Solid Formation Research Articles

Towards atomistic modelling of solid Pb-O formation and dissolution in liquid lead coolant: Interatomic potential development

Microscopic description of solid Pb-O formation and dissolution in liquid lead coolant is important for the modelling of fast neutron reactors. For this purpose, in this work we develop interatomic potential models for lead melt with dissolved oxygen. Potentials fitting is based on ab initio density functional theory (DFT) calculations and quantum molecular dynamics. Two different potential models are trained on the DFT data using the force-matching method: a computationally cheap embedded atom method (EAM) potential and a computationally expensive machine-learned moment tensor potential (MTP) that allows reproducing DFT data very accurately. The potentials are further validated to reproduce the properties of lead melt and the coordination of oxygen atoms in molten lead. The diffusion coefficient for oxygen in molten lead is calculated and compared with the available experimental data. We analyse how these interatomic potential models describe the crystal structure of the solid lead oxide to consider PbO nucleation and dissolution in molten lead. We extensively discuss the arising problems with the description of long-range electrostatic interactions. The possibility of matching the experimental data on the oxygen solubility limit by tuning the EAM potential is shown.

Identification of kidney stones in KUB X-ray images using VGG16 empowered with explainable artificial intelligence

A kidney stone is a solid formation that can lead to kidney failure, severe pain, and reduced quality of life from urinary system blockages. While medical experts can interpret kidney-ureter-bladder (KUB) X-ray images, specific images pose challenges for human detection, requiring significant analysis time. Consequently, developing a detection system becomes crucial for accurately classifying KUB X-ray images. This article applies a transfer learning (TL) model with a pre-trained VGG16 empowered with explainable artificial intelligence (XAI) to establish a system that takes KUB X-ray images and accurately categorizes them as kidney stones or normal cases. The findings demonstrate that the model achieves a testing accuracy of 97.41% in identifying kidney stones or normal KUB X-rays in the dataset used. VGG16 model delivers highly accurate predictions but lacks fairness and explainability in their decision-making process. This study incorporates the Layer-Wise Relevance Propagation (LRP) technique, an explainable artificial intelligence (XAI) technique, to enhance the transparency and effectiveness of the model to address this concern. The XAI technique, specifically LRP, increases the model's fairness and transparency, facilitating human comprehension of the predictions. Consequently, XAI can play an important role in assisting doctors with the accurate identification of kidney stones, thereby facilitating the execution of effective treatment strategies.

Postmortem 7Li NMR analysis for assessing the reversibility of lithium metal electrodes in lithium metal batteries

Despite the proficiency of lithium (Li)-7 NMR spectroscopy in delineating the physical and chemical states of Li metal electrodes, challenges in specimen preparation and interpretation impede its progress. In this study, we conducted a comprehensive postmortem analysis utilizing 7Li NMR, employing a standard magic angle spinning probe to examine protective-layer coated Li metal electrodes and LiAg alloy electrodes against bare Li metal electrodes within Li metal batteries (LMBs). Our investigation explores the effects of sample burrs, alignment with the magnetic field, the existence of liquid electrolytes, and precycling on the 7Li NMR signals. Through contrasting NMR spectra before and after cycling, we identified alterations in Li0 and Li+ signals attributable to the degradation of the Li metal electrode. Our NMR analyses decisively demonstrate the efficacy of the protective layer in mitigating dendrite and solid electrolyte interphase formation. Moreover, we noted that Li+ ions near the Li metal surface exhibit magnetic susceptibility anisotropy, revealing a novel approach to studying diamagnetic species on Li metal electrodes in LMBs. This study provides valuable insights and practical guidelines for characterizing distinct lithium states within LMBs.

Hydrophobic barrier-free laminated paper-based analytical device (LPAD) using a diameter-based measurement for determination of iodide in pharmaceutical products

This work presents, for the first time, an exploitation of an argentometric Mohr's method for iodide detection using diameter-based measurement on laminated paper-based analytical device (LPAD). Our LPAD is simplified fabricated with no required hydrophobic barrier for patterning a detection flow channel. In the absence of a flow channel, the liquid is imbibed radially into the filter paper outward from the small center inlet hole. This imbibition leads to the measurement of diameter after the formation of the precipitation product. For LPAD, a rectangular piece of Whatman filter paper is cut and positioned between a top laminating sheet, which has a hole punched for inlet, and a bottom laminating sheet. The central inlet hole enables access to the liquid on the paper. For iodide analysis, silver nitrate is dispensed first, followed by the iodide standard/sample. This process leads to the formation of pale-yellow silver iodide solids on the paper. The chromate indicator solution is subsequently loaded to the paper. The color of the chromate solution imparts a tint to the circular band of silver iodide solids, resulting in an intense yellow color. When the silver iodide precipitates are stained, the chromate solution typically serves as an indicator, chemically reacting to an excess silver nitrate solution moistened on paper. This reaction generates an outer reddish-brown ring of silver chromate. The distinct color contrast between the intense yellow (tinted silver iodide) and reddish-brown (silver chromate) allows for clear observation of the measurement boundary, facilitating diameter-based measurements of the circular band of silver iodide. We demonstrate the applicability in analysis of pharmaceutical KI tablets. The quantitative results obtained from diameter-based measurement LPAD show good agreement with those obtained from the potentiometric method. Our hydrophobic barrier-free LPAD is rapid, cost-effective, low liquid consumption and applicable for onsite analysis.

Tailoring plasmonic sensing strategies for the rapid and sensitive detection of hypochlorite in swimming water samples.

Atunable plasmonic sensor has been developedby varying the dextran content in the initially synthesized dextran-gold nanoparticle (dAuNPs) solution. A colloidal nanogold solution (dAuNPs-Sol) was initially prepared using dextran and gold salt in alkaline media by a one-pot green synthetic route. The dAuNPs-Sol was combined with varying amounts of dextran (ranging from 0.01 to 30.01%) to create a tunable probe, along with different solid formats, including tablet (dAuNPs-Tab), powder (dAuNPs-Powder), and composite (dAuNPs-Comp). Both the liquid and solid phase plasmonic probes were characterized using UV-vis spectroscopy, transmission electron microscopy (TEM) dynamic light scattering (DLS), and zeta potential analysis. The impact of dextran content in the dAuNP solution is studied in terms of surface charge and hydrodynamic size. The influence of operational treatments used to achieve solid dAuNPs probes is also explored. All plasmonic probes were employed to detect a broad range of OCl¯ concentrations (ranging from µM to mM) in water through aggregation followed by calculating a lower and upper limit of detection (LLoD, ULoD) of the proposed colorimetric sensors. Results indicate that the most sensitive detection is achieved with a lower dextran content (0.01%), which exhibits an LLoD of 50µM. The dAuNPs-Sol sensor is selective and demonstrates real-world applicability, as confirmed by interference analysis and successful testing with various water samples. Additionally, it is found that a 20 × concentration of dextran-coated gold nanoparticles could be attained without any changes in the particle morphology. This concentration is achieved through a straightforward process that does not require the use of a centrifuge machine. This finding highlights the practicality and simplicity of the method, indicating its potential for scalable and cost-effective production of concentrated dAuNPs without compromising their structural integrity.

Chitosan-TPP microcapsules for controlled drug release

Production of chitosan/sodium tripolyphosphate (CS/TPP) microcapsules via spray drying involves atomizing an emulsion containing CS, TPP, acetic acid (AcOH), and folic acid (FA) into fine droplets exposed to high-temperature, low-pressure gas flow. Solvent evaporation within the drying chamber leads to solid particle formation. Spray drying is valuable for creating solid CS/TPP microcapsules. Precise equipment parameter adjustments, like inlet temperature and gas flow rate, enable the study of microcapsule morphology, size, and properties. This adaptability allows for customization to specific pH dissolution ranges. The production method's impact on CS/TPP microcapsules was studied by modifying spray drier parameters, including inlet temperature and aspirator pressure, to enhance understanding of their behavior in solution under varied production conditions.
 In chitosan delivery systems, various approaches can encapsulate drug agents like folic acid, an analog to the cancer treatment drug methotrexate. Agents can be added to the chitosan solution pre-crosslinking, incorporated into gelation-inducing agents pre-mixing with chitosan, or included in the crosslinking mixture. Experiments were conducted to assess CS/TPP microcapsules' behavior when encapsulating agents like folic acid. Release profiles were analyzed to understand their drug delivery capabilities and potential as controlled release carriers.

Effective solid–solid and microwave-assisted formation of folic acid@titanium oxide nanoparticles for enhanced batch adsorptive uptake of toxic Cd(II) and Cu(II) pollutants

Synthesis of complicated multi-constituent nanocomposites for adsorption, removal and photocatalytic decomposition of miscellaneous pollutants is a tedious process with respect to the cost of synthesis, methodology and characterization of the produced materials. To find out a simple, short, and direct approach for preparation of an efficient nanomaterial from only two components is a challenging target. Therefore, it is aimed in this investigation to design and generate a potential nanosorbent by only combination of folic acid (Fol-Ac) with titanium oxide nanoparticles (TiO2NPs) via simple solid–solid and microwave-assisted formation of a novel Fol-Ac@TiO2NPs nanosorbent in less than 15 min. The assembled nanosorbent was confirmed by determination of the surface coverage using thermal gravimetric analysis 187.4 mg/g (425.6 µmol g−1), homogenous particles distribution with average particle size (56.92–96.74 nm) based on the TEM imaging. The surface was loaded with several effective and related functional groups to Fol-Ac and TiO2NPs as detected from the FT-IR analysis. The characterized Fol-Ac@TiO2NPs was then used as a novel nanosorbent to capture Cd(II) as a highly toxic divalent metal ion and Cu(II) as a moderately toxic ion via batch mode under the contribution of numerous experimental parameters. Zero charge point of Fol-Ac@TiO2NPs was identified at pHPZC = 6.6 to match with the optimum capture at pH 6.0–7.0 for both Cd(II) plus Cu(II) pollutants. Other parameters as reaction time and temperature as well as metal concentration were also performed and modeled to characterize the possible mechanisms via evaluation of the kinetic, thermodynamic and adsorption isotherm investigations, respectively. Fol-Ac@TiO2NPs nanosorbent was efficiently recycled providing 96.67–97.03 % and 91.34–92.47 % stability after the first and fifth cycles, respectively. Moreover, the efficient usage of Fol-Ac@TiO2NPs for uptake of Cd(II) plus Cu(II) pollutants from contaminated water samples was successfully performed providing 98.32–83.97 % and 93.45–83.39 %, respectively.

Sequential hydrothermal dechlorination and liquefaction of PVC

Poly(vinyl chloride) (PVC) is globally the third most produced plastic, but recycling PVC waste through mechanical means is difficult. Due to the high presence of chlorine in PVC, it is unsuitable for both pyrolysis and combustion. Consequently, there is a need to explore innovative methods for harnessing its energy potential. Hydrothermal liquefaction (HTL) is a topic of growing interest in the literature for chemical recycling of waste plastic or conversion into liquid energy carriers. In this work an innovative sequential hydrothermal processing strategy was tested for oil production from PVC. PVC at high loadings (20 wt.%) was first processed under subcritical conditions to produce a chlorine-free solid, which was then liquefied in supercritical conditions. Different temperatures were tested for the dechlorination stage, and at 300 °C 99% of chlorine was removed, while 94% of carbon remained in the solid residue. The mechanism behind the solid's formation was investigated by assessing activation energies, both with the addition of KOH as a neutralizing agent (120 kJ/mol) and without it (186 kJ/mol). Different temperatures were screened for an HTL supercritical stage (420–480 °C), but the maximum conversion of the dechlorinated solid was 47%, and the maximum mass yield of oil was 10%. Overall, the subcritical phase demonstrated its potential as a technology for producing chlorine-free solid material with a high energy density. The subsequent supercritical step partially valorized the dechlorinated solid by producing an aromatic-rich oil phase.

Hybrid Orbital Formation and Multicenter Bonding of Hydrogen Atoms and Molecules in Ti3C2${\rm Ti}_{3}{\rm C}_{2}$ MXenes

AbstractThe formation and stability of solids and molecules is not possible without chemical bonds, which are divided into covalent, ionic, metallic, and van der Waals bonds. A special type of intermolecular bond is hydrogen bonding, which plays a crucial role for chemical, biological, and physical processes. However, hydrogen shows a far more complex behavior when it is present in solids. In this paper, it is shown that the chemical bonding of hydrogen atoms and molecules extends far beyond the simple picture of conventional, ionic, covalent, and multicenter bonds. The interaction of H with its host material is particularly important for hydrogen storage in metallic materials such as MXenes. Hydrogen atoms and molecules form multicenter bonds in . On the surface and between two sheets this is limited to the formation of H–Ti bonds. However, H and on interstitial sites form multicenter bonds not only with nearest neighbor Ti atoms but also with carbon atoms. Interestingly, the H–C bonds are characterized by the formation of s–p hybrid orbitals. For molecules, multicenter bond formation is accompanied by an increase of the bond length to 2.07 and 1.85 Å for on the surface and at the interstitial site, respectively. On the other hand, placing between two sheets of leads to dissociation. For all H and complexes the vibrational eigenmodes are calculated. Their frequencies are in the range of 890 to 1610 , which indicates that the bonds are remarkably strong.

Aqueous Phase Reforming of Dairy Wastewater for Hydrogen Production: An Experimental and Energetic Assessment

The treatment of dairy industry effluents poses a significant challenge from the environmental point of view because of its high organic load. In this work, the aqueous phase reforming of lactose was investigated as a representative model compound for the production of renewable hydrogen. The tests were conducted using two different scenarios: the first one is referred to as direct aqueous phase reforming (APR); the second one proposed a pre-hydrogenation step, followed by APR. The implementation of this reactive pretreatment allowed for minimizing the solid by-product formation with respect to the direct APR, where most of the initial carbon ended up as solid residue. The pre-hydrogenation was investigated in the range of 180–220 °C, using Ru-based catalysts. In the best scenario (using 5% Ru/C), the carbon to solid was reduced by 95%, and up to 70% of the initial carbon was converted into gaseous compounds, hence contributing to the removal of the organic content of the wastewater while producing an energy carrier. Moreover, the hydrogen selectivity increased up to 70% (with respect to 2.5% for direct APR), thanks to hindering homogeneous reaction pathways that do not lead to hydrogen production. Finally, an energetic analysis was conducted to assess the possibility of coupling the APR with the dairy industry and quantifying the percentage of energy which may be produced in situ to satisfy industrial duties.

Mid-infrared imaging spectroscopic measurements of C2H4 frost simulating the outer solar system environments

In the dense and cold atmosphere of Titan, the presence of C2H4 haze has been confirmed by the observations of spacecraft. In the present study, original cryogenic experimental equipment was developed to simulate the low-temperature solid formation of C2H4 in combination with in-situ infrared spectroscopic measurements. As a result, out-of-plane bending vibration ν7 of solid-phase C2H4 located at ~ 10.5 μm was successfully detected with high sensitivity, and two-dimensional spectrographs of C2H4 at low temperatures were obtained. The obtained spectra of C2H4 can be fitted to the double Lorentzian function with various heights, central wavelengths, and full widths at half the maximum (FWHM) of the two-component Lorentzian functions. They were classified into three types using the fitting parameters. However, their spectral shapes are different from the amorphous, metastable, and crystalline forms obtained by the previous laboratory experiment in terms of the distance of two peak wavelengths and FWHM. The results may link to understanding the spectral band properties of C2H4 condensation in the haze component of Titan.Graphical

Ever Expanding Morphologic Patterns of Mesonephric-like Adenocarcinomas of the Uterine Corpus: A Report of Two Tumors and a Brief Review of the Literature.

Mesonephric-like adenocarcinoma (MLA) of the endometrium shows a variety of morphologic appearances, including small glands, tubules with eosinophilic materials in the lumen, prominent papillary patterns, spindled cells, solid formations, and corded and hyalinized patterns. Unique morphology, characteristic immunohistochemical staining patterns, molecular alterations, and awareness of the pathologists make it possible to identify this tumor accurately. This report of two additional morphologic patterns, intestinal goblet cells mimicking intestinal-type mucinous carcinoma and squamous differentiation with spindle and epithelioid cells mimicking carcinosarcoma of the endometrium will expand the literature on MLA.

Electrochemical Signatures of Potassium Plating and Stripping

Alkali metal anodes can enable unmatched energy densities in next generation batteries but suffer from insufficient coulombic efficiencies. To deduce details about processes taking place during galvanostatic cycling, voltage profiles are commonly analyzed, however the interpretation is not straightforward as multiple processes can occur simultaneously. Here we provide a route to disentangle and interpret features of the voltage profile in order to build a mechanistic understanding on alkali metal stripping and deposition, by investigating potassium metal deposition as a model case where processes and reactions are exaggerated due to the high reactivity of potassium. In particular, the importance of separating SEI formation and nucleation to correctly estimate the energy barrier for nucleation is demonstrated. Further, we show how the native layer formed on alkali metal foils gives rise to strong features in the voltage profile and propose forming alkali metal electrode through electrodeposition to mitigate these effects.

Dynamic Behavior of Spatially Confined Sn Clusters and Its Application in Highly Efficient Sodium Storage with High Initial Coulombic Efficiency.

Advanced battery electrodes require a cautious design of microscale particles with built-in nanoscale features to exploit the advantages of both micro- and nano-particles relative to their performance attributes. Herein, the dynamic behavior of nanosized Sn clusters and their host pores in carbon nanofiber) during sodiation and desodiation is revealed using a state-of-the-art 3D electron microscopic reconstruction technique. For the first time, the anomalous expansion of Sn clusters after desodiation is observed owing to the aggregation of clusters/single atoms. Pore connectivity is retained despite the anomalous expansion, suggesting inhibition of solid electrolyte interface formation in the sub-2-nm pores. Taking advantage of the built-in nanoconfinement feature, the CNF film with nanometer-sized interconnected pores hosting Sn clusters (≈2nm) enables high utilization (95% at a high rate of 1 A g-1) of Sn active sites while maintaining an improved initial Coulombic efficiency of 87%. The findings provide insights into electrochemical reactions in a confined space and a guiding principle in electrode design for battery applications.

Highly efficient, coke-free electrolysis of dry CO2 in solid oxide electrolysis cells

Dry CO2 electrolysis in solid oxide electrolysis cells (SOECs), a highly efficient, versatile method for converting CO2 into value-added products, is critically limited by carbon deposition on Ni-based fuel electrodes. We achieved efficient, coke-free CO2 electrolysis using SOECs by elaborately controlling the local gas environments. Multilayered electrode microstructures were systematically engineered to facilitate mass transport and maintain the CO partial pressure below the threshold for solid carbon formation. A fuel-electrode-supported cell with an improved electrode microstructure operated stably for 500 h without coking at 0.50 A cm−2 and 700 °C, whereas conventional ones failed immediately. Multiphysics modeling coupled with three-dimensional quantitative microstructural analysis confirmed our improved electrode successfully mitigated carbon deposition. Furthermore, the enhanced electrode substantially lowered the overpotential and increased the CO production rate by > 50 %. These results highlight the feasibility of coke-free dry CO2 electrolysis in SOECs using commercially viable materials by controlling the electrode transport properties.

Ultrasound mechanisms and their effect on solid synthesis and processing: a review.

Ultrasound proves to be an effective technique for intensifying a wide range of processes involving solids and, as such, is often used to improve control over both solids formation and post-treatment stages. The intensifying capabilities of ultrasonic processing are best interpreted in the context of the chemical, transport, and mechanical effects that occur during sonication. This review presents an overview of how ultrasound influences the processing and synthesis of solids across various material classes, contextualized within an ultrasound effect framework. By describing the mechanisms underlying the different effects of ultrasound on the solid synthesis and processing, this review aims to facilitate a deeper understanding of the current literature in the field and to promote more effective utilization of ultrasound technology in solid synthesis and processing.

Unveiling LiTFSI Precipitation as a Key Factor in Solid Electrolyte Interphase Formation in Li‐Based Water‐in‐Salt Electrolytes (Small 4/2024)

Unveiling LiTFSI Precipitation as a Key Factor in Solid Electrolyte Interphase Formation in Li‐Based Water‐in‐Salt Electrolytes (Small 4/2024)

Fatty aldehyde bisulfite adducts as a purification handle in ionizable lipid synthesis.

Rapid access to ALC-0315, a crucial component of the formulated Pfizer Covid vaccine, was obtained by employing solid adduct formation and filtration after an oxidation step in place of the standard chromatographic separation, allowing for a more scalable synthesis. Impurities were removed by formation of this fatty aldehyde bisulfite adduct at the penultimate step and by performing the final reductive amination directly with the fatty aldehyde bisulfite adduct. This eliminates chromatographic separations for all prepared aldehyde containing intermediates. Along with ALC-0315, FTT5 and SM-102 ionizable lipids were prepared utilizing this strategy. This work paves the way for more sustainable access to these critical ionizable lipids that would de-risk the world supply of important vaccines and medicines in the future.

Stabilization of lithium metal in concentrated electrolytes: effects of electrode potential and solid electrolyte interphase formation.

Lithium (Li) metal negative electrodes have attracted wide attention for high-energy-density batteries. However, their low coulombic efficiency (CE) due to parasitic electrolyte reduction has been an alarming concern. Concentrated electrolytes are one of the promising concepts that can stabilize the Li metal/electrolyte interface, thus increasing the CE; however, its mechanism has remained controversial. In this work, we used a combination of LiN(SO2F)2 (LiFSI) and weakly solvating 1,2-diethoxyethane (DEE) as a model electrolyte to study how its liquid structure changes upon increasing salt concentration and how it is linked to the Li plating/stripping CE. Based on previous works, we focused on the Li electrode potential (ELi with reference to the redox potential of ferrocene) and solid-electrolyte-interphase (SEI) formation. Although ELi shows a different trend with DEE compared to conventional 1,2-dimethoxyethane (DME), which is accounted for by different ion-pair states of Li+ and FSI-, the ELi-CE plots overlap for both electrolytes, suggesting that ELi is one of the dominant factors of the CE. On the other hand, the extensive ion pairing results in the upward shift of the FSI- reduction potential, as demonstrated both experimentally and theoretically, which promotes the FSI--derived inorganic SEI. Both ELi and SEI contribute to increasing the Li plating/stripping CE.

Probing Degradation in Lithium Ion Batteries with On-Chip Electrochemistry Mass Spectrometry.

The rapid uptake of lithium ion batteries (LIBs) for large scale electric vehicle and energy storage applications requires a deeper understanding of the degradation mechanisms. Capacity fade is due to the complex interplay between phase transitions, electrolyte decomposition and transition metal dissolution; many of these poorly understood parasitic reactions evolve gases as a side product. Here we present an on-chip electrochemistry mass spectrometry method that enables ultra-sensitive, fully quantified and time resolved detection of volatile species evolving from an operating LIB. The technique's electrochemical performance and mass transport is described by a finite element model and then experimentally used to demonstrate the variety of new insights into LIB performance. We show the versatility of the technique, including (a) observation of oxygen evolving from a LiNiMnCoO2 cathode and (b) the solid electrolyte interphase formation reaction on graphite in a variety of electrolytes, enabling the deconvolution of lithium inventory loss (c) the first direct evidence, by virtue of the improved time resolution of our technique, that carbon dioxide reduction to ethylene takes place in a lithium ion battery. The emerging insight will guide and validate battery lifetime models, as well as inform the design of longer lasting batteries.