nitrate and 2, 6-pyridinedicarboxylic acid (H2pydc). The complex 1 presents a three-dimensional supramolecular network structure due to the intermolecular NH···O, OH···O hydrogen bonds. Additionally, the crystals of 1 exhibit blue luminescence and demonstrate a highly selective and sensitive sensing capability for detection of Co2+ ions with a Ksv value of 1.22 × 104 M−1 and limit of detection (LOD) of 1.20 × 10−5 M. Furthermore, the fluorescence lifetime and quantum yield of the complex 1 is τ = 6.22 μs and Φ = 25.9 %.

Preparation and study of the structural and optical traits of Ag: Zro2 nanostructure thin films prepared via spin coating: Effect of spin speed on thin films properties

Thin films of silver: zirconium oxide (Ag: ZrO2), prepared using the spin coating method (SCM) with 2% silver nitrate (Ag NO3) and 1% zirconium nitrate (Zr (NO3) 4) on glass substrate at room temperature, with different spin speeds (1000, 2000 and 3000) rpm. X-ray diffraction (XRD) and Field Emission scanning electron microscopy were used to investigate the structural properties of the grown silver films. The optical properties of these thin films were distinguished by UV-vis spectroscopy. The films' polycrystalline nanostructure was revealed by X-rays, and the grain size shrank with increasing spin speed (from 1000 to 3000 rpm). The scanning electron microscope showed that the average particle size also decreases from (80.7 - 42.67) nm with an increase in the spin speed from (1000 - 3000). and Uv-vis spectroscopy showed that the transparency of the films increases, while the absorbance, coefficient attenuation, and absorption coefficient of the films decrease when the spin speed increases

Selective extraction of zirconium from zirconium nitrate solution in a pulsed stirred column

ABSTRACT Zirconium is an important structural and cladding material in nuclear industry. Zr and Hf coexist in nature, their separation is important for use in nuclear reactors. An in-house synthesized Alkyl Phosphine Oxide (APO) ligand has been identified which provides better separation factor and extraction compared to Tributyl Phosphate (TBP) at lower feed acidity. There is high amount of silica in zirconium nitrate solution which results in formation of emulsion in mixer-settler. A novel differential contactor, pulsed stirred column (PSC), is explored to prevent emulsion formation during selective extraction of Zr from nitrate medium. Experimental studies on extraction of Zr using APO based organic phase are carried out in the PSC having 20 mm inner diameter (ID) and 1 m active section height. Aqueous phase is zirconium nitrate solution containing 75 g/L Zr in nitrate medium. The effects of stirring speed and residence time on percentage extraction are investigated. 99.99% pure Zr is obtained from zirconium nitrate solution without any emulsion formation. At optimized operating conditions (aqueous phase flowrate 10 ml/min, organic phase flowrate 45 ml/min, pulsing velocity 1.25 cm/s, rotational speed 1000 rpm), extraction of Zr is found to be 54%. 100% stripping of loaded organic using 0.5 M oxalic acid as strippant is also achieved in the PSC.

Effects of pH and calcination temperature on gel-combustion synthesizability of BaZr0.8Y0.2O3 perovskite

Solid oxide fuel cells with their advantages such as high efficiency are now considered as efficient power generation equipment. Because of its proton conductivity, perovskite is used in ceramic fuel cell electrolyte, and the addition of dopant can improve its proton conductivity. In this research, BaZr0.8-xSrxY0.2O3 (x=0, 0.05, 0.1, and 0.15) perovskites were synthesized by gel-combustion method. Barium nitrate, zirconium nitrate, yttrium nitrate and strontium nitrate were used as raw materials. Based on DTA and TGA analyses, the required temperature for calcination was determined to be around 1000 °C. XRD and FTIR analyses were used to identify the phases. The synthesis was carried out under different conditions and the effects of pH and dopant percentage on the morphology and size of the particles were investigated by FESEM. The sintering process was completed at different temperatures and a relative density of 94% was obtained at 1470 °C.

Hierarchical Aggregation in a Complex Fluid─The Role of Isomeric Interconversion.

There is an ever-increasing body of evidence that metallic complexes involving amphiliphic ligands do not form normal solutions in organic solvents. Instead, they form complex fluids with intricate structures. For example, the metallic complexes may aggregate into clusters, and these clusters themselves may aggregate into superclusters. To gain a deeper insight into the mechanisms at play, we have used an improved force field to conduct extensive molecular dynamics simulations of a system composed of zirconium nitrate, water, nitric acid, tri-n-butyl phosphate, and n-octane. The important new finding is that a dynamic equilibrium between the cis and trans isomers of the metal complex is likely to play a key role in the aggregation behavior. The isolated cis and trans isomers have similar energies, but simulation indicates that the clusters consist predominantly of cis isomers. With increasing metal concentration, we hypothesize that more clustering occurs and the chemical equilibrium shifts toward the cis isomer. It is possible that such isomeric effects play a role in the liquid-liquid extraction of other species and the inclusion of such effects in flow sheet modeling may lead to a better description of the process.

EBM Technique Study on Microstructural Characterization of Al-Zr-N Coating

Through the implementation of the electron beam physical vapour deposition (EB-PVD) technique, an aluminium zirconium nitrate (Al-Zr-N) coating has been created in the current work on high speed steel (E19) substrates. Through the use of X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), nano indentation, and scratch tests, the structural morphological and mechanical properties of the substrate are investigated. The cause of tension relaxation and vacancy concentration is explained by the fluorite phase's lattice constant decreasing with rising deposition temperature. As the temperature of the substrate rises, the coating's increased surface roughness is explained by an increase in crystallite size [1]. TBCs are frequently applied to metal substrates using the Atmospheric Plasma Spraying (APS) and Electron Beam Physical Vapour Deposition (EB-PVD) methods. For the next generation of turbine engines, the high costs and relatively high thermal conductivities of EB-PVD coatings, as well as the short thermal lifetime of APS coatings, are significant drawbacks. Suspension Plasma Spraying (SPS) was evaluated in this study to enhance the thermal properties of TBC. The SPS process enables the creation of columnar micro-structures that are easily adjustable in terms of thermal conductivity and columnar structure compaction.

Micro-nano secondary phase greatly increases the plasticity of titanium-zirconium-molybdenum alloy

Improving ductility without sacrificing strength remains challenging for brittle molybdenum and its alloys. Titanium‑zirconium‑molybdenum alloy with the micro-nano-scale secondary phases (MN-TZM) was prepared using titanium sulfate, zirconium nitrate, fructose, and molybdenum powder as raw materials. The elongation at failure of the MN-TZM alloy was increased by 2.3 times to 15.1% without sacrificing strength. The fracture of the MN-TZM alloy exhibited cleavage and ductile tearing characteristics. Transmission electron microscopy and electron backscatter diffraction results indicate that dislocations can slip along the (110) plane at different strains, bypassing or even passing through the micro-nano-scale secondary phase (MN-SP) in MN-TZM alloys. The stacking faults and dislocation junctions of the MN-TZM alloy substructure avoid stress concentration and enhance the deformation ability. This study provides theoretical guidance for the industrial production of high-performance secondary-phase dispersion-strengthened structural materials, linking process-structure-properties relationships.

Microwave-Assisted Synthesis of Ceria-Zirconia Nanoparticles: Characterization and their Antimicrobial Studies

Ceria-zirconia (CZAA) nanoparticles with varied molar ratio of 1:1, 0.8:0.2, 0.6:0.4, 0.4:0.6 and 0.2:0.8 labelled as CZAA-0, CZAA-1, CZAA-2, CZAA-3 and CZAA-4 were prepared using cerium nitrate, zirconium nitrate and ascorbic acid as promoter. The X-ray diffraction, scanning electron microscopy, ultraviolet-visible, Raman and Fourier transform infrared spectra were used to characterize the prepared nanoparticles. The prepared CZAA nanoparticles were tested for antibacterial activity against Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus and Enterococcus faecalis bacterial strains as well as Aspergillus niger, Penicillium and Candida albicans fungal strains using the well diffusion method. They were shown to be highly antimicrobial agents to all pathogenic strains tested.

Supercritical Hydrothermal Synthesis of Nano-Zirconia: Reaction Path and Crystallization Mechanisms of Different Precursors

Nano-zirconia exhibits excellent mechanical properties (fracture toughness, hardness and flexural strength), thermal performance (thermal conductivity), optical properties and biological properties for various ceramic-based applications. Supercritical hydrothermal synthesis technology is an advanced and environmental-friendly method for preparing nanoscale powders. In this paper, the formation and crystallization of nano-zirconia during supercritical hydrothermal synthesis were systematically investigated. Different precursors (zirconium nitrate, zirconium oxychloride, zirconium acetate) reacted in supercritical water and the quality of nano-zirconia in different systems were comprehensively evaluated using XRD, TEM, IR, BET analysis. Finally, the most suitable precursor type was identified and the reaction path as well as crystallization mechanisms of different precursors were revealed.

Formation mechanism of coronal composite secondary phase in titanium-zirconium-molybdenum alloy

The coronal composite secondary phase has a high mismatch tolerance with the molybdenum matrix. TiO 2 particles located within the coronal structure that provide a semi-coherent interface with a mismatch degree of 8.70%, and ZrO 2 particles located outside the coronal structure that provide an incoherent interface with a mismatch degree as high as 41.61%. The ZrO 2 particles of the coronal composite secondary phase are partially attached to the TiO 2 in a coronal structure, which endows the ZrO 2 with the molybdenum matrix's higher interfacial bonding force. Titanium sulfate and zirconium nitrate are realized the mixing of Ti/Zr, TiO 2 /ZrO 2 molecules at atomic levels. Compared with Ti, Zr is more easily combined with oxygen, which leads to Zr in Ti/Zr solid solution being attracted by oxygen at high temperature to form ZrO 2 . The small addition of zirconium element lacks nucleation particles to form of ZrO 2 , so ZrO 2 can only adhere to more TiO 2 particles and nucleate, forming the second phase of the coronal composite structure. This study can guide the design of high-performance secondary phase strengthening alloys. • The coronal composite secondary phase and the Mo matrix have a high tolerance of mismatch degree. • ZrO 2 particles are attached to TiO 2 , which endows ZrO 2 with a higher interfacial bonding force with Mo. • The secondary phase particles have a fine particle size, uniform distribution, and strong adhesion. • Mixing at the molecular or atomic level, Zr is oxyphilic, enabling the formation of the coronal composite secondary phase.

Hydrophobic Modification of ZrO2-SiO2 Xerogel and Its Adsorption Properties to Rhodamine B.

Zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) and tetraethyl orthosilicate (TEOS) are used as the zirconium source and silicon source, respectively, and methyltriethoxysilane (MTES) as the hydrophobic modifier; the hydrophilic and hydrophobic ZrO2-SiO2 xerogels were prepared successfully. The xerogels were characterized using Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and N2 adsorption–desorption measurement. The adsorption mechanism of hydrophobic ZrO2-SiO2 xerogels to RhB was described by the kinetic and adsorption isotherms. The results showed that the introduction of Si-CH3 groups can make the average pore size, BET surface area, and total pore volume of ZrO2-SiO2 xerogel increase. The hydrophobic ZrO2-SiO2 xerogel displays an adsorption capacity of 169.23 mg·g−1 for RhB dye at 25 °C and pH = 3. The adsorption process of hydrophobic ZrO2-SiO2 xerogel to RhB followed a pseudo–second-order kinetic model. Fitting results from the D–R model of adsorption indicate that the adsorption of RhB onto the hydrophobic ZrO2-SiO2 xerogels is mainly physical, accompanied by a spontaneous heat absorption process. The regeneration and recycling properties of hydrophobic xerogels were investigated, and their recoverability and reusability were demonstrated.

Fabrication of Highly Transparent Y2O3 Ceramics via Colloidal Processing Using ZrO2-Coated Y2O3 Nanoparticles

An easy approach is described for the preparation of ZrO2-coated Y2O3 nanopowder from a solution of zirconium nitrate with commercial Y2O3 nanopowder. The evolution process of the ZrO2 coating layer upon calcination, such as the phase and microstructure of the particles’ surface, was studied. Calcination of the powder at 700 °C resulted in ZrO2-coated Y2O3 nanopowder. The rheological properties of the suspensions of ZrO2-coated Y2O3 powders were studied. A well-dispersed suspension with a solid loading of 35.0 vol% using ZrO2-coated Y2O3 nanopowder was obtained. The consolidated green body obtained by the centrifugal casting method showed improved homogeneity with a relative density of 50.2%. Transparent ceramic with high transparency and an average grain size of 1.7 µm was obtained by presintering at 1500 °C for 16 h in air, followed by post-HIP at 1550 °C for 2 h under 200 MPa pressure. The in-line transmittance at the wavelength of 1100 nm (1.0 mm thick) reached 81.4%, close to the theoretical transmittance of Y2O3 crystal.

Zirconia-Doped Methylated Silica Membranes via Sol-Gel Process: Microstructure and Hydrogen Permselectivity

In order to obtain a steam-stable hydrogen permselectivity membrane, with tetraethylorthosilicate (TEOS) as the silicon source, zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) as the zirconium source, and methyltriethoxysilane (MTES) as the hydrophobic modifier, the methyl-modified ZrO2-SiO2 (ZrO2-MSiO2) membranes were prepared via the sol-gel method. The microstructure and gas permeance of the ZrO2-MSiO2 membranes were studied. The physical-chemical properties of the membranes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), and N2 adsorption–desorption analysis. The hydrogen permselectivity of ZrO2-MSiO2 membranes was evaluated with Zr content, temperature, pressure difference, drying control chemical additive (glycerol) content, and hydrothermal stability as the inferred factors. XRD and pore structure analysis revealed that, as nZr increased, the MSiO2 peak gradually shifted to a higher 2θ value, and the intensity gradually decreased. The study found that the permeation mechanism of H2 and other gases is mainly based on the activation–diffusion mechanism. The separation of H2 is facilitated by an increase in temperature. The ZrO2-MSiO2 membrane with nZr = 0.15 has a better pore structure and a suitable ratio of micropores to mesopores, which improved the gas permselectivities. At 200 °C, the H2 permeance of MSiO2 and ZrO2-MSiO2 membranes was 3.66 × 10−6 and 6.46 × 10−6 mol·m−2·s−1·Pa−1, respectively. Compared with the MSiO2 membrane, the H2/CO2 and H2/N2 permselectivities of the ZrO2-MSiO2 membrane were improved by 79.18% and 26.75%, respectively. The added amount of glycerol as the drying control chemical additive increased from 20% to 30%, the permeance of H2 decreased by 11.55%, and the permselectivities of H2/CO2 and H2/N2 rose by 2.14% and 0.28%, respectively. The final results demonstrate that the ZrO2-MSiO2 membrane possesses excellent hydrothermal stability and regeneration capability.

Insight into the complexation of heptavalent technetium with tri-n-butyl phosphate: A computational study

The electronic structure and complexation behavior of heptavalent technetium with tri-n-butyl phosphate (TBP) are explored by applying Density Functional Theory (DFT) methodologies. The calculations suggest technetium can co-extract with zirconium through a monomeric or dimeric complex of zirconium nitrate pertechnetate and TBP. Hydrogen bonding plays a key role in binding pertechnetic acid with TBP molecules in the absence of co-extracting metal ions. The energy decomposition analysis clarifies the role of orbital and electrostatic interactions in the stability of these hydrogen–bonded complexes.

Beneficial effect of a zirconium-nitride-coated implant in total knee arthroplasty revision for suspected metal hypersensitivity

IntroductionRevision of total knee arthroplasty (rTKA) for suspicion of metal hypersensitivity (MHS) may require hypoallergenic implants. Results for coated implants have not been reported. The aim of the present study was to assess short-term results and survival of rTKA for MHS using a multilayer implant coating. HypothesisMultilayer implant coating improves functional results in rTKA, with survival comparable to primary coated implants. Material and methodsA single-center retrospective observational study included 28 patients (30 knees) undergoing rTKA for MHS using a coated implant between May 2011 and November 2016. Exclusion criteria comprised implant malpositioning and history of infection in the affected knee. Clinical and radiological results were assessed on the International Knee Society (IKS) and SF-36 functional scores and Ewald radiological score. Survival was calculated on Kaplan-Meier estimation. ResultsMean follow-up was 3.8 years. Mean IKS score increased by 40.2 points (40%) [range, 28.1–52.3] (p<0.05). Mean range of motion increased by 17° [range, 9.5–24.5°] (p<0.05). Mean physical and mental SF-36 components were respectively 44.7 and 46.1. Survivorship was 93%. DiscussionThere was significant functional improvement after rTKA for MHS. There were no short-term complications related to the zirconium nitrate coating. However, studies with longer follow-up will be needed for confirmation. Level of evidenceIV; retrospective study.

The formation mechanism of micro-nano secondary phase in solid-liquid doped TZM alloy

Among the various secondary phases distributed in the TZM (Titanium-Zirconium-Molybdenum) alloy matrix, the ones that can play a strengthening role are often those with a particle size smaller than 1 μm. In this study, titanium sulfate, zirconium nitrate, and fructose were used as raw materials. The TZM alloy with uniform distribution and an average secondary phase particle size of 940 nm (hereinafter referred to as MN-TZM alloy) was prepared through a solid-liquid doping preparation process. The thermodynamic calculation reveals the formation mechanism of the micro-nano-level secondary phase in the MN-TZM alloy. Thermogravimetric analysis (TG-DSC, TG-MS) and transmission electron microscope (TEM) confirmed the calculation results. The generation process of the micro-nano secondary phase evolution can be divided into four parts. The first stage is the process of solute dissolution at room temperature. In the second stage, doping and drying process take place below 100 °C. Third, reduction and secondary phase precursor incubation processes occur from 100 to 700 °C. Fructose decomposes (100 °C) to obtain organic carbon and water. The decomposition of zirconium nitrate (100 °C) yields NH 3 , H 2 O, ZrO 2 and Zr, while the titanium sulfate decomposes directly at 200– 242 °C to obtain SO 2 , H 2 O, TiO 2 and Ti. In the last stage, the secondary phase nucleates and grows up (700– 1800 °C). A large variety of micro-nano-scale and even nano-scale secondary phase particles have been discovered, including TiO 2 , ZrO 2 , ZrC and TiC. These observations provide necessary information for tracing back the secondary phase precipitation mechanism in the manufacturing process of high-performance molybdenum alloys. • The average grain size of MN-TZM alloy is 940 nm. • The micro-nano secondary phase reduces the average grain size of TZM alloy by 26%. • TZM alloy was prepared from titanium sulfate, zirconium nitrate, fructose and molybdenum powder for the first time. • The formation mechanism of micro-nano secondary phase in TZM alloy was clarified.

Zirconia prepared from UIO-66 as a support of Ru catalyst for ammonia synthesis

The development of effective Ru catalyst for ammonia synthesis is of important practical value and scientific significance because of the wide application of ammonia as a fertilizer and its promising applications in the renewable energy. Generally, ZrO2 was regarded as an inferior support for Ru catalyst used in ammonia synthesis. Here we prepare ZrO2 with monoclinic phase and carbon species from ZrCl4 following the preparation route of UiO-66 as well as ammonia treatment. Owing to the presence of a larger amount of hydrogen adsorption as well as the easier desorption of hydrogen species, the ill effect of hydrogen species on the nitrogen adsorption-desorption and ammonia synthesis can be effectively alleviated. The resulting ZrO2-supported Ru catalyst showed 4 times higher ammonia synthesis activity than the conventional Ru/ZrO2 obtained from zirconium nitrate.

Facile synthesis of Zr-based metal-organic gel (Zr-MOG) using “green” sol-gel approach

Zirconium-based metal–organic gels (Zr-MOG) was introduced to overcome the drawbacks such as macro-shaping and poor hydrostability of as-synthesized metal–organic frameworks in microcrystalline powder in industrial applications. Zirconium nitrate oxyhydrate and dicarboxylic acid were initially used as organic ligands to form a soft supramolecular structure in a sol–gel like processing method. Amorphous Zr-MOG were successfully synthesized without chloride ion and toxic modulators for the first time in an attempt to a sustainable and green approach. The estimated as well as observed pore size was at ca. 5 nm with a disordered wormhole-like structure analogous to mesoporous silica materials. The agitation method, aging duration and temperature were highly dependent factors for the formation of amorphous Zr-MOG xerogel in the absence of chloride ions and toxic organic solvents. The evidences suggested that simple and quick washing with ethanol of the obtained gel with aging in between as the key factor to successful formation at room temperature analogous to that of siliceous inorganic materials. X-ray photoelectron spectroscopy (XPS) spectra indicated that the Zr atoms and organic linker bonding were intact, forming an amorphous metal–organic gel network. The deconvolution of O1s spectra resulted in three peaks at 531.9 eV, 530 eV and 529 eV attributable to Zr-O-C, Zr-O-Zr and Zr-O bonds energy, respectively. The presence of Zr-O-C peak suggested successful formation of metal and organic moieties in Zr-MOG. In addition, the amorphous gel network was intact as evidenced in the presence of Zr-O-C peak in as-synthesized, dried gel.

Effect of Substrate-induced Strains on Ferroelectric and Dielectric Properties of Lead Zirconate Titanate Films Prepared by the Sol-gel Technique

Background: Lead Zirconate Titanate (PZT) films were synthesized by sol gel technique. The growth of films on ITO, Si\SiO2\Ti\Au, Si\Au and Si\SiO2\Ti\Al substrates discussed. In this study, Zirconium nitrate, lead acetate, and Ti (IV) isoproxide used as raw materials. Besides, acetic acid used as a solvent and 2-methoxy ethanol used as a stabilizer for Ti structure. Along with this, PZT films have perovskite structure, thin-film perovskite structure with high dielectric properties and hysteresis loop have been investigated. Methods: The effects of the type’s substrate on dielectric properties the ferroelectric properties were investigated and compared PZT film which deposited in different substrates. The films annealed at 600°C to complete crystalline films. XRD shows tetragonal PZT films have a strong perovskite structure with [100] prefer plane orientation. SEM and cross-section technique used to study for PZT surface films. Results: The dielectric constant at room temperature was different values depending on the types of substrate. The dielectric properties of the PZT films measured at 1 kHz were 120-400 dielectric constant and dielectric loss 0.02-0.08 at room temperature and 1 kHz. Conclusion: The largest remnant polarization (Pr) and coercive field (Ec) are obtained for PZT film deposited on Si\SiO2\Ti\Au substrate, equal to 26.6 mC/cm2 and 38.3 kV/cm, as compared to 16.3 mC/cm2 and 32.2 kV/cm2 for PZT film deposited on ITO substrate.