Development Of Materials Research Articles

Functionalized construction of multiple active centers for durability controlling during catalytic combustion of chlorinated aromatic hydrocarbons

The catalytic combustion of chlorine-containing VOCs primarily encounters the bottleneck of catalyst poisoning by chlorine, thereby impeding the further industrial application of this technology. The development of multi-active catalytic materials for discerning chlorine fixation, chlorine transfer, deep oxidation during elimination of chlorine-containing VOCs can mitigate catalyst chlorination and enhance stability. Herein, we utilizing LDHs as catalyst precursors and successfully synthesized flower-like Co2FexCr1-xOy catalyst with different functionalized reaction centers. The addition of Cr improved the surface lattice oxygen, oxygen vacancies, and acid sites of catalyst. The removal efficiency of CB can be achieved >90 % at 247 °C (WHSV = 33000 mL · g−1·h−1). The fixation of dissociated chlorine contributed by Cr not only enhances oxidation performance and directional adsorption of chlorine, but also improves carbon deposition resistance and catalyst sintering resistance significantly. Compared with Co2Fe1Oy, Co2Fe0.67Cr0.33Oy catalyst achieves a remarkable threefold reduction in surface carbon deposition. The DFT calculation revealed that water dissociation energy over the Co site is −0.72 eV, which is significantly lower than Fe (−0.59 eV) and Cr (−0.17 eV), facilitating water dissociation and subsequently removes a substantial amount of accumulated chlorine on Cr to form HCl. With the help of In situ DRIFT and GC/MS analysis, we found the efficient removal of chlorine atoms enhances the exposure of active sites on the catalyst surface with hydrolyzed hydroxyl group, which facilitating the conversion of aromatic hydrocarbons into a greater quantity of maleate and carboxylate species. This phenomenon is beneficial for the subsequent mineralization process of chlorobenzene. This work provide valuable insights for multi-active site catalysis mechanism in practical applications aimed at eliminating chlorinated organic waste gases from industrial emissions.

In-suit cemented strategy enables intumescent flame retardant transition from hyper-hydrophilic to hydrophobic and aggregation flame retardant effect simultaneously in polypropylene

To meet the stringent requirements of specific high-end manufacturing applications involving flame retardant polypropylene (PP) materials, it's imperative to overcome the inherent superhydrophilicity of intumescent flame retardants (IFR) while simultaneously further enhancing flame retardant efficiency. In addressing this challenge, novel in-situ cemented MVC-IFR microparticles characterized by a microparticle-aggregation effect and hydrophobic structure were successfully synthesized. The micro-aggregated MVC-IFR particles not only bolstered the hydrophobicity and charring flame retardancy of PP composites compared to conventional IFR but also exhibited superior resistance to water erosion. The water contact angle (WCA) of 3MVC-22IFR reached an impressive 159°, whereas the WCA of IFR stood at 0°. Moreover, when MVC-IFR and IFR were incorporated into PP, 3MVC-22IFR/PP displayed a WCA of 108° which was a hydrophobic composite, while 25IFR/PP exhibited a WCA of 81° which was a hydrophilic composite. Notably, the hydrophobic MVC-IFR showcased greater resistance to water exposure than hydrophilic IFR, thereby maintaining its flame retardant efficacy in practical applications. Furthermore, MVC-IFR microparticles with aggregation of acid, carbon, and gas sources, facilitated the charring reactions of different components, thereby enhancing its charring flame retardant effect in PP. Remarkably, 1MVC-24/PP not only attained a UL 94V-0 rating but also achieved a glow wire flammability index (GWFI) of > 960°C, a glow wire ignition temperature (GWIT) of 850°C, and an LOI value of 28.7%. In contrast, 25IFR/PP failed to secure a UL 94 rating and exhibited lower GWIT and LOI values. Crucially, the peak heat release rate and total smoke release of 1MVC-24IFR/PP were markedly reduced by 76% and 41%, respectively, compared with those of neat PP. In summary, this study presented a novel design concept and rules for flame retardant morphology, to find a way for the development of polyolefin materials boasting both high hydrophobicity and superior flame retardancy.

Recycled Low Density Polyethylene Reinforced with Deverra tortuosa Vegetable Fibers

In this work, natural fibers extracted from the medicinal aromatic plant Deverra tortuosa, with different sizes (S1 = 2 mm and S2 = 500 μm), were incorporated into recycled low density polyethylene (rLDPE) to produce sustainable biocomposites. Compounding was performed with different fiber concentrations (0 to 30% wt.) via twin-screw extrusion followed by injection molding. Based on the samples obtained, a comprehensive series of characterization was conducted, encompassing morphological and mechanical (flexural, tensile, hardness, and impact) properties. Additionally, thermal properties were assessed via differential scanning calorimetry (DSC), while Fourier transform infrared spectroscopy (FTIR) was used to elucidate potential chemical interactions and changes with processing. Across the range of conditions investigated, substantial improvements were observed in the rLDPE properties, in particular for the tensile modulus (23% for S1 and 104% for S2), flexural modulus (47% for S1 and 61% for S2), and flexural strength (31% for S1 and 65% for S2). Nevertheless, the tensile strength decreased (15% for S1 and 46% for S2) due to poor fiber–matrix interfacial adhesion. These preliminary results can be used for further development in sustainable packaging materials.

Theoretical study on arsenene as anode material for magnesium ion battery in rail transit

The development and regulation of high-performance anode materials contribute to the rapid development of ion batteries in rail transit. In this paper, based on the first-principles calculation method of density functional theory, the properties of two-dimensional arsenene materials are regulated by torsional deformation, and the feasibility of torsionally deformed arsenene as an electrode material for magnesium ion batteries is studied. The results show that the arsenene monolayer remains stable after being adsorbed by a single Mg ion. The properties of arsenene are indirect bandgap semiconductors with a band gap of 1.60 eV. In the current research scope, deformation does not change the semiconductor properties of intrinsic arsenene. As the torsion angle increases, the band gap gradually decreases. The Mg-adsorbed arsenene system exhibits quasi-metallic properties with a band gap of 0.07 eV. The torsional deformation transforms the adsorption system into a small band gap semiconductor. The torsion deformation makes the diffusion energy barrier of magnesium ions on the arsenene monolayer only 0.09 eV, which ensures an excellent charge–discharge rate. The research results provide a theoretical basis for the design of magnesium ion batteries in rail transit.

In-situ Synthesis of Bifunctional N-Doped CoFe₂O₄/rGO Composites for Enhanced Electrocatalysis in Hydrogen and Oxygen Evolution Reactions

The development of cost-effective and efficient materials for electrochemical water splitting using non-noble metal oxide is a promising strategy to promote clean energy and mitigate environmental issues. In this study, we synthesized N-doped CoFe2O4 (NCF) and various wt.% rGO-loaded N-doped CoFe2O4 (x = 1%, 3%, and 5%; denoted as NCFRx) using a hydrothermal method. Subsequently, the NCF and NCFR3 samples were annealed at four different temperatures (y = 550, 600, 650, and 700 °C; denoted as NCFR3-y). FE-SEM, TEM, and XPS studies revealed a strong interface between rGO nanosheets and N-doped CF, acting as electron transport carriers that enhance performance in hydrogen and oxygen evolution reactions (HER and OER). The electrochemical evaluation of the prepared materials was carried out in a 1.0M KOH electrolyte. The nickel foam (NF) electrode supported by the NCFR3-650 composite demonstrated excellent and stable electrocatalytic performance with a minimum overpotential of 73mV and 170mV at a current density of 10mA/cm2 for HER and OER, respectively, and achieved excellent faradaic efficiencies of 91.01% for OER and 90.48% for HER. These results confirmed that the NCFR3-650@NF composite catalyst was comparable to standard Pt/C and IrO2, exhibiting lower overpotential and Tafel slope at a current density of 10mA/cm2. The double layer capacitance (Cdl) of NCFR3-650@NF (7.70 mF/cm2) was higher than that of other electrocatalysts, indicating a large electrochemically active surface area. The structural properties of NCFR3-650@NF contributed to improved stability during long-term HER and OER analysis. Therefore, the developed NCFR3-650@NF electrocatalyst is a promising alternative to noble metal-centered systems for water splitting, offering overall high efficiency.

Experience of a tertiary acute care hospital in Southeast Asia in initiating patient engagement with the aid of digital solutions

IntroductionWith the goal of patient engagement, an initiative was formulated to equip each patient in the general wards with a tablet whereby they can access their health information and patient education materials and communicate with their healthcare team. This paper presented the methodology of the implementation efforts as well as an evaluation of the preliminary outcomes.MethodsThe process of hospital-wide implementation was shared using the implementation research logic model. The bedside tablets were rolled out hospital-wide in a step-wedge manner over 12 months. Barriers and facilitators to this implementation were discussed together with strategies to optimize the situation. Preliminary outcomes of the implementation were evaluated using the RE-AIM framework.ResultsThe initial adoption rate for the bedside tablet was low. Additional strategies, such as survey audits and provision of feedback, development of education materials for patients, facilitation, and purposefully re-examining the implementation strategies, were used to improve adoption. The trend of adoption increased over the course of 2 years from the start of implementation.DiscussionThe initial lower adoption rates may reflect Singapore's paternalistic healthcare culture. While this implementation was driven by the need to move away from paternalism and toward patient engagement, more time is required for significant cultural change.

Assembly of Fe@Zn-Coordination Polymer Composite: Iron Doping Foster the Luminescent Detection for Tetracycline, Uric Acid and Cr2O72− and Crystal Violet Degradation Efficiency

Coordination polymers exhibit a diverse array of applications across various fields, and through the development of composite materials, their utility and versatility are further enhanced, broadening their impact on our world. In this work We synthesized the first coordination polymer (CP) based on Zn and doped with Fe composites (Fe@Zn-CP Composite), which exhibit enhanced photocatalytic activity triggered by visible light. Using mixed ligands orotic acid potassium salt, 1,3 di (4-pyridyl) propane (dpp), and FeSO4 in a simple method at ambient temperature, the Zn-CP [Zn8(Or)8(dpp)4(H2O)8] was resynthesized here to form the Fe@Zn-CP composites. Zn-CP and Fe@Zn-CP Composite were both characterized by powder X-ray diffraction, FT-IR spectra analysis, and SEM-EDX analysis and elemental mapping analysis. It has been observed that Fe@Zn-CP Composite is as multi-functional luminescence sensor for MnO4−, Cr2O72− and Tetracycline with high sensitivity. In-depth research has also been done on the recyclable nature, and photocatalytic efficiency of Zn-CP and Fe@Zn-CP Composite for the decomposition of organic dyes Crystal Violet and Rose Bengal (RB) in contaminated water under the sunlight irradiation.

Optimizing the effect of heat treatment on the mechanical properties (tensile Strength and hardness) of Hyphaene Thebaica nut; A machine learning and Taguchi approach

The demand for innovative and sustainable biomaterials in healthcare and biotechnology has fueled the need for advancements in its engineering performance. However, the limited properties of biomaterials without the integration of synthetic reinforcements or supports pose a challenge. Consequently, there is a growing necessity for the development of full cycle eco-friendly materials. This study focuses on enhancing the mechanical properties of Doum palm nuts through heat treatment for engineering applications. The research employs the Taguchi optimization technique and genetic algorithms to determine the optimal combination of heating temperature and holding time, aiming to achieve the highest tensile strength and hardness. The results showcase the effectiveness of the proposed approach, revealing the optimal tensile strength of 7.32 MPa at a treatment temperature of 50 °C and a holding time of 120 min. Similarly, the optimum hardness of 60.3 Hv is attained at a heat treatment temperature of 100 °C and a holding time of 120 min. The study further investigates chemical changes through Fourier transform infrared analysis and optical micrographs. Regression models for tensile strength and hardness are developed, and the global optimum is found using a genetic algorithm solver. The findings of this study demonstrate significant and remarkable improvements in the mechanical properties of biomaterials, highlighting their potential for demanding engineering applications. The optimized heat treatment parameters provide a path towards enhanced biomaterials performance and offer promising avenues for the development of tougher and more resilient materials. This research contributes to the field of biomaterials engineering, paving the way for the design and production of eco-friendly materials with superior mechanical properties, thus addressing the ongoing demand for innovative and sustainable solutions in various industries.

Fidelity of Enhanced Recovery Protocol Implementation With Assessment of Hospital-Specific Materials

IntroductionVariability in implementation of enhanced recovery protocols (ERPs) often reduces the effects of an intervention on clinical outcomes. This study aimed to evaluate hospital-level implementation fidelity to a pediatric gastrointestinal surgery ERP by assessing site-specific implementation materials. MethodsThis document analysis study operationalized implementation fidelity as adherence to the creation of specified materials at each study site. During the 12-mo implementation phase within the stepped-wedge cluster randomized control trial, ENhanced Recovery In CHildren Undergoing Surgery, study sites were provided with materials (e.g., order sets), access to peer-counseling, and given key ERP elements spanning multiple phases of care. Sixteen of the 18 total study sites submitted implementation materials, including 14 anesthesia protocols, 11 order sets, and 16 sets of patient/family education materials. These materials were assessed and graded for fidelity using prespecified criteria. Hospital-level fidelity scores could range from 0 to a maximum score of 18, and were categorized as either high or low, based on whether the score was above or below/equal to the median. Descriptive statistics and Wilcoxon rank sum test were used for analysis. ResultsThe overall hospital-level median fidelity score for inclusion of ERP elements in the implementation materials was 10.5. The median score was 12.8 at nine high-fidelity sites and was 5.6 at nine low-fidelity sites (P < 0.01). Higher adherence was noted for avoiding prolonged fasting (n = 16/18 hospitals; 89%) and preventing nausea and vomiting (n = 16/18 hospitals; 89%) in anesthesia protocols and/or order sets. Lower adherence was noted for incorporation of minimally invasive surgical techniques (n = 2/18 hospitals, 11%) and of preoperative optimization of medical comorbidities (n = 0/18 hospitals, 0%) in implementation materials. ConclusionsDespite substantial resources to promote ERP elements, there was wide variation in fidelity for incorporating ERPs into implementation materials among hospital sites. Development of high-fidelity implementation materials for complex ERPs for gastrointestinal surgery in children may require longer than 12 months. Additional implementation strategies, resources, and modification of implementation-focused materials may be needed.

Study on the mechanism of improvement of mechanical properties of Al-Mg-Si aluminum alloys by Cu and Ce

First, the stability and tensile properties of the Al/Mg2Si interface doped with alloying elements in the Al-Mg-Si system of aluminum alloys are calculated from first principles. Then, the two experimental alloys with different components were heat treated and the properties were characterized. Calculations show that when the interface is doped with Cu, the tensile stress that the interface can withstand increases to 3.13 GPa; when the interface is doped with Cu and Ce, the tensile strain that the interface can withstand increases to 20% and the tensile stress that the interface can withstand increases to 4.17 GPa; when the interface is doped with Cu and Sc, the tensile strain that the interface can withstand increases to more than 25% and the tensile stress that the interface can withstand increases to 5.08 GPa or more. Characterization of the organization and properties of the experimental alloys showed that Ce not only increased the peak solid solution temperature of the alloys, but also increased the tensile and yield strengths of the alloys in the extruded state by 16% and 13.74%, respectively. During hot extrusion, Ce was able to promote the precipitation of precipitated phases. During aging, the addition of Ce promoted the aging precipitation of the alloy, which not only increased the number of precipitated phases in the alloy, but also refined the precipitated phases and enhanced the aging strengthening effect of the alloy. This study provides technical guidance for the development of new aluminum alloy materials with high strength and low cost.

Development and Characterisation of Myristic Acid-Paraffin Wax, Silica Fume and Zinc Oxide Cementitious Composites for Thermal Control in Buildings

This study focuses on the development of a cement-based phase change material (CBPCM) to improve thermal performance in construction applications. The CBPCM was synthesised by blending 90 wt% of myristic acid with 10 wt% of paraffin wax, absorbed into 10 wt% of silica fume to prevent leakage. Additionally, 5 wt% of zinc oxide was added to improve thermal conductivity. A leakage test conducted with 10 wt% of SF exhibited no signs of leakage during thermal cycling. Scanning electron microscopy (SEM) established the uniform dispersion of the nano-enhanced phase change material (NEPCM) within the cement. Fourier transform infrared spectroscopy (FTIR) analysis revealed no chemical structure changes after 100 thermal cycles. Thermogravimetric analysis (TGA) confirmed thermal stability in the temperature range of 74.8 to 236.64 °C with a mass loss of 6.3 wt%. The material demonstrated minimal variation in phase change temperatures and latent heats after 100 cycles. The latent heat of the CBPCM was 1.09 J/g during melting and 1.887 J/g during solidification. Incorporating NEPCM into the cement increased the thermal conductivity of the cement matrix to 0.559 W/m K. These findings underline the potential of the CBPCM for energy-efficient construction, offering enhanced thermal storage, stability, and conductivity.

Chitosan/pre-gelatinized waxy corn starch composite edible orally disintegrating film for taurine delivery

In this study, chitosan/per-gelatinized waxy corn starch composite edible orally disintegrating films (ODFs) incorporated with taurine were prepared and the morphology, release behavior and storage stability of the ODFs were investigated. The XRD, ATR-FTIR and microscopic investigation results revealed that taurine could be uniformly dispersed in the film matrix. The optimal level of taurine addition was 1.0% (w/w). The incorporation of taurine improved the apparent morphology, mechanical properties and water holding capacity while slightly increased the film thickness, disintegration time and contact angle of the composite films. In addition, taurine exhibited a rapid release behavior in the films. The fitted results of the Ritger-Peppas model indicated that the release mechanism of taurine in the composite films was mainly Fickian diffusion with minor skeleton erosion. As a delivery carrier, the composite film had a positive effect on the preservation of taurine, increasing the retention of taurine by 8.34% ± 1.48% during storage. The study confirmed the feasibility for the development of taurine ODF carriers and provided a basis for the development of functional packaging materials.

Influence of non-stoichiometric design concepts on the optical properties of Sm-doped Gd2Zr2O7 transparent ceramics

The concept of non-stoichiometric design, as a historically significant strategy in material design, plays a crucial role in the development and innovation of materials. Particularly in the domain of red-orange fluorescence, the importance of the rare earth Sm element has been increasingly emphasized. This study successfully prepared non-stoichiometric Gd2Zr2O7 transparent ceramics doped with Sm using combustion and vacuum sintering. X-ray diffraction analysis indicates that the obtained powders are composed of fine defect fluorite structure grains, while the final ceramics exhibit pyrochlore/defect fluorite phase. Initially, non-stoichiometric design optimizes the optical transmittance of ceramics. The maximum transmittance of the X = -0.1 ceramic exhibits the highest transmittance 82.4% @ 1134 nm. Furthermore, photoelectrons captured by native defects energy levels can transfer to the Sm excited states, optimizing the fluorescence property of ceramics. The fluorescence intensity of the X = 0.8 ceramic is about five times that of the X = 0 ceramic.

Hydrogen Separation Membranes: A Material Perspective

The global energy market is shifting toward renewable, sustainable, and low-carbon hydrogen energy due to global environmental issues, such as rising carbon dioxide emissions, climate change, and global warming. Currently, a majority of hydrogen demands are achieved by steam methane reforming and other conventional processes, which, again, are very carbon-intensive methods, and the hydrogen produced by them needs to be purified prior to their application. Hence, researchers are continuously endeavoring to develop sustainable and efficient methods for hydrogen generation and purification. Membrane-based gas-separation technologies were proven to be more efficient than conventional technologies. This review explores the transition from conventional separation techniques, such as pressure swing adsorption and cryogenic distillation, to advanced membrane-based technologies with high selectivity and efficiency for hydrogen purification. Major emphasis is placed on various membrane materials and their corresponding membrane performance. First, we discuss various metal membranes, including dense, alloyed, and amorphous metal membranes, which exhibit high hydrogen solubility and selectivity. Further, various inorganic membranes, such as zeolites, silica, and CMSMs, are also discussed. Major emphasis is placed on the development of polymeric materials and membranes for the selective separation of hydrogen from CH4, CO2, and N2. In addition, cutting-edge mixed-matrix membranes are also delineated, which involve the incorporation of inorganic fillers to improve performance. This review provides a comprehensive overview of advancements in gas-separation membranes and membrane materials in terms of hydrogen selectivity, permeability, and durability in practical applications. By analyzing various conventional and advanced technologies, this review provides a comprehensive material perspective on hydrogen separation membranes, thereby endorsing hydrogen energy for a sustainable future.

High-temperature oxidation resistance and wear properties of functionally graded CrHfNbTaTiN high-entropy nitride coating on Ti alloy

High-entropy nitrides have emerged as promising alternatives to traditional protective coatings due to their excellent comprehensive properties. However, there is still a long-standing technical challenge in the design and manufacture of hard and high-temperature stable high-entropy nitride coatings. This study utilized first-principles calculations to evaluate the thermodynamic stability between high-entropy nitrides and corresponding high-entropy metals, as well as titanium alloy substrates, confirming the rationality of the structural design of the functional gradient high-entropy ceramic coating. Subsequently, a double-glow plasma surface alloying technique were conducted to prepare a CrHfNbTaTiN functional gradient high-entropy ceramic coating on titanium alloy, followed by high-temperature cyclic oxidation experiments and high-temperature ball-on-disk wear tests. The research demonstrates that the gradient composition coating exhibits strong interfacial bonding, with an adhesion strength of around 40 N. It maintains excellent oxidation resistance in environments below 700 °C and displays good high-temperature wear resistance. This study contributes to providing insights and guidance for the further development of high-temperature, high-hardness, and wear-resistant materials.

Computational Intelligence for Modeling the Rheological Properties of the Developed Hydrated Lime-Based Alkali-Activated Materials

The development of alkali-activated materials (AAMs) has gained attention as a sustainable alternative to Portland cement-based concrete. A key factor in AAM performance is its rheological behavior, which influences workability and pumpability. Accurate prediction of these properties is vital for optimizing mix design. This study introduces a computational framework using ensemble and non-ensemble machine learning (ML) techniques to model the yield stress (YS) and plastic viscosity (PV) of AAMs. A comprehensive dataset from previous experiments was used to train models, including artificial neural networks (ANN), gene expression programming (GEP), decision tree, random forest, adaptive boosting, and gradient boosting. The models achieved R² values exceeding 0.95 and correlation coefficients above 0.97. Error metrics, such as MAPE, MAE, MSE, and RMSE, further validated the models’ generalizability. A parametric analysis showed that a 20% increase in hydrated lime (HL) content raised YS by 350Pa, which is similar to the effect of varying fly ash (FA) from 60% to 100%. A 40% increase in FA and HL content increased PV by 4Pa.s and 25Pa.s, respectively. A 3% rise in sodium silicate led to a 400Pa increase in YS, while a similar increase in sodium hydroxide raised YS by 170Pa and PV by 15Pa·s. Overall, this study provides an effective tool for optimizing AAM mix designs by accurately predicting rheological properties and quantifying the impact of key parameters, contributing to the advancement of sustainable cementitious materials in construction.

One stone two birds: Simultaneous control of eutrophication and microplastic pollution via surface functionalized nano-Fe3O4

Microplastics (MPs) aggregate with phytoplankton to form aggregates that impede light and oxygen penetration, and the adsorbed nitrogen and phosphorus are either taken up by algae or released into the water column, thereby exacerbating water eutrophication. Therefore, it is imperative to simultaneously control nutrients (N and P) and MPs pollution in water. To address this, nano-Fe3O4 with different surface modifications (–COOH, –NH2, and –OH) was developed to control these mixed pollutants. The results showed that the surface modification can enhance the affinity for NH4+, PO43- and polyethylene microplastic (PE-MP), which can achieve exceptional adsorption capacities for NH4+-N (18.45 mg/g), PO43--P (30.04 mg/g), and PE-MP (1611 mg/g). OH-Fe3O4 efficiently removed NH4+-N (2 mg/L), PO43--P (5 mg/L), and PE-MP (1 g/L, 13 μm) from two types of water, achieving removal rates of 80 %, 95 %, and 62 % in freshwater, and 78 %, 94 %, and 70 % in seawater, respectively. FTIR, XPS, kinetic analysis, and density functional theory (DFT) calculations revealed that nano-Fe3O4 provides abundant active sites for MPs and PO43- through electrostatic adsorption and hydrogen bonding, while there is a Fe-O-P bond with PO43-. The NH4+ can be adsorbed on MPs via ion exchange. In addition, –COOH enhances affinity for NH4+, –NH2 increases the holding capacity for PO43-, and –OH strengthens PE-MP adsorption. The environmental impact of the production of nano-Fe3O4 demonstrates the economic feasibility and environmental friendliness of this process. The findings of this study offer promising data that can inform the future development of sustainable and cost-effective materials to combat eutrophication and MPs pollution.

Pursuing ultrahigh strength–ductility CoCrNi-based medium-entropy alloy by low-temperature pre-aging

Developing high-performance alloys with gigapascal strength and excellent ductility is crucial for modern engineering applications. The concept of multi-component high/medium entropy alloys (H/MEAs) provides an innovative approach to designing such alloys. In this work, we developed the Co1.5CrNi1.5Al0.2Ti0.2 MEA, which exhibits outstanding mechanical properties at room temperature through low-temperature pre-aging followed by annealing treatment. Tensile testing reveals that the MEA possesses an ultrahigh yield strength of 20±0785 MPa, an ultimate tensile strength of 2365 ± 70 MPa, and exceptional ductility of 15.8% ±1.7%. The superior tensile properties are attributed to the formation of fully recrystallized heterogeneous structures (HGS) composed of ultrafine grain (UFG) and fine grain (FG) regions, along with discontinuous precipitation of coherent nano-size lamellar L12 precipitates. The mechanical incompatibility between the UFG region and the FG regions during deformation induces the accumulation of a large number of geometrically necessary dislocations at the interface, resulting in strain distribution and hetero-deformation-induced (HDI) stress accumulation, contributing significantly to HDI strengthening. HDI strengthening, precipitation strengthening, and grain boundary strengthening are the primary mechanisms responsible for the ultra-high yield strength of the MEA. During deformation, the dominant deformation mechanisms include dislocation slip, deformation-induced stacking faults, and Lomer–Cottrell locks, with minor deformation twinning. The synergistic interaction of these multiple deformation modes provides the MEA with excellent work hardening capability, delaying plastic instability and achieving an excellent combination of strength and ductility. This study provides an effective strategy for synergistically strengthening MEAs by combining HDI strengthening with traditional strengthening mechanisms. These findings pave the way for the development of advanced structural materials with high performance tailored for demanding applications in engineering.

Self-removing salt crystals

A newly discovered mechanism by which salt crystals leap off nanoengineered surfaces may lead to the development of industrial materials that resist the buildup of minerals from fresh and salt water.

Development of new cathode materials for all-iron redox flow batteries using hard carbon-based composites containing niobium pentoxide

We report in this study new cathodes for all-Fe RFBs synthesized using carbon flakes dispersed in plasticizing and hardening agents to obtain hard and dense carbon (HC) materials in the absence and presence (HC-Nb) of niobium pentoxide (Nb2O5). These cathode materials exhibited excellent resistance to wear in acidic solutions and larger potential intervals for water stability (e.g., 1200–1300 mV) compared to conventional graphite (e.g., 800 mV). These characteristics decreased the parasitic occurrence of hydrogen evolution reaction (HER) using a laboratory-made battery cell during the charging process. The latter was based on the Fe0/Fe2+ and Fe2+/Fe3+ redox couples present in the anode and cathode compartments, respectively. The different ex-situ and in-situ characterization studies evidenced that the presence of Nb2O5 in HCs substantially changed their physicochemical properties. The highest heterogenous kinetic rate constant (k0) representing the electrocatalytic activity for electron transfer was verified for the cathode containing 10 wt% Nb2O5. An electromotive force (EMF) of 1.053 V was verified for the fully charged all-Fe RFB. Galvanostatic charge–discharge (GCD) studies revealed excellent coulombic efficiency (> 88 %) after 300 cycles. A pH control by acid addition as a function of the battery operation is necessary to avoid iron hydroxide formation on the anode’s surface.