Solid-liquid Phase Research Articles

Feasibility study of AZ31B deposition made by novel powder bed friction stir process with optimal process parameters and tool features selection

The current work focused on the feasibility study of an in-house developed process at a laboratory scale named Powder Bed Friction Stir (PBFS) for AZ31B powder deposition. It employs friction stirring as a heating source instead of a laser or electron beam, as in powder bed fusion which can potentially mitigate the issues arising from liquid-solid phase transformation. A suitable process parameter and tool design was chosen through experimentation. Two sets of process parameters were selected for rotational and translational motion as 1200 rpm & 900 rpm and 360 mm/min & 200 mm/min, respectively. The material deposition is affected by tool design, so five different tools were explored. The overall height of the successful deposition was 7 mm with process parameters 1200 rpm & 360 mm/min, and (Circular Protruded Feature) CPFII tool in total 35 passes keeping layer thickness (0.2 mm). Microstructure and phase analysis were carried out using (Scanning Electron Microscopy) SEM and (X-ray Diffraction) XRD, respectively, to study the grain refinement, presence of (Inter Metallic Compounds) IMCs, and participation of the slip system in the deformation process. The resulting grain refinement was 78%, with increased basal plane intensity in the deposit. The current study offered an extension of solid-state additive manufacturing as PBFS for Mg alloys.

Graphitizing modification of the axial zone of cast iron rolling rolls in the liquidus-solidus temperature range

Purpose. To develop a method for calculating a process of graphitizing modification of unsolidificated liquid-solid zone to reduce transcrystallinity of the macrostructure and the amount of cementite in the center of castings. Methodology. The duration of solidification of the castings was determined by the kinetic curves of liquidus, solidus and pouring boundary in coordinates of relative thickness of the solidified metal layer – the parametric criterion of Gulyaev. Findings. A methodology for the process of modification of the axial zone of rolling was developed, the mass and time of adding aluminum were determined according to the amount of liquid-solid phase that remains after the solidification of the working layer. On the example of a rolling roll weighing 1115 kg, 0.488 kg of aluminum was added into liquid-solid zone after the working layer solidified. Movement of aluminum to the front of crystallization is provided by centrifugal forces and adding of aluminum along the height of the roll. Originality. For the first time, the kinetic curves of liquidus, solidus and pouring boundary have been plotted in coordinates of the relative thickness of the solidified metal layer x/R and /R2 – the parametric criterion of Gulyaev for rolled cast iron alloys cooled in chill-sand molds of various sizes. A methodology was developed for calculating the process of aluminum modification of the axial zone of rolling rolls after solidification of the working layer in the barrel which was set at the pouring boundary. The amount of aluminum depends on the remains of the liquid-solid phase. Practical value. Graphitizing modification reduces transcrystallinity of the macrostructure and the amount of cementite in the axial zone of castings. A promising direction for further development is the development of new methods for manufacturing castings due to physical and mechanical effects on the two-phase zone, deoxidation and alloying of the central zones of castings.

Application and mechanism analysis of functionalized ionic liquids in copper regeneration from electroplating sludge

Hydrometallurgy is the main method to regenerate valuable metals from electroplating sludge and reduce its environmental hazards. As a key step to efficiently recover metals, it is important to choose an environmentally friendly and efficient leaching agent. In this work, four green ionic liquid (ILs) ([BMIm]HSO4, [HOOCMIm]HSO4, [BSO3HMIm]HSO4, and [BSO3]Py.HSO4) were used to leach copper from copper–rich electroplating sludge (C–ES). The tested ILs could effectively leach copper from C–ES, but functionalized ILs have better leaching efficiency, especially sulfonate ILs, which could remove 100% of Cu from C–ES under optimal conditions. Kinetics studies showed that the leaching process of controlled by chemical reaction and material diffusion, and the apparent activation energies were 39.21, 0.98, 14.47, and 41.93 kJ mol−1, respectively. Introducing functional groups (such as carboxyl and sulfonate group) which can complex with metals on cations can enhance the H+ release and complexation ability of ILs, improve the mass transfer efficiency between liquid–solid phase, and thus improve the copper leaching ability by ILs. These findings are of great significance for selecting functional ILs to efficiently regenerate copper and the resource utilization from C–ES.

Macro-encapsulation of metal balls prepared by waste aluminum cans in ceramic capsules with reserved space

Phase change materials (PCMs) form the core of thermal energy storage (TES) for enhancing solar and industrial waste heat recovery. Metals have attracted growing attention due to their unique advantages, including high latent heat storage and high thermal conductivity. The application of metallic PCMs in TES is limited by the absence of appropriate packaging technology. Volume expansion during the solid-liquid phase can cause breakage of the protective coatings. This study proposes a “double-layer coating, recycling inner layer” method for the encapsulation of metallic PCMs. Waste aluminum cans (WACs) were selected as the PCM for cost reasons. The alloy balls prepared using the WACs were sequentially coated with an alkane mixture and ceramic slurry. The alkane mixture melts and discharges during the baking process, leaving a void for the phase-change volume expansion. The shell was gradually densified, and the metallic PCM was completely encapsulated after the heat treatment. The prepared MAEPCMs heat-treated at 1200 °C showed excellent mechanical properties, high heat storage capacity, and thermal cycle stability. The force required for compressive failure was approximately 2623 N. In addition, the total heat storage capacity reached approximately 198.6 kJ/kg at the temperature range of 600–700 °C, of which the latent heat accounted for more than 98.5%. There was no erosion between the alloy and the shell material, and the cumulative mass change was less than 8 wt. % after 600 thermal cycles. This study provides a structurally stable and low-cost technique for the preparation of durable macro-encapsulated PCMs with a high heat storage capacity and high thermal conductivity.

The Regulatory Mechanism of Transthyretin Irreversible Aggregation through Liquid-to-Solid Phase Transition.

Transthyretin (TTR) aggregation and amyloid formation are associated with several ATTR diseases, such as senile systemic amyloidosis (SSA) and familial amyloid polyneuropathy (FAP). However, the mechanism that triggers the initial pathologic aggregation process of TTR remains largely elusive. Lately, increasing evidence has suggested that many proteins associated with neurodegenerative diseases undergo liquid-liquid phase separation (LLPS) and subsequent liquid-to-solid phase transition before the formation of amyloid fibrils. Here, we demonstrate that electrostatic interactions mediate LLPS of TTR, followed by a liquid-solid phase transition, and eventually the formation of amyloid fibrils under a mildly acidic pH in vitro. Furthermore, pathogenic mutations (V30M, R34T, and K35T) of TTR and heparin promote the process of phase transition and facilitate the formation of fibrillar aggregates. In addition, S-cysteinylation, which is a kind of post-translational modification of TTR, reduces the kinetic stability of TTR and increases the propensity for aggregation, while another modification, S-sulfonation, stabilizes the TTR tetramer and reduces the aggregation rate. Once TTR was S-cysteinylated or S-sulfonated, they dramatically underwent the process of phase transition, providing a foundation for post-translational modifications that could modulate TTR LLPS in the context of pathological interactions. These novel findings reveal molecular insights into the mechanism of TTR from initial LLPS and subsequent liquid-to-solid phase transition to amyloid fibrils, providing a new dimension for ATTR therapy.

Validating the reversible redox of alkali-ion disulfonyl-methanide as organic positive electrode materials

Alkali-ion reservoir organic positive electrode materials with high redox potential emerge as promising candidates for rocking-chair batteries. Despite recent major advances on coordinated Li-enolates and conjugated Li-sulfonamides, alike chemistries remain rare with clearly enormous room to explore and investigate. Herein, we report a new high-voltage redox functionality for alkali-ion storage based on aromatic di-sulfonyl methanide. The versatile paradigm chemistry of di-alkali p-phenylene-bis-diethylsulfonyl methanide (denoted as A2-p-TESO2, where A = Li+, Na+, K+) displays high voltage (3.13 vs Li+/Li), a two-electron reversible redox in both liquid phase and solid phase electrochemistry. A2-p-TESO2 also shows great stability under ambient air conditions in their alkali-ion reservoir states. This work not only suggests a new charge storage mechanism for organic batteries but also highlights the versatility of organic chemistry in designing new redox functionalities for next-generation organic rechargeable batteries.

Laboratory Scale Continuous Flow Systems for the Enantioselective Phase Transfer Catalytic Synthesis of Quaternary Amino Acids.

The use of stereoselective phase-transfer catalysis as a reliable method for the enantioselective synthesis of optically active α-amino acid derivatives using achiral Schiff base esters has been well-developed in batch in the last 40 years. Recently, continuous flow technology has become of great interest in the academy and industry, since it offers safer process operating conditions and higher efficiency compared to a traditional batch processing. Herein, we wish to report the first example of enantioselective phase transfer benzylation of alanine Schiff base ester, under continuous flow conditions. Two different methodologies were investigated: a liquid-solid phase transfer catalytic benzylation using a packed-bed reactor and a liquid-liquid phase transfer catalytic benzylation in continuous stirred-tank reactors. Liquid-liquid phase transfer process in flow showed slightly better productivity than the batch process, while solid-liquid phase transfer benzylation proved much more advantageous in terms of productivity and space-time yield. Furthermore, continuous flow system allowed the isolation of benzylated product without any work up, with a significant simplification of the process. In both cases, phase transfer asymmetric benzylation promoted by Maruoka catalyst demonstrated high enantioselectivity of target quaternary amino ester in flow, up to 93% ee.

Two-phase dual-signal-readout immunosensing platform based on multifunctional carbon nano-onions for ovarian cancer biomarker detection.

In order to detect early tumor markers and gain valuable time for treatment, there is an urgent need to develop a fast, cheap, and ultrasensitive multi-reading sensing platform. Herein, a solid/liquid two-phase dual-output biosensor was explored based on a sensitized sonochemiluminescence (SCL) strategy and a multifunctional carbon nano-onion (CNO) probe. It is clear that ultrasonic radiation caused the formation of hydroxyl radicals (˙OH), triggering the SCL signal of the emitter lucigenin (Luc2+). Meanwhile, titanium carbide nanodots and ethanol were used to enhance the SCL signal, and an astonishingly linear enhancement of the SCL intensity was produced with increasing ethanol concentration. More importantly, the CNOs, with their excellent photothermal properties and adsorption capacity, can output both the temperature signal and an enhanced SCL strength from the solid-liquid phase. Through inter-calibration of the signals from the two-phases, this biosensor shows excellent analytical performance for the detection of the ovarian cancer biomarker, human epididymis-specific protein 4, from 10-5 to 10 ng mL-1 with a low detection limit of 3.3 fg mL-1. This work not only provides a novel two-phase signal-output mode that broadens the scope of multiperformance joint applications of CNOs, but also enriches the quantitative detection of point-of-care testing.

Temperature dependence of the viscoelastic properties of a natural gastropod mucus by Brillouin light scattering spectroscopy.

Brillouin spectroscopy was used to probe the viscoelastic properties of a natural gastropod mucus at GHz frequencies over the range -11 °C ≤ T ≤ 52 °C. Anomalies in the temperature dependence of mucus longitudinal acoustic mode peak parameters and associated viscoelastic properties at T = -2.5 °C, together with the appearance of a peak due to ice at this temperature, suggest that the mucus undergoes a phase transition from a viscous liquid state to one in which liquid mucus and solid ice phases coexist. Failure of this transition to proceed to completion even at -11 °C is attributed to glycoprotein-water interaction. The temperature dependence of the viscoelastic properties and the phase behaviour suggest that water molecules bind to glycoprotein at a temperature above the onset of freezing and that the reduced ability of this bound water to take on a configuration that facilitates freezing is responsible for the observed freezing point depression and gradual nature of the liquid-solid transition.

LOCAL THERMAL NON-EQUILIBRIUM CONDITION FOR THE FLOW OF WALTERS-B FLUID OVER A SHEET SATURATED IN A POROUS MEDIUM

Local thermal non-equilibrium (LTNE) has garnered significant interest in engineering applications like electronic cooling, heat pipes, nuclear reactors, drying technology, and multiphase catalytic reactors. Owing to this, the study numerically emphases on the LTNE effects on the flow of Walters-B liquid over a stretching sheet with Dufour and Soret effects. The LTNE model, which creates distinct thermal profiles for both solid and liquid phases, is utilized to formulate the energy equations, which constitutes the novelty of the present study. The governing equations for the flow assumptions are transformed to ordinary differential equations using the apt similarity transformations. The Runge-Kutta approach and the shooting technique are then used to numerically solve these reduced equations. The significant results of the current analysis are that an upsurge in Dufour number diminutions the heat transport in liquid phase. The increase in Soret number advances the mass transport. The augmented values of viscoelastic parameter drop down the velocity, but advance the fluid phase heat transference. Finally, the heat transport of the liquid phase increases and solid phase drops as inter-phase heat transfer parameter rises.

Heredity of clusters in liquid Ta rapid solidification process and its correlation with local symmetry

Metallic glass (MG) has received intensive attention in the fields of amorphous physics and materials science, owing to its excellent mechanical properties, good corrosion resistance, and large elastic deformation limit. Comparing with traditional oxide glass, the limited glass-forming ability (GFA) seriously restricts the application of MG in engineering. Therefore, the GFA has been a hot scientific issue in the field of amorphous material research. Recently, scientists have fully realized that GFA is closely related to the local atomic structure in liquid as well as its evolution features. Since the MG is called the “freezing” liquid, exploring the correlation of local atomic structures between liquid phase and solid phase under rapid solidification conditions is helpful in understanding the microstructural mechanism of GFA. Therefore, the rapid solidification process of liquid Ta is investigated via molecular dynamics simulation. The pair correlation function (PDF), the largest standard cluster (LSC), and the reverse atomic trajectory tracking methods are used to characterize and analyze the microstructure and its evolution during the rapid solicitation of liquid Ta. The results show that the local atomic configurations of the rapidly solidified Ta are various Kasper clusters as well as their distorted configurations, among of which [1/444, 10/555, 2/666] deformed icosahedron (or Z13 cluster) accounts for the highest proportion. The trend of hereditary ability of clusters revealed by the onset temperature of continuous heredity is consistent well with that by the fraction of staged heredity. The geometric symmetry of clusters can be quantitatively characterized by using the local symmetry parameter (LSP). The hereditary ability of clusters is closely related to their LSP. The local five-fold symmetry is beneficial to enhancing hereditary ability, while local four- and six-fold symmetry are disadvantageous for that. The probability of clusters with the same LSC index emerging in the energy range follows the Gaussian distribution, and the expected average atomic potential energy <inline-formula><tex-math id="M3">\begin{document}$ {E}_{\rm exp}^{j} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20231153_M3.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20231153_M3.png"/></alternatives></inline-formula> is almost linearly related to the LSP, and <inline-formula><tex-math id="M4">\begin{document}$ {E}_{\rm exp}^{j} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20231153_M4.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20231153_M4.png"/></alternatives></inline-formula> decreases with the increase of LSP<sub>5</sub>. The high local five-fold symmetry reduces the average atomic potential energy of LSC, thereby enhancing its configurational heredity. These findings have guiding significance in improving GFA through regulating the local symmetry of liquid monatomic metals or alloys.

An Innovative Approach to Prepare Liquid-Solid Dual-Phase Flowable Tritium Breeder with Low MHD Effect

In present paper, a novel flowable tritium breeder is prepared by mixing the Li2TiO3 micro-powders and liquid GaInSn alloy, where GaInSn alloy is used to simulate the fluid behaviors of lithium-based liquid tritium breeder, forming a type of composite characterized by liquid-solid dual phase. In detail, the effects of the volume fraction of ceramic micro-powders on viscosity and conductivity of the composite in magnetic field are the focus. The XRD results prove that the obtained Li2TiO3 micro-powders contained Li2TiO3 phase without impurities. The results shows that once the magnetic field intensity exceeds the critical value, the viscosity of liquid GaInSn metal becomes significantly greater than that of liquid-solid dual-phase composites. Furthermore, the addition of Li2TiO3 micro-powders could effectively reduce the magneto hydro dynamic (MHD) fluid effect, and the dual-phase composites exhibit comparatively lower flow resistance under the strong magnetic field. Moreover, the conductivity of the tritium breeder composites decreases rapidly with the addition of Li2TiO3 micro-powders. The MHD pressure-drop-increasing rate decreases with the increase of viscosity, which indicates that the addition of Li2TiO3 micro-powders effectively reduces the MHD effect. The conductivity of the composites increased slightly and then remained stable after static placing for several tens of minutes. The present investigation provides a novel insight into the fabrication strategy of tritium breeder materials with low MHD effect.

The PRALINE database: protein and Rna humAn singLe nucleotIde variaNts in condEnsates.

Biological condensates are membraneless organelles with different material properties. Proteins and RNAs are the main components, but most of their interactions are still unknown. Here, we introduce PRALINE, a database for the interrogation of proteins and RNAs contained in stress granules, processing bodies and other assemblies including droplets and amyloids. PRALINE provides information about the predicted and experimentally validated protein-protein, protein-RNA and RNA-RNA interactions. For proteins, it reports the liquid-liquid phase separation and liquid-solid phase separation propensities. For RNAs, it provides information on predicted secondary structure content. PRALINE shows detailed information on human single-nucleotide variants, their clinical significance and presence in protein and RNA binding sites, and how they can affect condensates' physical properties. PRALINE is freely accessible on the web at http://praline.tartaglialab.com.

Control of the Crystallization and Phase Separation Kinetics in Sequential Blade‐Coated Organic Solar Cells by Optimizing the Upper Layer Processing Solvent

AbstractSequential deposition of the active layer in organic solar cells (OSCs) is favorable to circumvent the existing drawbacks associated with controlling the microstructure in bulk‐heterojunction (BHJ) device fabrication. However, how the processing solvents impact on the morphology during sequential deposition processes is still poorly understood. Herein, high‐efficiency OSCs are fabricated by a sequential blade coating (SBC) through optimization of the morphology evolution process induced by processing solvents. It is demonstrated that the device performance is highly dependent on the processing solvent of the upper layer. In situ morphology characterizations reveal that an obvious liquid–solid phase separation can be identified during the chlorobenzene processing of the D18 layer, corresponding to larger phase separation. During chloroform (CF) processing of the D18 layer, a proper aggregation rate of Y6 and favorable intermixing of lower and upper layers results in the enhanced crystallinity of the acceptor. This facilitates efficient exciton dissociation and charge transport with an inhibited charge recombination in the D18/CF‐based devices, contributing to a superior performance of 17.23%. These results highlight the importance of the processing solvent for the upper layer in the SBC strategy and suggest the great potential of achieving optimized morphology and high‐efficiency OSCs using the SBC strategy.

Hydration makes a difference! How to tune protein complexes between liquid-liquid and liquid-solid phase separation.

Understanding how protein rich condensates formed upon liquid-liquid phase separation (LLPS) evolve into solid aggregates is of fundamental importance for several medical applications, since these are suspected to be hot-spots for many neurotoxic diseases. This requires developing experimental approaches to observe in real-time both LLPS and liquid-solid phase separation (LSPS), and to unravel the delicate balance of protein and water interactions dictating the free energy differences between the two. We present a vibrational THz spectroscopy approach that allows doing so from the point of view of hydration water. We focus on a cellular prion protein of high medical relevance, which we can drive to undergo either LLPS or LSPS with few mutations. We find that it is a subtle balance of hydrophobic and hydrophilic solvation contributions that allows tuning between LLPS and LSPS. Hydrophobic hydration provides an entropic driving force to phase separation, through the release of hydration water into the bulk. Water hydrating hydrophilic groups provides an enthalpic driving force to keep the condensates in a liquid state. As a result, when we modify the protein by a few mutations to be less hydrophilic, we shift from LLPS to LSPS. This molecular understanding paves the way for a rational design of proteins.

Liquid-solid phase transition time characteristics of CCD aluminum layer metal induced by nanosecond pulse laser

Liquid-solid phase transition time characteristics of CCD aluminum layer metal induced by nanosecond pulse laser

Solid-liquid phase transition inside van der Waals nanobubbles: an atomistic perspective.

The liquid-solid phase transition during the confinement of a van der Waals bubble is studied using molecular dynamics simulations. In particular, argon is considered inside a graphene bubble, where the outer membrane is a sheet of graphene, and the substrate is atomically flat graphite. A methodology to avoid metastable states of argon is developed and implemented to derive a melting curve of trapped argon. It is found that in the confinement, the melting curve of argon shifts toward higher temperatures, and the temperature shift is about 10-30 K. The ratio of the height to the radius of the GNB (H/R) decreases with increasing temperature. It also most likely undergoes an abrupt change through the liquid-crystal phase transition. The semi-liquid state of argon was detected in the transition region. At this state, the argon structure stays layered, but the atoms travel distances of several lattice constants.

Photoliquefaction and phase transition of m-bisazobenzenes give molecular solar thermal fuels with a high energy density.

A series of m-bisazobenzene chromophores modified with various alkoxy substituents (1; methoxy, 2; ethoxy, 3; butoxy, 4; neopentyloxy) were developed for solvent-free molecular solar thermal fuels (STFs). Compounds (E,E)-1-3 in the crystalline thin film state exhibited photoliquefaction, the first example of photo-liquefiable m-bisazobenzenes. Meanwhile, (E,E)-4 did not show photoliquefaction due to the pronounced rigidity of the interdigitated molecular packing indicated by X-ray crystallography. The m-bisazobenzenes 1-4 exhibited twice the Z-to-E isomerization enthalpy compared to monoazobenzene derivatives, and the latent heat associated with the liquid-solid phase change further enhanced their heat storage capacity. To observe both exothermic Z-to-E isomerization and crystallization in a single heat-up process, the temperature increase of differential scanning calorimetry (DSC) must occur at a rate that does not deviate from thermodynamic equilibrium. Bisazobenzene 1 showed an unprecedented gravimetric heat storage capacity of 392 J g-1 that exceeds previous records for well-defined molecular STFs.

Thermal free-surface immersed-boundary lattice Boltzmann method for free surface flows with a liquid-solid phase transition

This paper reports on the progress of the liquid-solid phase transition modeling of water in open channel flow by using the lattice Boltzmann method with the immersed boundary modification. The phase transition in a fluid flow has a moving interface between the liquid and solid state, which leads complicated treatments in existing numerical models. By applying the immersed boundary modification in the lattice Boltzmann method and the non-iterative enthalpy approach for the separation of the states, the moving boundary of the melting or solidification front is solved without any difficulty. The ice bed and the submerged ice cover under dynamic flow conditions is exercised to demonstrate the model performance. The model is extremely suitable in the formulation in terms of its simple and compact framework extendable to any dimensions.

Interfacial free energy at the liquid-solid phase boundary calculated by the method of capillary fluctuations

The interfacial free energy at the liquid-solid phase boundary was calculated for some close packed metals (Au, Cu, Al) and silicon. For calculations, the method of capillary fluctuations at temperatures close to the melting point of the studied materials was used. The formation of the two-phase system at the atomic level was carried out using the method of molecular dynamicssimulations by means of the LAMMS classical molecular dynamics package. The interfacial stiffness for materials with different crystallographic orientation of the phase boundary was determined from the analysis of the fluctuation spectrum, which in turn was obtained by Fourier transformation of the oscillations of the interphase boundary. It was shown that the value of the free energy increases in the series Al→Au→Cu→Si