Strontium Nitrate Research Articles

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.

Study of the La1−xSrxMnO3 Cathode Film Prepared by a Low Power Plasma Spray Method with Liquid Solution Precursor for a Solid Oxide Fuel Cell

A perovskite La1−xSrxMnO3 cathode thin film for an oxygen ion conducting solid oxide fuel cell was prepared using a low power (8.8 kW) liquid solution plasma spray method. Usually, a 30–50 kW Ar plasma torch with temperature higher than all the melting points of solid precursors is essential to synthesis oxides thin film. However, using the liquid precursors as the feeding materials, the required power can be reduced and save a lot of thermal budget. The precursors are water solutions of lanthanum nitrate hexahydrate, manganese(II) nitrate tetrahydrate, and strontium nitrate. The atomic percentage of La in the plasma sprayed La1−xSrxMnO3 cathode film is lower than that of La in the feeding precursor into the torch, which is due to the low boiling temperature of La(NO3)3 precursor. The oxygen stoichiometry of La1−xSrxMnO3−δ deduced from the valence state of Mn measured by X-ray absorption spectroscopy shows an oxygen deficit structure. The measured low resistivity of 0.07–0.09 Ωcm at room temperature for this La1−xSrxMnO3−δ is essential for oxygen ion transport in the cathode thin film of a solid-state fuel cell.

Effect of the Fe/Ba and Fe/Sr ratios on the phase composition, dielectric properties and magnetic characteristics of M-type hexaferrites prepared by the hydrothermal method

Powders of BaFe12O19 and SrFe12O19 ferrites are synthesized by hydrothermal method from iron, strontium, and barium nitrates. The ratio of iron and barium (strontium) cations in the precursor solution was varied to establish the optimal conditions for the maximum yield of hexaferrite. X-ray diffraction, Mössbauer spectroscopy, vibrating sample magnetometry and dielectric spectroscopy are used for the characterization of the obtained materials. At a high Fe/Ba (Fe/Sr) ratio, the powders contain α-Fe2O3 as a secondary phase, which significantly reduces the magnetization and slightly decrease the coercivity. At the same time, a low Fe/Ba (Fe/Sr) ratio leads to the formation of BaFe2O4 (SrFeO3-x), which also leads to a decrease in magnetization and a sharp drop in the coercivity. Powders with a high content of hexaferrite are characterized by excellent coercive force (>5 ​kOe) and can be considered as a material for permanent magnets.

THE PREPARATION AND CHARACTERIZATION OF THE RED FLAME COMPOSITION BASED ON STRONTIUM NITRATE, MAGNESIUM, AND POLYVINYL CHLORIDE

This paper presents the influence of oxidizer/fuel ratios on several energetic characteristics (the heat of combustion, gaseous volume, burning rate) of the red flame pyrotechnic containing strontium nitrate, magnesium, polyvinyl chloride, and novolac resin. Based on the received experimental data and theoretical calculation results, the reasonable strontium nitrate/magnesium ratio of 58/15 is determined. The pyrotechnic mixture has the heat of combustion of 921 cal/g, a gaseous volume of 260 ml/g, a burning rate of 2.02 mm/s at a pressed density of 1.60 g/cm3, a color purity of 89%, a decomposition temperature of 481.5oC, and less sensitive to friction and impact.

Surface analysis of titanium disks with strontium coating.

Peri-implantitis is one of the most common complications after dental implant placement. Researchers have demonstrated that the peri-implantitis tends to occur around dental implants with a rough surface rather than those with a smooth surface. We aimed to investigate the ability of a smooth titanium (Ti) surface containing strontium (Sr) to enhance bone formation as a result of strontium's capacity to support osteoblast proliferation and differentiation. A thin titanium oxide film was formed on an as-mirror polished Ti surface by dipping in 5% sodium hypochlorite (NaOCl) solution for 24 h, followed by thermal treatment at 350°C. The Ti surface was then treated with 1% strontium nitrate (Sr(NO3)2) solution and turned in spin coater. The surface morphology, chemical composition, and release of strontium ions (Sr2+) were evaluated. The results demonstrate that strontium in the form of Sr2+ was successfully doped into the titanium dioxide (TiO2) film by this simple chemical treatment.

Synthesis,growth, spectral, optical and thermal studies of phthalate strontium nitrate hydrochloric acid (PASNHCL) single crystal

In present investigation, the nonlinear optical single crystal of phthalic acid strontium nitrate hydrochloric acid (PASNHCL) was grown by the solution evaporation method from a mixture of an aqueous solution at room temperature. The grown PASNHCL crystals crystalline nature, cell parameters, functional groups, and elemental compositions were characterized by PXRD, UV-Vis-NIR, FTIR, FT-Raman, EDX, and Thermal analysis.The PXRD analysis shows the PASNHCL crystal has good crystalline nature. Single crystal XRD confirmed that the grown crystal belonged to the orthorhombic system with space group of P222with alattice parameters a = 6.785 Å, b = 7.420 Å, c = 11.637 Åand volume 585.86 Å3. UV-Vis-NIR spectrum study reveals that the lower cut off wavelength was found to be 333 nm and the crystal has good optical transparency. The presence of functional groups was identified by FTIR spectrum. The Thermogravimetric analysis curves confirms melting point of the grown PASNHCL is 233.17 C. Itis interesting to note that PASNHCL [Sr+(C8H7N2O10)Cl−] single crystal has a greatly resourceful second harmonic generation (SHG) material for Optoelectronics applications.

Exothermic synthesis of ceramic materials based on barium and strontium aluminosilicates

Ceramic materials were synthesized in the RO(R=Ba, Sr)–Al2O3–SiO2 system using exothermic synthesis from solutions containing barium and strontium nitrates, silica and organic reducing agents (glycine and carbamide). It was shown that only the use of a mixture of glycine and carbamide as well as the addition of ammonium nitrate allows carrying out a complete exothermic synthesis with the formation of an X-ray amorphous product with a small fraction of the crystalline phase. It was established that monophase materials based on barium and strontium aluminosilicates (BaAl2Si2O8 and SrAl2Si2O8) are formed when the obtained X-ray amorphous product is heat-treated at the temperatures above 10000C. Ceramics from synthesized materials sintered at 15500C has a high refractoriness, open porosity of 0–1.0%, compressive strength of 115–120 MPa; dielectric constant of 3.25–6.0 (at the frequency of 1 MHz) and the loss tangent of (1.5–5.2)10–3. The results shows that the exothermic synthesis ensures the preparation of nano- and sub-microcrystalline powders in the system RO(R=Ba, Sr)–Al2O3–SiO2. Materials based on the obtained aluminosilicates can be used in the manufacture of protective structures for devices operating in the radio frequency band, in radar installations of aviation and rocket technology, in microwave elements, etc.

In-vitro mineralization of bio-coated 3D printed metallic implant under simulated body conditions

Titanium alloy, Ti6Al4V is a popular bio-metallic implant material due to its biocompatibility and inert nature. Further, by controlling the porosity of Ti6Al4V alloy through 3D printing not only helps it exhibit properties comparable to human bones, but also results in relatively rougher surface for improved coating adhesion. To induce bioactive characteristics in Ti6Al4V alloys, they are generally coated with Hydroxyapatite (HAp). In the present study in-vitro mineralization of polydopamine treated 3D printed Ti6Al4V alloy specimen, which are HAp coated and further doped with strontium and silver nitrate for improved bioactivity and anti-microbial characteristics respectively, is carried out for a maximum of 28 days’ time duration. These coated specimens are then characterized through Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) for microstructural analysis, and further evaluated for weight gain and coating thickness. SEM data suggests a consistent apatite formation over a period of time across the different coating groups. Although the samples containing Sr & Ag were initially showing lower Ca & P atomic % in range of 50 and 29 respectively, but there is a substantial increase in atomic percentages of both Ca and P to 66 & 33% respectively, completely covering the Ti surface homogeneously as evidenced by elemental mapping results after 28 days’ time duration. This study is helpful to understand the phenomenon of apatite formation over the period of time on different biofunctional coatings when compared to pure HAp coatings.

Study on Preparation of a Luminescent Signal Agent with HTPB Propellant

The paper put forward transforming HTPB propellant into a luminescent signal agent in order to seek a solution for its reuse after retirement. Considering comprehensively that HTPB propellants have similar content and pyrotechnic composition, a red luminescent signal agent was designed and the preparation process was analysed. On the basis of safe pulverization, strontium nitrate was added into HTPB propellant as flame colorant and they recombined with shellac as binder according to the mass ratio of 30:65:4. The modified luminescent signal agent had good compatibility by DSC test. Its brightness, chroma and luminescence time all met the relevant industry requirements. A resource reuse route for a large quantity of discarded HTPB propellant was innovated, which has certain military and economic value.

PCL-Coated Multi-Substituted Calcium Phosphate Bone Scaffolds with Enhanced Properties.

Ionic substitutions within the hydroxyapatite lattice are a widely used approach to mimic the chemical composition of the bone mineral. In this work, Sr-substituted and Mg- and Sr-co-substituted calcium phosphate (CaP) scaffolds, with various levels of strontium and magnesium substitution, were prepared using the hydrothermal method at 200 °C. Calcium carbonate skeletons of cuttlefish bone, ammonium dihydrogenphosphate (NH4H2PO4), strontium nitrate (Sr(NO3)2), and magnesium perchlorate (Mg(ClO4)2) were used as reagents. Materials were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Whole powder pattern decomposition refinements of XRD data indicated that increased magnesium content in the Mg- and Sr-co-substituted scaffolds was related to an increased proportion of the whitlockite (WH) phase in the biphasic hydroxyapatite (HAp)/WH scaffolds. In addition, refinements indicate that Sr2+ ions have replaced Ca2+ sites in the WH phase. Furthermore, PCL-coated Mg-substituted and Sr- and Mg-co-substituted scaffolds, with the HAp:WH wt. ratio of 90:10 were prepared by vacuum impregnation. Results of compression tests showed a positive impact of the WH phase and PCL coating on the mechanical properties of scaffolds. Human mesenchymal stem cells (hMSCs) were cultured on composite scaffolds in an osteogenic medium for 21 days. Immunohistochemical staining showed that Mg-Sr-CaP/PCL scaffold exhibited higher expression of collagen type I than the Mg-CaP/PCL scaffold, indicating the positive effect of Sr2+ ions on the differentiation of hMSCs, in concordance with histology results. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis confirmed an early stage of osteogenic differentiation.

Identification of Typical Solid Hazardous Chemicals Based on Hyperspectral Imaging

The identification of hazardous chemicals based on hyperspectral imaging is an important emergent means for the prevention of explosion accidents and the early warning of secondary hazards. In this study, we used a combination of spectral curve matching based on full-waveform characteristics and spectral matching based on spectral characteristics to identify the hazardous chemicals, and proposed a method to quantitatively characterize the matching degree of the spectral curves of hazardous chemicals. The results showed that the four hazardous chemicals, sulfur, red phosphorus, potassium permanganate, and corn starch had bright colors, distinct spectral curve characteristics, and obvious changes in reflectivity, which were easy to identify. Moreover, the matching degree of their spectral curves was positively correlated with their reflectivity. However, the spectral characteristics of carbon powder, strontium nitrate, wheat starch, and magnesium–aluminum alloy powder were not obvious, with no obvious characteristic peaks or trends of change in reflectivity. Except for the reflectivity and the matching degree of the carbon powder being maintained at a low level, the reflectivity of the remaining three samples was relatively close, so that it was difficult to identify with the spectral curves alone, and color information should be considered for further identification.

Strontium-Doped Nickel Oxide Nanoparticles: Synthesis, Characterization, and Cytotoxicity Study in Human Lung Cancer A549 Cells.

In this manuscript, the grown and annealed strontium-doped nickel oxide nanoparticles (SrNiONPs) were synthesized using a precipitation method with nickel nitrate and strontium nitrate as precursor agents with trisodium citrate. Various characterization techniques, including X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-visible, and zeta sizer, were used to thoroughly examine the samples. The XRD pattern (21nm) was used to calculate the size, phases, and crystallinity of the material (SrNiONPs). In addition to characterization, the material was tested for cytotoxicity in lung cancer cells (A549). The viability test in A549 cells was performed using [3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide] (MTT) and Neutral Red Uptake (NRU) assay with SrNiONPs concentration ranging from 1 to 100μg/mL. According to the MTT and NRU data, the toxicity studies are dose-dependent. SrNiONPs also increased reactive oxygen species (ROS) and were involved in apoptosis (A549 cells). Furthermore, quantitative PCR (qPCR) data revealed that the mRNA levels of apoptotic genes marker like p53, bax, and caspase-3 were upregulated, whereas bcl-2, an anti-apoptotic gene, was downregulated. As a result, apoptosis was mediated by the p53, bax, caspase3, and bcl-2 pathways, implying a potential mechanism by which SrNiONPs mediate their toxicity.

Enhanced surface hardening of hydrated concrete composite by strontium nitrate (Sr(NO3)2) aqueous solution

This study experimentally investigates the effects of strontium nitrate (Sr(NO3)2) aqueous solution on hardened concrete composite as a surface hardening method. Density, void content, water sorptivity, and surface abrasion resistance of the concrete mixture treated by Sr(NO3)2 solution were measured under diverse curing and treatment scenarios. The results showed that 30% Sr(NO3)2 aqueous solution increases the density by 1.0% and 2.2% and also decreases the void content by 7.4% and 14.4% with the water-cement ratio (w/c) of 0.5 and 0.4, respectively. Water sorptivity of the treated hardened concrete was decreased by 26.4% and 34.0% from the lithium silicate and sodium silicate treatments, respectively. In addition, the Sr(NO3)2 treatment increases the surface abrasion by 45% from the control specimen and about 25–30% from the two silicate-based treatments. X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were conducted to investigate the micro-morphologies, microstructure, and elemental characteristics. The results illustrate that (1) microstructures of hydrated cement matrix are densified, (2) portlandite (CH) in the matrix decreases as time elapses, (3) multiple types of hydrated aluminosilicate minerals (i.e. zeolites) are formulated, and (4) more subsequent polymerization related to C–S–H/C-A-S-H occurs. Lastly, the densifying and strengthening mechanisms of the hydrated cement by the Sr(NO3)2 treatment process are presented and discussed.

Investigation of the Thermal Aging Behavior of Pyrotechnic Tracer Composition by Spectroscopic Techniques Coupled with Principal Component Analysis

AbstractThis work aims to investigate the aging behavior related to heat of a pyrotechnic tracer composition (PTC) sample composed of strontium nitrate as an oxidizer and dual‐fuel of Mg and Mg−Al alloy. Fresh and thermally aged samples were examined using nondestructive spectroscopic techniques, namely Raman spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD). The obtained results showed that aging for 20, 40, and 60 days at 65 °C does not provoke noticeable chemical or structural changes, whereas, after 60 days, the changes are visible, and become more obvious after aging for 120 days. These changes are caused by the partial decomposition of strontium nitrate and the oxidation of magnesium, which are followed by the generation of degradation products such as Sr(NO2)2, MgO, and Mg(OH)2. On the other hand, the applicability of FTIR and XRD associated with a chemometric tool, the principal component analysis, as a simple and useful technique has been also assessed to discriminate the spectra of the aged samples. It has been revealed that these combined approaches can be effectively used to recognize the main compositional and structural changes within the pyrotechnic tracer composition affected by the thermal degradation process.

Controlled Growth of Strontium Sulfate Particles in Aqueous Solution: Inhibition Effects of a Bubble Column Evaporator

In the oil industry, strontium sulfate (SrSO4) scale deposits have long plagued oilfield and gas production operations. This remains an unsolved problem. We here show how the bubble column evaporator (BCE) can be used to control aqueous precipitation from salt solutions. Mixtures of strontium nitrate and sodium sulfate in the BCE system were used to precipitate strontium sulfate at different degrees of supersaturation. The effectiveness of the BCE system was compared to standard mechanical stirring. The precipitation of strontium sulfate in both processes was monitored through turbidimeter, particle counting, Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). The results show that the BCE system has a significant inhibition effect and so can be used to control precipitation growth rate, even from supersaturated solutions. This remarkable effect also provides new insights into mechanisms of crystallisation, of bubble interactions and mineral flotation.

The production of less harmful and less toxic sparklers in an experiment for school students

AbstractIn this article, a new and simple way of producing sparklers is presented as a school experiment. These sparklers are more environmentally friendly and less health threatening than sparklers produced with existing preparation methods. The problem of conventional sparklers is the toxicity of barium nitrate, which is used as the oxidizer. The substitution of this oxidizer with strontium nitrate and also the reduction of the weight proportion makes the new mixture less dangerous and less toxic. Various tests for the categorization of high-energetic materials show that the newly developed sparklers are not classified as explosives. Furthermore, the tests demonstrate that the newly developed sparklers are not as dangerous as commercial sparklers. Due to their lower health risk, these new sparklers are well suited for use in school education. In addition, expenditure for this experiment is low and integrating it into the upper secondary level curriculum is easy. Sparklers are an impressive example of redox reactions from everyday life. The experiment is a best-practice application for chemistry education, incorporating current results of chemistry research.

Improving the mechanical properties of strontium nitrate doped dicalcium phosphate cement nanoparticles for bone repair application

Advances in the science and technology of bone materials and cements have been expanded over the past several years. The combination of reinforcing materials with bone cement has been proven with the increase in strength and biocompatibility of the porous scaffold. The aim of this study was to investigate and compare four specific types of the scaffold. The effect of strontium nitrate on dicalcium phosphate (DCaP) bone cements made by co-precipitation method was investigated. In this study, a pure sample of brushite (Br) and strontium nitrate containing (3 wt%, 7 wt%, and 10 wt%) were prepared. The phase composition of the samples was examined by X-ray diffraction (XRD) and their microstructure and morphology were examined using field emission scanning electron microscopy (FESEM) technique. The bioactivity of the samples was evaluated in the simulated body fluid (SBF) and the biodegradability of the samples was measured in the phosphate buffer saline (PBS). The mechanical properties of the sample such as compressive strength and elastic modulus were investigated. Bioactivity and biodegradability tests confirm the result of compressive strength. The SEM images showed that the prepared scaffolds were porous with 55–65% porosity and the interconnected porosity dimention is around 50–100 μm. The obtained results indicated that with increasing hydroxyapatite (HA) and brushite in the nanocomposite, the porosity increased, the size of the porous decreased and the elastic modulus increased. The results of cell culture indicated biocompatibility and non-toxicity of the synthesized scaffolds increased more than 0.989. Also, the ultimate strength of brushite-dicalcium phosphate cements depends on the degree of cement conversion, the porosity of the cement, the size of the crystal and the filler particles. The sample containing 3 wt% strontium nitrates with hydroxyapatite (HA) and brushite (Br) showed proper mechanical and biological properties before and after immersion in SBF solution.

Rational construction of novel strontium hexaferrite decorated graphitic carbon nitrides for highly sensitive detection of neurotoxic organophosphate pesticide in fruits

As a growing aspect of agriculture purposes, an extensive number of pesticides and insecticides that have been used to produce yield, and particularly, through toxic organo-pesticides and herbicide. Moreover, the long-term usage of organo-pesticides leads to health problems, which causes serious health threat to human beings. Therefore, monitoring the level of organo-pesticides in food products is highly essential for practical applications to ensure food safety. Herein, we successfully synthesized strontium hexaferrite (nanorods) decorated on porous graphitic carbon nitride (SrFe12O19/g-C3N4) electrocatalyst through the incorporation of metal precursors such as strontium nitrate, ferric nitrate, melamine and glucose via a facile hydrothermal process with excellent electrochemical performance towards the detection of fenitrothion (FTN). The structural and chemical features of the as synthesized SrFe12O19/g-C3N4 electrocatalyst were characterized by various spectroscopic and analytical methods. The SrFe12O19/g-C3N4/SPCE shows a most-improved electrocatalytic performances compared to other modified and unmodified SPCEs. Mainly, the SrFe12O19 NRs were highly interconnected with the g-C3N4 matrix, which provides a sufficient electrocatalytic ability for the rapid electrochemical performances and it has achieved higher BET surface area of 325 m2/g. Moreover, our proposed electrochemical sensor performs a good detection range from 0.005 to 378.15 μM with a low detection limit of 0.0014 μM (S/N=3) and sensitivity of the modified sensor is 19.23 μA μM−1 cm−2. The practicality of the proposed SrFe12O19/g-C3N4 modified sensor was manifested by the profitably determination of FTN in various fruits samples with acceptable recoveries.

Application of the EOQ (Economic Order Quantity) Method in Determining Chemical Supplies in PT. Semen Indonesia

The competition among products has become commonplace in the industrial world in Indonesia. PT. Semen Indonesia is a company with extraordinary development prospects. Quality control is needed in order to control the product so that when it arrives at the consumer the product is in its best condition, or when the product is still in process, production can be maximized. The method used in this research is Economic Order quantity (EOQ). Based on the resercah, the number of orders for each ingredient is for ammonium nitrate 1, barium chloride 1, ethanol 3, glycerol 1, hydrocloric acid 2, sodium hydroxide 3, strontium nitrate 2. Then, the ROP point or time to reorder each ingredient is for ammonium nitrate 2, barium chloride 4, ethanol 33, glycerol 16, hydrocloric acid 21, sodium hydroxide 4, strontium nitrate 13.Keywords: EOQ (Economic Order Quantity), Chemical Supplies, PT.Semen Indonesia

Reactivity of Aluminum and Titanium Oxides under the Conditions of the Synthesis of Strontium and Barium Titanates in Water Fluid Media

Strontium and barium titanates deposited on a porous support (α-Al2O3) are synthesized by the treatment of previously deposited precursors (titanium oxide, strontium nitrate, or barium nitrite) in a water fluid medium at 400°C. The obtained samples are characterized by X-ray powder diffraction (XRD) analysis and scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) spectroscopy. It is found that, in the presence of titanium oxide, α-Al2O3 is partially hydrated to form basic aluminum hydroxide AlO(OH) (boehmite), which is not detected by XRD after the treatment of α-Al2O3 in a water fluid. SEM with EDX spectroscopy demonstrates that strontium ions under the conditions of the treatment in a water fluid preferably interact with titanium oxide to form SrTiO3, although the aluminum oxide content in the samples is much higher. The conditions are determined for obtaining systems with different spatial distributions of the supported component inside the granules of the support by varying the procedure of its preliminary impregnation with the titanium oxide precursor.