Chloride Sulfate Research Articles

Study on the Chloride–Sulfate Resistance of a Metakaolin-Based Geopolymer Mortar

The chloride–sulfate corrosion environment of concrete is a significant engineering problem. This paper investigates the effect of the complete/semi–immersion mode on the durability of concrete in a chloride–sulfate environment by using different granulated blast furnace slag (GBFS) dosage rates (10–50%) of a metakaolin (MK)-based geopolymer mortar. The chloride–sulfate corrosion environment is discussed by analyzing the apparent morphology, mass change, and mechanical property change in specimens at the age of 120 d of erosion combined with XRD and SEM. The high Ca content in GBFS has an important effect on the strength and erosion resistance of the metakaolin geopolymer (MGP) group mortar; an increase in the GBFS dosage makes the MGP group mortar denser, and the initial strength of the MGP group mortar is positively correlated with the dosage of GBFS. After 120 d of erosion, the GBFS dosage is negatively correlated with erosion resistance, with the high GBFS dosage groups showing more severe damage. Semi-immersion resulted in more severe deterioration at the immersion–evaporation interface zone due to the difference in the ionic concentration and the ‘wick effect’ at the immersion–evaporation interface zone. Compared with the commonly used OPC mortar, the M40 and M50 groups have improved strength and corrosion resistance and are suitable for engineering environments in highly erosive areas.

Versatile synthesis of 2-functionalized dihydrothiazolo[2,3-b]quinazolines through regioselective electrophilic intramolecular heterocyclization of 3-alkenyl-2-thioxoquinazolin-4-ones

Electrophilic intramolecular heterocyclizations of 3-alkenyl-2-thioxoquinazolin-4-ones, induced by halogens, NBS, sulfuryl chloride, protic acids, selenium, or tellurium halides, proceed with high regioselectivity. This process leads to the formation of 2-functionalized dihydrothiazolo[2,3-b]quinazolines, showcasing the versatility and reliability of this synthetic route across various electrophilic reagents.

The Improving Role of Basalt Fiber on the Sulfate-Chloride Multiple Induced Degradation of Cast-In-Situ Concrete.

In salt lake areas, the cast-in-situ concrete structure has been corroded by the combination of sulfate and chloride for a long time. The incorporation of basalt fiber materials into concrete helps to improve the durability of concrete. In this paper, experiments were conducted to study the corrosion deterioration mechanisms of basalt fiber-reinforced cast-in-situ concrete under sulfate, chloride, and combined attack. The appearance, size, mass, flexural, and compressive strength of specimens were investigated during the immersion period to determine the changes in the physical and mechanical properties of specimens. Moreover, the microstructure and mineral changes of specimens during the immersion period were observed by Scanning Electron Microscope (SEM), Energy Dispersive Spectrometer (EDS), X-ray diffraction (XRD), and Thermogravimetric (TG)/ Derivative Thermogravimetric (DTG) analyses. Results show that premixed chloride has a significant detrimental influence on the strength development of cast-in-situ concrete, with concrete powder spalling occurring on the surface of the specimen. Severe corrosion degradation of specimens occurs under the external sulfate and internal chloride combined attack, resulting in lower flexural and compressive strength. The compressive strength and flexural strength of the corroded specimens decreased by 15.4% and 24.8%, respectively, compared with the control group at 28 days. Moreover, premixed basalt fiber has a beneficial influence on cast-in-situ concrete. When the basalt fiber content is 0.5%, the flexural strength of the specimen is increased by 16.2%. The filling and bridging effect of basalt fiber alleviates the negative effects caused by corrosion. In addition, increasing fiber content is beneficial for enhancing its effectiveness when the fiber content is less than 0.5%. This paper provides a valuable reference for the application of basalt fiber-reinforced cast-in-situ concrete under the condition of sulfate-chloride compound corrosion.

Experimental investigation of metakaolin ingredients on bonding of steel fibers to cement in paste of steel fiber concrete under sulfate and sulfate–chloride attack

The present study aimed to produce specimens made from steel fibers/metakaolin (SFs/MK) composite concrete that would achieve superior strength characteristics and controlled cracking behavior under aggressive media (i.e. sodium sulfate and sodium chloride). The composite of SF and concrete is full of porosity, creating weak zone in the specimens. Therefore, the use of clay materials is required to reduce the porosity. In this context, the general physical and chemical properties of clay, including structure and the percentage of alumina and quartz, play a significant role in forming composites with suitable mechanical properties. The changes in weight of SFs, effects of the aging period in terms of strength, and effect of aggressive solution are investigated and compared with SF reinforced concrete. The findings from N2 adsorption-desorption, field emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRD), X-ray fluorescence (XRF) and compressive strength tests indicate that MK with disordered stacking and higher percentage of alumina, and lower quartz content provides better bonding in the concrete composite. According to the experiments conducted in this study, a 15.0 % MK and 2.0 % SF replacement of cement increased the sulfate and chloride resistance due to porosity, and water absorption values, respectively.

Argyrodite–Li6PS5cl/Polymer–Based Highly Conductive Composite Electrolyte for All–Solid–State Batteries

The intense focus of research is on all–solid–state lithium–ion batteries (ASSLBs) with solid electrolytes (SEs) owing to their potential qualities such as high energy, high power density, and enhanced safety compared to conventional Lithium Ion batteries (LIBs).1 In spite of the numerous advantages of ASSLBs, a lot of issues still need to be solved before commercialization.2 Typically, SEs demonstrate lower ionic conductivity (σ) compared to liquid electrolytes.1 For instance, lithium phosphorous oxynitride (LiPON), a frequently employed SE, exhibits an σ of ca. 10–6 S/cm. In contrast, a liquid electrolyte like lithium hexafluorophosphate in ethylene carbonate and propylene carbonate demonstrates a higher σ of ca. 10–2 S/cm at room temperature.1 So far, extensive research has been conducted on Argyrodite–Li6PS5Cl (LPSCl) electrolytes, yielding promising results for their applications in Li–ion and Li–S batteries.3However, a significant challenge in using argyrodite LPSCl in ASSLBs applications is the interface instability between the LPSCl and electrodes. During charge-discharge (CD) cycling, LPSCl tends to oxidize, leading to the production of elemental sulfur, polysulfides, phosphates, and lithium chloride at the electrode interface.3These side products ultimately hinder cycling stability and can result in dendrite formation at the interface. Another important drawback of LPSCl is its non–negligible electronic conductivity, which allows for smooth electron transport through the LPSCl electrolyte.4Consequently, Li dendrites can be directly deposited at the grain boundaries of LPSCl particles, leading to a serious self–discharge issue.4 In this study, we have developed a composite electrolyte of LPSCl/polymer to enhance the contact between the electrolyte and electrodes and suppress dendrite formation at the grain boundary of the LPSCl ceramic. The monomer, triethylene glycol dimethacrylate (TEGDMA), is utilized for in–situ polymerization through thermal curing to create the Argyrodite LPSCl/polymer composite electrolyte. Additionally, the ball–milling technique was employed to modify the morphology and particle size of the LPSCl ceramic. The ball–milled LPSCl/polymer composite electrolyte (BLPSCl–P) demonstrates slightly higher ionic conductivity (ca. 2.21 × 10–4 S/cm) compared to the as–received LPSCl/polymer composite electrolyte (ALPSCl–P) (ca. 1.65 × 10–4 S/cm) at 25 °C (Figure 1). Furthermore, both composite electrolytes exhibit excellent compatibility with Li–metal and display cycling stability for up to 1000 hours (375 cycles) (Figure 1), whereas the as–received LPSCl (ALPSCl) and ball–milled LPSCl (BLPSCl) electrolytes maintain stability for up to 600 hours (225 cycles) at a current density of 0.4 mA/cm2. The SSB with the BLPSCl–P delivers high specific discharge capacity (138 mAh/g), Coulombic efficiency (99.97%), and better capacity retention at 0.1C, utilizing the battery configuration of coated NMC811//electrolyte//Li–Indium (In) at 25 °C. Figure 1 REFERENCES (1) Li, S.; Zhang, S. Q.; Shen, L.; Liu, Q.; Ma, J. Bin; Lv, W.; He, Y. B.; Yang, Q. H. Progress and Perspective of Ceramic/Polymer Composite Solid Electrolytes for Lithium Batteries. Adv. Sci. 2020, 7 (5).(2) Lee, S. E.; Sim, H. T.; Lee, Y. J.; Hong, S. B.; Chung, K. Y.; Jung, H. G.; Kim, D. W. Li6PS5Cl–Based Composite Electrolyte Reinforced with High–Strength Polyester Fibers for All–Solid–State Lithium Batteries. J. Power Sources 2022, 542 (6), 231777. (3) Lee, Y. G.; Fujiki, S.; Jung, C.; Suzuki, N.; Yashiro, N.; Omoda, R.; Ko, D. S.; Shiratsuchi, T.; Sugimoto, T.; Ryu, S.; Ku, J. H.; Watanabe, T.; Park, Y.; Aihara, Y.; Im, D.; Han, I. T. High–Energy Long–Cycling All–Solid-State Lithium Metal Batteries Enabled by Silver–Carbon Composite Anodes. Nat. Energy 2020, 5 (4), 299–308.(4) Yang, X.; Gao, X.; Jiang, M.; Luo, J.; Yan, J.; Fu, J.; Duan, H.; Zhao, S.; Tang, Y.; Yang, R.; Li, R.; Wang, J.; Huang, H.; Veer Singh, C.; Sun, X. Grain Boundary Electronic Insulation for High–Performance All–Solid–State Lithium Batteries. Angew. Chem. Int. Ed. 2023, 62 (5). Figure 1

Copper leaching from complex chalcopyrite-rich ores: Utilizing mechanical activation and wastewater-based sulfuric acid system

Complex chalcopyrite-rich ore is crucial in global copper resources, but is highly refractory in conventional sulfate leaching system. In this paper, we explore the leaching of complex chalcopyrite-rich ores employing a mechanically activated pretreatment combined with wastewater with high concentrations of chloride. The investigation delves into various parameters, including reaction temperature (60 to 90 °C), sulfuric acid concentration (0.005 to 2.0 M), chloride concentration (0 to 1.5 M), liquid/solid ratio (0 to 200), stirring speed (100 to 580 rpm), leaching time (0 to 4 h) and grinding time (0 to 7 h), to evaluate their impact on copper recovery from complex chalcopyrite-rich ores. Furthermore, a comprehensive kinetic analysis of copper leaching behavior was studied, encompassing specific surface area, amorphization degree, grain size, and microstrain. In the sulfuric acid system utilizing wastewater, the presence of mechanical activation and chloride content enhances copper leaching while mitigating the passivating effect of elemental sulfur. Notably, following a leaching period of 4 h at 80 °C, the copper leaching efficiency remarkably reached 89.46 %. In addition, kinetic analysis of copper leaching at temperatures ranging from 60 to 90 °C via a shrinking core model with R2 > 97 %, indicates that the leaching process of copper is primarily governed by solid product layer diffusion, with an activation energy of 54.32 kJ/mol. These findings highlight the efficacy of the proposed approach in optimizing copper recovery from complex chalcopyrite-rich ores, offering insights into the underlying mechanisms driving the leaching process.

Identification and time evolution of thionyl chloride (SOCl2) radiolysis products

Abstract Innovative solutions are needed to reduce the amount of high-level waste generated by used nuclear fuel recycling strategies to support the widespread adoption of sustainable nuclear fission energy technologies. To this end, a new sulfur chloride-based process has been developed to recycle zirconium alloy-based materials, which make up a significant fraction of high-level radioactive waste. To support the continued development of this process, we present new data on the potential reaction pathways over time of the products arising from the gamma and electron beam radiolysis of neat thionyl chloride (SOCl2). Interrogation of the gamma irradiated liquid by Raman spectroscopy provided more conclusive identification of the SOCl2 degradation products, specifically sulfur dichloride (SCl2), molecular chlorine (Cl2), sulfur dioxide (SO2), and sulfuryl chloride (SO2Cl2). In comparison, the high dose rate (∼107 Gy s−1) electron beam irradiations formed significantly more degradation products. For both cobalt-60 gamma and electron beam irradiations, the observed degradation products were found to evolve as a function of time post-irradiation via the same reaction pathways, with indication of a solvent regeneration mechanism. These findings are fortuitous for process development, as such a mechanism would be beneficial for process longevity and cost effectiveness.

ЗАХИСТ ВІД КОРОЗІЇ НАФТОПЕРЕРОБНОГО ОБЛАДНАННЯ ЗА ДОПОМОГОЮ ІНГІБІТОРІВ З ВІДНОВЛЮВАЛЬНОЇ СИРОВИНИ.ОГЛЯД

The article provides information about corrosion problems in the oil refining industry and the scale of losses associated with it. The causes of corrosion associated with the presence of sulfur compounds, hydrochloric acid and chlorides, naphthenic acids, etc. in oil are described. A set of methods aimed at reducing the corrosion effect of these components is given. The use of inhibitors is one of the most effective and widespread such methods. The use of corrosion inhibitors from renewable raw materials is becoming more and more popular. The article provides an overview of literary sources related to the study of “green” corrosion inhibitors.

Water quality assessment of Bheemasandra Lake, South India: A blend of water quality indices, multivariate data mining techniques, and GIS.

An integrated approach combining water quality indices (WQIs), multivariate data mining, and geographic information system (GIS) was employed to examine the water quality of Bheemasandra Lake, located adjacent to a sewage treatment plant (STP) in Tumakuru city, India. The analysis of 22 lake water samples, examined before and after the monsoons, revealed that the physicochemical parameters namely - electrical conductivity, biochemical oxygen demand, turbidity, total dissolved solids, ammoniacal nitrogen, nitrates, phosphates, magnesium, total hardness, total alkalinity, and calcium - exceeded the acceptable limits stipulated by national and international standards. The Canadian Council of Ministers of the Environment WQI (pre-monsoon: 25.3; post-monsoon: 33.9) and weighted arithmetic WQI (pre-monsoon: 3398; post-monsoon: 2093) designated the water as unsafe for drinking. Irrigation WQIs (sodium adsorption ratio, sodium percentage, residual sodium carbonate, magnesium hazard, permeability index, and potential salinity) implied water's suitability for irrigation. However, electrical conductivity indicated otherwise. Industrial WQIs (Larson-Skold Index, Langelier Index, Aggressive Index, and Puckorius Scaling Index) illustrated scaling propensity and the chloride sulfate mass ratio alluded galvanic corrosion potential. Hierarchical cluster analysis gathered 22 sampling points into two clusters (cluster 1: relatively lower polluted regions; cluster 2: highly polluted regions) for each season based on similarities in water features. Principal component analysis extracted four (79.07% cumulative variance) and six (87.14% cumulative variance) principal components before and after the monsoons, respectively. These components identified the primary pollution sources as urban sewage and natural lithological processes. WQI maps, created using the inverse distance weighted interpolation technique, enhanced the visualization of spatial-temporal variations. This study highlights the dire consequences of urbanization, STP pollution, and sewage management failures, necessitating that concerned authorities should implement policies and measures to curb the negative impacts on the environment and public health.

Determining rational parameters for the treatment of concentrated wastewater from etching site by using combined systems producing sediments of predefined composition

The object of this study is model solutions, spent sulfuric acid and chloride acid etching solutions, degreasing of metal products at enterprises. The paper reports results of research on the possibility of obtaining sediments of predefined composition and reducing the consumption of chemical reagents in comparison with conventional cleaning schemes. The systematization of the elements of the technological scheme has been shown, which provides for the treatment of concentrated wastewater of the etching area in combined systems with obtaining sediments of predefined composition and is the basis for the implementation of resource-saving technology. Rational parameters were established for the state (рН=3‒4, Eh=+0.3‒+0.33 V, and rH2=16.3–19.38 V) and technological parameters (degree of iron extraction ψ=0.8, reagent consumption from the stoichiometric norm of B=0.8). Such parameters provide the proper conditions for the oxidation of organic compounds and their co-precipitation with insoluble iron hydroxy compounds (the maximum degree of extraction of organic impurities is 86 %). The formed precipitate corresponds to the FeOOH.nH2O composition, contains 2‒3 % of organic impurities, and is subject to burial. As a result of studies on the treatment of concentrated iron-containing wastewater, the obtained sediment is ready for further utilization by processing. The composition of this sediment corresponds to the natural mineral limonite FeOOH (Fe2O3.nH2O) and is formed at pH values from 3.5 to 7.5 with rH2 values from 26 V to 21 V and at technological regeneration parameters of pH=4.0–4.6; rH2 =23.34–32.25 V. As a result of research into the deep purification of wastewater using a magnetic device, a suspension of sediment of ferromagnetic impurities (hydroxo compounds of iron) is obtained, which could be the basis for extraction or production of magnetically favorable dispersed material.

Direct Synthesis of Glycosyl Chlorides from Thioglycosides.

Reported herein is a new method for the direct synthesis of glycosyl chlorides from thioglycosides using sulfuryl chloride at rt. A variety of thioglycosides and thioimidates could be used as substrates. Both acid- and base-sensitive protecting groups were found compatible with these reaction conditions. Preliminary investigation of the reaction mechanism indicates chlorination of the leaving group at the anomeric sulfur as the key step of the reaction.

NMI-SO2Cl2-Mediated Amide Bond Formation: Facile Synthesis of Some Dihydrotriazolopyrimidine Amide Derivatives as Potential Anti-Inflammatory and Anti-Tubercular Agents.

Facile access to some novel biologically relevant dihydrotriazolopyrimidine carboxylic acid-derived amide analogues using NMI/SO2Cl2, and aromatic and aliphatic primary and secondary amines, is reported herein. The role of N-methylimidazole (NMI) as the base and sulfuryl chloride (SO2Cl2) as the coupling reagent has been effectively realized in accessing these molecules in good to excellent yields. The feasibility of the developed protocol has also been extended to the gram-scale synthesis of N-benzylbenzamide in a 75% yield from benzoic acid and benzyl amine. The newly synthesized compounds were tested via in vitro anti-inflammatory and anti-tubercular activity studies. The compounds 6aa and 6be were found to be the most active anti-inflammatory agents, whereas 6cb and 6ch were found to exhibit promising anti-tubercular potency when compared to other synthesized molecules. The structure-activity relationship (SAR) studies revealed the importance of the presence of electron-donating functionalities in enhancing the anti-inflammatory potential of the newly synthesized molecules. However, the presence of electron-withdrawing substituents was found to be significant for improving their anti-tubercular potency.

Synthesis, crystal structure, and thermodynamic properties of two new selenate chlorides: M2Cu(SeO4)Cl2 with M = K and Rb

Two new selenate chlorides have been prepared for the first time by hydrothermal method. Their crystal structures have been determined. Both compounds are related to the chlorothionite mineral structure type but not isostructural to each other. K2Cu(SeO4)Cl2 crystallize in the orthorhombic system with the space group Pnma (#62) and unit cell parameters a = 7.7941(2)Å, b = 6.1297(2) Å, c = 16.6644(5) Å, V = 796.15(4) Å3, Z = 4 whereas Rb2Cu(SeO4)Cl2 crystallize in monoclinic system, P21/n (#14), and parameters a = 8.0701(3), b = 12.9474(5), c = 16.9354(7), β = 103.657(2)°, V = 1719.49(12) Å3, Z = 8. Potassium compound are isostructural to the related sulfate chloride, while rubidium selenate is differ from their sulfate analogue and from prototype compound K2Cu(SO4)Cl2. Both examined crystal structures feature copper ions in planar coordination CuO2Cl2 which form isolated magnetic chains along ⟨0 1 0⟩ direction in the structure. The study of M2Cu(SeO4)Cl2 was carried out in measurements of magnetic susceptibility χ(T) = M/B in the temperature range 2–350 K, magnetization M(B) at 2 K and specific heat Cp(T) in the range 2–120 K. At lowering temperature, the magnetic susceptibility exhibits no anomalies and follows by Curie law. An increase of the Cp(T) curve below 3 ÷ 8 K indicates the release of magnetic entropy. The study of thermodynamic properties unexpectedly shows that the investigated selenates M2Cu(SeO4)Cl2 (M = K and Rb) behave like paramagnets and the interaction between copper ions in the structural chains is negligible, opposite related sulfates demonstrating 1D magnetic behavior for Cu2+ magnetic ions.

Trends in estuarine pyrite formation point to an alternative model for Paleozoic pyrite burial

The early Paleozoic Era (∼540–420 Ma) was an interval of profound biogeochemical changes including increasing oxygen (O2) and the onset of bioturbation (sediment mixing by animals). It is hypothesized that incipient bioturbation caused a monotonic decrease in sedimentary burial of pyrite (FeS2), which would have slowed atmospheric O2 accumulation. However, pyrite accumulation can exhibit complex responses to dynamic, low-O2 environmental conditions. To assess pyrite burial in a potential modern analogue to early Paleozoic environments, we collected sediment cores from the Chesapeake Bay, an estuary with multiple gradients in sulfate concentration, hypoxia intensity, organic carbon flux and lability, and bioturbation. Results indicate that pyrite accumulation is maximized not under strong sulfate depletion in highly reducing sediments, but rather in sediments that occupy the mid-range of sulfate–chloride ratios. This probably occurs through efficient replenishment of pore water sulfate and/or through the generation of sulfur redox intermediates, which promote pyrite formation via the polysulfide reaction pathway. In light of these results and in contrast to earlier models, we hypothesize that mild early Paleozoic bioturbation temporarily increased pyrite burial efficiency by stimulating higher sulfate reduction rates and increasing sedimentary sulfide retention. Compiled sulfur and carbon data from a geochemical database indicate that median sulfur-carbon ratios of fine-grained marine siliciclastic rocks increased from the Ediacaran through the Ordovician, then decreased and became much less variable from the Silurian onward. Thus, the Cambrian and Ordovician Periods may constitute a distinct interval of the Proterozoic-Phanerozoic transition in which bioturbation temporarily accelerated O2 buildup. This transition probably ended in the Silurian, when pO2 rose to sufficient levels to homogenize sedimentary carbon–sulfur cycling.

Physico-chemical assessment of surface water from mining activities in Maiganga coal mine, Gombe state, Nigeria

Purpose. Surface water from mining activities may undergo various physico-chemical changes that can impact its quality and ecological health. This study conducted a comprehensive physico-chemical assessment of surface water affected by mining operations, with a particular emphasis on heavy metal content. Methods. These parameters were chosen due to their importance as indicators of water quality and potential contamination. Water samples were collected from different locations within and around Maiganga Coal mine area and analyzed using standard laboratory techniques. The assessment included the measurement of physico-chemical parameters such as temperature, total dissolved solids and concentrations of heavy metals such as chromium, lead, manganese, cadmium and copper. Also, cations and anions such as calcium, magnesium, sodium, potassium, nitrate, chloride sulfate and fluoride that can impact water quality were considered. Findings. The results of the physico-chemical assessment revealed substantial variations of chromium (0.00-0.03 mg/l), lead (0.00-0.05 mg/l), manganese (0.00-12.11 mg/l), cadmium (0.10-0.14 mg/l) and copper (0.00-1.02 mg/l) concentrations. Also, cations and anions such as calcium (0.00-1.13 mg/l), magnesium (11.90-30.07 mg/l), sodium (0.20-1.11 mg/l), potassium (0.10-0.66 mg/l), nitrate (3.90-4.78 mg/l), chloride (84.0-319.0 mg/l), sulphate (8.0-240.0 mg/l) and fluoride (0.00-0.89 mg/l) can impact water quality levels across the sampled surface water bodies. Originality. Evidence of acid mine drainage, caused by mine effluents that are limited to surface water and do not reach groundwater, has been found through analysis of data from wells, ponds, and streams. Practical implications. These variations obtained could be attributed to the discharge of acidic or alkaline substances associated with coal mining activities.

Hydrochemical Characterisation of Groundwaters in a Crystalline Basement Environment: The Case of Fractured Aquifers in the Poni Watershed in the South-West Region of Burkina Faso, West Africa

The Poni watershed is located in the south-west of Burkina Faso. Its geology is made up of fractured crystalline and crystallophyllian basement, where fractured aquifers are the most exploited for water needs. The aim of this study is to determine the physico-chemical characteristics of the groundwater in the fractured aquifers of the Poni watershed in order to gain a better understanding of the mineralisation processes and hydrochemical properties of the groundwater in these aquifers. To do this, approaches based on the determination of Calcite Saturation Indices (CSI) and Dolomite Saturation Indices (DSI), Principal Component Analysis (PCA) and hydrochemical properties show that the majority of groundwater in the basin is undersaturated with respect to carbonates (79.37%) and divided into three families in relation to circulation speed: very slow circulation water (20.63%), slow circulation water (55.56%) and fast circulation water (23.81%). The approaches also show that the mineralisation of groundwater in the basin is governed by the acid hydrolysis of minerals in the surrounding rocks, residence time and surface inputs. They are characterised by calcic and magnesian bicarbonate facies (85.7%), calcic bicarbonate facies (6.35%), sodium and potassium bicarbonate facies (1.59%) and calcic and magnesian sulphate chlorides (6.35%).

Surface Reconditioning of Lithium Metal Electrodes by Laser Treatment for the Industrial Production of Enhanced Lithium Metal Batteries

AbstractIncorporating lithium metal anodes in next‐generation batteries promises enhanced energy densities. However, lithium's reactivity results in the formation of a native surface film, affecting battery performance. Therefore, precisely controlling the chemical and morphological surface condition of lithium metal anodes is imperative for producing high‐performance lithium metal batteries. This study demonstrates the efficacy of laser treatment for removing superficial contaminants from lithium metal substrates. To this end, picosecond‐pulsed laser radiation is proposed for modifying the surface of lithium metal substrates. Scanning electron microscopy (SEM) revealed that different laser process regimes can be exploited to achieve a wide spectrum of surface morphologies. Energy‐dispersive X‐ray spectroscopy (EDX) confirmed substantial reductions of ≈80% in oxidic and carbonaceous surface species. The contamination layer removal translated into interfacial resistance reductions of 35% and 44% when testing laser‐cleaned lithium metal anodes in symmetric all‐solid‐state batteries (ASSBs) with lithium phosphorus sulfur chloride (LPSCl) and lithium lanthanum zirconium oxide (LLZO) solid electrolytes, respectively. Finally, a framework for integrating laser cleaning into industrial battery production is suggested, evidencing the industrial feasibility of the approach. In summary, this work advances the understanding of lithium metal surface treatments and serves as proof of principle for its industrial applicability.

Laser peening induced mitigation of severe pitting corrosion in titanium stabilized 321 steel

Titanium stabilized 321 stainless steel, as a structural component in oil and petrochemical industries, often susceptible to severe pitting corrosion under aggressive corrosion environments (sulfuric acid and chloride ions). This study explores the applicability of laser peening without protective coating (at 6 GW cm−2 intensity and 75 % pulse overlap rate) to enhance the electrochemical stability of 321 steel against such severe pitting corrosion. Laser peening altered surface-mechanical and electrochemical properties were investigated by AFM, SEM and potentiodynamic polarization/impedance spectroscopy techniques. On the account of laser peening induced compressive residual stress (-408 MPa) hardness enhancement, a stable/dense and uniform oxide film was formed on 321 steel, subsequently mitigating the pitting corrosion. By contrast, unpeened surface exhibited more number of wider and deeper merged pits (maximum diameter of ∼ 2197 μm). Laser peening promoted oxidation has been confirmed via elemental composition analysis. A twentyfold enhancement in charge transfer resistance and improved oxide film resistance, attributed from the laser peening increased defect density as demonstrated by the improved hardness, evidenced a highly electrochemical stability on 321 steel.

Regioselective synthesis of 2-aminophenols from N-arylhydroxylamines.

A novel strategy for the synthesis of 2-aminophenols in the absence of metals and oxidants was described. The 2-aminophenols were efficiently obtained through a cascade [3,3]-sigmatropic rearrangement and in situ hydrolysis process by using readily available N-arylhydroxylamines and the in situ-generated methyl chlorosulfonate from commercially available sulfuryl chloride and methanol under mild conditions. This method could be scaled up and has a wide substrate scope with great functional group tolerance and high regioselectivity. The 2-aminophenol products could be readily converted into structurally diverse functional molecules in good yields under various conditions.

Durability Assessment of Recycled Aggregate Geopolymer Concrete Mixed with Wastewater

The advancement of an environmentally friendly setting is complex due to the significant carbon footprint of cement, substantial construction and demolition waste, and large quantities of industrial waste wastewater. This study aims to increase building sustainability by analyzing the long-term durability of recycled aggregate geopolymer concrete (RGC) manufactured using four different wastewaters. To evaluate each wastewater’s effect on sulfuric acid resistance and chloride ion migration (CIM) at various curing times, RGC was used in place of fresh water in the tests. The results revealed that, when it came to acid attack, RGC made with fertilizer industry wastewater had the highest mass loss (41% higher compared to control concrete) and CIM (29% higher compared to control concrete). According to statistical studies, using wastewater from textile, fertilizer, and sugar firms did not substantially alter mass loss from acid attack or CIM.