Liquid Research Articles

Modification of liquid phase and microstructure of sintered mullite by different additives

Modification of liquid phase and microstructure of sintered mullite by different additives

Effect of ferrotitanium slag particle size on properties of Al2O3–SiC–C castables

Ferrotitanium slag can be used to replace bauxite to fabricate refractories owing to its high refractoriness (>1790 °C) and Al2O3 content (≥70 wt%). However, impurities in the ferrotitanium slag is harmful to the materials. In this paper, the mechanical properties and molten slag resistance of Al2O3–SiC–C castables were improved by replacing part of bauxite with large size ferrotitanium slag (8-5 mm). The large size ferrotitanium slag contained a small amount of impurities, which reacted with SiO2 at high temperature to form CaO–Al2O3–SiO2–TiO2 liquid layer on the surface of particles. Under the action of the liquid phase, the ferrotitanium slag particles and the matrix were combined more closely. With the decrease of the particle size of ferrotitanium slag, the slag resistance of the castables began to decrease. This was because the specific surface area of the particles with smaller particle size was relatively larger, large contact area with molten slag resulted in worse slag resistance. Meanwhile, decreasing ferrotitanium slag particle size brought the increase of apparent porosity of Al2O3–SiC–C castables, resulting in weak mechanical properties.

Exploring the oxidation chemistry of diethyl carbonate in lithium-ion battery thermal runaway using SVUV-PIMS

With the extensive applications of lithium-ion batteries and widespread concerns about their security, it is necessary to deeply understand the reaction mechanism of thermal runaway process of Li-ion batteries. Oxygen released from cathode and anode materials could react with electrolyte solvents with increased temperatures. However, the chemical mechanism remains elusive due to the complexity of the battery system. In this work, we developed a method to study the oxidation chemistry of electrolyte solvents and oxygen in lithium-ion battery thermal runaway process. The liquid phase oxidation of diethyl carbonate (DEC) with oxygen was studied in a closed autoclave with diverse oxygen concentrations, temperatures and reaction times. The samples were measured by synchrotron vacuum ultraviolet radiation photoionization mass spectrometry (SVUV-PIMS) to quantitatively analyze the oxidation products. It was found that the onset reaction temperature is less than 120 °C, which indicates that it maybe occurs in the early stage of Li-ion battery thermal runaway. Besides, the feasible reaction scheme is discussed to rationalize the formation of the primary products.

Phase equilibria of CaO–Al2O3–CaO·TiO2 system at 1500 °C in hydrogen atmosphere

The phase diagram of CaO–Al2O3-TiOx system is of great importance in guiding the design of metallurgical slag systems for Al–Ti alloy steel, controlling Ti-bearing inclusions in molten steel, and regulating the mineral phase of vanadium-titanium magnetite. In the present work, the high temperature equilibration-quench technique was adopted, and the types and compositions of equilibrium phases were identified by Electron Probe Micro Analysis (EPMA) and X-ray diffraction (XRD). The isothermal section of CaO–Al2O3–CaO·TiO2 system at 1500 °C in H2 atmosphere was constructed for the first time. There are 7 three-phase fields, 10 two-phase fields, and a single liquid phase field. On this basis, according to the theoretical analysis of the crystal structure, the formation energy analysis based on first-principles calculations, and the related theories of defect chemistry, the formation mechanisms of CaTiO3 and Ca3Ti2O7 solid solution with were determined, respectively. Additionally, the experimental phase diagram was utilized to discuss the dissolution type and the equilibrium solubility of typical inclusions (Al2O3, Ti3O5, and CaO·TiO2) in Al–Ti alloy steel.

Solid–Liquid Phase Equilibria of Potassium–Ammonium–Magnesium Chloride System at 323.2 and 348.2 K

Solid–Liquid Phase Equilibria of Potassium–Ammonium–Magnesium Chloride System at 323.2 and 348.2 K

Liquid-to-Gas transfer of sodium in a liquid cathode glow discharge

Abstract Plasma-liquid interactions have been extensively studied with a focus on the transport of reactive species from the plasma to the liquid phase and their induced liquid phase chemistry and resulting applications. While solute transfer from the liquid to the gas phase in plasmas has been widely used in analytical chemistry, the underlying processes remain relatively unexplored. We report spatially and temporally resolved absolute density measurements of sodium in a plasma with a NaCl solution cathode using two-photon absorption laser induced fluorescence (TaLIF). The observed non-linear increase in sodium density with solution conductivity is shown to correlate with droplet generation as visualized by Mie scattering. The findings are explained by droplet generation by electrospray induced by Taylor cone formation as underpinning mechanism for the introduction of sodium in the plasma.An analytical sheath model combined with a scaling law shows an increase in electric field force with solution conductivity that is consistent with the observed non-linear increase in sodium density in the plasma with solution conductivity.

Viscosity of Al-Ni-Co-Nd(Sm) glass-forming melts at high temperatures.

Obtaining amorphous alloys with good mechanical and anticorrosion properties is an important problem of modern condensed matter physics. Since the preparation of amorphous alloys involves casting them from liquid state, information on the properties of the melts is needed. Viscosity is one of the most informative structure-sensitive property of melts. In this paper viscosity of some glass-forming Al-Ni-Co-Nd(Sm) melts with different ratio of transition metals was studied using damped oscillation method in a wide temperature range up to 1550 K. Activation energies of the viscous flow were calculated from the experimental data. The hysteresis of viscosity temperature dependences during heating and subsequent cooling was found. It can be associated with a melt transition to a more homogeneous state. The repeated heating and cooling of the melts without crystallization lead to Arrhenius type of viscosity temperature dependences.

Solid-State Electrocatalysis in Heteroatom-Doped Alloy Anode Enables Ultrafast Charge Lithium-Ion Batteries.

Electrocatalysis is generally confined to dynamic liquid-solid and gas-solid interfaces and is rarely applicable in solid-state reactions. Here, we report a paradigm shift strategy to exploit electrocatalysis to accelerate solid-state reactions in the context of lithium-ion batteries (LIBs). We employ heteroatom doping, specifically boron for silicon and sulfur for phosphorus, to catalyze electrochemical Li-alloying reactions in solid-state electrode materials. The preferential cleavage of polar dopant-host chemical bonds upon lithiation triggers chemical bond breaking of the host material. This solid-state catalysis, distinct from liquid and gas phases, requires a critical doping concentration for optimal performance. Beyond a critical concentration of ∼1 atom %, boron and sulfur doping drastically reduces activation energies and accelerates redox kinetics during lithiation/delithiation processes, leading to markedly enhanced rate performance in boron-doped silicon and sulfur-doped black/red phosphorus anode. Notably, a sulfur-doped black phosphorus anode coupled with a lithium cobalt oxide cathode achieves an ultrafast-charging battery, recharging 80% energy of a battery in 302 Wh kg-1 in 9 min, surpassing the thus far reported LIBs.

Eight-color chiral spin liquid in the S=1 bilinear-biquadratic model with Kitaev interactions

Multipolar spin systems provide a rich ground for the emergence of unexpected states of matter due to their enlarged spin degree of freedom. In this study, with a specific emphasis on S=1 magnets, we explore the interplay between spin nematic states and spin liquids. Based on the foundations laid in the prior work [R. Pohle , ], we investigate the S=1 Kitaev model with bilinear-biquadratic interactions, which stabilizes, next to Kitaev spin liquid, spin nematic and triple-q phases, also an exotic chiral spin liquid. Through a systematic reduction of the spin degree of freedom—from CP2 to CP1 and ultimately to a discrete eight-color model—we provide an intuitive understanding of the nature and origin of this chiral spin liquid. We find that the chiral spin liquid is characterized by an extensive ground-state degeneracy, bound by a residual entropy, extremely short-ranged correlations, a nonzero scalar spin chirality marked by Z2 flux order, and a gapped continuum of excitations. Our work contributes not only to the specific exploration of S=1 Kitaev magnets but also to the broader understanding of the importance of multipolar spin degree of freedom on the ground state and excitation properties in quantum magnets. Published by the American Physical Society 2024

Early prediction of spinodal-like relaxation events in supercooled liquid water.

Several computational studies on different water models reported evidence of a phase transition in supercooled conditions between two liquid states of water differing in density: the high-density liquid (HDL) and the low-density liquid (LDL). Yet, conclusive experimental evidence of the existence of a phase transition between the two liquid water phases could not be obtained due to fast crystallization in the region where the phase transition should occur. For the same reason, the investigation of possible transition mechanisms between the two phases is committed to computational investigations. In this work, we simulate an out-of-equilibrium temperature-induced transition from the LDL to the HDL-like state in the TIP4P/2005 water model. To structurally characterize the system relaxation, we use the node total communicability (NTC) we recently proposed as an effective order parameter to discriminate the two liquid phases differing in density. We find that the relaxation process is compatible with a spinodal-like scenario. We observe the formation of HDL-like domains in the LDL phase and we characterize their fluctuating behavior and subsequent coarsening and stabilization. Furthermore, we find that the formation of stable HDL-like domains is favored in the regions where the early formation of small patches of highly connected HDL-like molecules (i.e., with very high NTC values) is observed. Besides characterizing the LDL- to HDL-like relaxation from a structural point of view, these results also show that the NTC order parameter can serve as an early-time predictor of the regions from which the transition process initiates.

Eco‐Friendly Production of 2D Ti3C2Tx MXene and Cytotoxicity Mitigation Toward Biomedical Applications

Abstract 2D MXenes find applications in several technology fields. Solution processing techniques can facilitate the integration of these materials within the technological supply chain. Here, a highly concentrated (up to 1.5 g L−1) and stable dispersion of 2D Ti3C2Tx MXene flakes is produced by an environmentally friendly liquid phase exfoliation process (LPE) in dihydrolevoglucosenone (Cyrene). The flakes preserve their elemental composition after 6 months, while those exfoliated in N‐Methyl‐2‐pyrrolidone (NMP), a commonly used solvent, undergo significant oxidation. The cytotoxicity of the MXene flakes in Cyrene and in NMP is investigated by assessing the cellular viability in a human keratinocyte (HaCaT) cell line, which is a relevant model for skin applications. The data show that the MXene flakes in Cyrene induce cytotoxic effects for a dose > 1 µg cm−2, as similarly observed for the MXene flakes in NMP. Efforts are made to overcome this by collecting the MXene flakes and redispersing them in a solution of bovine serum albumin (BSA). MXene in BSA does not affect cellular viability and cell morphology, possibly due to the formation of a protective protein corona around the individual MXene flakes. These findings illustrate an environmentally friendly strategy to produce biocompatible 2D MXene for biomedical applications.

Measuring the Electric Fields of Ions Captured in Crown Ethers.

Controlling reactivity with electric fields is a persistent challenge in chemistry. One approach is to tether ions at well-defined locations near a reactive center. To quantify fields arising from ions, we report crown ethers that capture metal cations as field sources and a covalently bound vibrational Stark shift probe as a field sensor. We use experiments and computations in both the gas and liquid phases to quantify the vibrational frequencies of the probe and estimate the electric fields from the captured ions. Cations, in general, blue shift the probe frequency, with effective fields estimated to vary in the range of ∼0.2-3 V/nm in the liquid phase. Comparison of the gas and liquid phase data provides insight into the effects of mutual polarization of the molecule and solvent and screening of the ion's field. These findings reveal the roles of charge, local screening, and geometry in the design of tailored electric fields.

The Geology, Fluid Inclusions, and O‐S Isotopes of the Mibei Gold Deposit, Hunan Province, Southern China

AbstractThe Mibei gold deposit, located in the southwestern part of the Xuefengshan uplift zone, the middle section of the Jiangnan orogenic belt in southern China, has estimated gold resources of approximately seven tons. This deposit is primarily a quartz vein‐type gold deposit, with ore bodies occurring mainly within Neoproterozoic metasediments. The main metallic minerals in the ore are pyrite, chalcopyrite, and arsenopyrite. In this study, the petrography and microthermometry of ore‐forming fluid inclusions, oxygen isotopes of gold‐bearing quartz, and sulfur isotopes of gold‐bearing sulfides and arsenopyrite were analyzed. Three types of fluid inclusions were identified: type Ia three‐phase inclusions comprising vapor and two phases of liquids (VCO2 + LCO2 + LH2O), type Ib two‐phase liquids (LCO2 + LH2O), type II two‐phase vapor‐rich inclusions (V/V + L > 50%), and type III pure liquid inclusions. Type I inclusions were heated uniformly to the liquid phase, type II inclusions were heated uniformly to the gas phase, and type III inclusions were heated without change. In general, the temperature range of homogenization to liquid phase of fluid inclusions in the Mibei gold deposit is 204–227°C. The salinity of the inclusion ranges from 4.6 to 12.2 wt% NaCl equiv. The δ 18OSMOW of gold‐bearing quartz varies from 16.9‰ to 17.5‰. The δ 18OH2O of gold‐bearing quartz are varied from 6.5‰ to 7.5‰. The δ34S values of gold‐bearing pyrite range from 1.7‰ to 6.8‰. The δ34S values of gold‐bearing arsenopyrite range from 5.6‰ to 5.9‰. The δ34S values of pyrite from wall rocks slate range from 6.4‰ to 11.6‰. This evidence implies that the ore‐forming fluids of the Mibei gold deposit originated from magmatic‐hydrothermal processes, mixing with minor S from the surrounding metasediments. Combined with the evolution of the Jiangnan orogenic belt, due to the magmatic and tectonic activities of the Xuefengshan uplift during the Caledonian period, the fault seal mechanism controlled the ore‐forming process. Overall, the Mibei gold deposit is more akin to a magmatic‐hydrothermal gold deposit.

Investigating effects of sintering mean residence time on engineering properties of coal ash‐based lightweight aggregate

AbstractThis study examines the effect of sintering mean residence time (MRT) on the engineering properties and morphological structure of lightweight aggregates (LWA) manufactured from waste coal combustion ash (W‐CCA). A thermodynamics‐based framework was used to tune LWA manufacturing processes. A minimum 35% liquid phase (by mass) and a lower bound viscosity of 100 Pa·s of molten material were found necessary to successfully produce LWA. Using W‐CCA's chemical composition and FactSage thermodynamic modeling, the sintering temperature for LWA was set to 1075°C. Green spherical pellets made using a pelletizer were sintered at MRT of 5.1, 14.8, and 25.9 min to test LWA physical‐mechanical properties including, unit weight, specific gravity, water absorption, and compressive strength. Results indicated that unit weight ranged from 752 to 800 kg/m3, providing desirable lightweight properties. Oven dry specific gravity ranged from 1.24 to 1.43, complying with ENI13055 specification for LWA. Water absorption capacity decreased as MRT extended from 5.1 to 14.8 min and then increased as MRT proceeded from 14.8 to 25.9 min, achieving an average absorption capacity of 26% ± 1.5%. The inverse effect was noticed for compressive strength as LWA sintered with an MRT of 14.8 min demonstrated the highest compressive strength of 14.7 ± 1.8 MPa. The initial decrease in water absorption and increase in compressive strength are attributed to the efficient sintering of the LWA's internal structure. The inverse effect observed as MRT proceeded from 14.8 to 25.9 min was believed to be a result of thermal cracking due to extensive heat exposure. MRT of 14.8 min is recommended for LWA production using the coal ash utilized in this study for its buoyancy characteristics, sufficient absorption capability, and higher compressive strength.

Crystal Structure of Bis(1-butyl-1-methypyrrolidinium) Perthiodicarbonate Complex

Bis(1-butyl-1-methypyrrolidinium) perthiodicarbonate was obtained by the reaction of carbon disulfide with 1-butyl-1-methypyrrolidinium acetate ([BmPyrro][Ac]) in the liquid phase. Structural characterization of this original complex was achieved by single-crystal X-ray diffraction (SCXRD) analysis. The asymmetric unit of the title compound, C2S6·2C9H20N, consisted of two crystallographically 1-methyl-1-butyl pyrrolidinium cations and one perthiodicarbonate anion. The complex C2S6·2C9H20N crystallized in the monoclinic space group, C 2/c, and possessed the following cell parameters: a = 16.0970(10) Å, b = 14.7140(9) Å, c = 12.3280(8) Å, α = 90°, β = 112.3730(12)°, γ = 90°, V = 2700.11 Å3, and Z = 8, Z’ = 0.5.

Impact of Nuclear Quantum Effects on the Structural Properties of Protonated Water Clusters.

Nuclear quantum effects (NQEs) play a crucial role in hydrogen-bonded systems due to quantum tunneling and proton fluctuation. Our understanding of how NQEs affect microstructures mainly focuses on bulk phases of liquids and solids but remains deficient for water clusters, including their hydrogen nuclei, hydrogen-bonded configurations, and temperature dependence. Here, we conducted ab initio molecular dynamics (MD) and path integral MD simulations to investigate the influence of NQEs on the structural properties of protonated water clusters H+(H2O)n (n = 3, 6, 9, 12). The results reveal that the NQEs become less evident as the cluster size increases due to the competition between NQEs and electrostatic interactions. Simulations of several H+(H2O)6 isomers at different temperatures indicate that the effect of elevated temperature on proton transfer is related to the initial structure. Interestingly, the process of proton transfer also involves the interconversion between Zundel-type and Eigen-type isomers. These findings significantly deepen our understanding of ion-water and water-water interactions, opening new avenues for the study of hydrated ion clusters and related systems.

Abnormal endothermic liquid–liquid phase transition upon cooling Pd40Ni40P20 melts

Liquid–liquid phase transition (LLPT) is the transformation of a liquid from one distinctive structure to another with the same composition. However, the origin of the structural variation at LLPT is still controversial. Here, we used ab initio molecular dynamics simulation to verify and investigate a high-temperature LLPT in a Pd40Ni40P20 melt; this melt showed a reduction in the nuclei interference of the conventional low-temperature LLPT. An abnormal endothermic LLPT was confirmed with flash differential scanning calorimetry, indicating a change in the atomic short-range-order structure around the P–P bond and a decrease in the number of specific icosahedral-like clusters, such as ⟨0 2 8 0⟩ and ⟨0 2 8 1⟩. The structural change of the P-centered clusters changed the solidification path through potential energy adjustments. Our results showed the structural mechanism of the unusual endothermic phenomenon and provided a different insight into regulating the properties of metallic glasses.

Wavelet Cross-Correlation Signal Processing for Two-Phase Flow Control System in Oil Well Production

An algorithm based on continuous measurement of multiphase flows of oil well production has been designed to improve the efficiency of the technical control of oil production processes in the field. Separation-free, non-contact measurement of multiphase flows of oil well products allows increasing the efficiency of managing oil production processes in the field. Monitoring the current density using radioisotope measuring transducers (RMTs) allows obtaining information about the structure of the flow in the form of the distribution of gas inclusions and the speed of movement of liquid and gas in a two-phase flow. Fluid velocity measurement is based on digital processing of RMT signals, applying a continuous or discrete undecimated wavelet transform to them, and assessing the cross-correlation of wavelet coefficients in individual subspaces of the wavelet decomposition. The cross-correlation coefficients of two RMT signals located at a base distance, calculated in the subspaces of the wavelet decomposition, characterize the speed of movement of gas bubbles of different sizes in a vertical pipe. The measurement assumes that the velocity of the liquid phase of the oil flow in a vertical pipe mainly corresponds to the velocity of small bubbles. This speed should be determined by the maximum cross-correlation of wavelet coefficients in the corresponding decomposition subspace. Computer modeling made it possible to evaluate the characteristics of the algorithm for controlling the speed of liquid movement in the gas–liquid flow of oil well products and determine the mass flow rate of the liquid and the relative value of the gas content. The implementation of the algorithm in a multi-channel version of the device allows monitoring an entire cluster of wells in the field.

The autophagy adaptor TRIAD3A promotes tau fibrillation by nested phase separation.

Multiple neurodegenerative diseases are characterized by aberrant proteinaceous accumulations of tau. Here, we report a RING-in-between-RING-type E3 ligase, TRIAD3A, that functions as an autophagy adaptor for tau. TRIAD3A(RNF216) is an essential gene with mutations causing age-progressive neurodegeneration. Our studies reveal that TRIAD3A E3 ligase catalyses mixed K11/K63 polyubiquitin chains and self-assembles into liquid-liquid phase separated (LLPS) droplets. Tau is ubiquitinated and accumulates within TRIAD3A LLPS droplets and, via LC3 interacting regions, targets tau for autophagic degradation. Unexpectedly, tau sequestered within TRIAD3A droplets rapidly converts to fibrillar aggregates without the transitional liquid phase of tau. In vivo studies show that TRIAD3A decreases the accumulation of phosphorylated tau in a tauopathy mouse model, and a disease-associated mutation of TRIAD3A increases accumulation of phosphorylated tau, exacerbates gliosis and increases pathological tau spreading. In human Alzheimer disease brain, TRIAD3A co-localizes with tau amyloid in multiple histological forms, suggesting a role in tau proteostasis. TRIAD3A is an autophagic adaptor that utilizes E3 ligase and LLPS as a mechanism to capture cargo and appears especially relevant to neurodegenerative diseases.

Digestate from an Agricultural Biogas Plant as a Factor Shaping Soil Properties

In the context of a circular economy, special attention should be paid to the rational management of biodegradable waste. Currently, a potentially valuable waste material, rich in ingredients available to plants, is digestate, obtained as a by-product in agricultural biogas plants. The presented study aimed to determine the impact of digestate (DIG) from an agricultural biogas plant on soil reaction (pH), electrical conductivity (EC), sorption properties (SBC, HAC, CEC, BS), and chemical composition of soil. The research was based on a pot experiment in which increasing doses of liquid (LD) and solid (SD) forms of DIG were used in corn cultivation, balanced in terms of the amount of N introduced into the soil. The composition of DIG varied and depended on the LD or SD form. The LD was characterized by a lower pH value and higher EC compared to the SD form. The LD contained much less TC, fewer macroelements, and fewer trace elements. The application of LD significantly increased in the soil the content of TC, Ntot, available K, P, Fe, and Mn, and exchangeable cations K+. The SD significantly increased the content of available P, Mg, and Mn and exchangeable cations Ca2+ and Mg2+ in the soil. Both forms of digestate increased the total content of heavy metals (Cu, Cr, Pb, and Ni) in the soil. However, they did not pose a threat to the environment concerning their legally permissible levels.