Properties Of Liquid Phase Research Articles

Effect of nano-aluminum hydroxide on the liquid phase properties and fire-fighting foam performance of the mixed surfactants solution

Short-chain fluorocarbon surfactants show synergistic effects with hydrocarbon surfactants in foaming and foam stability. Nano-aluminum hydroxide (nano-ATH) was added as an additive to the short-chain fluorocarbon surfactant mixture solution, which was found to increase the surface tension and viscosity of the surfactant mixture solution, and decrease the foaming properties of the solution, as measured by Wilhelmy method, Waring Blender method and viscometer. By measuring zeta potential experiments, surfactant molecules were found to be adsorbed on nano-ATH through charge gravity, which increased the desorption energy of nano-ATH. Measuring the visco-elastic modulus of the solution by rheometer, it was found that nano-ATH increased the visco-elastic modulus of the surfactant mixture solution, which improved the foam's resistance to the external disturbances. Observed by the image analysis system on the foam, the uniform distribution of nano-ATH in the liquid film reduced the coarsening and coalescence speed of foam. Through the self-developed oil resistance test, nano-ATH enhanced the oil resistance stability and inhibition of fuel vapor diffusion of the foam by about 12 %; through self-developed foam fire extinguishing and anti-burning tests, nano-ATH shortened the fire extinguishing time of the two-phase foam by 25 %, and showed better fire extinguishing and anti-burning performance than the foam.

Microstructure and tensile properties of transient liquid phase (TLP) sintering repaired Ti–6Al–4V alloys with large area hole defect

Repairing defects in titanium alloy components is economically justified due to their high cost. In this work, Ti–6Al–4V samples with large area hole defects are repaired by transient liquid-phase sintering. The microstructure and tensile properties after repair have been investigated. The factors of different base powder morphology and the ratio of braze metal are also studied. The results show that by using spherical Ti64 alloy powder with 40 wt% TiZrCuNi braze alloy powder, an overall repair effect with high-density repair zone and good interface combination can be obtained at 960 °C for 3 h. The tensile strength of the as-repaired exceeds that of the matrix, but the elongation is lower than that of the matrix. Finally, the repair experiment conducted at various angles demonstrates this technique's strong practical feasibility.

Geometric deep learning for molecular property predictions with chemical accuracy across chemical space

Chemical engineers heavily rely on precise knowledge of physicochemical properties to model chemical processes. Despite the growing popularity of deep learning, it is only rarely applied for property prediction due to data scarcity and limited accuracy for compounds in industrially-relevant areas of the chemical space. Herein, we present a geometric deep learning framework for predicting gas- and liquid-phase properties based on novel quantum chemical datasets comprising 124,000 molecules. Our findings reveal that the necessity for quantum-chemical information in deep learning models varies significantly depending on the modeled physicochemical property. Specifically, our top-performing geometric model meets the most stringent criteria for “chemically accurate” thermochemistry predictions. We also show that by carefully selecting the appropriate model featurization and evaluating prediction uncertainties, the reliability of the predictions can be strongly enhanced. These insights represent a crucial step towards establishing deep learning as the standard property prediction workflow in both industry and academia.Scientific contributionWe propose a flexible property prediction tool that can handle two-dimensional and three-dimensional molecular information. A thermochemistry prediction methodology that achieves high-level quantum chemistry accuracy for a broad application range is presented. Trained deep learning models and large novel molecular databases of real-world molecules are provided to offer a directly usable and fast property prediction solution to practitioners.

Effect of dissolved KOH and NaCl on the solubility of water in hydrogen: A Monte Carlo simulation study.

Vapor-Liquid Equilibria (VLE) of hydrogen (H2) and aqueous electrolyte (KOH and NaCl) solutions are central to numerous industrial applications such as alkaline electrolysis and underground hydrogen storage. Continuous fractional component Monte Carlo simulations are performed to compute the VLE of H2 and aqueous electrolyte solutions at 298-423K, 10-400bar, 0-8 molKOH/kg water, and 0-6 molNaCl/kg water. The densities and activities of water in aqueous KOH and NaCl solutions are accurately modeled (within 2% deviation from experiments) using the non-polarizable Madrid-2019 Na+/Cl- ion force fields for NaCl and the Madrid-Transport K+ and Delft Force Field of OH- for KOH, combined with the TIP4P/2005 water force field. A free energy correction (independent of pressure, salt type, and salt molality) is applied to the computed infinite dilution excess chemical potentials of H2 and water, resulting in accurate predictions (within 5% of experiments) for the solubilities of H2 in water and the saturated vapor pressures of water for a temperature range of 298-363K. The compositions of water and H2 are computed using an iterative scheme from the liquid phase excess chemical potentials and densities, in which the gas phase fugacities are computed using the GERG-2008 equation of state. For the first time, the VLE of H2 and aqueous KOH/NaCl systems are accurately captured with respect to experiments (i.e., for both the liquid and gas phase compositions) without compromising the liquid phase properties or performing any refitting of force fields.

Performance improvement of glass-based lightweight aggregates through thermodynamic modelling design and lightweight mortar validation

To reduce environmental impact of sintered lightweight aggregates (LWAs), in this study, novel glass-based LWAs were produced from municipal solid wastes at 900 °C. The mix was designed by thermodynamic modelling to optimize the phase composition, liquid phase properties, and microstructure of the LWAs. Results demonstrated that the inclusion of incinerated sewage sludge ash (ISSA) increased the viscosity of the liquid phase, resulting in a refined pore structure characterized by smaller, more isolated pores, and thicker pore walls. Additionally, ISSA facilitated the formation of various crystalline phases (e.g. wollastonite) to stabilize the pore structure, thereby enhancing densification and matrix strength. Leaching behaviour tests confirmed the suitability of glass-based LWAs for environmentally safe lightweight products. Lightweight mortars incorporating developed LWAs exhibited a high 28-day compressive strength (up to 57.9 MPa) with a low density of 1688 kg/m3 and a low thermal conductivity of 1.0 W/(m·K). The energy simulation revealed substantial reductions in energy consumption when the lightweight mortars were utilized in the building compared with the reference building using normal-weight C30 concrete, underscoring its promising role in conserving energy and reducing carbon emissions.

Dielectric anisotropy in self-assembling MXene-based lyotropic nematic compounds

The formation of a lyotropic liquid crystal phase at the level of MXene-based aqueous dispersions due to the self-assembling capacity of these two-dimensional (2D) materials has been previously successfully reported. However, the influence of electrical external factors has been less studied in spite of the fact that understanding the electrical behaviour of 2D-based liquid crystal compounds is vital for fostering the development of new innovative applications. Consequently, within this paper, we report an in-depth evaluation of the dielectric properties of liquid crystalline phases in Ti3C2 MXene aqueous dispersions. The dependence on the low voltage of planar ε⊥′ to homeotropic ε∥′ orientational transition is emphasized and discussed, while the influence of the electric field frequency at the level of dielectric anisotropy is assessed in respect to various concentrations of MXene flakes within the same 2D-based compounds. Nonetheless, dielectric spectroscopy highlights the biphasic nature (containing both nematic and isotropic phases) of the studied aqueous Ti3C2 MXene inks visible up to 20% MXene. Above this concentration, the existence of a pure nematic phase in the dispersion of highMXene concentration (>20 wt%) was detected based on the evaluation of dielectric permittivity against various voltage values.

The interactions between zeolite and two cellulose derivatives: A comprehensive analysis of liquid and solid phase properties

This study investigates the impact of cellulose-derived polymers, anionic carboxymethylcellulose (CMC), and cationic cellulose (CC) on the colloidal and thermal stability of zeolite Na-X materials. By exploring polymer adsorption onto Na-X surfaces and characterising the resultant materials, using FT-IR, XPS, SEM, PSD, CHN, and zeta potential, the research unveils how CMC and CC modify zeolite properties. This investigation elucidates the potential roles of these polymers in colloidal systems with zeolites, revealing their promise for crafting organic-inorganic materials. Additional insight was also provided by careful examination of the thermal stability (TGA-DSC) of the obtained cellulose/zeolite materials. Furthermore, the study distinguishes the different adsorption mechanisms of CMC and CC, with CMC relying on some weak interactions (H-bonding and van der Waals forces), while CC interacts mainly via electrostatic forces. Both CMC and CC can act as stabilizing agents, with CMC being more efficient and using both electrosteric and depletion stabilizations. Importantly, the concentration of CC plays a role in bridging flocculation, highlighting the concentration-dependent nature of the stabilization mechanism.

Densification, microstructure, thermal and mechanical properties of Si3N4 ceramics: Effect of Y2Si4N6C and MgSiN2 content

The rapid development of third-generation semiconductors urgently requires ceramic substrates with excellent performance. In this work, silicon nitride (Si3N4) ceramics were successfully prepared via gas-pressure sintering (GPS) using Y2Si4N6C and MgSiN2 as additives. The influence of Y2Si4N6C–MgSiN2 content on the liquid phase properties and microstructure of Si3N4 ceramics was clarified. The use of Y2Si4N6C–MgSiN2 not only did not introduce additional oxygen but also consumed SiO2 and purified the β-Si3N4 lattice. The increase in N/O formed a nitrogen-rich liquid phase, which led to the microstructure of Si3N4 ceramics having a bimodal distribution. The relationship between different degrees of bimodal microstructure and properties was explored. When the Y2Si4N6C–MgSiN2 content was 9 wt%, Si3N4 ceramics obtained excellent thermal and mechanical properties due to lattice purification, Si3N4/Si3N4 continuity increase, the largest average grain diameter, and a bimodal distribution microstructure with moderate grain size distribution. The thermal conductivity was 116.7 W m−1 K−1, the fracture toughness was 10.7 ± 0.35 MPa m1/2, and the bending strength was 767 ± 29.6 MPa.

Microstructure and mechanical properties of transient liquid phase bonding Ti3SiC2 ceramic to SUS430 steel using an Al interlayer

Microstructure and mechanical properties of transient liquid phase bonding Ti3SiC2 ceramic to SUS430 steel using an Al interlayer

Tailored anion radii of molten-salts systems toward graphite regeneration with excellent energy-storage properties

Graphite, as the typical non-renewable resource, low-cost recycling of graphite from spent lithium-ion batteries (LIBs) enjoys great significance in economic growth and resources reusing. However, the traditional regenerated manners still suffer from the incomplete repairing, especially the inferior isotropy. Herein, assisted by salt melt synthesis (SMS), the effect recycling process to repair spent graphite is successfully developed. Tailored by the melting-boiling points and ionic strength of molten salts, the as-regenerated graphite performed different repaired properties, including interlayer distance, grain size, and crystallinity, leading to a difference in electrochemical performance. As Li-storage anodes, the as-optimized sample displayed an attractive lithium-storage capability of 352 mAh g−1 after 200 loops at 1.0 C. Even at 5.0 C, it could exhibit about 175 mAh g−1. Simultaneously, supported by of detailed kinetic analysis, the evolutionary properties of molten liquid phase could improve interlayer isotropy, thereby enhancing rate performance. Moreover, for repairing spent graphite, the cost of the proposed process is 745.74 $ t−1, and the recycling profit for regenerating graphite is approximately 7200 $ t−1. Given this, this work was expected to offer the effective repairing manners of spent graphite, meanwhile demonstrating the feasibility about the molten salt approach.

Effects of Cu/SnAgCu Powder Fraction and Sintering Time on Microstructure and Mechanical Properties of Transient Liquid Phase Sintered Joints.

The effects of the sintering duration and powder fraction (Ag-coated Cu/SnAgCu) on the microstructure and reliability of transient liquid phase sintered (TLPS) joints are investigated. The results show that two main intermetallic compounds (IMCs, Cu6Sn5 and Cu3Sn) formed in the joints. The Cu6Sn5 ratio generally decreased with increasing sintering time, Cu powder fraction, and thermal treatment. The void ratio of the high-Cu-fraction joints decreased and increased with increasing sintering and thermal stressing durations, respectively, whereas the low-Cu-fraction counterparts were stable. We also found that the shear strength increased with increasing thermal treatment time, which resulted from the transformation of Cu6Sn5 and Cu3Sn. Such findings could provide valuable information for optimizing the TLPS process and assuring the high reliability of electronic devices.

Accurate Free Energies of Aqueous Electrolyte Solutions from Molecular Simulations with Non-polarizable Force Fields.

Non-polarizable force fields fail to accurately predict free energies of aqueous electrolytes without compromising the predictive ability for densities and transport properties. A new approach is presented in which (1) TIP4P/2005 water and scaled charge force fields are used to describe the interactions in the liquid phase and (2) an additional Effective Charge Surface (ECS) is used to compute free energies at zero additional computational expense. The ECS is obtained using a single temperature-independent charge scaling parameter per species. Thereby, the chemical potential of water and the free energies of hydration of various aqueous salts (e.g., NaCl and LiCl) are accurately described (deviations less than 5% from experiments), in sharp contrast to calculations where the ECS is omitted (deviations larger than 20%). This approach enables accurate predictions of free energies of aqueous electrolyte solutions using non-polarizable force fields, without compromising liquid-phase properties.

In silico study of therapeutic deep eutectic solvent for tetracaine liquid delivery

The development of a drug delivery liquid formulation of ester – based tetracaine local anaesthetic is synthesised in silico via the formation of a therapeutic deep eutectic solvent in combination with citral, a natural monoterpenoid. The properties of the obtained liquid system, studied at the nanoscopic level, are derived from a combination of quantum chemistry and classical molecular dynamics simulations. The intermolecular forces (hydrogen bonding) were analysed and their relationship with liquid phase properties were established. Water effect on the liquid phase properties were also considered in terms of competing for hydrogen bonding sites in the components of the developed fluid. The systems proposed in this work were studied using CIT (HBA) 1:1 TET (HBD) molar ratio at temperatures ranging from 288 K to 318 K and 1 bar. The hydrogen bond network developed between the oxygen atom in citral molecules and the –NH group in tetracaine molecules under those conditions, confirmed via minimal cluster analysis, is maintained during the addition of water up to 1.3 wt% as the water molecules do not disrupt the intermolecular hydrogen bond but develop new interactions (hydrogen bonds) with citral and tetracaine monomers presented in the fluid. The reported results probed the suitability of the considered system as an alternative drug delivery method as well as the possibility of developing deep eutectic-based formulation of anaesthetics using natural compounds due to the formation of effective and strong intermolecular hydrogen bonds.

Numerical and experimental investigation on droplet entrainment mechanism and closed equations of two-fluid model

As a clean and low-carbon energy source, natural gas is an important force in achieving carbon peaking and carbon neutrality goals. Affected by the strong force of gas and liquid during mining and transportation, it exhibits the phenomenon of droplet entrainment. Entrained droplets change the properties of gas and liquid phases, which is crucial for accurate measurement of liquid film thickness, gas holdup, pressure drop and flow rates in natural gas pipelines. The measurement of entrained droplets has always been a focus and difficulty in the two-phase flow research field. Therefore, numerical simulation combined with experimental measurement are presented to study the droplet entrainment mechanism and closed equations of two-fluid model. The specific parameter settings for simulating horizontal gas–liquid annular flow based on numerical method are discussed, and effective simulation of droplet entrainment and deposition in annular flow is achieved. By comparing liquid film thickness and wave velocity from the simulation results with the experimental results, the correctness of the simulation method is verified. Then, the mechanism and dynamic evolution process of entrained droplets in annular flow are revealed, and the generation and deposition characteristics of entrained droplets are studied. As a result, the closed equations of two-fluid model such as droplet velocity, gas–liquid interface velocity, and gas–liquid interface friction factor are established. The proposed two-fluid model is validated using dual mode ultrasound and differential pressure sensors, demonstrating its good applicability and extrapolation.

Transferable Water Potentials Using Equivariant Neural Networks.

Machine learning interatomic potentials (MLIPs) have emerged as a technique that promises quantum theory accuracy for reduced cost. It has been proposed [J. Chem. Phys. 2023, 158, 084111] that MLIPs trained on solely liquid water data cannot accurately transfer to the vapor-liquid equilibrium while recovering the many-body decomposition (MBD) analysis of gas-phase water clusters. This suggests that MLIPs do not directly learn the physically correct interactions of water molecules, limiting transferability. In this work, we show that MLIPs using equivariant architecture and trained on 3200 liquid water structures reproduces liquid-phase water properties (e.g., density within 0.003 g/cm3 between 230 and 365 K), vapor-liquid equilibrium properties up to 550 K, the MBD analysis of gas-phase water cluster up to six-body interactions, and the relative energy and the vibrational density of states of ice phases. We show that potentials developed using equivariant MLIPs allow transferability for arbitrary phases of water that remain stable in nanosecond long simulations.

Variations in redox properties of biochar and humic acid induced by interactive molecular exchange

Biochar and humic substances are prevalent redox pools in the environment, which is critical to electron transfer in geochemical cycles and pollution control processes. The dissolution of biochar and the sorption of humic substances on biochar have the potential to redistribute redox substances, consequently altering the redox properties of solid and liquid phases. However, studies have often focused on either sorption or dissolution separately, overlooking the mutual effects and not involving redox properties. Herein, molecular interactions between biochar and humic acid (HA) and variations in their redox properties were elucidated using UPLC Orbitrap MS and mediated electrochemical measurement. The dissolution of biochar was far greater than the sorption of HA constituents, and HA enhanced the dissolution of biochar through molecular exchange. But preferential sorption of oxygenated aromatics to pine char (pi500) mainly by hydrogen bonding and higher saturated molecules to starch char (st700) mainly by hydrophobic interactions caused the oxygenated functional groups on biochar to increase (1 ~ 1.5 times). Thus the Electron exchange capacities (EEC) of pi500 and st700 turned to 1 ~ 3 times, and the EEC of HA decreased ca. 50%. Absorption (partition) caused more sorption of HA constituents to pi500 than to st700, while larger surface area resulted in higher EEC of st700 with sorbed HA. The enrichment of redox constituents on biochar is promising for its long-term use in waste reclamation and pollution control. The findings can aid in the understanding of variations in redox properties under interactions between pyrolytic and natural organic matter.Graphical

Theory of melting lines.

Our understanding of the three basic states of matter (solids, liquids, and gases) is based on temperature and pressure phase diagrams with three phase transition lines: solid-gas, liquid-gas, and solid-liquid lines. There are analytical expressions P(T) for the first two lines derived on a purely general-theoretical thermodynamic basis. In contrast, there exists no similar function for the third, melting, line (ML). Here, we develop a general two-phase theory of MLs and their analytical form. This theory predicts the parabolic form of the MLs for normal melting, relates the MLs to thermal and elastic properties of liquid and solid phases, and quantitatively agrees with experimental MLs in different system types. We show that the parameters of the ML parabola are governed by fundamental physical constants. In this sense, parabolic MLs possess universality across different systems.

Correction: Effects of Homogenization Heat Treatment on Microstructure, Mechanical and Corrosion Properties of Transient Liquid Phase (TLP)-Bonded Inconel 617/AISI 310 Stainless Steel

Correction: Effects of Homogenization Heat Treatment on Microstructure, Mechanical and Corrosion Properties of Transient Liquid Phase (TLP)-Bonded Inconel 617/AISI 310 Stainless Steel

Generating Function for Projected Entangled-Pair States

Diagrammatic summation is a common bottleneck in modern applications of projected entangled-pair states, especially in computing low-energy excitations of a two-dimensional quantum many-body system. To solve this problem, here we extend the generating-function approach for tensor-network diagrammatic summation, a scheme previously proposed in the context of matrix product states. Taking the form of a one-particle excitation, we show that the excited state can be computed efficiently in the generating-function formalism, which can further be used in evaluating the dynamical structure factor of the system. Our benchmark results for the spin-1/2 transverse-field Ising model and Heisenberg model on the square lattice provide a desirable accuracy, showing good agreement with known results. We then study the spin-1/2J1-J2 model on the same lattice and investigate the dynamical properties of the putative gapless spin liquid phase. We conclude with a discussion on generalizations to multiparticle excitations. Published by the American Physical Society 2024

Cloud-Resolving ICON Simulations of Secondary Ice Production in Arctic Mixed-Phase Stratocumuli Observed during M-PACE

Abstract Field measurements and modeling studies suggest that secondary ice production (SIP) may close the gap between observed Arctic ice nucleating particle (INP) concentrations and ice crystal number concentrations ni. Here, we explore sensitivities with respect to the complexity of different INP parameterizations under the premise that ni is governed by SIP. Idealized, cloud-resolving simulations are performed for the marine cold air outbreak cloud deck sampled during the Mixed-Phase Arctic Cloud Experiment (M-PACE) with the Icosahedral Nonhydrostatic (ICON) model. The impact of the droplet shattering (DS) of raindrops and collisional breakup (BR) in addition to the existing Hallet–Mossop rime splintering mechanism were investigated. Overall, 12 different model experiments (12-h runs) were performed and analyzed. Despite the considerable amount of uncertainty remaining with regard to SIP mechanisms and their process representation in numerical models, we conclude from these experiments that (i) only simulations where DS dominates the SIP signal (potentially amplified by BR) capture observed ice-phase and liquid-phase cloud properties, and (ii) SIP events cluster around the convective outflow region and are structurally linked to mesoscale cloud organization. In addition, interactions with primary nucleation parameterizations of varied complexity were investigated. Here, our simulations show that (i) a stable long-lived mixed-phase cloud (MPC) can be maintained in the absence of primary nucleation once SIP is established, (ii) experiments using a computationally more efficient relaxation-based parameterization of primary nucleation are statistically invariant from simulations considering prognostic INP, and (iii) primary nucleation at cloud-top controls the areal extent of the mixed-phase cloud region, and reduces SIP efficacy via DS due to increased depletion of cloud liquid throughout the entire cloud column. Significance Statement Secondary ice production (SIP) remains a key challenge in our understanding of boundary layer mixed-phase clouds. Here, we use sensitivity experiments performed with the ICON model at the cloud-resolving scale to explore potential interactions between primary nucleation, SIP, and mesoscale cloud organization. We simulate an Arctic single-layer cold air outbreak stratocumulus deck that was sampled during the M-PACE campaign. We find that once established, SIP alone is sufficient to maintain the mixed-phase cloud state until the end of the simulation. Our sensitivity analysis also shows that numerically more efficient treatments of immersion freezing are statistically invariant from simulations with a full prognostic INP budget.