Explore the vast range of titles available.

Introduction. Studies have been carried out with the following types of an aluminum-silicon AlSi18 alloy: unmodified, modified by a standard P modifier, modified by a SiC nanomodifier, and modified by a combination of both types if modifiers. The paper discusses the influence of the different types of modifiers and the combination of them on the shape and size of the primary Si crystals and their distribution in the structure of the alloy, as well as on the shape and size of the Si crystals in the eutectic composition.

Pure phases of Pb, Sn and Pb 70 Bi 30 , their combinations and the eutectics (Pb 25 Sn 75 , Pb 44 Bi 56 and Pb 29 Bi 46 Sn 25 ) of the Pb–Bi–Sn system were prepared and evaluated for electrochemical reduction of CO 2 at − 2.0 V (vs Hg/HgO). The bulk composition, the phase structure and the surface composition were characterized by inductively ICP-AES, XRD and XPS respectively. The phases obtained from XRD data matches well with the ternary phase diagram of Pb, Bi and Sn. The electrochemical characterization was done by CV and LSV. The formation rate of formate ions was compared for all the alloy catalysts at − 2.0 V (vs Hg/HgO) in CO 2 saturated 0.5 M NaHCO 3 . It was observed that addition of both Bi and Sn individually or both concurrently to Pb increases the rate of formate ion production for Pb–Bi, Pb–Sn binary systems and the Pb–Bi–Sn ternary system respectively. Interestingly, it was found out that the eutectic compositions of each alloy system (both binary and ternary) were electrocatalytically superior (Pb–Bi–Sn eutectic (Pb 29 Bi 46 Sn 25 ) > Pb–Sn eutectic (Pb 25 Sn 75 ) > Pb–Bi eutectic (Pb 44 Bi 56 )). Further, on these high performing eutectics, the hydrogen evolution is greatly suppressed.

Metallic zinc is an attractive anode material for aqueous rechargeable batteries because of its high theoretical capacity and low cost. However, state-of-the-art zinc anodes suffer from low coulombic efficiency and severe dendrite growth during stripping/plating processes, hampering their practical applications. Here we show that eutectic-composition alloying of zinc and aluminum as an effective strategy substantially tackles these irreversibility issues by making use of their lamellar structure, composed of alternating zinc and aluminum nanolamellas. The lamellar nanostructure not only promotes zinc stripping from precursor eutectic Zn 88 Al 12 (at%) alloys, but produces core/shell aluminum/aluminum sesquioxide interlamellar nanopatterns in situ to in turn guide subsequent growth of zinc, enabling dendrite-free zinc stripping/plating for more than 2000 h in oxygen-absent aqueous electrolyte. These outstanding electrochemical properties enlist zinc-ion batteries constructed with Zn 88 Al 12 alloy anode and K x MnO 2 cathode to deliver high-density energy at high levels of electrical power and retain 100% capacity after 200 hours. Aqueous rechargeable Zn-ion batteries are attractive energy storage devices, but their wide adoption is impeded by the irreversible metallic Zn anode. Here the authors report lamellar-nanostructured eutectic Zn/Al alloys as reversible and dendrite-free anodes for improved battery performance.

Stabilization of reactive intermediates is an enabling concept in biomass fractionation and depolymerization. Deep eutectic solvents (DES) are intriguing green reaction media for biomass processing; however undesired lignin condensation is a typical drawback for most acid-based DES fractionation processes. Here we describe ternary DES systems composed of choline chloride and oxalic acid, additionally incorporating ethylene glycol (or other diols) that provide the desired ‘stabilization’ function for efficient lignocellulose fractionation, preserving the quality of all lignocellulose constituents. The obtained ethylene-glycol protected lignin displays high β-O-4 content (up to 53 per 100 aromatic units) and can be readily depolymerized to distinct monophenolic products. The cellulose residues, free from condensed lignin particles, deliver up to 95.9 ± 2.12% glucose yield upon enzymatic digestion. The DES can be recovered with high yield and purity and re-used with good efficiency. Notably, we have shown that the reactivity of the β-O-4 linkage in model compounds can be steered towards either cleavage or stabilization, depending on DES composition, demonstrating the advantage of the modular DES composition. Deep eutectic solvents (DES) are intriguing green reaction media for biomass processing, however, undesired lignin condensation is a typical drawback. Here the authors develop a tunable ternary DES system that allows for stabilization of reactive intermediates for efficient lignocellulose fractionation.

The L ↔ Al + Al11Ce3 technologically important eutectic transformation in Al–Ce binary alloys, containing from 5 to 20 wt.% Ce and ranging from hypo- to hypereutectic compositions, was examined along with the microstructure and properties of its solidified product. A combination of thermal analysis and metallography determined the coordinates of the eutectic point at 644.5 ± 0.6 °C and 10.6 wt.% Ce, clarifying the existing literature ambiguity. Despite the high entropy of melting of the Al11Ce3 phase, in hypoeutectic alloys the eutectic was dominated by the regular morphology of periodically arranged lamellae, typical for non-faceted systems. In the lamellar eutectic, however, the faceting of Al11Ce3 was identified at the atomic scale. In contrast, for hypereutectic compositions, the Al11Ce3 eutectic phase exhibited complex morphology, influenced by the proeutectic Al11Ce3 phase. The Al11Ce3 eutectic phase lost its coherency with Al; it was deduced that a partial coherency was present only at early stages of lamellae growth. The orientation relationships between the Al11Ce3 and Al in the eutectic structure, leading to partial coherency, were determined to be [0 0 1]Al ║ [1¯ 1 1]Al11Ce3 with (0 4 4¯)Al ║ (2¯ 0 0)Al11Ce3 and [0 1 1]Al ║ [3¯ 0 1]Al11Ce3 with (2¯ 0 0)Al ║ (0 6 0)Al11Ce3. The Al11Ce3 phase with a hardness of 350 HV and Al matrix having 35 HV in their eutectic arrangement formed in situ composite, with the former playing a role of reinforcement. However, the coarse and mostly incoherent Al11Ce3 eutectic phase provided limited strengthening and the Al–Ce alloy consisting of 100% eutectic reached at room temperature a yield stress of just about 70 MPa.

The overarching demand of modern electronics and electrification of transportation has tremendously increased usage of rechargeable lithium‐ion batteries (LIBs). As a result, massive amounts of solid waste are generated from the end‐of‐life LIBs and expected to increase by two‐ to threefolds in the near future. Without proper recycling strategies and infrastructure, the immediate threat of environmental pollution and wastage of resources is clear. One way to circumvent these challenges is to recycle the spent LIBs and recover the components and materials, especially heavy metals for future repurposing applications. This review highlights the recent discoveries on the use of deep eutectic solvents (DESs) as an economical and environmentally friendly medium for metal recovery from spent LIBs. Herein, how the different hydrogen donors and acceptors affect the overall performance of DES in terms of leaching efficiency, time, temperature, and metal recovery rates are outlined. Very importantly, the mechanism of metal leaching from the metal oxides using DES is discussed. Finally, some potential strategies and opportunities for further development of novel DES for metal‐recovery from not only spent LIBs but also other industries such as, mining, oil, and agriculture are outlined. Deep eutectic solvents (DESs) are a new class of green solvents, which brings unique characteristics such as low cost, non‐toxic, biodegradable, and easy to synthesize. They have been recently explored as promising leaching agents to recover metals from spent batteries. The present review highlights recent strategies to design and develop novel DES and their potential for effective battery recycling.

For the analysis of plant-based meat substitutes and the determination of Maillard reaction products such as acrylamide, 5-hydroxymethylfurfural and furaneol, a novel and effective procedure based on hydrophobic natural deep eutectic solvent and liquid chromatography coupled with tandem mass spectrometry was developed for the first time. The 49 compositions of the deep eutectic solvents were designed and screened to select the most suitable option. The terpenoids eugenol and thymol in a molar ratio of 2:1 were selected as precursors for solvent formation, allowing effective extraction of the target analytes. The developed procedure comprised two main steps: extraction — in which the analytes are isolated from the solid sample due to the salting-out effect and pre-concentrated in the deep eutectic solvent, and back-extraction — in which the analytes are re-extracted into the formic acid solution for subsequent mass spectrometric detection. As the density of the aqueous phases changed during the extraction and back-extraction steps, the phenomenon of inversion of the coalesced organic phase was observed, which simplified the withdrawing of the phases. The linear range was 1–50 ng/mL for acrylamide, 10–1000 ng/mL for 5-hydroxymethylfurfural and 200–1000 ng/mL for furaneol with coefficients of determination above 0.9952. The developed method was fully validated and found recoveries were in the range 83–120%, with CVs not exceeding 4.9%. The method was applied to real sample analysis of pea-based meat substitutes.

Carbon dots are often synthesized in the presence of a carbon source and passivating agents in which they are crucial for an enhanced fluorescence. The solvent choice and/or combination to be used in the synthesis of these nanoparticles can influence their surface chemical composition, morphology, and fluorescence properties. In this study, highly fluorescent carbon dots were synthesized using deep eutectic solvents of different compositions as green solvent media and doping agent. Resulting carbon dots were then separated by their hydrophilicity/hydrophobicity using a three-phase solvent system (water/acetone/chloroform) and compared with traditional centrifugation-based separation method. Carbon dots with a size below 20 nm and quantum yield reaching 50% were obtained. Many properties of them including surface functional groups, optical, fluorescence, and electric properties were shown to be determined by the deep eutectic solvent composition.

Eutectic high-entropy alloys (EHEAs) offer a good balance between strength and ductility alongside excellent castability and chemical homogeneity. However, identifying optimal eutectic compositions in HEAs has been a persistent challenge primarily due to the lacuna of higher-order phase diagrams. Since their discovery in 2014, following sporadic reports, the compositional design of EHEAs has relied on a trial-and-error empirical approach through experimental adjustments, which is time-consuming, costly, and often ineffective. Recently, the CALPHAD (CALculation of PHAse Diagrams) methodology has emerged as an effective alternative to empirical approaches despite its notable limitations. Combinatorial approaches have also been explored to design EHEA compositions, albeit with significant reliance on existing databases. However, despite a decade of efforts, there remains no universal design strategy for EHEA compositions to date, highlighting the need to address this research gap. To this end, the present article provides a critical review of the hitherto reported efforts in the composition design and development of EHEAs, categorizing them broadly into empirical, CALPHAD, and combinatorial approaches for the first time. This analysis aims to underscore the persistent challenges in designing EHEA compositions and provide insights to guide future research toward more effective strategies.

Phase stability, and the limits thereof, are a central concern of materials thermodynamics. However, the temperature limits of equilibrium liquid stability in chemical systems have only been widely characterized under constant (typically atmospheric) pressure conditions, whereunder these limits are represented by the eutectic. At higher pressures, the eutectic will shift in both temperature and chemical composition, opening a wide thermodynamic parameter space over which the absolute limit of liquid stability, i.e., the limit under arbitrary values of the thermodynamic forces at play (here pressure and concentration), might exist. In this work, we use isochoric freezing and melting to measure this absolute limit for the first time in several binary aqueous brines, and nodding to the etymology of “eutectic”, we name it the “cenotectic” (from Greek “κοινός-τῆξῐς”, meaning “universal-melt”). We discuss the implications of our findings on ocean worlds within our solar system and cold ocean exoplanets; estimate thermodynamic limits on ice crust thickness and final ocean depth (of the cenotectic or “endgame” ocean) using measured cenotectic pressures; and finally provide a generalized thermodynamic perspective on (and definition for) this fundamental thermodynamic invariant point. The authors define the cenotectic — the low-temperature stability limit for a liquid under arbitrary thermodynamic conditions — and measure it for several aqueous solutions of relevance to extraterrestrial oceans using isochoric freezing/melting.