Barium Salts Research Articles

A Novel Corrosion Inhibitor for Preventing the SO42- Transportation in Concrete

Chemical erosion of reinforced concrete by SO42− in saline soil is the main factor of steel corrosion and concrete damage. Therefore, we synthesized a novel corrosion inhibitor based on barium salts for improving the SO42− resistance property of concrete. In this study, the effects of corrosion inhibitor on the workability, compressive strength and SO42− corrosion resistance property of concrete have been investigated. The results showed that with increased of corrosion inhibitor the slump of concrete has increased firstly and then decreased, compressive strength also showed a trend of firstly increasing and then decreasing. More importantly, with the increase of corrosion inhibitor, the SO42− corrosion resistance property of concrete have improved obviously.

Vanadium-Containing Ionic Liquids Derived from Complexes of Modified Edta as Catalysts of Epoxy-Anhydride Ring-Opening Copolymerization.

A new type of vanadium-containing ionic liquids (ILs) was synthesized by cation exchange from barium salts of oxidovanadium(IV) complexes stabilized by edta and its congeners (dcta, oedta, and heedta) serving as pentadentate ligands. All starting barium salts and several magnesium and cesium salts, serving as models for the cation exchange, were structurally characterized by single-crystal XRD analysis. The synthesized ILs consisting of organic cations (Bu4N+, Bmim+, and Bu4P+) and complex anions ([VO(edta)]2-, [VO(dcta)]2-, [VO(oedta)]-, and [VO(heedta)]-) were characterized by analytical and spectroscopic methods including EPR spectroscopy and cyclic voltammetry. Then, ILs were tested as catalysts for the ring-opening copolymerization of epoxy resin with cyclic anhydride showing significant catalytic activity, which led to production of highly cross-linked glassy thermosets. A detailed isothermal DSC kinetic study was performed for the most promising IL showing that the progress of cross-linking can be successfully fitted by the Kamal-Sourour model. Based on the DSC and NIR results, the initiation mechanism of the cross-linking in the presence of vanadium-containing IL was suggested. IL had ability to activate a rapid hydrolysis of anhydride cycle and the formed carboxyl groups initiated a polyesterification. In parallel, the role of imidazolium cation of IL for the initiation of chain-growth anionic copolymerization is also discussed.

Conversion of Metal Pyrazolate/(Hydr)oxide Clusters into Nanojars: Solution vs Solid-State Structure and Magnetism.

Nanojars are a class of anion binding and extraction agents composed of a series of [Cu(μ-OH)(μ-pz)]n (pz = pyrazolate; n = 26-36) supramolecular metal-organic complexes. In contrast to other anion binding agents amenable to liquid-liquid extraction, nanojars only form by self-assembly around the target anion, and guest-free nanojar hosts cannot be isolated. An extraordinary binding strength toward highly hydrophilic anions such as carbonate and sulfate was demonstrated by the inability of Ba2+ ions to precipitate the corresponding insoluble barium salts from nanojars. Herein, we provide an additional proof for the superior robustness of the nanojar framework based on competition experiments with other transition metal pyrazolate/(hydr)oxide complexes. In addition to the mass spectrometric characterization, we present variable-temperature nuclear magnetic resonance studies with an emphasis on the influence of the paramagnetic Cu2+ centers on 1H hyperfine shifts, along with X-ray crystallographic analysis of two polymorphs of (MePh3P)2[CO3⊂{Cu(OH)(pz)}27], including the highest (cubic) symmetry nanojar crystal lattice obtained to date as well as magnetism studies for the first time. Furthermore, we provide evidence for the first molybdate-incarcerating nanojars, [MoO4⊂{Cu(μ-OH)(μ-pz)}n]2- (n = 28, 31-33), formed by rearrangement from [MoVI8O12(μ-O)9(μ-pz)6(pzH)6·3pzH] in the presence of Cu2+ ions.

Efficient separation and recovery of barium from barium slag via hydrometallurgical approach: Process design, thermodynamics research and mechanism investigation

The accumulation of barium slag (Bs) not only presents significant environmental challenges but also results in the inefficient utilization of resources. The present study investigates the scientific problems of hydrometallurgical methods for converting compounds containing barium in Bs into desired barium salts, with a specific focus on acid treatment, flocculation and precipitation of soluble barium from the leaching solution, as well as heavy media separation in the Bs residue. The experimental findings demonstrate that over 98.5% of the compounds containing barium undergo successful conversion into BaCO₃ and BaSO₄, achieving high purities of 98.7% and 79.4%, respectively. A crucial aspect of the mechanism lies in the interaction among ions, which facilitates the conversion of compounds containing barium into the desired barium salts. Additionally, the utilization of flocculants significantly enhances the efficiency and rate of flocculation for the BaCO₃ turbid fluid, wherein PAM and C-PAM exhibit superior effects in comparison to A-PAM. The reduction in the thickness of the electrical double layer, achieved through the application of flocculants, plays a pivotal role in expediting particle precipitation. Moreover, thermodynamic analysis illuminates the energy changes and the transformation processes during the recovery of barium from Bs. The study concludes by presenting a strategy for cleaner production to recover desired barium salts with Bs.

Application of sulfate ion fixation in internal sulfate attack: The gel containing barium salt

Sulfate attack is one of the most important factors affecting the durability of concrete, and the corrosion sources of internal sulfate attack (ISA) mostly come from the raw materials of concrete. Adding corrosion resistance admixtures to concrete is one of the most effective ways to prevent internal sulfate attack. By wrapping barium salt with SA gel, the modified barium chloride admixture (MB) is obtained which can exist stably in concrete and release barium ions to form barium sulfate in a sulfate environment. The modified barium salt has little effect on the cement workability and hydration process and even can improve the mechanical properties slightly. When the MB content reaches 6% (MB-6), the strength improvement effect is most obvious. Compared with the P-0, the 7d compressive strength of MB-6 is increased by 9.14%, and the 28d compressive strength is increased by 5.77%. It can be seen by SEM that the amount and crystal size of ettringite in the cement mixed with admixtures are reduced. The corrosion resistance of the matrix can be further improved by using a modified barium chloride-silica fume composite admixture (MB-F). After 90 days of internal sulfate attack, the strength of the MB-F even improves slightly. When the modified barium chloride to silica fume ratio is 4:6, the cement-based material achieved the best resistance to internal sulfate attack. In addition to MB, which can make sulfate ions fixation and inhibit the formation of ettringite, silica fume can also consume calcium hydroxide and generate more C-S-H gel, which compacts the weak part of the matrix and greatly improves the resistance to internal sulfate attack of cement-based materials. It provides the possibility for the application of modified barium salt in external sulfate attack.

Decellularized small intestine scaffolds: a potential xenograft for restoration of intestinal perforation

ABSTRACTSmall intestine perforation is a serious medical condition that requires immediate medical attention. The traditional course of treatment entails resection followed by anastomosis; however, it has complications such as small bowel syndrome (SBS), anastomotic leakage, and fistula formation. Here, a novel strategy is demonstrated, that utilizes the xenogeneic, decellularized goat small intestine as a patch for small intestine regeneration in cases of intestinal perforation. The goat small intestine scaffold underwent sodium dodecyl sulfate decellularization, which revealed consistent, quick, and effective decellularization. Decellularization contributed the least amount of extracellular matrix degradation while maintaining the intestinal architecture. By implanting the decellularized goat small intestine scaffolds (DGSIS) on the chorioallantoic membrane (CAM), no discernible loss of angiogenesis was seen in the CAM region, and this enabled the DGSIS to be evaluated for biocompatibility in ovo. The DGSIS was then xeno-transplanted as a patch on a small intestine perforation rat model. After 30 days post transplant, barium salt used as contrast gastrointestinal X-ray imaging revealed no leakage or obstruction in the small intestine. Histology, scanning electron microscopy, and immunohistochemistry assisted in analyzing the engraftment of host cells into the xeno patch. The xeno-patch expressed high levels of E-cadherin, α-smooth muscle actin (α-SMA), Occludin, Zonnula occluden (ZO-1), Ki 67, and Na+/K+-ATPase. The xeno-patch was consequently recellularized and incorporated into the host without causing an inflammatory reaction. As an outcome, decellularized goat small intestine was employed as a xenograft and could be suitable for regeneration of the perforated small intestine.

Hydrazine Sulfonic Acid, NH3 NH(SO3 ), the Bigger Sibling of Sulfamic Acid.

The reaction of hydrazine hydrate, N2 H4 ⋅ H2 O, and SO3 leads to hydrazine sulfonic acid (Pca21 , a=849.59(4) pm, b=482.18(2) pm, c=832.17(4) pm). Structure elucidation reveals the zwitter-anionic nature of the compound according to NH3 NH(SO3 ). With the barium salt Ba[NH2 NH(SO3 )]2 (H2 O), a first salt of hydrazine sulfonic acid has been prepared (P , a=489.75(5) pm, b=737.52(7) pm, c=1317.4(1) pm, α=88.238(4)°, β=84.761(4)°, γ=79.701(4)°). The compounds were characterized by vibrational spectroscopy, DFT calculations and thermal analyses.

Structure and Electronic Properties of Large Oligomeric Heterometallic 3d/CeIV Polyoxometalates.

Merging the rich chemistry of Ce(IV) polyoxometalates (POMs) with that of 3d polyanions remains a challenge due to the strong competition between these highly oxophilic lanthanide cations and 3d metallic ions for coordination to lacunary molecular metal oxides. We report herein the characterization of an unprecedented water stable hexameric CeIV/CoII POM (Ce12Co6) made of two {(SiW9)2Ce6} units connected to a {(SiW10)2Co6(PO4)2} core. In addition, the pentameric CeIV/NiII compound Ce6Ni8, where two {PW9Ni3W} and a {PW10Ni2} fragments are grafted on a {(PW9)2Ce6} moiety, has been obtained. Magnetic studies of Ce6Ni8 revealed ferromagnetic interactions between the NiII centers constituting the {Ni3PW10} fragments, in agreement with the geometry of such a trinuclear cluster. Related insoluble barium salts of Ce12Co6 and Ce6Ni8 were also prepared, allowing their solid-state electrochemical investigations and showing in particular that in Ce12Co6, both the cobalt, cerium, and silicotungstate moieties are electroactive. Finally, photophysical studies demonstrate the formation of long-lived reduced POMs photosensitized by [Ru(bpy)3]2+, suggesting that Ce12Co6 and Ce6Ni8 could be used as efficient reservoirs of reduction equivalents for photocatalytic reactions.

Micro crystalline cellulose aided surface modification and deposition of green polyelectrolytes for the improved hydrophilicity and flame retardancy of polyamide 66 fabric

In this work, microcrystalline cellulose (MCC) treated polyamide 66 (PA66) textiles were coated with green and naturally abundant polysaccharides specifically, chitosan (CS) and sodium alginate (SA) together with phytic acid (PA) via layer by layer (LbL) deposition. The prime focus of such treatment was to intensify both the hydrophilic and flame retardant properties of PA66 fabric substrates. Subsequently, the prepared coatings were further subjected to cross-linking modification by dipping them into the barium (Ba) salt solution. Obtained results indicated that the MCC-modified PA66 exhibited a water contact angle (WCA) value of 00 and revealed a drop in peak heat release rate (pHRR) up to 31 % with complete suppression of melt-dripping. Meanwhile, the Ba-ion-induced cross-linking treatment further escalated this reduction up to 36 % by adding enhanced thermal stability, improved char quality along better wash durability of as prepared coatings. In addition, the combined modification of PA66 textiles with MCC and Ba-ion handed a superb enhancement of physical properties like tensile strength by ca. 50 % compared to the pure PA66. Thus, this MCC-assisted surface modification paves the way for a new kind of greener treatment of PA66 textiles in attaining superior hydrophilic and flame retardant properties of the same.

Energetic Salts of a Tri-Annulated Ring System.

Energetic salts of a triazolyl-tetrazinyl-aminotriazine ring system are characterized as energetic materials. Previously known sodium, ammonium, hydrazinium, barium, and triaminoguanidinium salts as well as the parent free acid were synthesized according to literature procedures and fully characterized for the first time as energetic materials. The silver salt was also synthesized and characterized for the first time as an energetic material. Generally, these materials form hydrates that are insensitive to mechanical stimuli; however, in cases in which anhydrous materials can be obtained, high sensitivities are possible.

Effect of slowly released barium ions on chloride binding in Portland cement paste

The sulfate from gypsum in Portland cement can weaken the chloride binding. In this study, barium ions (Ba2+) were loaded in expanded perlite (EP) to prepare Ba/EP composites and then added to the Portland cement paste. The chloride ion binding capacity and the setting time of the cement-Ba/EP composite system were verified. The diffusion of Ba2+ in the cement paste was observed by SEM-EDS, and the phase assemblage was examined by XRD, TG-DTG, and NMR. The results showed that the Ba2+ loading capacity of the Ba/EP composites reached 59.3 wt%, and only 14.6 wt% Ba2+ was released in the first 3 h, demonstrating the slow release of Ba2+. The addition of Ba/EP composites reduced the negative effect on the setting time of the Portland cement paste compared to the direct addition of barium salt. The 3 wt% Ba/EP composites could increase the chloride binding capacity by 16 %, 18 %, and 32 % at 7 d, 28 d, and 240 d, respectively. Due to the precipitation of Ba2+ on SO42−, the migration of Ba2+ simultaneously caused the migration of SO42− in the opposite direction. The Ba2+ released from the Ba/EP composites promoted the stability of Friedel’s salt at the late age, which improved the chloride binding of Portland cement paste in the long term.

Removal of free acids from heavy alkylbenzene sulfonic acid by a novel three-step method

Excessive amounts of free acids will significantly reduce the quality of heavy alkylbenzene sulfonic acid and its downstream products. To get rid of the excess free acids in heavy alkylbenzene sulfonic acid, a novel three-step deacidification technique called barium salt neutralization method was developed with the aware of “process intensification” in this work. Various factors affecting the deacidification process were thoroughly studied. Results show that using this deacidification method, the free acids content in heavy alkylbenzene sulfonic acid can be reduced from 1.5% to less than 0.1% at the producing condition of room temperature, atmospheric pressure, reusable green solvent, and short time. The free acids removal rate and recovery rate of feed can reach to 96.7% and 95.3%, respectively. It has been demonstrated that the barium salt neutralization method is an effective way to lower the amount of free acids in heavy alkylbenzene sulfonic acid, and can be readily turned into practical applications.

The synthesis of calcium and barium salts of carboxymethylamine-methylalkylphenol and their effect on properties of ДС -11 engine oil

The authors suggest a simple environmental-friendly method to obtain the additives with anticorrosion and washing properties. Described method is based on the interaction of hydroxides of the alkaline-earth metals with carboxymethylamine-methylalkylphenol obtained via the reaction of the industrial alkylphenol with formaldehyde and the aminoacetic acid. The effect of synthesized compounds – calcium and barium salts of carboxymethylamine-methylalkylphenol on the anticorrosion and washing properties of ДС -11 oil has been studied. It was established that they show high anticorrosion and washing performance. In 2.5% concentration of the additive, the corrosion of ДС -11oil is eliminated. The compounds studied do not worsen other properties including the viscosity index and freezing temperature of studied ДС -11 oil. It was revealed that the composition from barium salts of carboxymethylamine-methylalkylphenol and ИХП-21 additive shows high anticorrosion, antioxidation and washing properties as well.

Efficient stabilization of barium- and gypsum-bearing tailings by one-step dry ball milling—An ingenious inspiration

The stockpiling of massive amounts of easily leachable barium-containing slag poses an unpredictable risk to the environment and human health. Current researches into the treatment of barium ion (Ba2+) contamination are largely focused on end-of-pipe treatment, with few options for front-end sequestration. In this study, gypsum dihydrate was used to passivate barium carbonate (BaCO3) to form a hard-to-leach barium salt (BaSO4) directly by simple dry ball milling, successfully to prevent barium leaching from the landfilling. Phase identifications of the samples before and after ball milling were performed to confirm the production of BaSO4 and acidic leaching of the milled sample was performed to identify the Ba2+ passivation. Additionally, large amount of CaCO3 as the byproduct of forming BaSO4 may be used as a slow-release base for efficiently treating acidic wastewater containing heavy metals. This research may open up a new green process to treat both barium-containing and gypsum tailings, and eventually achieves the purpose of treating waste with waste.

Dissolution behavior of DTPA-promoted barium slag and synthesis of submicron BaSO4 particles

Barium slag (BS) is a kind of industrial solid waste generated in barium salt production. Barium in BS can be considered as a secondary source as the content of BaO is as high as 34.80%. The main existent forms of barium in BS are BaSO4, BaCO3 and BaSiO3. It is challenging to dissolve BaSO4 using conventional acids and alkalis due to the low solubility. In this study, diethylenetriaminepentaacetic acid (DTPA) was introduced to investigate the dissolution behavior of barium in BS, and the DTPA complex solution was acidified to release barium for submicron BaSO4 products preparation. Leaching tests were carried out at DTPA concentrations of 0.025–0.30 mol/L, liquid solid ratio of 10–100 mL/g, pH of 8.0–13.0, and reaction temperature of 20–80 °C. The leaching efficiency of barium was 78.64% under the conditions of using 0.10 mol/L DTPA solution (pH of 12.0) at 80 °C for 300 min with the liquid solid ratio of 50 mL/g. BaSO4 products were obtained by the addition of H2SO4 to acidify the leachate at pH ranges of 9.0–7.5. Characterization results from X-ray diffraction, scanning electron microscopy, transmission electron microscopy and dynamic light scattering indicated that the BaSO4 products were nearly sphere particles with the average diameter of 300–500 nm. This work demonstrates that DTPA can dissolve barium in BS and acidifying Ba-DTPA leachate can dissociate barium ions. Furthermore, barium source in BS can be recovered in the form of submicron BaSO4 products through DTPA complexation and decomplexation process.

Green diesel production from Karanja oil using mesoporous Ba(HPW12O40) solid acid catalyst

Highly mesoporous Ba(HPW12O40) heterogeneous acid catalysts were successfully synthesized by the two-step impregnation method and characterized for their catalytic activities, the trans-esterification reaction of Karanja oil was evaluated. The various amounts of catalyst were loaded in the acidic medium and then Barium salt of tungstophosphoric acid. The acid catalyst was characterized using a techniques like FT-IR, XRD, BET, TGA, SEM and EDX.The results indicate that Ba2+ was incorporated into the HPW12O40 framework via isomorphous substitution between Ba2+ ions. During the tests, it was observed that Ba (HPW12O40), for transerterification of pongamia oil (89%) at optimized reaction conditions of 120 °C, 16:1 methanol to reactant molar ratio, 0.75 wt% catalyst loading, and 3 hrs reaction time. The results show that all of the solids have catalytic activity in the cracking reaction, which lowers the ultimate acidity of the products. The solids also have catalytic activity in the transesterification of triglycerides, resulting in high ester yields of 95% from Pongamia oil. The biodiesel production from pongamia oils was characterized by FTIR analysis and 1H- NMR spectroscopy. With significant activity and stability, the used catalysts could be recycled up to three times.

Elucidating the effect of barium halide promoters on La2O3/CaO catalyst for oxidative coupling of methane

The industrialization of oxidative coupling of methane (OCM) is restricted by the low once through yield of C2 hydrocarbons. Recently, the halogen-assisted OCM process has been attempted to overcome this issue, but the reaction stability was poor due to the rapid loss of gas-phase halides or molten alkali halides. In this work, the barium salts, particularly barium halides (BaCl2 and BaF2), were demonstrated to be efficient promoters to improve the OCM reactivity of La2O3/CaO catalyst by increasing both C2 selectivity and C2H4/C2H6 ratio, and simultaneously achieving outstanding reaction stability. The promoting mechanism can be understood in two aspects. On the one hand, the introduction of barium salts increased the amount of surface electrophilic oxygen species, serving as the alkaline active sites for selective methane activation. On the other hand, the barium halide additives induced the in-situ formation of methyl halide intermediates facilitating C2H6 dehydrogenation, and their intimate contact with catalyst substrate restricted the rapid halogen loss and thereby improved the catalytic stability. This work not only provides a class of efficient OCM catalyst, but also offers a highly stable halogen-assisted reaction strategy.

Barium 5-(tert-butyl)-2,3-dihydroxybenzenesulfonate

Catechols and their derivatives attract great scientific interest due to the broad spectrum of their functional properties, including complexation, redox behavior, association ability and antioxidant activity. Because of the low molecular mass and two-electron redox process, they are considered to be a promising energy storage compound in different types of electrochemical power sources, such as metal-ion batteries or redox flow batteries. Herein, we report a preparation of the sterically hindered sulfonated catechol, namely the barium salt of 5-(tert-butyl)-2,3-dihydroxybenzenesulfonic acid, by the direct sulfonation of 4-tert-butylcatechol, by concentrated sulfuric acid. The proposed procedure is green and atom-economic, providing the desired product in high yield after simple purification. The solvent-free procedure is inexpensive and highly scalable, which enables direct industrial production of the title product. The resulting product was characterized by the 1H and 13C nuclear magnetic resonance (NMR) and ESI-high resolution mass spectrometry (ESI-HRMS).

Features of the Clinical Course, Diagnosis and Intensive Care of Acute Barium Poisoning

Acute barium poisoning is a rare but extremely dangerous type of poisoning in the structure of chemical injuries. The article provides a brief overview of the pathogenesis, clinical course and principles of intensive therapy of acute intoxication with this metal, as well as clinical examples of severe poisoning with barium salts with a negative and positive outcome in victims who used counterfeit barium carbonate instead of barium sulfate.

Small compound - big colors: synthesis and structural investigation of brightly colored alkaline earth metal 1,3-dimethylviolurates.

A series of brightly colored alkaline earth metal 1,3-dimethylviolurates M(Me2Vio)2 have been prepared and fully characterized. The title compounds AE(Me2Vio)2·nH2O (AE = Mg, n = 6 (3); AE = Ca, n = 8 (4), AE = Sr, n = 6 (5); AE = Ba, n = 4 (6)) were obtained by neutralizing 1,3-dimethylvioluric acid monohydrate (=H(Me2Vio)·H2O; 2) with 0.5 equiv. of the corresponding metal dihydroxides AE(OH)2. The hair-like appearance of the Sr derivative 5 prevented the growth of single-crystals. This problem could be solved by crystallizing the crown ether derivative Sr(Me2Vio)2(18-crown-6) (5a). The isolated salts exhibit intense colors ranging from red to purple. Various attempts to prepare the beryllium derivative Be(Me2Vio)2 failed. Instead, work-up of the reaction mixtures provided pink crystals of a new modification of 2 formulated as [H3O][Me2Vio] (2b) as shown by an X-ray diffraction study. An unexpected oxidation reaction of the barium salt Ba(Me2Vio)2 led to formation of the novel mixed-anion salt Ba(Me2Vio)(Me2NO2Barb)·2H2O (8, Me2NO2Barb- = 1,3-dimethyl-5-nitrobarbiturate anion). Compound 8 could also be synthesized deliberately by treatment of Ba(OH)2 with a 1 : 1 mixture of 2 and 1,3-dimethyl-5-nitrobarbituric acid (7, =H(Me2NO2Barb)·H2O). All new compounds were fully characterized by their IR, Raman, NMR (1H, 13C{1H}) and UV-vis spectra as well as elemental analyses. Single-crystal X-ray diffraction studies revealed that the solid-state structures of compounds 3, 4, 5a and 6 are governed by the typical coordination behavior of the alkaline-earth metals, i.e. increasing coordination numbers and a decreasing degree of hydration when going from Mg to Ba. The dimensions of the structures range from hydrogen-bonded ions (3) over monomeric, neutral complex molecules (4, 5a), to polymeric networks (6). The successful isolation of the mixed-anion barium salt 8 adds a new facet to the coordination chemistry of violurate and related ligands.