Eutectic Research Articles

Weakly Solvating Cyclic Ether‐Based Deep Eutectic Electrolytes for Stable High‐Temperature Lithium Metal Batteries

Deep eutectic electrolytes (DEE) have emerged as an innovative approach to address the instability and safety issues of lithium metal batteries at elevated temperatures. However, in practice, there is often an undesirable incompatibility between the eutectic mixture and electrodes, and also an insufficient reduction stability of DEE due to the increased Li+ concentration. Herein, we designed a new DEE by utilizing weakly solvating tetrahydropyran (THP) solvent. Due to the high reduction resistance of THP and concentrated lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), this DEE demonstrates enhanced compatibility with Li metal anode and high temperature tolerance with LiMn2O4 cathode. The Li||LiMn2O4 cell (1.6 mAh cm−2) shows a high capacity retention of 96.02% after 600 cycles at room temperature. More importantly, this Li||LiMn2O4 cell achieves a remarkable high‐temperature performance with a high capacity retention of 91.72% after 120 cycles and low self‐discharge after storage for 240 hours at a high temperature of 55 °C, which is critical for LiMn2O4 cathode. Overall, this electrolyte design provides an alternative pathway for the development of DEEs for high‐temperature and high‐voltage lithium metal batteries, which can also be expanded to other batteries.

Weakly Solvating Cyclic Ether‐Based Deep Eutectic Electrolytes for Stable High‐Temperature Lithium Metal Batteries

Deep eutectic electrolytes (DEE) have emerged as an innovative approach to address the instability and safety issues of lithium metal batteries at elevated temperatures. However, in practice, there is often an undesirable incompatibility between the eutectic mixture and electrodes, and also an insufficient reduction stability of DEE due to the increased Li+ concentration. Herein, we designed a new DEE by utilizing weakly solvating tetrahydropyran (THP) solvent. Due to the high reduction resistance of THP and concentrated lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), this DEE demonstrates enhanced compatibility with Li metal anode and high temperature tolerance with LiMn2O4 cathode. The Li||LiMn2O4 cell (1.6 mAh cm−2) shows a high capacity retention of 96.02% after 600 cycles at room temperature. More importantly, this Li||LiMn2O4 cell achieves a remarkable high‐temperature performance with a high capacity retention of 91.72% after 120 cycles and low self‐discharge after storage for 240 hours at a high temperature of 55 °C, which is critical for LiMn2O4 cathode. Overall, this electrolyte design provides an alternative pathway for the development of DEEs for high‐temperature and high‐voltage lithium metal batteries, which can also be expanded to other batteries.

Depicting polymorphism in eutectic mixtures

The current investigation reveals the presence of polymorphism within linezolid eutectic mixtures containing syringic acid, fumaric acid, and isonicotinamide. Linezolid was combined with the said coformers through co-grinding in 1:1 stoichiometric ratios to produce binary mixtures. Through techniques such as differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform infrared (FTIR) spectroscopy, the eutectic nature of these mixtures was confirmed. Polymorphism was identified further through the emergence of an exothermic event positioned between the two melting endotherms in DSC thermograms. This endo-exo-endo transition signifies the thermally-induced polymorphic transformation occurring within the eutectic mixtures. The observed behavior was validated through real-time visual analysis using hot-stage microscopy analysis (HSM). Utilizing PXRD data, quantitative phase analysis (QPA) was employed to determine the weight fractions of individual components in various eutectic polymorphs, yielding reliable outcomes. The morphological characteristics and surface alterations of eutectic polymorphs were scrutinized via scanning electron microscopy (SEM). Moreover, eutectic polymorphs formed by the combination of linezolid and isonicotinamide demonstrated fivefold increase in aqueous solubility and a fourfold faster intrinsic dissolution rate (IDR) compared to marketed linezolid.

Outstanding electrocatalytic activity and corrosion property of NiCr nanoparticle alloys electrodeposited from a choline chloride/urea deep eutectic solvent

Nickel-chromium alloys are known for their superior corrosion resistance, wear resistance, and hardness, making them a topic of significant interest. This study explores the electrodeposition of Ni-Cr alloys onto a glassy carbon electrode from a choline chloride/urea deep eutectic solvent. Electrochemical techniques, including cyclic voltammetry and chronoamperometry, were utilized to explore the deposition process. Voltametric analysis revealed that Ni-Cr alloys could be electrodeposited from the reline DES through a single potential step. The analysis of current density transients indicated that the electrocrystallization of Ni-Cr follows a three-dimensional (3D) nucleation and diffusion-controlled mechanism on the bimetallic growing surface. Additionally, the presence of the Ni(II) component was found to significantly enhance the kinetics of Ni-Cr phase formation, facilitating rapid deposition from the eutectic mixture. Surface characterization techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) mapping, and X-ray diffraction (XRD), confirmed the uniform distribution of elements, the formation of the Ni-Cr phase, and its crystalline structure. The high quality of nickel-chromium alloys obtained from DES highlights their potential applications in various engineering fields, particularly in surface coating and metal protection.

3, 4-Bis (3-nitrofurazan-4-yl) furoxan (DNTF) and 4-methoxy-1-methyl-3, 5-dinitro-1H-pyrazole (DMDNP) based molten carrier with high energy and low sensitivity: eutectic design and desensitization effect

Utilizing insensitive explosives to form a eutectic with 3, 4-bis (3-nitrofurazan-4-yl) furoxan (DNTF) proved to be an effective method for reducing its sensitivity and melting point. In this study, the interaction between DNTF and 4-methoxy-1-methyl-3, 5-dinitro-1H-pyrazole (DMDNP) was simulated using the interaction region indicator (IRI), revealing that the intermolecular forces in the mixture are stronger than those of the individual components. Co-molten mixtures of DNTF-DMDNP with varying compositions were prepared through electrostatic spraying technology, and a binary phase diagram was established using differential scanning calorimetry (DSC). The experimentally extrapolated molar ratio of the DNTF-DMDNP eutectic was determined to be 48.7/51.3, with a eutectic point at approximately 338.2K. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) tests confirmed that no chemical reactions or crystal transformations occurred during the preparation of the eutectic. The thermal decomposition temperatures at different heating rates and apparent activation energy of the eutectic fell within the range between those of DNTF and DMDNP. Addition of even just 10% DMDNP significantly reduced mechanical sensitivity in co-molten mixtures, resulting in a rapid decrease from 100% to 12% friction sensitivity. The detonation velocity of the DNTF-DMDNP eutectic measured at 8.47kms-1 only experienced a slight decrease by about 0.78kms-1 (8.4%) compared to pure DNTF, indicating efficient desensitization by incorporating DMDNP with minimal energy loss potentiality. Furthermore, adjusting composition allowed for control over detonation performance and sensitivity in melt-cast explosives composed of DNTF-DMDNP.

Comprehensive impact of pre-treatment methods on white radish quality, water migration, and microstructure

The preprocessing stage is crucial in vegetable processing, significantly influencing the final product's quality. This study investigates the effects of various pre-pre-treatment methods, including cutting, blanching, osmotic, and ultrasound-assisted osmotic treatment, on the quality characteristics, water migration, and microstructure of white radish. The results showed that osmosis and ultrasound-assisted osmosis has the least effect on the total color difference (ΔE) and the greatest water loss (WL) (p < 0.05); blanching has the least effect on the hardness and eutectic points (p < 0.05); and the blanching-ultrasound-assisted osmosis has the greatest solid gain (p < 0.05). The increase of WL led to a decrease in hardness (−0.82). By analyzing the quality characteristics of different pre-treatment methods, contributing to the development of suitable pre-treatment methods for different products and optimization pre-treatments according to requirements. The mechanism of quality characteristics of pre-treatments on products is the future research direction.

Effect of Heat Treatment Temperature on Carbon Flux Characteristics Using Ultra-Rapid Carburizing above Eutectic Temperature

Effect of Heat Treatment Temperature on Carbon Flux Characteristics Using Ultra-Rapid Carburizing above Eutectic Temperature

Modeling Europium (II/III) ion solvation in the LiCl-KCl eutectic mixture with polarizable force fields

The solvation processes of Europium (II/III) ions within the molten salt eutectic mixture, 3LiCl-2KCl, are investigated over temperatures ranging from 673 K to 1173 K. New polarizable ion force fields are proposed to model Europium ions in a molten salt eutectic mixture with a goal of accurately capturing the underlying physics in the solutions. In contrast to rigid-ion models, the polarizable Drude model with an adjusted WBK (Wang-Buckingham) force field significantly improves predictions for diffusion coefficients, the average diffusion activation energy, and changes in excess ion chemical potential and partial molar entropy, producing good agreement with experimental measurements.

Direct determination of diffusion flux in alloys via spatial separation of flux

Despite the importance of atomic diffusion in controlling high temperature deformation, it remains difficult to generally determine diffusion flux through alloys. We present thermomechanical nanomolding, where a nanomold is filled by the alloy's diffusion flux under a stress gradient, to determine the flux diffusing through an alloy's microstructure. This flux is collected in the nanomold forming nanorods. Length and composition analyses of the formed nanorods allow us to determine rate and composition of the flux, and further allow estimation of the constituents’ diffusivities in this flux. We verify this technique on metals and simple alloys, and then reveal diffusive flux in general alloys. Notably, for alloys that can access a eutectic composition in their alloy system, the flux's composition is that of the eutectic, which can be very different from the alloy's nominal composition. Moreover, the flux's overall diffusivity is greatly enhanced. This, so far unknown, eutectic mechanism is present in the majority of multicomponent alloys. These insights into diffusion flux in alloys can be used to guide the development of alloys with particularly low diffusivity or particularly high diffusivity. More generally, the presented method provides a novel toolbox to reveal the rich underlying diffusion-controlled mechanisms of deformation of alloys in general.

Maximizing filler content and manufacturing highly thermal conductive composite materials through eutectic liquefaction of epoxy resin

We report novel research results demonstrating the production of polymer nanocomposites with high thermal conductivity. The use of diluents, a conventionally used method to reduce viscosity and increase processability, had clear limitations that could not be used for solid epoxy, but in this study, the melting point of the epoxy itself was reduced through the introduction of the eutectic system, allowing the solid epoxy to be converted into a liquid phase. By utilizing eutectic liquid (EL) derived from ketone-containing epoxy resin (DBPE) and diphenylamine (DPA), we achieved maximal filler content. Unlike DBPE’s solid form at 135 °C, EL displayed liquidity with a viscosity of 50 Pa·s at 50 °C, enabling curing with isophorone diamine (IPDA) below DBPE’s melting point. While DBPE/IPDA yielded a tensile strength of 7.2 MPa due to uneven mixing, EL/IPDA reached 44.3 MPa, marking a 520 % improvement. EL’s viscosity dropped dramatically, reaching 0.06 Pa·s at 98 °C. The EL/IPDA mixture’s viscosity at 98 °C was 150 Pa·s, allowing up to 80 wt% hexagonal boron nitride (h-BN) filler. This led to a thermal conductivity of 16 W/m·K, 20 wt% higher than DGEBA’s 60 wt% filling rate. Notably, EL/h-BN composites achieved 16 times the thermal conductivity of DGEBA/h-BN composites, which is 1 W/m·K. Lowering the melting point and viscosity expanded curing agent choices, enhanced tensile strength, increased filler content, and heightened thermal conductivity, showcasing EL’s remarkable potential.

Efficient fractionation of lignin from Camellia oleifera shell by acidic deep eutectic solvent under mild conditions

In this study, ethylene glycol-oxalic acid deep eutectic system (DES) was used for delignification of Camellia oleifera shell (COS). The effects of treatment temperature and time on lignin removal rate, lignin purity and yield were investigated. At the treatment temperature and treatment time of 90 °C and 6 h, the residue rate, lignin removal rate and yield values of 42.33 %, 67.79 % and 45.84 %, respectively. The structure of lignin was ascertained by performing Fourier transform infrared spectroscopy (FT-IR) and two-dimensional nuclear magnetic resonance spectroscopy (2D HSQC NMR), the spectra of which indicated that COS lignin mainly comprises guaiacyl (G) units, followed by syringyl (S) units. Thermal analysis of lignin was conducted based on thermogravimetric analysis (TG) and differential scanning calorimetry (DSC), and the glass transition temperature of lignin was determined to be between 90 and 130 °C. The results in this study indicated that ethylene glycol-oxalic DES system can be used to facilitate the efficient delignification of COS.

Synergistic resource recovery of hydrogen sulfide and carbon dioxide in ionic liquid deep eutectic solution: Construction and development

Synergistic resource recovery of hydrogen sulfide and carbon dioxide in ionic liquid deep eutectic solution: Construction and development

Transformation of Mg-bearing minerals and its effect on slagging during the high-alkali coal combustion

To better understand the mineralogical, release-transformation patterns and ash deposition of Mg-bearing minerals, Wucaiwan Coal (WCW), Meihuajing Coal (MHJ), and slag of water wall from a power plant were collected and high-temperature ash transformation experiments were conducted. X-ray fluorescence (XRF), X-ray diffractometer (XRD), scanning electron microscope coupled with energy dispersive spectrometer (SEM-EDS), and simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC) were used to analyze the mineralogy, chemical composition, and characteristics. The results show that the Mg-bearing minerals in high-alkali coal and ash include dolomite, chlorite, forsterite, melilite, akermanite, diopside, bredigite, pyroxene, periclase, spinel, and magnesioferrite. During combustion, the release of Mg is affected by its mode of occurrence. Mg-bearing minerals gradually transform into thermally stable minerals, including spinel, periclase, and pyroxene, with the transformation pathway being dolomite → Mg-bearing silicate (diopside, akermanite, bredigite) → pyroxene/spinel/periclase. Moreover, Ca has a competitive and synergistic effect on the transformation of Mg-bearing minerals, which depends on the relative content of Si and Al in ash. Spinel is the primary Mg-bearing mineral in high-temperature ash, and Fe may substitute for both Mg and Al. In coal combustion, the formation of Mg-Al-Fe and Mg-Al-Fe-Si-Ca eutectic systems from Mg-bearing minerals causes slagging on the water wall and worsens water wall corrosion.

Green extraction of natural indigoid from Baphicacanthus cusia (Nees) Bremek using hydrophilic and hydrophobic deep eutectic solvent technology

This study focused on the development of an alternative and more environmentally friendly extraction solvent, a deep eutectic system (DES), for extracting indigoid pigments, specifically indigo and indirubin, from Baphicacanthus cusia (BC). BC is recognized in the textile industry as a natural vat dye and in traditional Chinese medicine as "Qing-Dai". It is known for treating inflammatory diseases such as psoriasis. In this study, 46 DES systems were compared with conventional methods. The hydrophobic DES, a terpenoid and fatty acid system comprising thymol:decanoic acid (DES40), and the hydrophilic DES, a choline chloride-based system comprising choline chloride: p-toluenesulfonic acid (DES19), showed significant extraction improvements. DES40 and DES19 achieved approximately 26-fold higher indigo content compared to classical ethanol and outperformed the harsh organic solvent dichloromethane. The green extraction process was optimized using a Box–Behnken design, considering parameters such as temperature, time and co-solvent. DES19 maximized indigo and indirubin content to 270.91±14.38 and 5.70±0.11mg/g, respectively, while DES40 yielded 108.28 ± 3.9 and 0.16 ± 0.00mg/mg/g, respectively. Safety evaluations using a cell-based MTT model with human skin cells in keratinocytes and fibroblasts showed that both DES19 and DES40 were safe at all concentrations tested. These results indicate that a more environmentally friendly solvent technology for the extraction of indigoids from BC using the DES is an efficient and potential application in the textile and pharmaceutical industries.

An Investigation into the Preparation, Characterization, and Therapeutic Applications of Novel Gefitinib/Capric Acid Deep Eutectic Systems

An Investigation into the Preparation, Characterization, and Therapeutic Applications of Novel Gefitinib/Capric Acid Deep Eutectic Systems

Microstructure and wear characteristics of austenitic stainless steel coatings fabricated through various directed energy deposition

Austenitic stainless steels are widely used in automotive and marine environments because of their high toughness, corrosion resistance, and wear resistance. The present comparative study focuses on the microstructure and wear resistance of double-layer austenitic stainless-steel coatings prepared on a ductile iron substrate using circular spot high-speed laser-directed energy deposition (DED) and broad-beam laser-DED. The results indicate that while the deposition process does not alter the physical phase of coating, it does influence the preferred orientation of surface grains. Both coatings exhibit characteristics of hypoeutectic alloys, where the harder eutectic structure serves as a skeleton to resist external pressure. The high-speed laser-DED coating demonstrates higher hardness and wears resistance due to its denser eutectic structure. In addition, its finer microstructure produces smaller wear debris, contributing to the formation of a denser oxide film, thereby enhancing wear resistance.

Pimozide and Adipic Acid: A New Multicomponent Crystalline Entity for Improved Pharmaceutical Behavior

Pimozide is a first-generation antipsychotic used in the treatment of schizophrenia, Gilles de la Tourette syndrome, and other chronic psychoses. Its in vivo efficacy is limited by poor solubility and consequent poor bioavailability. Therefore, adipic acid was used as a coformer for the preparation of a binary product with improved pharmaceutical properties. The thermal behavior of the liquid-assisted grinding products of compositions included in the range 0.1 &lt; XPMZ &lt; 0.9 has been interpreted using a thermo-dynamic model according to which the two components originate a new crystalline entity in molar ratio pimozide:adipic acid 0.66:0.33, which forms an eutectic system with adipic acid. The model was confirmed using the quantitative analysis of the melting peaks and using the X-ray diffraction measurements from powders and single crystals. In particular, the latter have demonstrated that the new entity resulting from the pimozide:adipic acid 0.66:0.33 composition is actually salt [PMZH]2[adipate]. The crystalline product was characterized, from a pharmaceutical perspective, in terms of solubility and wettability (contact angle). Then, a tablet formulation was developed, and its dissolution behavior was compared to a commercial product considered as a reference. The new entity showed improved pharmaceutical properties in terms of solubility and wettability compared to the pure drug in both deionized water and bio-relevant fluids simulating oral administration in fed and fasted conditions. The tablets containing the new crystalline form can make this virtually insoluble drug available for absorption within minutes regardless of the variability in gastric conditions.

Composite Solid Electrolytes

The review describes composite electrolytes based on classical salt matrix phases, and also shows the possibilities of creating composites using simple or complex oxide matrices, where simple substances, salts, simple and complex oxides are used as heterogeneous dopant. The magnitude of the composite effect of electrical conductivity is discussed from the point of view of various theories of its quantitative description. The reasons for the occurrence of the composite effect are summarized. The effect of increasing ionic conductivity is due to the disorder of the surface layer in the intergranular space, amorphization or spreading of the matrix phase or the phase of heterogeneous dopant over the surface of the other phase due to the difference in surface energy, as well as the possibility of joint manifestation of these effects when using complex oxide eutectic composites with treatment above the temperature of the eutectic system.

Ligand‐Free Zn Catalyzed Synthesis of Functionalized Indoloacridines

AbstractAn efficient, ligand‐free, and Zn‐catalyzed dehydrogenation of acridinol/ cyclization of imine product/ dehydrogenative C(sp3)‐H functionalization utilizing ChCl‐based deep eutectic solvent system for the assembly of functionalized indoloacridines 9 is reported. The protocol features mild reaction conditions, VOCs free process, broad substrate scope, and applicable gram‐scale synthesis. Furthermore, absorption and solvatochromism properties were explored for the synthesized compounds.

Research on enhancing thermal conductivity of phase change microcapsules with nano-copper

Abstract The unique ability of phase change materials (PCMs) to store and release heat makes their integration into building materials promising for reducing energy consumption and enhancing sustainability. In this work, a novel high-thermal-conductivity microencapsulated phase change material was prepared, with nano-copper embedded in the microcapsule structure. This modification enhanced thermal conductivity while largely preserving the material’s latent heat storage capacity. Poly(ethyl acrylate) (PEA) is chosen as the capsule shell, whereas a eutectic mixture of decanoic acid (CA) and lauric acid (LA) serves as the core material. The analysis results indicate that as the shell-core mass ratio decreases, the microcapsule size increases, and both thermal conductivity and thermal diffusivity gradually decrease. Moreover, the latent heat capacity of microencapsulated phase change material (MEPCM) increases. When the shell-core mass ratio is 1:1.5, the melting latent heat and solidification latent heat are 81.85 J/g and 88.68 J/g, respectively. nano-copper doping enhances the material's thermal conductivity and thermal diffusivity by 47.5 % and 50 %, respectively, leading to a 20.3 % improvement in heat storage efficiency. After 200 cycles of testing, the material maintains good thermal reliability and chemical stability. Mortar-based composite materials containing microcapsules were prepared. The mortar composite materials containing microcapsules exhibited minimal influence from heating and cooling, with those containing nano-copper microcapsules demonstrating superior thermal response speeds. The method of doping and modifying MEPCM with nano-copper is a promising approach for effectively reducing the impact of temperature fluctuations on the internal comfort of buildings, improving energy utilization efficiency, and providing reliable solutions for temperature-sensitive applications.