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Hydraulic energy is a key component of the global energy mix, yet there exists no practical way of harvesting it at small scales, from flows with low Reynolds number. This has triggered a search for alternative hydroelectric conversion methodologies, leading to unconventional proposals based on droplet triboelectricity, water evaporation, osmotic energy, or flow-induced ionic Coulomb drag. Yet, these approaches systematically rely on ions as intermediate charge carriers, limiting the achievable power density. Here, we predict that the kinetic energy of small-scale “waste” flows can be directly and efficiently converted into electricity thanks to the hydroelectronic drag effect, by which an ion-free liquid induces an electronic current in the solid wall along which it flows. This effect originates in the fluctuation-induced coupling between fluid motion and electron transport. We develop a nonequilibrium thermodynamic formalism to assess the efficiency of such hydroelectric energy conversion, dubbed hydronic energy. We find that hydronic energy conversion is analogous to thermoelectricity, with the efficiency being controlled by a dimensionless figure of merit. However, in contrast to its thermoelectric analogue, this figure of merit combines independently tunable parameters of the solid and the liquid, and can thus significantly exceed unity. Our findings suggest strategies for blue energy harvesting without electrochemistry, and for waste flow mitigation in membrane-based filtration processes. [ABSTRACT FROM AUTHOR]

Water motion‐induced energy harvesting has emerged as a prominent means of facilitating renewable electricity from the interaction between nanostructured materials and water over the past decade. Despite the growing interest, comprehension of the intricate solid–liquid interfacial phenomena related to solid state physics remains elusive and serves as a hindrance to enhancing energy harvesting efficiency up to the practical level. Herein, the study introduces the energy harvester by utilizing inversion on the majority charge carrier in graphene materials upon interaction with water molecules. Specifically, various metal electrode configurations are employed on reduced graphene oxide (rGO) to unravel its distinctive charge carriers that experience the inversion in semiconductor type upon water contact, and exploit this characteristic to leverage the efficacy of generated electricity. Through the strategic arrangement of the metal electrodes on rGO membrane, the open‐circuit voltage (Voc) and short‐circuit current (Isc) have exhibited a remarkable augmentation, reaching 1.05 V and 31.6 µA, respectively. The demonstration of effectively tailoring carrier dynamics via electrode configuration expands the practicality by achieving high power density and elucidating how the water‐induced carrier density modulation occurs in 2D nanomaterials. [ABSTRACT FROM AUTHOR]

Understanding the role of surface morphology and molecular structure interface thermal transport is essential for designing thermal management materials. In the present work, models of solid–liquid interfaces were created by placing liquid n-alkane between two platinum crystals. The effect of different levels of crystal surface roughness–flat, small, and large-scale grooves–and polymer chain lengths, under varying solid–liquid affinity, on the interface thermal resistance (ITR) were assessed using non-equilibrium molecular dynamics simulations. The overall trend confirmed that grooved surfaces have higher ITR than flat surfaces at low affinity, and lower ITR values were observed at high affinity. Large grooves enabled more favourable polymer orientations than those of small grooves, resulting in a smaller ITR. However, long chains did not facilitate heat transfer normal to the interface because they preferentially aligned parallel to it. For efficient heat transfer, a balance between the roughness scale and polymer length must be considered. [ABSTRACT FROM AUTHOR]

Strong metal‐support interaction (SMSI) plays a vital role in tuning the geometric and electronic structures of metal species. Generally, a high‐temperature treatment (>500 °C) in reducing atmosphere is required for constructing SMSI, which may induce the sintering of metal species. Herein, we use molten salts as the reaction media to trigger the formation of high‐intensity SMSI at reduced temperatures. The strong ionic polarization of the molten salt promotes the breakage of Ti−O bonds in the TiO2 support, and hence decreases the energy barrier for the formation of interfacial bonds. Consequently, a high‐intensity SMSI state is achieved in TiO2 supported Ir nanoclusters, evidenced by a large number of Ir−Ti bonds at the interface, at a low temperature of 350 °C. Moreover, this method is applicable for triggering SMSI in various supported metal catalysts with different oxide supports including CeO2 and SnO2. This newly developed SMSI construction methodology opens a new avenue and holds significant potential for engineering advanced supported metal catalysts toward a broad range of applications. [ABSTRACT FROM AUTHOR]

In-situ electrochemical Raman spectroscopy measures the relationship between the Raman spectrum signal and the electrode's potential or current intensity, by utilizing the scattering phenomenon of the substance molecules induced by the incident light. It can provide molecular-level structural information about the electrode's surface（interface）. This technology enables the acquisition of molecular vibrational information and real-time monitoring of structural information related to chemical reactions at the electrochemical interface, making it widely applicable in the field of material interface characterization. Starting from the principle of in-situ electrochemical Raman spectroscopy, this paper comprehensively describes the progress of in situ electrochemical Raman spectroscopy based on rough metal electrodes in solid-liquid interface analysis, such as molecular adsorption, oxygen evolution, hydrogen evolution, and oxygen reduction reaction. Furthermore, this paper explores the relationship between the interface structure, reaction processes, catalytic intermediates, and the Raman signal intensity. The catalytic process reaction mechanism and the catalytic mechanism of the catalytic material were presented. Lastly, an outlook was provided on the scientific challenges pertaining to insitu electrochemical Raman spectroscopy at solid-liquid interfaces in the subsequent phase. [ABSTRACT FROM AUTHOR]

High-purity copper is essential for fabricating advanced microelectronic devices, particularly integrated circuit interconnects. As the industry increasingly emphasizes scalable and efficient purification methods, this study investigates the multi-physics interactions during the semi-continuous directional solidification process, utilizing a Cu-1 wt.%Ag model alloy. Coupled simulation calculations examine the spatial distribution patterns of the impurity element silver (Ag) within semi-continuously solidified ingots under varying pulling rates and melt temperatures. The objective is to provide technical insights into the utilization of the semi-continuous directional solidification method for high-purity copper purification. The findings reveal that increasing the pulling rate and melt temperature leads to a downward shift in the solid–liquid interface relative to the mold top during processing. Alongside the primary clockwise vortex flow, a secondary weak vortex emerges near the solid–liquid interface, facilitating the migration of the impurity element Ag toward the central axis and amplifying radial impurity fluctuations. Furthermore, diverse pulling rates and melt temperature conditions unveil a consistent trend along the ingot's height, which is characterized by an initial increase in average Ag content, followed by stabilization and then a rapid ascent during the late stage of solidification, with higher pulling rates and melt temperatures expediting this rapid ascent. Leveraging these insights, a validation experiment using 4N-grade recycled copper in a small-scale setup demonstrates the effectiveness of the semi-continuous directional solidification process for high-purity copper production, with copper samples extracted at 1/4 and 3/4 ingot heights achieving a 5N purity level of 99.9994 wt.% and 99.9993 wt.%, respectively. [ABSTRACT FROM AUTHOR]

In this study, molecular dynamics (MD) simulations were employed to elucidate the processes and underlying mechanisms that govern the adsorption and accumulation of gas (represented by N2) at the hydrophobic solid–liquid interface, using the GROMACS program with an AMBER force field. Our findings indicate that, regardless of surface roughness, the presence of water molecules is a prerequisite for the adsorption and aggregation of N2 molecules on solid surfaces. N2 molecules dissolved in water can cluster even without a solid substrate. In the gas–solid–liquid system, the exclusion of water molecules at the hydrophobic solid–liquid interface and the adsorption of N2 molecules do not occur simultaneously. A loosely arranged layer of water molecules is initially formed on the hydrophobic solid surface. The two-stage process of N2 molecule adsorption and accumulation at the hydrophobic solid/liquid interface involves initial adsorption to the solid surface, displacing water molecules, followed by N2 accumulation via self-interaction after saturating the substrate's surface. The process and underlying mechanisms of gas adsorption and accumulation at hydrophobic solid/liquid interfaces elucidated in this study offer a molecular-level understanding of nano-gas layer formation. [ABSTRACT FROM AUTHOR]

Protocell models play a pivotal role in the exploration of the origin of life. Vesicles are one type of protocell model that have attracted much attention. Simple single-chain amphiphiles (SACs) and organic small molecules (OSMs) possess primitive relevance and were most likely the building blocks of protocells on the early Earth. OSM@SAC vesicles have been considered to be plausible protocell models. Pyrite (FeS2), a mineral with primitive relevance, is ubiquitous in nature and plays a crucial role in the exploration of the origin of life in the mineral–water interface scenario. "How do protocell models based on OSM@SAC vesicles interact with a mineral–water interface scenario that simulates a primitive Earth environment" remains an unresolved question. Hence, we select primitive relevant sodium monododecyl phosphate (SDP), isopentenol (IPN) and pyrite (FeS2) mineral particles to build a protocell model. The model investigates the basic physical and chemical properties of FeS2 particles and reveals the effects of the size, content and duration of interaction of FeS2 particles on IPN@SDP vesicles. This deepens the understanding of protocell growth mechanisms in scenarios of mineral–water interfaces in primitive Earth environments and provides new information for the exploration of the origin of life. [ABSTRACT FROM AUTHOR]

The roles of surface characteristics of the feldspar surface on ice nucleation have remained elusive. Here, simple strategies are reported to quantitatively analyze the effects of the surface morphology and molecular composition of the potassium‐feldspar surface on ice nucleation. The steps are found to be responsible to the high ice nucleation efficacy according to the fact that water drop freezing temperature increases by about 4.5 °C atop the freshly cleavage feldspar surface being rich of steps comparing to the flattened ones. After the molecular component and atomic structure are destroyed by the fluorination, a tremendous decrease of the ice nucleation temperatures by around 9.0 °C is observed on both cleavage and flattened surfaces, and the steps still improve the ice nucleation activity of the hydrophobic cleavage surfaces. The influence of the surface composition also implies the importance of the molecular component and structure specificity on K‐feldspar in facilitating ice nucleation. [ABSTRACT FROM AUTHOR]

Constructing uniform covalent organic framework (COF) film on substrates for electronic devices is highly desirable. Here, a simple and mild strategy is developed to prepare them by polymerization on a solid‐liquid interface. The universality of the method is confirmed by the successful preparation of five COF films with different microstructures. These films have large lateral size, controllable thickness, and high crystalline quality. And COF patterns can also be directly achieved on substrates via hydrophilic and hydrophobic interface engineering, which is in favor of preparing device array. For application studies, the PyTTA‐TPA (PyTTA: 4,4′,4′′,4′′′‐(1,3,6,8‐Tetrakis(4‐aminophenyl)pyrene and TPA: terephthalaldehyde) COF film has a high photoresponsivity of 59.79 μA W−1 at 420 nm for photoelectrochemical (PEC) detection. When employed as an active material for optoelectronic synaptic devices for the first attempt, it shows excellent light‐stimulated synaptic plasticity properties such as short‐term plasticity (STP), long‐term plasticity (LTP), and the conversion of STP to LTP, which can be used to simulate biological synaptic functions. [ABSTRACT FROM AUTHOR]

Constructing uniform covalent organic framework (COF) film on substrates for electronic devices is highly desirable. Here, a simple and mild strategy is developed to prepare them by polymerization on a solid‐liquid interface. The universality of the method is confirmed by the successful preparation of five COF films with different microstructures. These films have large lateral size, controllable thickness, and high crystalline quality. And COF patterns can also be directly achieved on substrates via hydrophilic and hydrophobic interface engineering, which is in favor of preparing device array. For application studies, the PyTTA‐TPA (PyTTA: 4,4′,4′′,4′′′‐(1,3,6,8‐Tetrakis(4‐aminophenyl)pyrene and TPA: terephthalaldehyde) COF film has a high photoresponsivity of 59.79 μA W−1 at 420 nm for photoelectrochemical (PEC) detection. When employed as an active material for optoelectronic synaptic devices for the first attempt, it shows excellent light‐stimulated synaptic plasticity properties such as short‐term plasticity (STP), long‐term plasticity (LTP), and the conversion of STP to LTP, which can be used to simulate biological synaptic functions. [ABSTRACT FROM AUTHOR]

A three-dimensional multi-physics model of the effect of process parameters on the evolution of the solid–liquid interface during solidification of large-scale Ti-6 wt% Al-4 wt% V (TC4) alloy by[Ballantyne, 1977 #483] (VAR) and a macroscopic model of grain nucleation and growth was established. The simulation results qualitatively reveal the evolution of solid–liquid interface and central cross-sectional solidification structure under various melting conditions, indicating that the melting zone depth increased while the mushy zone width and the number of grains decreased with the increase of melting power; the depth of the melting zone and the width of the mushy zone increase sharply with the increase in solidification velocity, the average grain radius increased, while the number of grains decreased; when the ingot diameter increased from 260 mm to 660 mm, the depth of the melting zone increased and gradually remained stable, and the width of the mushy zone gradually decreased. [ABSTRACT FROM AUTHOR]

Reaction intermediates buried within a solid-liquid interface are difficult targets for physiochemical measurements. They are inherently molecular and locally dynamic, while their surroundings are extended by a periodic lattice on one side and the solvent dielectric on the other. Challenges compound on a metal-oxide surface of varied sites and especially so at its aqueous interface of many prominent reactions. Recently, phenomenological theory coupled with optical spectroscopy has become a more prominent tool for isolating the intermediates and their molecular dynamics. The following article reviews three examples of the SrTiO3-aqueous interface subject to the oxygen evolution from water: reaction-dependent component analyses of time-resolved intermediates, a Fano resonance of a mode at the metal-oxide–water interface, and reaction isotherms of metastable intermediates. The phenomenology uses parameters to encase what is unknown at a microscopic level to then circumscribe the clear and macroscopically tuned trends seen in the spectroscopic data. [ABSTRACT FROM AUTHOR]

Free energies of a solid surface and a solid–liquid interface play significant roles in thermodynamics. Due to the limited availability of experimental data, computational methods offer effective alternatives for calculating these properties. This study adopts advanced frameworks of the logarithmic mean force dynamics method to present an enhanced sampling approach for the calculation of the free energy at different temperatures. To achieve this, the free energy profile is constructed along with a pre‐established collective variable within the melting transition and cleavage processes. The values of the solid surface and solid–liquid interface free energies are then extrapolated from the excess free energy related to the formation and persistence of the solid surface or the solid–liquid interface. Furthermore, this methodology is employed to calculate the temperature dependence of the free energy measurements for the (100) and (110) surfaces and interfaces of Cu. It is shown that this methodology is robust and readily applicable in contemporary models of atomic interactions and various systems. [ABSTRACT FROM AUTHOR]

The adsorption mechanism of different polymers containing ionic polyamino acids monomers in the chain structure at the solid–liquid interface was investigated. Initially, the influence of molecular weight and solution pH on simple polyamino acids (poly(L-aspartic acid) and poly(L-lysine) binding was determined. Considering the obtained dependencies, the polymer adsorption layer conformation was proposed in the systems containing block copolymers (both diblock and symmetrical triblock) consisting of polypeptide as well as poly(ethylene glycol) fragments. The presented studies focused on the application of two experimental methods. The polymer adsorption was carried out using the batch method and the adsorbate concentration was determined spectrophotometrically. Then, the turbidimetric measurements were taken. The analysis of the obtained results showed that the adsorption process of block copolymers depends on two factors. Firstly, the solution pH determines both the nature of the interactions of the copolymer structural units with the solid surface and the conformation of the polypeptide chains. The second parameter influencing the adsorption layer structure is the ratio of the lengths of both blocks. Introducing a short PEG fragment into the polymer main chain may improve the polymer adsorption properties by increasing the number of interactions with the adsorbent surface. [ABSTRACT FROM AUTHOR]

The rational design of electrocatalysis has emerged as one of the most thriving means for mitigating energy and environmental crises. The key to this effort is the understanding of the complex electrochemical interface, wherein the electrode potential as well as various internal factors such as H‐bond network, adsorbate coverage, and dynamic behavior of the interface collectively contribute to the electrocatalytic activity and selectivity. In this context, the authors have reviewed recent theoretical advances, and especially, the contributions to modeling the realistic electrocatalytic processes at complex electrochemical interfaces, and illustrated the challenges and fundamental problems in this field. Specifically, the significance of the inclusion of explicit solvation and electrode potential as well as the strategies toward the design of highly efficient electrocatalysts are discussed. The structure‐activity relationships and their dynamic responses to the environment and catalytic functionality under working conditions are illustrated to be crucial factors for understanding the complexed interface and the electrocatalytic activities. It is hoped that this review can help spark new research passion and ultimately bring a step closer to a realistic and systematic modeling method for electrocatalysis. [ABSTRACT FROM AUTHOR]

Composite phase change materials with sugar alcohol as the phase change material and highly thermally conductive ceramics as the porous skeleton are widely used in various thermal storage systems. The interfacial thermal conductance (ITC) between the phase change materials under different phases and the skeleton is an important factor affecting the rate of heat storage (release) in thermal storage systems. The ITC between ceramics(AlN, SiC) and sugar alcohols (mannitol and galactitol) in the solid and liquid states is investigated by means of both time-domain thermoreflectance and molecular dynamics simulations. The results show that the ITC between phase change materials and ceramic is better in liquid state than in solid state, and that the ITC between mannitol and ceramic is better, and that the ITC betweenAlN and sugar alcohol is better. More low-frequency phonons are involved in the thermal transport of the sugar alcohols in the liquid state, with an average overlap energy of about 9.5% higher than that of the solid state and an average phonon participation rate of about 6.8% higher. It was also found that it isthe H atom in the sugar alcohol that is linked to the C atom that governs the ITC. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of surface reconstruction was critical to developing high performance lattice oxygen oxidation mechanism (LOM) based perovskite electrocatalysts. Traditionally, the primary determining factor of the surface reconstruction process was believed to be the oxygen vacancy formation energy. Hence, most previous studies focused on optimizing composition to reduce the oxygen vacancy formation energy, which in turn facilitated the surface reconstruction process. Here, for the first time, we found that adding oxyanions (SO42−, CO32−, NO3−) into the electrolyte could effectively regulate the solid–liquid interface, significantly accelerating the surface reconstruction process and enhancing oxygen evolution reaction (OER) activities. Further studies indicated that the added oxyanions would adsorb onto the solid–liquid interface layer, disrupting the dynamic equilibrium between the adsorbed OH− ions and the OH− ions generated during surface reconstruction process. As such, the OH− ions generated during surface reconstruction process could be more readily released into the electrolyte, thereby leading to an acceleration of the surface reconstruction. Thus, it was expected that our finding would provide a new layer of understanding to the surface reconstruction process in LOM‐based perovskite electrocatalysts. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of surface reconstruction was critical to developing high performance lattice oxygen oxidation mechanism (LOM) based perovskite electrocatalysts. Traditionally, the primary determining factor of the surface reconstruction process was believed to be the oxygen vacancy formation energy. Hence, most previous studies focused on optimizing composition to reduce the oxygen vacancy formation energy, which in turn facilitated the surface reconstruction process. Here, for the first time, we found that adding oxyanions (SO42−, CO32−, NO3−) into the electrolyte could effectively regulate the solid–liquid interface, significantly accelerating the surface reconstruction process and enhancing oxygen evolution reaction (OER) activities. Further studies indicated that the added oxyanions would adsorb onto the solid–liquid interface layer, disrupting the dynamic equilibrium between the adsorbed OH− ions and the OH− ions generated during surface reconstruction process. As such, the OH− ions generated during surface reconstruction process could be more readily released into the electrolyte, thereby leading to an acceleration of the surface reconstruction. Thus, it was expected that our finding would provide a new layer of understanding to the surface reconstruction process in LOM‐based perovskite electrocatalysts. [ABSTRACT FROM AUTHOR]

The development of novel drug delivery systems (DDSs) with promising antibacterial properties is essential for facing the emergency of increasing resistance to antimicrobial agents. The antibacterial features of quercetin and its metal complexes have been broadly investigated. However, several drawbacks affect their activity and effectiveness. In this work, we propose a DDS based on a pH-responsive cobalt(II)-coordinated assembly containing quercetin and polyacrylic acid. This system is suggested to trigger the release of the model drug in a pH-dependent mode by exploiting the localized acidic environment at the bacterial infection sites under anaerobic conditions. The delivery system has been designed by accurately examining the species and the multiple equilibria occurring in solution among the assembly components. The formation of cobalt(II) complexes with quercetin in the absence or presence of the pH-responsive polyacrylic acid was investigated in buffered aqueous solution at pH 7.4 using spectrophotometric (UV-Vis) and calorimetric (ITC) techniques. The determined binding affinities and thermodynamic parameters that resulted are essential for the development of a DDS with improved binding and release capabilities. Furthermore, the affinity of the polymer–cobalt(II) complex toward the model antimicrobial flavonoid was explored at the solid–liquid interface by quartz crystal microbalance (QCM-D) experiments, which provided marked evidence for drug loading and release under pH control. [ABSTRACT FROM AUTHOR]

This work is concerned with the improvement of silicon photovoltaic solar cells using elec- tromagnetic stirring in prior processing by controlling the hydrodynamics of the silicon bath during ingot solidification. The vertical Bridgman directional solidification furnace called VB2 was numerically investigated using a controlled power-down technique under forced convection generated by a travelling magnetic field, i.e. a full 3D numerical model of the VB2 furnace has been developed using the Comsol MultiphysicsTM software. Enthalpy formulation based on fixed-grid techniques is used for the phase-change phenomena considering magnetohydro- dynamic forced convection created by a Lorentz force generated by a specific cylindrical Bitter coil. The model provides the temperature distribution in the entire furnace as well as specific details regarding the solidification process (i.e. solidification fraction and solid-liquid interface shape), flow patterns and melt velocities. The obtained numerical results show good consist- ency with experimental measurements and analysis, on the one hand, and can be considered as useful orientation to improve the solidification process, on the other hand. It is shown that the travelling magnetic field acting in the melt drives a moderately turbulent flow which has a significant impact on the solid-liquid interface in terms of morphology and symmetry during silicon solidification and, consequently, on the tight control of the crystallization process that can affect the silicon crystal morphology and impurity distributions. [ABSTRACT FROM AUTHOR]

Moving boundaries of electric double layer at solid–liquid interface enables unprecedented persistent energy conversion and provokes a kinetic photovoltaic effect by moving an illumination region along the semiconductor‐water interface. Here, we report a transistor‐inspired gate modulation of kinetic photovoltage by applying a bias at the semiconductor‐water interface. The kinetic photovoltage of both p‐type and n‐type silicon samples can be facilely switched on/off, stemming from the electrical‐field‐modulated surface band bending. In contrast to the function of solid‐state transistors relying on external sources, passive gate modulation of the kinetic photovoltage is achieved simply by introducing a counter electrode with materials of desired electrochemical potential. This architecture provides the ability to modulate the kinetic photovoltage over three orders of magnitude and opens up a new way for self‐powered optoelectronic logic devices. [ABSTRACT FROM AUTHOR]

Moving boundaries of electric double layer at solid–liquid interface enables unprecedented persistent energy conversion and provokes a kinetic photovoltaic effect by moving an illumination region along the semiconductor‐water interface. Here, we report a transistor‐inspired gate modulation of kinetic photovoltage by applying a bias at the semiconductor‐water interface. The kinetic photovoltage of both p‐type and n‐type silicon samples can be facilely switched on/off, stemming from the electrical‐field‐modulated surface band bending. In contrast to the function of solid‐state transistors relying on external sources, passive gate modulation of the kinetic photovoltage is achieved simply by introducing a counter electrode with materials of desired electrochemical potential. This architecture provides the ability to modulate the kinetic photovoltage over three orders of magnitude and opens up a new way for self‐powered optoelectronic logic devices. [ABSTRACT FROM AUTHOR]

Whether or not specific ion effects determine the charge storage properties of aqueous graphene and graphite-based supercapacitors remains a highly debated topic. In this work we present a multiscale quantum mechanics – classical molecular dynamics (QMMD) investigation of aqueous mono- and divalent salt electrolytes in contact with fully polarizable charged graphene sheets. By computing both the electrochemical double layer (EDL) and quantum capacitance we observe a constant electrode specific capacitance with cationic radii and charge. Counterintuitively, we determine that a switch in the cation adsorption mechanism from inner to outer Helmholtz layers leads to negligible changes to the EDL capacitance, this appears to be due to the robust electronic structure of the graphene electrodes. However, the ability of ions (such as K+) with a relatively low hydration free energy to penetrate the inner Helmholtz plane and adsorb directly on the electrode surface is found to slow their diffusion parallel to the interface. Ions in the outer Helmholtz layer are found to have higher diffusivity at the surface due to their position in ion channels between water layers. Our results show that surface effects such as the surface polarization and the partial dehydration and local structuring of ions on the surface underpin the behaviour of cations at the interface and add a vital new perspective on trends in ion mobilities seen under confinement. [Display omitted] [ABSTRACT FROM AUTHOR]

An innovative and versatile set-up for in situ and real time measures in an electrochemical cell is described. An original coupling between micro-Raman spectroscopy and atomic force microscopy enables one to collect data on opaque electrodes. This system allows for the correlation of topographic images with chemical maps during the charge exchange occurring in oxidation/reduction processes. The proposed set-up plays a crucial role when reactions, both reversible and non-reversible, are studied step by step during electrochemical reactions and/or when local chemical analysis is required. [ABSTRACT FROM AUTHOR]

Highly dispersed SrO in amorphous ZrO 2 or SiO 2 , SrO–ZrO 2 , and SrO–SiO 2 mixed oxides were synthesized by applying the solid–liquid interface reaction of Sr(OH) 2 •8 H 2 O in the solid phase with an equal number of moles of Zr(OC 3 H 7) 4 or with twice the number of Si(OC 2 H 5) 4 moles dissolved in 2-propanol. After heat treating at 723 K, the SrO–ZrO 2 catalyst exhibited a higher activity than the conventional solid base MgO catalyst for the base-catalyzed retroaldol reaction of diacetone alcohol. The catalytic activity of SrO–ZrO 2 was higher by a factor of 1.5 than that of MgO prepared by the thermal decomposition of hydrated magnesium oxalate (MgC 2 O 4 •2H 2 O). By contrast, the highest activity of SrO–SiO 2 obtained by thermal activation at 673 K was much lower than that of MgO. The active SrO–ZrO 2 catalyst was composed of catalytically inactive species of SrZrO 3 , and small amounts of Sr(OH) 2 and SrCO 3. The expected active species of SrO was not detected in powder X-ray diffraction analysis in any sample. The formation of SrO in small crystal size dispersed in amorphous ZrO 2 was strongly expected. Similar results were obtained in the SrO–SiO 2 sample. An active site formed on SrO–ZrO 2 surface is proposed. [Display omitted] • Active solid base was synthesized by a solid–liquid interface reaction of Sr(OH) 2 •8H 2 O with Zr(OC 3 H 7) 4. • The formation of SrO in small crystal size dispersed in amorphous ZrO 2 was strongly expected. • The solid–liquid interface reaction is useful to prepare well mixed binary metal oxide. [ABSTRACT FROM AUTHOR]

Thermal transport properties of the solid–liquid interface continue to be in urgent research need with the widespread use of nanoscale fluid cooling, particle-assisted therapy, and lubrication technologies. In this paper, we developed an experimental system of Continuous wave frequency domain thermal reflection for measuring the thermal conductivity of liquids and interfacial thermal conductance of the solid–liquid and a two-way heat transport model based on the transmission line theory model, and the thermal conductivity, the interfacial thermal conductance and the contact angle of liquids on the surface of the aluminum sensing layer were measured for water, ethanol and hexadecane. In addition, we simulated the thermal transport at the Al /water interface by molecular dynamics with simulation results agreeing with experimental results. The results show that solid/liquid interface thermal transport depends on the transverse mode coupling of liquid wettability, increase the force interaction between solid and liquid molecules which couples the energy of low-frequency phonons to the liquid, thus making the interfacial thermal conductance decrease. [ABSTRACT FROM AUTHOR]

In the preparation of a superamphiphobic surface, the most basic method is to reduce the surface free energy of the interface. The C—F bond has a very low surface free energy, which can significantly change the wettability of the solid–liquid interface and make it a hydrophobic or oleophobic, or even superamphiphobic surface. Based on the analysis of a large number of research articles, the preparation and application progress in fluoropolymer emulsion were summarized. After that, some corresponding thoughts were put forward combined with our professional characteristics. According to recent research, the status of the fluoropolymer emulsion preparation system was analyzed. In addition, all related aspects of fluoropolymer emulsion were systematically classified in varying degrees. Furthermore, the interaction between fluoropolymer structure and properties, especially the interaction with nanomaterials, was also explored. The aim of this review is to try to attract more scholars' attention to fluorocarbon interfacial materials. It is expected that it will make a certain theoretical and practical significance in the preparation and application of fluoropolymer. [ABSTRACT FROM AUTHOR]

Electricity is the basic and essential need for every single person and guarantees the development of society, industry, and the economy. The limited conventional fossil fuel meets the challenge of the sharply increasing demand, while may lead to severe pollution. Emerging green energy harvesting systems can convert ambient kinetic, thermal, and solar energy to electricity effectivity. In this review paper, the authors provide an overview of the new and emerging methods, droplet‐based electricity generators, that convert energy from the ubiquitously existing water droplets. The authors begin with a brief introduction of the working principle for droplet‐based power generators. Existing configurations of the droplet‐based power generator are also summarized, including 1) single electrode, 2) transistor‐based, and 3) direct current generator. Then, a detailed discussion of the design and operation factors that may impact the energy harvesting efficiency of droplet‐based power generators is provided. Hybrid energy harvester that integrates droplet‐based power generators with other triboelectric, pyroelectric, and photovoltaic‐based devices are summarized. Finally, challenges and perspectives regarding the future development of droplet‐based power generators are described. The reviews demonstrate a highly efficient method for energy harvesting from water droplets to meet the vital needs of the energy crisis. [ABSTRACT FROM AUTHOR]

Anomalous solid-like liquids at the solid–liquid interface have been recently reported. The mechanistic factors contributing to these anomalous liquids and whether they can stably exist at high vacuum are interesting, yet unexplored, questions. In this paper, thin slices of silica tubes soaked in hexadecane were observed under a transmission electron microscope at room temperature. The H-spectrum of hexadecane in the microtubules was measured by nuclear magnetic resonance. On the interior surface of these silica tubes, 0.2–30 μm in inside diameter (ID), a layer (12–400 nm) of a type of non-volatile hexadecane was found with thickness inversely correlated with the tube ID. A sample of this anomalous hexadecane in microtubules 0.4 μm in ID was found to be formable by an ion beam. Compared with the nuclear magnetic resonance H-spectroscopy of conventional hexadecane, the characteristic peaks of this abnormal hexadecane were shifted to the high field with a broader characteristic peak, nuclear magnetic resonance hydrogen spectroscopy spectral features typical of that of solids. The surface density of these abnormal hexadecanes was found to be positively correlated with the silanol groups found on the interior silica microtubular surface. This positive correlation indicates that the high-density aggregation of silanol is an essential factor for forming the abnormal hexadecane reported in this paper. [ABSTRACT FROM AUTHOR]

The negative differential thermal resistance (NDTR) effect has received a lot of attention for its potential applications in thermal switching and thermal management. Therefore, it is crucial to explore and develop new ways to improve the NDTR performance. In this work, the influence of the surfactant on NDTR effect in the solid-liquid system has been investigated by using molecular dynamics simulation. It is found that the NDTR window and the maximum heat flux through the system can be extended significantly by using surfactant. With increasing temperature differences, the surfactant molecules are deported from the high-temperature interface and adsorbed on the low-temperature interface. The wettability transition of the high-temperature interface from hydrophilic to superhydrophobic is responsible for the enhanced NDTR effect. In addition, the effect of surfactant concentration and solid-surfactant coupling strength on the NDTR effect is also examined. The results show that there is an optimal surfactant concentration and solid-surfactant coupling strength for an optimized NDTR effect. The results in this paper provide a new idea for the design of thermal thermistor. [ABSTRACT FROM AUTHOR]

• Wettability and boiling performance of HDNs on the substrate simulated. • Positive wettability effects of HDNs compared with single deposited nanoparticle. • HDNs advance the nucleation time and increase the heat flux by 46.9 % at most. • HDNs enhance the matching strength of atomic vibration at the interface. The present work utilizes Molecular Dynamics (MD) method to study the physical mechanism of the effect of hybrid deposited nanoparticles (HDNs) on the boiling heat transfer by changing the wettability of the substrate. Three kinds of nanofluid simulation models are established, in which water molecules are used as the base fluid, and nanoparticles are hydrophilic deposited particles, hydrophobic deposited particles and HDNs, respectively. Compared with hydrophilic and hydrophobic deposited nanoparticles, it is found that the equilibrium contact angles of droplet containing HDNs decreases by 2.22° and 6.99° respectively during wetting simulation, indicating that HDNs improve the wettability of the substrate. By simulating the boiling process of three fluids, it is found that HDNs advance the start time of explosive boiling by 0.15 ns at most, that is, accelerate the nucleation time of bubbles, and increase the heat flux by 46.9 % at most, indicating that the heat convection near the substrate is enhanced. In addition, HDNs improve the vibration matching degree of atoms between the solid-liquid interface and enhance the heat transfer between the substrate and the fluid. The results of boiling simulation verify the conclusion that HDNs improve the wettability of the substrate and thus enhance the heat transfer inferred by droplet wetting simulation. [ABSTRACT FROM AUTHOR]

Superhydrophobic biological fluid‐repellent surfaces (SBFRSs) have attracted great attention in the treatment of blood and urine‐related diseases because of their unique wettability and compatibility, which creates a new path for the development of medical apparatus and instruments, and are expected to create advances in various fields. Here, this review provides an up‐to‐date summary of research progress on the repellent mechanism and application of SBFRSs. The underlying physical and chemical principles for designing superhydrophobic surfaces are first introduced. Then, the dialectical influences of solid‐liquid interactions between superhydrophobic surfaces and biological fluids on the wettability and compatibility are emphatically expounded. Subsequently, attention is drawn to the recent applications of SBFRSs in biomedical fields, such as surgical medical apparatus, implant materials, extracorporeal circulation devices, and biological fluid detection. Finally, the outlook and challenges in terms of employing SBFRSs are also discussed. This review is expected to provide a comprehensive guidance for the preparation of SBFRSs with compatibility and long‐term superhydrophobic stability that is closely related to clinical applications. [ABSTRACT FROM AUTHOR]

"How to break through the preparation theory and technology of large size crystal materials" is one of the top ten frontier scientific questions released by China Association for Science and Technology in 2021, which revealing the crystal growth mechanism and breaking through the key growth technologies are the two trends of the development of large size functional crystals. At the atomic or molecular scale, the crystal growth can be described as a thermal activation process with a barrier or an ultrafast growth of crystal without barrier, which is related to the specific system and growth direction. Based on the properties of interface, the smooth interface grown by the way of step expansion, and the rough interface has no obvious solid-liquid stratification, and the growth can be completed by local atomic solidification. The advances of growth theory and technology for the large-size crystals in recent years have been summarized from three aspects: model, technology of growth and its application and the application of molecular dynamics in crystal growth. At present, there are many methods to grow large-size crystals, but the crystal quaility is poor and performance is unstable. The reasons are that the existing technology do not take the micro-mechanism of crystal growth into consideration, and the relationship among crystal growth mechanisms and external factors such as temperature and flow rate are not clear. Using machine learning force field and molecular dynamics simulation method to establish solid-liquid interface and to simulate crystal growth would be an effective way to explore the micro-mechanism of crystal growth. [ABSTRACT FROM AUTHOR]

The nanoscale structure and dynamics of proteins on surfaces has been extensively studied using various imaging techniques, such as transmission electron microscopy and atomic force microscopy (AFM) in liquid environments. These powerful imaging techniques, however, can potentially damage or perturb delicate biological material and do not provide chemical information, which prevents a fundamental understanding of the dynamic processes underlying their evolution under physiological conditions. Here, we use a platform developed in our laboratory that enables acquisition of infrared (IR) spectroscopy and AFM images of biological material in physiological liquids with nanometer resolution in a cell closed by atomically thin graphene membranes transparent to IR photons. In this work, we studied the self-assembly process of S-layer proteins at the graphene-aqueous solution interface. The graphene acts also as the membrane separating the solution containing the proteins and Ca2+ ions from the AFM tip, thus eliminating sample damage and contamination effects. The formation of S-layer protein lattices and their structural evolution was monitored by AFM and by recording the amide I and II IR absorption bands, which reveal the noncovalent interaction between proteins and their response to the environment, including ionic strength and solvation. Our measurement platform opens unique opportunities to study biological material and soft materials in general. [ABSTRACT FROM AUTHOR]

The present study proposes various thermal circuit models (TCMs) to predict interfacial thermal resistances (ITRs) between water and a nanostructure surface. The effects of water models, nanopillar widths on nanostructure surfaces, and composite surfaces on the relationship between ITRs calculated by non-equilibrium molecular dynamics simulations and ITRs predicted by TCMs are investigated in water-copper and water-graphene-copper systems. The results reveal that the ITRs predicted by some TCMs are slightly affected by water pressure, while MD-calculated ITRs of the nanostructure surfaces in the Wenzel states agree with most of the predicted ITRs. Additionally, it is demonstrated that water molecules in the groove of a nanostructure surface play a crucial role in TCMs in the Cassie-Baxter states. Considering the effective contact region of water molecules in the groove in the Cassie-Baxter states, the use of TCMs can effectively reduce the prediction error of ITRs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phase transformation boundary diffuses from the surface to the bulk of cocrystals. • A relationship between supersaturation rate and phase transition pathway is revealed. • Porous solids recrystallized at cocrystal surface facilitate the water penetration. • Intermolecular interactions between drug and polymer improve dissolution. Cocrystals easily undergo solution-mediated phase transformation at the surface of dissolving cocrystals during dissolution, which significantly deteriorates the solubility advantage of cocrystals. Here, a new scenario for the phase transformation of liquiritigenin (LQ) cocrystals in which the boundary of phase transformation diffuses along the surface to the bulk of the cocrystal was identified. Additionally, depending on the rate of supersaturation generation, phase transformation processes to the anhydrate and hydrate of LQ compete during cocrystal dissolution. The liquiritigenin–nicotinamide (LQ–NIC) cocrystal yielded a higher supersaturation rate, causing the nucleation kinetics to dominate the recrystallization process and the formation of a metastable form of LQ. However, in the liquiritigenin–isoniazid (LQ–INZ) cocrystal, the low supersaturation rate leading to recrystallization was controlled by thermodynamics and the subsequent formation of monohydrates of LQ (less soluble). As a result, in plain buffer, a multistep pathway for phase transformation of the LQ–NIC cocrystal was observed, in which the cocrystal was firstly converted into the anhydrate LQ (metastable form) and subsequently transformed into LQ·H 2 O. A one-step phase transformation was observed for the LQ–INZ cocrystal, where the cocrystal was directly converted to LQ·H 2 O. In a buffer containing the Eudragit E100 (E100) additive, for the LQ–NIC cocrystal, the dissolution performance was improved, which can presumably be attributed to the solubilization effect of E100 on the anhydrate and the inhibitory effect on the transformation of the anhydrate to the monohydrate. However, for the LQ–INZ cocrystal, a negligible improvement in drug concentration was observed in the presence of E100 because of the slight effects of E100 on the solubility of LQ·H 2 O. These findings provide valuable insights into the phase transformation pathways of cocrystals at the solid-liquid interface and the effects of additives on the dissolution behavior of cocrystals. [ABSTRACT FROM AUTHOR]

During electrocatalytic reactions, the electrode, adsorbates, electrolyte ions, and solvent molecules at the electrode-electrolyte interface each play an important role. Electrochemical X-ray photoelectron spectroscopy (XPS) holds great promise for deciphering these roles, providing the oxidation state or bonding environment of every element present at the interface. However, combining the vacuum required for XPS with the wet environment needed for electrochemistry constitutes a technical challenge, requiring purpose-built instrumentation and spectro-electrochemical cell design. Here, we present a laboratory-based electrochemical XPS instrument optimized for operando studies on nano-structured electrocatalysts. The core of the system is a 3D printed spectro-electrochemical cell containing a membrane-electrode-graphene assembly. We show that this design enables us to probe the electrode surface, interfacial water, and interfacial ions under well-defined potential control. Meanwhile, the introduction of a mesoporous membrane into the assembly enables the transport of any molecular or ionic reactant towards the working electrode, opening the way to study any aqueous phase electrocatalytic system using laboratory-based electrochemical XPS. We exemplify this for the oxygen reduction reaction. • Laboratory-based operando XPS for measurements during electrocatalytic reactions. • 3D printed spectro-electrochemical flow cell. • Compatible with any aqueous phase reaction. • Characterization of the electrode surface structure, interfacial water, and adsorbed ions demonstrated. [ABSTRACT FROM AUTHOR]

• CFD simulations clarified the gas atomization process for FeCoNiCrMoBSi HEA. • Experimentally observed, the size distribution of gas-atomized HEA powder concentrates in the 30∼40 μm range, aligning with numerical simulations. • The FCC structure and eutectic microstructural characteristics are observed in the gas-atomized FeCoNiCrMoBSi HEA powder. • The estimated cooling rate of secondary droplets ranges from 1.22 × 104 K/s to 2.64 × 105 K/s. The intricate processes governing the gas atomization of molten metal droplets and their subsequent solidification hold paramount significance in materials science. Computational fluid dynamics simulations have emerged as indispensable tools for unraveling the complexities inherent in metal melt atomization. This study employed the volume of fluid method and the shear-stress transport k-ω turbulence model to simulate the primary atomization process of a FeCoNiCrMoBSi high-entropy alloy. Subsequently, the discrete phase model and Taylor analogy breakup model, based on the gas Weber number and incorporating primary atomization outcomes as initial conditions, were utilized to simulate droplet formation during the secondary atomization process. Analysis of the particle size distribution at the outlet of the geometric model demonstrated excellent agreement with experimental data for gas-atomized FeCoNiCrMoBSi high-entropy alloy powder. Furthermore, comprehensive characterization analyses were conducted to probe the phase constitution and structure of FeCoNiCrMoBSi powder produced by gas atomization. The results revealed that, irrespective of particle size, the powder exhibited a face-centered cubic structure and distinctive eutectic microstructural characteristics. The numerical simulation provided insights into the solidification process of secondary droplets by integrating inverse pole figure data for gas-atomized powder across varying particle sizes. The estimated cooling rate of secondary droplets ranged from 1.22 × 104 K/s to 2.64 × 105 K/s. These findings significantly advance the understanding of the gas atomization mechanism of the FeCoNiCrMoBSi high-entropy alloy, paving the way for the development of more efficient manufacturing processes for advanced materials. [Display omitted] [ABSTRACT FROM AUTHOR]

• Observing the growth behavior of a grain boundary with variated groove in mc-Si. • Proposing a geometric model with consideration of different kinetic models of facets. • Reproducing the observed results by our model with a comparable results. • Suggesting that vicinal growth could be one of groove facet kinetics in Si. • Perturbations may come from parallel dislocations. The morphology of the solid–liquid interface and the GB development during directional solidification process of multi-crystalline silicon (mc-Si) has been studied with an in situ observation system. A small angle grain boundary was observed to have a gradually increasing faceted groove, finally reaching a steady state. A geometric model is used to simulate the growth of groove facets with consideration of different facet growth kinetics. It appears that the kinetics of a face vicinal to a {1 1 1} plane is most likely to reproduce the observed behavior. Later on, variations of groove size and grain boundary direction occurred. The geometric simulation results show that such perturbations could be produced by the interaction of single dislocations with one of the vicinal facets. [ABSTRACT FROM AUTHOR]

Understanding the adsorption mechanisms of organic corrosion inhibitors at metal/water interfaces is crucial for designing corrosion inhibitors. Imidazole adsorption at copper/water surfaces was investigated via ab initio molecular dynamics simulations. The adsorption energy of imidazole on copper in water is slightly more positive than that in vacuum, which is attributed to the hydrogen bond interaction between imidazole and water molecules. Imidazole adsorption changes interfacial water density and dipole distribution, disrupts hydrogen bond networks, and decreases water residence time at the interface. These characteristics are considered to be correlated to the decreased corrosion rate induced by imidazole adsorption. • The interactions between copper surface, imidazole, and water are carefully revealed. • The imidazole adsorption is affected by the hydrogen bond between imidazole and water. • Imidazole adsorption changes interfacial water density and dipole distribution. [ABSTRACT FROM AUTHOR]

Ceramic membrane fouling is a constraint in the treatment of acid mine drainage (AMD), leading to a decrease in efficiency over time. Here, it is described via first-principles calculations the physical and chemical phenomena occurring on the surface of TiZrO 4 filtration membranes due to the adsorption of eight potential fouling compounds [CuS, FeS, Fe 2 S 3 , CaS, Al(OH) 3 , Fe(OH) 3 , Fe(OH) 2, and Cu(OH) 2 ]. The interaction of these fouling molecules was performed onto nanostructured TiZrO 4 surfaces with several pores representing the filtration membranes employed in the treatment of AMD. The adsorption energies reveal that the adsorption is feasible with all the fouling molecules studied, and it is strongly related to the molecular polarity of the adsorbate. Consequently, the adsorption of metal sulfides is more feasible than hydroxides with adsorption orders of CaS>FeS>CuS>Fe 2 S 3 , and Al(OH) 3 >Fe-hydroxides>Cu(OH) 2. The outcomes suggest that the metal sulfide adsorption depends on the adsorbate intrinsic polarity, solvent effects, adsorbate van der Waals radius, and membrane surface topology, while the adsorption of hydroxides is less influenced by the last two factors. Density-based binding and energy decomposition analyses indicate strong electrostatic attractions and covalent bonds at the adsorbate-membrane interface supporting the chemical fouling onto ceramic filtration membranes. According to our theoretical results and the elevated concentration of Cu and Fe in AMD, we propose that FeS and CuS are mainly responsible for the fouling onto TiZrO 4 membrane surfaces. These results offer valuable information on the adsorption phenomena at TiZrO 4 membrane surfaces, which can be useful for metallurgy, industrial water treatment, food industry, biotechnology, and pharmaceutical applications. [Display omitted] • Metal sulfides are chemisorbed on TiZrO 4 mainly through S-Ti or S-Zr covalent bonds. • Electrostatic effects drive the adsorption mechanism of metal sulfides. • The higher the sulfide polarity, the greater the adsorption on TiZrO 4 surfaces. • Metal sulfides adsorb more easily on TiZrO 4 surfaces than hydroxides. • Effects of polarization of the solvent decreases the adsorbate-membrane interaction. [ABSTRACT FROM AUTHOR]

Solid–liquid interfaces are ubiquitous in scientifically and technologically important systems, and they govern complex chemophysical processes such as those in electrochemistry and heterogeneous catalysis. Atomic‐level elucidation of interfacial structures has been extensively pursued; however, related research is still limited. A major obstacle lies in the intrinsic character of interfaces: they are located between two bulk phases that make the application of spectroscopic or surface‐science techniques be difficult. Although this suggests the possibility of employing computational approaches to explore interfacial structures, modern molecular simulation methods suffer from an inability to simulate large interfacial systems in a sufficient time scale at the all‐atom resolution. To develop a method capable of simulating solid–liquid interfaces, we have been developing a mean‐field quantum mechanics/molecular mechanics (QM/MM) method. This Review briefly summarizes the theoretical background of mean‐field QM/MM, as well as recent efforts to advance it. Furthermore, we summarize several studies performed based on this method. [ABSTRACT FROM AUTHOR]

The electrical double‐layer plays a key role in important interfacial electrochemical processes from catalysis to energy storage and corrosion. Therefore, understanding its structure is crucial for the progress of sustainable technologies. We extract new physico‐chemical information on the capacitance and structure of the electrical double‐layer of platinum and gold nanoparticles at the molecular level, employing single nanoparticle electrochemistry. The charge storage ability of the solid/liquid interface is larger by one order‐of‐magnitude than predicted by the traditional mean‐field models of the double‐layer such as the Gouy–Chapman–Stern model. Performing molecular dynamics simulations, we investigate the possible relationship between the measured high capacitance and adsorption strength of the water adlayer formed at the metal surface. These insights may launch the active tuning of solid–solvent and solvent–solvent interactions as an innovative design strategy to transform energy technologies towards superior performance and sustainability. [ABSTRACT FROM AUTHOR]

The electrical double‐layer plays a key role in important interfacial electrochemical processes from catalysis to energy storage and corrosion. Therefore, understanding its structure is crucial for the progress of sustainable technologies. We extract new physico‐chemical information on the capacitance and structure of the electrical double‐layer of platinum and gold nanoparticles at the molecular level, employing single nanoparticle electrochemistry. The charge storage ability of the solid/liquid interface is larger by one order‐of‐magnitude than predicted by the traditional mean‐field models of the double‐layer such as the Gouy–Chapman–Stern model. Performing molecular dynamics simulations, we investigate the possible relationship between the measured high capacitance and adsorption strength of the water adlayer formed at the metal surface. These insights may launch the active tuning of solid–solvent and solvent–solvent interactions as an innovative design strategy to transform energy technologies towards superior performance and sustainability. [ABSTRACT FROM AUTHOR]

Self-diffusion of ions in the protic ionic liquid ethylammonium nitrate (EAN) was studied by 1H NMR pulsed field gradient techniques between 294 and 393 K in the presence of a PTFE insert in a 5-mm NMR tube. At all temperatures, the bulk diffusion of ions (measured by 1H and 15N NMR) can be described by a unique diffusion coefficient. The presence of solid hydrophobic surfaces of PTFE induces regions of EAN in their vicinity, where diffusion of ions, both cations and anions, is reduced compared to the bulk values. An additional line-shape analysis in 1H NMR spectra showed that local mobility of ethylammonium cations in the surface layers near PTFE is also reduced. • 1H and 15N NMR was used to study diffusivity of ethylammonium nitrate enclosed between PTFE surfaces. • The presence of solid hydrophobic surfaces of PTFE induces regions of EAN where diffusion of cations and anions, is reduced. • Line-shape analysis in 1H NMR spectra showed that local mobility of EA cations in the surface layers near PTFE is reduced. [ABSTRACT FROM AUTHOR]

The results of molecular dynamics (MD) simulations of the crystallization process in one-component materials and solid solution alloys reveal a complex temperature dependence of the velocity of the crystal-liquid interface featuring an increase up to a maximum at 10-30% undercooling below the equilibrium melting temperature followed by a gradual decrease of the velocity at deeper levels of undercooling. At the qualitative level, such non-monotonous behaviour of the crystallization front velocity is consistent with the diffusioncontrolled crystallization process described by the Wilson-Frenkel model, where the almost linear increase of the interface velocity in the vicinity of melting temperature is defined by the growth of the thermodynamic driving force for the phase transformation, while the decrease in atomic mobility with further increase of the undercooling drives the velocity through the maximum and into a gradual decrease at lower temperatures. At the quantitative level, however, the diffusional model fails to describe the results of MD simulations in the whole range of temperatures with a single set of parameters for some of the model materials. The limited ability of the existing theoretical models to adequately describe the MD results is illustrated in the present work for two materials, chromium and silicon. It is also demonstrated that the MD results can be well described by the solution following from the hodograph equation, previously found from the kinetic phase-field model (kinetic PFM) in the sharp interface limit. The ability of the hodograph equation to describe the predictions of MD simulation in the whole range of temperatures is related to the introduction of slow (phase field) and fast (gradient flow) variables into the original kinetic PFM from which the hodograph equation is obtained. The slow phase-field variable is responsible for the description of data at small undercoolings and the fast gradient flow variable accounts for local non-equilibrium effects at high undercoolings. The introduction of these two types of variables makes the solution of the hodograph equation sufficiently flexible for a reliable description of all nonlinearities of the kinetic curves predicted in MD simulations of Cr and Si. [ABSTRACT FROM AUTHOR]

Supramolecular amphiphiles are a topic of widespread interest in supramolecular chemistry and the characterisation of their properties at the interfacesis at the basis of industrial and biotechnology applications. This work focuses on the determination of the adsorption features of supramolecular amphiphiles, formed by the host-guest complexation of a p-sulfonatocalix[4]arene with selected cationic surfactants, at the solid–liquid interface monitored by quartz crystal microbalance with dissipation monitoring (QCM-D) experiments. The adsorption process resulted to be favourite and strongly affected by the length of the surfactant alkyl chain and somehow by the nature of the polar head. The adsorption isotherms highlighted the key role played by the calixarene scaffold in the CMC value, the amount of material absorbed and the efficiency of the adsorption process on a gold substrate. Furthermore, the kinetic profiles provided significant insights on the different mechanisms of adsorption undergone by either conventional or supramolecular amphiphilic systems. [ABSTRACT FROM AUTHOR]

• Al 2 O 3 /Er 2 O 3 /ZrO 2 solidified ceramics were prepared via high frequency induction zone melting. • The crushing and second ball milling are beneficial to get the fine and united eutectic. • There is a certain range of molar ratio for samples to obtain the eutectic microstructure. • Ceramics with eutectic point mole composition might have non-eutectic microstructure. • Eutectic growth was divided into four processes based on the microstructure at the solid-liquid interface. Directionally solidified Al 2 O 3 /Er 2 O 3 /ZrO 2 ceramics were prepared with high frequency induction zone melting. Their phase components, microstructure and growth characters were investigated. The results indicated that the raw material powder with uniform oxides' distribution could be obtained via the green body's crushing and second ball-milling, which was benefited to get the fined and unified eutectic microstructure. The phase components of each sample were consistent with the prediction originated from the position of their composition in the phase diagram. The microstructures of eutectic and hyper/hypo-eutectic were basically a network with interpenetrated crystal phases, and a small amount of coarsened phase existed in the form of colony structure in the latter, the microstructure was refined with the increase of the ZrO 2 concentration. The quasi-eutectic with colony structure could be prepared at the molar ratio of raw materials determined by the volume fraction. In addition, a large number of coarsened phases appeared in the microstructures of the samples with the eutectic molar ratios, so the corresponding samples were non-eutectic. These results demonstrated that the composition might be more important than the growth rate in the preparation of non-eutectic samples with eutectic microstructure, and the selection of the composition of solidified ceramics should not depend too much on the phase diagram. The eutectic growth could be divided into four processes according to the microstructures of precursor and solidified ceramics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu droplets demonstrate superior wettability and the fastest spreading on Fe(1 1 1) surfaces, while exhibiting the poorest wettability and lowest spreading rate on Fe(0 0 1) surfaces. • The wetting process comprises a fast-spreading regime driven by inertia and a slow-spreading regime governed by surface tension, with dissolution reactions further enhancing the wetting kinetics. • On Fe(0 0 1) surfaces, the spreading of precursor films can be described by the molecular-kinetic model, while the main bodies of the droplets follow the hydrodynamic model. • On Fe(1 1 0) and (1 1 1) surfaces, the main limiting factor for spreading is the friction dissipation between the main bodies of the droplets and the precursor films, in line with the molecular-kinetic model. Molecular dynamics simulations were performed to investigate the wetting behavior of Cu droplets on three distinct Fe surfaces: Fe(0 0 1), Fe(1 1 0), and Fe(1 1 1). The results reveal that Cu droplets exhibit a relatively stable layering order near the solid–liquid interface on all Fe surfaces while displaying different three-phase contact line structures. Influenced by the substrate surface structure and the extent of interfacial reactions, Cu droplets demonstrate superior wettability and the fastest spreading on Fe(1 1 1) surfaces, while exhibiting the poorest wettability and lowest spreading rate on Fe(0 0 1) surfaces. The spreading of Cu droplets on all Fe surfaces exhibits a similar driving mechanism, while is applicable to different spreading kinetic models emphasizing varying dissipation channels. The wetting process comprises a fast-spreading regime driven by inertia and a slow-spreading regime governed by surface tension, with dissolution reactions further enhancing the wetting kinetics. On Fe(0 0 1) surfaces, the spreading of precursor films can be well described by the molecular-kinetic model, while the primary dissipation mechanism for the main bodies of the droplets is the viscous dissipation within liquids, consistent with the hydrodynamic model. Conversely, on Fe(1 1 0) and (1 1 1) surfaces, the main limiting factor for spreading is the friction dissipation between the main bodies of the droplets and the precursor films, in line with the molecular-kinetic model. These findings offer new insights into the wetting phenomena of metal/metal systems, particularly the liquid metal embrittlement associated with Cu(l)/Fe(s) wetting. [ABSTRACT FROM AUTHOR]