Search Results (2,167)

In the context of sustainable development, improving the durability of engineering materials and the service life of engineering projects is an important path to address engineering sustainability and low-carbon development. This study addresses the durability issues of steel fiber-reinforced cementitious materials (SFRCMs) under the combined action of stray current and chloride ions in metro engineering. Through simulated stray current-accelerated corrosion tests, combined with compressive strength tests and X-ray computed tomography (X-CT) analysis, the effects of steel fiber volume content (0.5%, 1.0%, 1.5%) and electrification duration (0–72 h) on the mechanical properties and corrosion mechanisms were systematically investigated. The results indicate that steel fiber content significantly influences corrosion rate and strength degradation. Specimens with 1.5% fiber content exhibited the highest initial compressive strength (58.43 MPa), but suffered a severe strength loss rate of 37.67% after 72 h of electrification. In contrast, specimens with 1.0% fiber content demonstrated balanced performance, achieving both high initial strength and superior corrosion resistance (19.66% strength loss after 72 h). X-CT analysis revealed that corrosion products initially filled pores during early stages but later induced microcracks in the matrix. Higher fiber content specimens exhibited increased large-pore ratios due to fiber agglomeration, accelerating chloride ion penetration. Furthermore, digital volume correlation (DVC) analysis demonstrated that steel fibers effectively dispersed loads and reduced stress concentration. However, post-corrosion fiber volume loss weakened their crack resistance capacity, highlighting the critical role of fiber integrity in structural durability. Full article

Regulating the crystallization dynamics of perovskite films is key to improving the efficiency and operational stability of (FA_0.83MA_0.17Cs_0.05)Pb(I_0.85Br_0.15)₃ perovskite solar cells (PSCs). However, precise regulation of the crystallization process remains challenging. Here, we introduce a reactive anti-solvent strategy based on the Kornblum reaction to modulate crystallization via in-situ chemical transformation. Specifically, trans-cinnamoyl chloride (TCC) is employed as a single-component anti-solvent additive that reacts with dimethyl sulfoxide (DMSO) in the perovskite precursor solution. The resulting acylation reaction generates carbonyl-containing products and sulfur ions. The carbonyl oxygen coordinates with Pb²⁺ ions to form Pb–O bonds, which retard rapid crystallization, suppress heterogeneous nucleation, and facilitate the growth of larger perovskite grains with improved film uniformity. Additionally, the exothermic nature of the reaction accelerates local supersaturation and nucleation. This synergistic crystallization control significantly enhances the film morphology and device performance, yielding a champion power conversion efficiency (PCE) of 23.02% and a markedly improved fill factor (FF). This work provides a new pathway for anti-solvent engineering through in-situ chemical regulation, enabling efficient and scalable fabrication of high-performance PSCs. Full article

Aluminum is widely used in many industries like automotive, aerospace and construction because of its low weight, good mechanical strength and resistance to corrosion. This resistance comes mainly from a passive oxide layer that forms on its surface. However, when aluminum is exposed to harsh environments, especially those containing chloride ions in marine environments, this layer can break down and lead to localized corrosion, such as pitting. This study examined aluminum profiles at different processing stages, including homogenization and aging, anodizing and pre-anodizing followed by painting. Corrosion behavior of samples was studied using two electrochemical methods. Potentiodynamic polarization was used to measure corrosion rate and current density, while Electrochemical Impedance Spectroscopy (EIS) helped to understand the behavior of protective layers and corrosion progression. Tests were carried out in a 3.5% NaCl solution at room temperature. EIS results were analyzed using equivalent circuit models to better understand electrochemical processes. Overall, this study shows how surface treatment affects corrosion resistance and highlights advantages of EIS in studying corrosion behavior in a more reliable and repeatable way. Full article

This study deciphers the anionic modulation mechanism of halide ions (F⁻/Cl⁻) in cobalt-based hydroxides for oxygen evolution reaction (OER). Phase-pure Co(OH)₂, Co(OH)F, and Co₂(OH)₃Cl were fabricated via substrate-independent hydrothermal synthesis to eliminate conductive support interference. Electrocatalytic evaluation on glassy carbon electrodes demonstrates fluoride’s superior regulatory capability over chloride. X-ray photoelectron spectroscopy (XPS) analyses revealed that F⁻ incorporation induces charge redistribution through Co → F electron transfer, optimizing the electronic configuration via ligand effects. F⁻ incorporation simultaneously guided the anisotropic growth of 1D nanorods and reduced surface energy, thereby enhancing the wettability of Co(OH)F. The engineered Co(OH)F catalyst delivers exceptional OER performance: 318 mV overpotential at 10 mA/cm² in 1 M KOH with 94% current retention over 20 h operation. This study provides a synthetic strategy for preparing pure-phase Co(OH)F and compares halide ions’ effects on enhancing OER activity through electronic structure modulation and morphological control of basic cobalt salts. Full article

A key goal when managing copper alloy heritage is preventing “bronze disease,” which damages surface detail and may disintegrate objects by oxidation and hydrolysis of nantokite (CuCl), forming voluminous copper trihydroxychlorides (Cu₂(OH)₃Cl). The success of mitigation strategies is difficult to evaluate due to the complexity of copper alloy corrosion profiles, limitations in non-destructive analytical methods and incomplete understanding of the corrosion mechanisms and reactions involved in bronze disease. Without better understanding, it is impossible to design truly effective solutions for the safe storage and display of archaeological copper alloys. Advancing current understanding, this paper examines oxidation and hydrolysis of CuCl using oxygen consumption, Fourier transform infrared spectroscopy and Raman spectroscopy, recognised as the basis of bronze disease. Variables potentially affecting bronze disease processes are evaluated, including relative humidity (RH) (15–80%RH at 20 °C) and the presence of metallic copper with CuCl and their respective ratios. Results confirm that these variables influence the reaction mechanisms and kinetics of bronze disease. The rate of oxidation and hydrolysis of CuCl accelerates with RH, and its effect is quantified. The presence of copper is shown to be important for producing bronze disease; it facilitates a cyclic reaction forming Cu₂(OH)₃Cl, increases its formation rate at lower RH than by hydrolysis of CuCl alone and prevents formation of soluble chloride compounds. The formation of Cu₂(OH)₃Cl without counteracting copper ions is shown to promote formation of CuCl₂ and CuCl₂·2H₂O, accelerating bronze disease. This new understanding is used to better quantify risk of bronze disease as a function of RH, providing a more quantitative tool for managing preservation of archaeological copper alloy collections. Full article

Solute carrier family 12 (SLC12) encodes electroneutral cation-coupled chloride cotransporters responsible for transmembrane ion transport (Na⁺, K⁺, and Cl⁻), which play a critical role in aquatic osmoregulation. However, the SLC12 gene of Exopalaemon carinicauda (EcSLC12) has not been systematically identified or functionally characterized. In this study, six EcSLC12 genes were identified across the genome and classified into N(K)CC, KCC, CCC9, and CIP subfamilies. Three NKCC1 homologous genes (EcSLC12A2.1, EcSLC12A2.2, and EcSLC12A2.3) were reported for the first time in crustaceans. The EcSLC12 family exhibited distinct expression patterns in response to low-salinity, high-alkalinity, and saline–alkaline stress. EcSLC12A2.2 was highly expressed in the gill, and its expression was closely correlated with saline–alkaline acclimation. Additionally, EcSLC12A2.2 knockdown decreased E. carinicauda survival under saline–alkaline stress. Thus, EcSLC12A2.2 plays critical roles in osmotic regulation and saline–alkaline acclimation. This study provides crucial insights into E. carinicauda’s saline–alkaline tolerance mechanisms, and the discovery of multiple NKCC1 homologs fills a gap in the crustacean SLC12 gene family research. Full article

In order to investigate the change in the axial compression performance of circular recycled concrete-filled steel tubular short columns under chloride ion corrosion, 24 circular recycled concrete-filled steel tubular (RCFST) short columns and 12 circular natural concrete-filled steel tubular (NCFST) short columns for axial compression tests after being subjected to different corrosion degrees were designed. The experimental parameters include the corrosion degree (0, 2, 4, 6, 8, 10, 12, 14%) and the recycled concrete replacement rate (0, 100%). The experimental results show that the damage mode of the specimen after corrosion is localized buckling deformation of the steel tube. Due to the good confinement effect of the steel tube, the internal concrete was crushed only at the localized buckling part of the steel tube. The stiffness and ductility decreased significantly with increasing corrosion degree. As the corrosion degree increased from 0 to 14%, the stiffness of the circular RCFST short columns decreased by approximately 36.3%, and the ductility dropped by around 23.3%. And the corrosion resistance of the circular RCFST short column was worse than that of the circular NCFST short column. Based on the experimental results, the ultimate load capacity calculation model of the circular concrete-filled steel tubular short column is proposed. Full article

Increasing evidence points to members of the chloride intracellular ion channel (CLIC) protein family performing a variety of functions within cells—classifying them as moonlighting proteins—and serving as natural cellular antioxidant protective agents. Apart from their role as membrane-inserting ion channels, members of the CLIC family also possess enzymatic oxidoreduction activity in their soluble form. The current study is the first to specifically examine the S-glutathionylation catalytic activity of several purified recombinant CLIC protein members (rCLIC1, rCLIC3, and rCLIC4) by directly measuring their ability to deglutathionylate and glutathionylate a synthetic model peptide via an in vitro tryptophan fluorescence quenching assay. Effects of pH and temperature on this activity were also assessed. Our findings provide insights into a likely previously uncharacterised mechanism by which CLIC proteins serve as cellular antioxidant protective enzymes via their S-glutathionylation capabilities. Full article

In this work, eco-friendly ceric ammonium nitrate (CAN) and ferric chloride hexahydrate catalysts in ethanol/acetonitrile systems were used to efficiently synthesize novel dihydropyrimidinone (-thione) derivatives via the Biginelli reaction. The obtained compounds with phenolic fragments at the C4 position demonstrated enhanced antioxidant properties. Significant structure–activity relationships were indicated by three complementary assays (PFRAP, ABTS, and AAPH-induced DNA oxidation): oxo-derivatives demonstrated superior ferric ion reduction (PFRAP), while thio-substituted analogs consistently outperformed their carbonyl counterparts in radical scavenging. Remarkably, all compounds surpassed the reference antioxidant BHT, demonstrating the potential of synthesized dihydropyrimidine structures as multifunctional antioxidants for therapeutic applications. The study also shows the relationship between the catalyst–solvent system and its effect on product yields, using ceric ammonium nitrate and ferric chloride hexahydrate. Full article

Composite scaffolds based on a hydrogel matrix modified with hydroxyapatite, magnesium, or zinc compounds are promising for filling and regenerating osteochondral defects due to the specific biological properties of these modifiers. The aim of this work was to evaluate the influence of hydroxyapatite, nano-hydroxyapatite, magnesium chloride, and zinc oxide on mechanical properties, swelling ability, behavior in a simulated biological environment (ion release, stability, bioactivity), and antibacterial effects. Furthermore, the influence of the hydrogel matrix (alginate, gelatin, alginate/gelatin) on the selected properties was also assessed. The results showed that the addition of ZnO improved the mechanical properties of all types of matrices most effectively. Additionally, zinc ions were gradually released into the environment and partially incorporated into the formed apatite. The released zinc ions increased the inhibition zones of Staphylococcus aureus growth; however, this effect was observed only in scaffolds with an alginate matrix. This indicates that hydrogel plays a key role in antibacterial effects, beyond the contribution of antibacterial additives. No effect of magnesium on bacterial growth inhibition was observed despite its rapid release. Magnesium ions promoted efficient secretion of apatite during incubation, although it was not stable. The addition of nano-HAP significantly increased the stability of the apatite precipitates. Full article

Scandium(III) (Sc(III)) is the smallest among the trivalent ions in Group 3, which includes yttrium(III) and lanthanides (III) with a hydration number of 8 and 8–9, respectively. The hydration number of Sc(III) in aqueous solutions reported so far varies from six to ten and remains an open question. In general, applying pressure and temperature to aqueous solutions perturbs the water structure and ion solvation, providing insight into the nature of ion solvation. In the present study, we perform neutron scattering measurements of a 1 m (mol/kg) ScCl₃ aqueous solution in D₂O (hereafter H is used to symbolize the hydrogen atom instead of D) under the thermodynamic conditions from 0.1 MPa/298 K to 4 GPa/523 K. Using the empirical potential structure refinement (EPSR) method, the neutron scattering data are analyzed to extract the site–site pair distribution functions, coordination number distributions, angle distributions, and spatial density functions (3D structure). A predominant Sc(III) species is [Sc(OH₂)₇]³⁺ with a distorted pentagonal bipyramidal geometry together with appreciable amounts of contact ion pair species [ScCl_n(OH₂)_(6−n)]⁽³⁻ⁿ⁾⁺ (n = 1–3) and [Sc(OH₂)₈]³⁺ with mean Sc–Cl and Sc–OH₂ distances of 2.42 and 2.11 Å, respectively. An aqua chloride ion is surrounded on average by 7.8 and 10.9 water molecules with a Cl–H₂O distance of 3.10 Å at 0.1 MPa/298 K and 4 GPa/523 K, respectively. Applying GPa pressure transforms the tetrahedral network structure of water under ambient conditions to a dense, randomly packed structure with a mean coordination number of 12.6, resulting in an increase in the first-neighbor distance from 2.77 to 2.89 Å. The hydrogen bonds between water molecules remain linear but are largely distorted at high temperatures and high pressures. The present results provide a hint for understanding the underlying mechanism of high-pressure and temperature coordination chemistry and in applied fields, such as processes in geochemistry of the Earth’s upper mantle and pressure-induced protein denaturation. Full article

Lifetimes of Ag/AgCl electrodes determine whether it is possible to monitor the concentration of chloride ions in marine concrete structures. A novel manufacturing method, pulse current electrodeposition at a low current density, was proposed to prepare the long-lifetime Ag/AgCl electrode. Influences of electrodeposition duration were investigated on the Nernst response, exchange current density, and lifetime of Ag/AgCl electrodes, and the properties were also compared to those of the ones electrodeposited by applying constant currents. Ag/AgCl electrodes prepared with the pulse current exhibited a wider potential response, a higher exchange current density, and a longer lifetime than those prepared by the constant current under the same equivalent charge transfer conditions. AgCl film on the electrode prepared with the pulse current displayed a thicker layer, a lower density of micropores, a higher Cl/O ratio, and a lower Ag/Cl ratio than those of its counterpart electrodeposited by applying the constant current. The lifetime of the Ag/AgCl electrode was mainly determined by the thickness of AgCl films in the concrete environment. The lifetimes of the Ag/AgCl electrode, which was prepared with a 0.1 mA cm⁻² pulse current for 15 h, were 420 h in pore solution and more than 3500 h in mortar, respectively. In addition, the potential of this Ag/AgCl electrode did not show any significant decrease after 3500 h in the mortar without Cl⁻. The results suggest that pulse current electrodeposition is an effective method to improve the lifetimes of Ag/AgCl electrodes in concrete. Full article

The olive industry is transitioning from traditional to super-high-density (SHD) systems to optimize production costs and address labor shortages. This shift coincides with increasing challenges from soil salinization and deteriorating irrigation water quality. This study evaluated salinity tolerance in three novel olive cultivars (Lecciana, Coriana, and Sikitita) against the established SHD references Arbequina and Arbosana under controlled greenhouse conditions over five months with increasing NaCl concentrations (25, 50, and 75 mM). The analysis revealed distinct adaptation mechanisms among cultivars. Arbosana exhibited balanced tolerance across parameters, with minimal biomass reduction and remarkable photosynthetic resilience. Lecciana demonstrated superior ion regulation, maintaining the highest K⁺/Na⁺ ratios across all salinity levels despite pronounced shoot growth sensitivity at high salinity. Sikitita showed moderate tolerance through biomass maintenance but with significant photosynthetic sensitivity under stress. Arbequina displayed effective chloride exclusion and consistent shoot growth despite biomass sensitivity, whereas Coriana presented notable biomass increases at moderate salinity but poor ion discrimination. Tissue-specific analysis revealed common compartmentalization patterns across cultivars, with roots accumulating the highest Na⁺ and Cl⁻ concentrations. These data identify Arbosana and Lecciana as promising candidates for salinized SHD orchards. Full article

We present a dual-mode optical sensing strategy for selective and sensitive detection of sulfide ions (S²⁻), employing copper-anchored nitrogen-doped graphene quantum dots (Cu@N-GQDs) as bifunctional nanozymes. The Cu@N-GQDs were synthesized via citric acid pyrolysis in the presence of ammonium hydroxide (serving as both nitrogen source and reductant) and copper chloride, leading to uniform incorporation of copper oxide species onto the N-GQD surface. The resulting nanohybrids exhibit two synergistic functionalities: intrinsic fluorescence comparable to pristine N-GQDs, and significantly enhanced peroxidase-like catalytic activity attributed to the anchored copper species. Upon interaction with sulfide ions, the system undergoes a dual-optical response: (i) fluorescence quenching via Cu-S complexation, and (ii) inhibition of peroxidase-like activity due to the deactivation of Cu catalytic centers via the interaction with S²⁻. This dual-signal strategy enables sensitive quantification of S²⁻, achieving detection limits of 0.5 µM (fluorescence) and 3.5 µM (colorimetry). The sensor demonstrates excellent selectivity over competing substances and high reliability and precision in real tap water samples. These findings highlight the potential of Cu@N-GQDs as robust, bifunctional, and field-deployable nanozyme probes for environmental and biomedical sulfide ion monitoring. Full article

This paper addresses the issue of reduced lifespan of coastal concrete piles due to chloride ion corrosion. A combination of concrete mix optimization and pile geometry improvement measures is proposed. Based on the diffusion coefficient optimization of Fick’s second law, the service life prediction of concrete piles in corrosive environments is completed. The results show that, compared to single slag incorporation and the “slag-fly ash” dual-component mix, the “slag-fly ash-corrosion inhibitor” triple-component concrete achieves a 28-day compressive strength of 67.4 MPa, and the chloride ion diffusion coefficient is reduced to 1.14 × 10⁻¹² m²/s, significantly improving overall performance. Finite element simulations reveal that, compared to ordinary square piles, cut-corner square piles can effectively alleviate stress concentration at the pile tip and reduce settlement. The maximum stress is 3.94 MPa, and the settlement is 22.64 mm, representing reductions of about 16.3% and 15.5%, respectively, compared to ordinary square piles. Concrete service life prediction confirms that the concrete with corrosion inhibitors has a predicted service life of 31.5 years, extending 7.4 years and 13.3 years longer than the single slag and the “slag-fly ash” dual-component groups, respectively. The “material-structure” optimization theory proposed in this study provides a theoretical basis and technical path for the long-life design of coastal engineering pile foundations. Full article