Barium Nitrate Research Articles

Advantages and disadvantages of barium oxide addition to bimetallic Pd-Rh three-way catalysts supported on zirconia-doped alumina

Due to enhanced high-temperature stability, zirconia-stabilized alumina is widely used as a support of three-way catalysts. The addition of barium oxide is known to improve the catalytic performance of the composition. In order to go in-depth about the effects of BaO addition, a series of samples was prepared using nitrates and complex salts as a precursor. The interaction of BaO with alumina was found to change dramatically the metal-support interaction of the latter with metals. Thus, the presence of BaO resulted in the sintering of Pd with the formation of agglomerated Pd0 species, which explains a lower activity in CO oxidation of the BaO-doped samples after thermal treatment. Contrarily, the addition of barium nitrate showed a positive effect, inhibiting the collapse of the porous structure of the support, which was the most crucial and accompanied by the formation of the α-Al2O3 phase when no barium nitrate was added.

Eco-friendly technology for “Nitrofos” fertilizer obtained from radioactive man-made waste

The article presents the results of research into the process of purification of phosphoric acid from radioactive isotopes after extraction of uranium, thorium, and REE. It is shown that the main purification of acid is achieved in the process of gypsum precipitation with sulfuric acid and barium nitrate. Additional purification of nitrate-phosphate solution is achieved after uranium extraction and sorption-extraction purification of REE. The sorption raffinate with a concentration of P2O5 25 g/L, REE 0.5 g/L and NH4NO3 300 g/L were used for fertilizer production. Additional purification of NH4NO3 solution from isotopes 226Ra, 210Po, 227Ac is achieved in the process of REE extraction purification. The aggregate of all refining processes of purification of nitrate-phosphate solution from radioactive isotopes provided NP-fertilizer “Nitrofos”, which meets the quality standards. Extraction of P2O5 from raw materials into NP-fertilizer – 90%; extraction of REE from raw materials into collective chemical concentrate – 95%; direct commercial extraction of REE from raw materials into the product – 85%.

Forensic Analysis of Recrystallized Inorganic Oxidizing Salts Used in Pyrotechnic-Based Improvised Explosive Devices Using Light Microscopy and Micro-Raman Spectroscopy

This study aimed to evaluate the advantages and challenges of analyzing post-blast pyrotechnic pipe bombs using a combination of light microscopy and micro-Raman spectroscopy. Two simulated improvised explosive devices (IEDs) were constructed and exploded using pyrotechnics as the main charge and consisted of several different components to simulate common materials that might be found in authentic bombing scenarios. In order to develop a rapid explosives residue recovery technique, a wet and dry swabbing process was compared to determine the most efficient swabbing method of recovery for inorganic oxidizers in post-blast debris. Samples were recrystallized using a water recrystallization method followed by in situ analysis using polarized light microscopy (PLM) and micro-Raman spectroscopy, targeting euhedral and subhedral crystals. While the water recrystallization had effects on the resulting Raman spectrum, such as peak intensity reduction, ultimately, the final salt identifications were not affected. The detection of several inorganic oxidizers post-blast included the identification of potassium perchlorate (KClO4), potassium nitrate (KNO3), and barium nitrate (Ba(NO3)2). The detection of KNO3 using microscopy alone was more challenging due to its relatively low abundance compared to KClO4 but was achieved with micro-Raman spectroscopy. Additionally, the mixing of inorganic oxidizers within single crystals was also observed. The results indicated that the combined approach of microscopy and micro-Raman spectroscopy enabled the successful detection of inorganic oxidizing salts in a post-blast scenario, as well as describing the advantages and limitations of this combination of techniques.

Novel BaO-decorated carbon-tolerant Ni-YSZ anode fabricated by an efficient phase inversion-impregnation approach

In this study, an efficient phase inversion-impregnation approach is developed for fabricating BaO-decorated Ni-8 mol% yttria-stabilized zirconia (YSZ) anode-supported tubular solid oxide fuel cells (SOFCs) toward anti-coking. This technique involves a simple phase-inversion process, along with the saturated barium nitrate solution as coagulation bath. Experimental results show that BaO nanoislands with particle size of less than 100 nm have been successfully and uniformly introduced inside the Ni-YSZ anode. The corresponding peak power densities are determined to be 0.30 W cm−2 and 0.22 W cm−2 at 800 °C in wet hydrogen and methane fuel, respectively. The long-term stability in methane fuel with the BaO-decorated anode is significantly improved with respect to the pristine one. Density functional theory (DFT) calculations suggest that the loading of BaO nanoislands can efficiently capture and dissociate the H2O molecules to generate OH, which subsequently serves as effective carbon elimination medium. The OH diffusion from BaO to BaO/Ni interface coupling with the formation of COH is the key step involved in the carbon elimination mechanism. The as-proposed phase inversion-impregnation approach exhibits advantage in time and cost savings compared to traditional impregnation methods, providing a new route for fabricating anti-coking SOFC anodes.

Luminescence characteristics and kinetic parameters of LiBaPO4: Tb3+, Dy3+ phosphors synthesized by sol-gel method

LiBaPO4: Tb3+, Dy3+ phosphors were prepared via sol-gel method by using the stoichiometric amounts of lithium nitrate LiNO3, barium nitrate Ba(NO3)2 and ammonium dihydrogen phosphate NH4H2PO4 as base materials. Morphology by scanning electron microscopy (SEM), structure by X-ray diffraction (XRD), thermal properties by Differential thermal analysis (DTA)/Thermogravimetric Analysis (TGA) and structural characteristics by Fourier transform infrared spectroscopy (FT-IR) were investigated. This paper presents luminescence properties using spectra from radioluminescence (RL), photoluminescence (PL), cathodoluminescence (CL) and, thermoluminescence (TL) and the influence of RE dopants (Tb3+, Dy3+) on the luminescent behavior of LiBaPO4. Computerized Glow Curve Deconvolution (CGCD) and Peak Shape Method were used to determine the kinetic parameters and the obtained results were evaluated. The RL results of un-doped LiBaPO4 showed the presence of a well-defined peak at 417 nm and a weaker band around 685 nm. Strong emissions were detected in the sample doped with Dy3+ correspond to 4F9/2→6Hj transitions. Blue, yellow and red emissions were observed with transitions of 4F9/2 → 6H15/2, 4F9/2 → 6H13/2 and 4F9/2 → 6H11/2, respectively. As for LiBaPO4: Tb3+, green emissions originated from the characteristic transitions (5D3 → 7FJ (j = 6–3) and 5D4 → 7FJ (j = 6–1)) of Tb+3 ion was seen. The RL, PL and CL spectra were identical, suggesting these green emissions. Dy3+ doped sample has three glow curves located at 72 °C, 145 °C and 204 °C, while the main temperature peak is measured at 240 °C for Tb3+ doped sample. Chromotographic studies of LiBa0·98PO4: Dy3+0.02 reveals that calculated x and y color coordinates (0.3122, 0.3233) are very close to the white light.

Structure, morphology, dielectric study of Ba-doped SrTiO3 by sol-gel method for optical applications

The goal of this study is to fabricate barium-doped strontium titanate nanomaterial utilizing the sol–gel technique and a range of barium nitrate concentrations. Electrical Structural properties, CV, FTIR, and SEM of all samples had been studied. The X-ray diffraction (XRD) results of the samples showed the cubic structure of strontium titanate. The Cyclic Voltammetry (CV) is performed on all the samples in light and dark conditions, the results showed enhanced current in the CV graph with the increase of Barium concentration from 5, 10, 15, and 20%. The increase in absorption characteristics were also observed when the doping of Ba increased. The bandgap was measured through resistivity and a decrease in bandgap was noted. Pure SrTiO3 morphology showed an oval/spherical crystalline phase when the dopant concentration was increased to 20%, the results show an asymmetrical shape. Keithley's source meter was used to measure all samples' dielectric characterization, which included the dielectric constant, dielectric loss, electrical susceptibility, and conductivity. The results revealed a decline in the dielectric characteristics. It was also observed that when the doping concentrations increase, the dependency of the samples on frequency as well as on temperature also increases.

EDLC performance of plasticized NBG electrolyte inserted with Ba(NO3)2 salt: Impedance, electrical and electrochemical properties

The great challenge in front of energy storage devices is to reduce the microplastics in the ocean and their potential harm to human health through drinking. The microplastics topic mainly results from the increasing usage of electronic devices and their components. Developing green electrolytes based on natural polymers and plasticizers is unique in overcoming microplastic issues. Natural beef gelatin (NBG) based plasticized polymer electrolyte films doped with barium nitrate (Ba(NO3)2) and glycerol (Gly) were fabricated using a solution casting process. The NBG electrolyte containing 12 wt.% Ba(NO3)2 and 50 wt.% Gly-has the maximum ionic conductivity, 4.87 × 10−5 S cm−1, at room temperature. The electrochemical performance of plasticized NBG:Ba(NO3)2 was examined utilizing impedance spectroscopy, with an emphasis on the dielectric characteristics and electric modulus parameters. With electrochemical stability up to 2.65 V, the plasticized specimen with the highest conducting demonstrated eligibility for use in energy storage devices. Transference number measurement (TNM) proved the dominancy of ions as a charge carrier in the plasticized NBG:Ba(NO3)2 system, yielding an electron transference number of 0.045 and an ion transference number of 0.955. The absence of redox peaks in the cyclic voltammograms suggests a capacitive charge accumulation in the plasticized electrolyte near to the electrode surface other than the Faradaic process. The triangle-shaped galvanostatic charge-discharge (GCD) plot shows a comparatively low drop voltage. The constructed electric double layer capacitor (EDLC) using activated carbon displays energy and power densities of 3.41 W/kg and 336.4 Wh/kg, respectively, at the first cycle. The EDLC performances of plasticized NBG:Ba(NO3)2 demonstrated the cell has potential industrial use as an energy storage device.

Comment on crystal growth, spectral, structural, linear, and third-order nonlinear optical and mechanical studies of a novel semi-organic single-crystal l-methionine barium nitrate (LMBN) for optical limiting applications

Comment on crystal growth, spectral, structural, linear, and third-order nonlinear optical and mechanical studies of a novel semi-organic single-crystal l-methionine barium nitrate (LMBN) for optical limiting applications

Interactions between γ-alumina surfaces in water and aqueous salt solutions

Particle agglomeration is relevant to numerous industrial applications and consumer products. The present work explores interactions between and agglomeration of gamma (γ)-alumina nanoparticles in pure water and dilute aqueous salt solutions. To characterize surface- and salt-specific effects, potential of mean force (PMF) profiles between γ-alumina surfaces ([110] and [100] facets) are extracted using classical molecular dynamics (MD) simulations. Supporting experiments are conducted using dynamic light scattering (DLS) to investigate agglomeration at the macroscale. The ion pairs considered are sodium chloride, ammonium acetate, barium nitrate, and barium acetate; sampling a broad range of the Hofmeister series. As particle surfaces approach contact, free-energy fluctuations of the PMF profiles reflect structural adjustments of the intervening aqueous phase. We extract values for the cohesive energy from the MD results, and parse the resultant effective pair interactions into van der Waals and electrostatic contributions. Molecular scale findings from simulations correlate with hydrodynamic radii of γ-alumina nanoparticles, obtained from DLS experiments. The results highlight the applicability of molecular simulations to identify the origins of macroscale observables.

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.

The catalytic performance of Ba-Ce-Cu catalysts for N2O decomposition

Series of Ba-Ce-Cu catalysts were prepared by citric acid method and used for N2O decomposition, and the doping effects of Ba and Ce on CuO were studied. It was found that the activity and the tolerance of the catalyst to the impurity gases (NO, O2, H2O) can be effectively modified by the doping components. The Ba0.2Cu displayed much high activity to the reaction due to the significant effect of Ba stabilizing the active Cu+ species in the catalyst, but low tolerance to NO. The Ba0.2Ce0.5Cu catalyst exhibited not only higher catalytic activity compared with the Ba0.2Cu due to the synergistic effect of Ba and Ce, but also strong tolerance to NO, as the CeO2 in the catalyst could remove the adsorbed NOx species from the Cu+ through forming barium nitrate and catalyzing the latter decomposition.

Золь-гель синтез нанодисперсных твердых растворов на основе гексаферрита бария состава SrXBa(1–Х)Fe12O19

The present paper provides data on the sol-gel synthesis of M-ferrite with the SrxBa(1–x)Fe12O19 (х = 0; 0.3; 0.5; 0.7; 1) composition. The synthesis technique is based on the preparation of a polymeric citrate complex from citric acid and nitrates of barium, strontium, and iron, its calcination at 500 °C followed by mechanochemical activation, and calcination at 700 °C. The target product is a dark brown powder, which has been studied by the XRD and SEM methods, energy-dispersive X-ray spectroscopy and differential scanning calorimetry (DSC). The single-phase state of the obtained samples is confirmed by powder X-ray diffraction. The X-ray patterns of the synthesized hexaferrites match the X-ray patterns of reference com-pounds from the ICDD database for all diffraction maxima. The unit cell parameters of the samples have been calculated from the X-ray diffraction patterns. They linearly depend on the degree of barium substitution in hexaferrite, that is, the successful replacement of barium ions in the crystal lattice by strontium ions, due to the Vegard rule for solid solutions. Morphological pa-rameters have been studied using SEM, the analysis of the obtained images indicates the for-mation of nanodispersed hexaferrites, for which the average particle size is 50 nm. The average particle size, calculated by the Scherrer's formula, equals 25 nm. The usual hexagonal form of hexaferrite particles has not been observed in the SEM images due to the small particle size. En-ergy-dispersive X-ray spectroscopy of the obtained images indicates a high degree of homogeni-zation for the chosen synthesis technique. Using the DSC method we obtained values of Curie temperature which show it’s increases linearly with an increasing of Sr weight percent

PREVENTION OF PREVIOUS OPERATION OF CHARGES OF PYROTECHNICAL PRODUCTS BASED ON MIXTURES OF MAGNESIUM, ALUMINUM POWDER AND METAL WASTE IN THE CONDITIONS OF EXTERNAL THERMAL ACTIONS

Mathematical models of external heating of charges of pyrotechnic products based on compacted mixtures of aluminum-magnesium alloy powders and nitrate-containing oxidizers (sodium, potassium, strontium, and barium nitrates) were refined by taking into account the temperature dependence of their thermophysical properties (volumetric heat capacity and coefficient of thermal conductivity), which allowed to more accurately determine the critical values of heat flows and durations of their influence.
 New data were obtained to determine the critical ranges of the change in the burning rate of mixtures under conditions of elevated heating temperatures and external pressures for various values of technological parameters (the coefficient of excess oxidizer α; the average particle size of metal fuel powders dм microns and oxidizer dN), exceeding the ranges of which leads to premature ignition mixtures under conditions of external thermal effects and leads to unstable explosive development of their combustion process and fire-hazardous destruction of pyrotechnic products.

Exothermic synthesis of ceramic materials based on the system Zn2SiO4‒RO (R ― Ba, Sr)‒Al2O3‒SiO2

The synthesis of ceramic materials in the Zn2SiO4‒RO (R ― Ba, Sr)‒Al2O3‒SiO2 system was carried out using the technology of exothermic synthesis from solutions including zinc, barium and strontium nitrates, silica and organic reducing agent (glycine and carbamide). It is shown that the implementation of an exothermic process followed by calcination at a temperature of 1000 °C contributes to the formation of crystalline phases of willemite (Zn2SiO4), barium aluminosilicates (BaAl2Si2O8) and strontium (SrAl2Si2O8). The dependence of the quantitative phase composition and parameters of the elementary cells of the crystalline phases is established. Sintering of synthesized materials occurs at a temperature of 1275 °C. The dielectric permittivity of sintered materials is 5,33‒6,06 and the tangent of the dielectric loss angle is 1,5·10‒3‒3,16·10‒3 at a frequency of 1 MHz, the minimum values correspond to ceramics based on the Zn2SiO4‒BaAl2Si2O8‒SrAl2Si2O8 triple system. Ill. 5. Ref. 19. Tab. 2.

‘Green firecrackers’ with reduced barium emissions in particulate matter

Ambient air quality is affected due to the emission of pollutants on a large scale after the bursting of firecrackers. Traditionally in all firecrackers, barium (Ba) compounds are used as oxidizers and also to impart green colour flame. Combustion products of barium compounds are water soluble and readily absorbed by the body affecting human health. Thus, the inherent risk of Ba pollution due to the bursting of firecrackers has consequent health effects. To reduce the ambient air pollution caused due to burning of conventional firecrackers, CSIR NEERI has developed reduced emission firecrackers (green crackers). This is achieved by reducing the amount of chemicals, barium nitrate, shell size and addition of additives such as zeolite and iron oxide. This study aims to specifically investigate the influence of additives on the level of barium in reduced emission firecrackers. Four types of conventional and reduced emission firecrackers were selected and tested inside a firecracker emission testing facility to check the levels of barium in PM10 and PM2.5. The measured mean concentrations of all types of reduced emission crackers (green crackers) provided by fireworks manufacturers show significantly reduced barium concentration by 30–60% compared to conventional crackers depending on the type of firecrackers, shell size and amount of chemicals used. The possible reason for reduced Ba level is attributed to i) reduced usage of Ba(NO3)2 and ii) formation of heavy density compounds, leading to soil fallout.

Nitrocellulose‐Based Green‐Light Illuminants: A Study of Barium Nitrate Particle Size on Spectral Performance

AbstractWhile a typical military flare includes a metal fuel (aluminum, magnesium, boron, etc.) to increase combustion temperature and therefore spectral performance, the replacement of these fuels to reduce smoke (non‐light emitting species) is still desired. Nitrocellulose (NC) is known to be a “smokeless” propellant and, in this work, used solely as the fuel component in the pyrotechnic flare composition. Two levels of nitration, 12.2% N and 13.4% N content, are studied and while the influence of nitration content is shown, this work focuses on the role of barium nitrate (Ba(NO3)2) particle size. For formulations with 13.4% N content, reducing the Ba(NO3)2 particle size fraction from 250–300 μm to ≤25 μm results in the dominant wavelength being reduced from 569 nm to 558 nm. Combustion products collected from formulations using the 250–300 μm Ba(NO3)2, were characterized and indicated barium carbonate (BaCO3) as the major condensed phase product. This indicates that the formation of barium oxide (BaO) from the slow decomposition of Ba(NO3)2, coupled with the release of CO2 from NC, likely results in the following reaction: BaO+CO2→BaCO3. While unexpected, this implies that controlling early chemistry during combustion may allow significant improvements in spectral performance by inhibiting non‐light emitting specie formation.

Deposition Fe2O3 Doping Barium Ferrites Thin Films on Glass without Annealing and Study their Microwave Properties

The series of ferrites samples doped by Barium with general formula Barium nitrate Ba(NO3)2 was prepared, The Chemical Spray Pyrolysis (CSP) technique method of preparation of thin films for Iron (III) nitrate Fe(NO3)3.9H2O at (X) values ranging from 0.0 to 7%, where (X) represents the proportion of Barium in ferrite. doping, as well as the factors affecting the preparation of these films, which were deposited on glass Many techniques are used to analyze and test the prepared, sintering temperature has been used which is (450ºC temperature the substrate), to determine the effect of sintering temperature on the final specifications of the samples, (Network analyzer device) has been used to study the microwaves absorption in the range of (X- band) with a frequency range (8 -12.5 GHz). Also X-ray diffraction analysis (XRD) has been used to determine the crystal structure and purity of the prepared samples and to calculate the average grain size and micro strain, The samples were examined using a scanning electron microscope device to evaluate the crystal size and to see distribution style after the sintering process, Also the resonance peaks for all types of ferrite appeared at frequencies(9.350, 11.825, and 11.983)

Hydration Structures on γ-Alumina Surfaces With and Without Electrolytes Probed by Atomistic Molecular Dynamics Simulations.

A wide range of systems, both engineered and natural, feature aqueous electrolyte solutions at interfaces. In this study, the structure and dynamics of water at the two prevalent crystallographic terminations of gamma-alumina, [110] and [100], and the influence of salts─sodium chloride, ammonium acetate, barium acetate, and barium nitrate on such properties─were investigated using equilibrium molecular dynamics simulations. The resulting interfacial phenomena were quantified from simulation trajectories via atomic density profiles, angle probability distributions, residence times, 2-D density distributions within the hydration layers, and hydrogen bond density profiles. Analysis and interpretation of the results are supported by simulation snapshots. Taken together, our results show stronger interaction and closer association of water with the [110] surface, compared to [100], while ion-induced disruption of interfacial water structure was more prevalent at the [100] surface. For the latter, a stronger association of cations is observed, namely sodium and ammonium, and ion adsorption appears determined by their size. The differences in surface-water interactions between the two terminations are linked to their respective surface features and distributions of surface groups, with atomistic-scale roughness of the [110] surface promoting closer association of interfacial water. The results highlight the fundamental role of surface characteristics in determining surface-water interactions, and the resulting effects on ion-surface and ion-water interactions. Since the two terminations of gamma-alumina considered represent interfaces of significance to numerous industrial applications, the results provide insights relevant for catalyst preparation and adsorption-based water treatment, among other applications.

Influence of Nitrate Species A(NO<sub>3</sub>)<sub>2</sub> on Physico-Mechanical Properties of the Aluminosilicate Adhesives for Wooden Structure

The article presents the results of studies of the positive effect of compounds of the type A(NO3)2, as modifiers of the aluminosilicate adhesive of the composition Na2O∙Al2O∙6SiO2∙20H2O, on increasing the strength of adhesive joints of wood of various species. The grade strength increases 1.39 times compared to the strength of the adhesive that does not contain these compounds. According to the degree of influence on the shear strength along the fibers, the additives can be ranked in the series Ba (NO3)2 > Ca (NO3)2 > Mg (NO3)2 > 95%Ca (NO3)2+5%NH4NO3. It is noted that for gluing samples from a pine substrate, it is advisable to add magnesium and barium nitrates to the aluminosilicate glue in an amount of 1% (by weight); beech wood - calcium and barium nitrates in the amount of 1 and 0.5% (by weight); oak wood - calcium nitrates in an amount of 1% (by mass), a mixture of nitrates in an amount of 0.5% (by mass) and barium nitrate in an amount of 0.5 and 1.5% (by mass). According to the influence on the strength of adhesive joints, the substrates can be ranked in the order beech > oak > pine. Further studies will present the results of the effect of alkaline earth metal nitrates on the deformation properties of adhesive joints and on rheokinetic and colloid-chemical properties.

ECOFRIENDLY (GREEN) FIRECRACKERS VS OLD FIRECRACKERS AND THEIR HEALTH EFFECTS: A SYSTEMIC REVIEW

Fireworks are any composition or device designed to produce a visible or audible effect made outof hazardous chemicals. The key hazards involved in firework industries are toxic fumes, fire andexplosion. The objective of this review is to differentiate between old firecrackers and ecofriendly/green firecrackers and their health hazards. Published articles were searched from Med Line, PubMed, Google Scholar and Cochrane library. It is observed that the air concentration of heavy metalsfound in old firecrackers was high during and after firecrackers bursting activities which lead tohealth effects like skin, respiratory, neurological, multiple degrees of burn etc. In ecofriendly firecrackers, the reduction in the chemicals like barium nitrate, potassium nitrate and sulphur leadsto reduction in PM2.5. Enough information is not available related to the ecofriendly firecrackers;hence, drawing a conclusion related to their health at present is difficult. The review identifiedmany health effects as well as accidents (or incidents) related to firecrackers bursting,manufacturing and transportation. Ecofriendly/ Green firecrackers area better substitute of oldfirecrackers as their composition has less harmful contents. Further studies are required toconclude the effects of ecofriendly/green fire crackers as the complete list of their formulations arestill not available.