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Causticizing precipitated calcium carbonate (CPCC) as a by-product of the green liquor causticizing process can be used as paper filler to save resources and reduce costs. In this study, CPCC was prepared with green liquor and quicklime, which were obtained from an alkali recovery line of a paper mill. The factors influencing crystal morphology of CPCC, such as slaking temperature, slaking time, and causticizing time were investigated. The morphology of CPCC was observed and analyzed for optimizing reaction conditions. The following were compared: properties of CPCC obtained in this study, conventional CPCC (white mud) from a paper mill, and commercial PCC as fillers. The results showed that slaking time and causticizing time were important for morphology control. Spindle-like and rod-like CPCC obtained in this study had better drainability and retention, higher paper bulk, opacity, and physical strength compared to conventional CPCC, and had nearly the same performances as commercial PCC.

Abstract: The fabrication of mica‐based composites with good mechanical properties is very important especially for electrical insulation applications. In this study, a new aramid fibrid along with chopped fibers was introduced into a mica system, and the composites were prepared using a papermaking machine. It was found that the mechanical properties of both fibrid–mica composite (F‐M paper) and fiber/fibrid–mica composite (A‐M paper) were largely improved in comparison with the reference sample (M paper) with an increase in the content of fibrid or hybrid floc/fibrid. This enhancement can be attributed to two mechanisms: (1) enhanced interfacial adhesion derived from the addition of fibrids with good flexibility and wrapping properties and (2) significant reinforcing due to the frameworks originating from the addition of chopped flocs with high modulus and rigid‐rod morphology. Interestingly, a synergetic effect of enhanced interfacial adhesion and reinforcing could also be observed when both flocs and fibrids were introduced, which further improved the mechanical properties. Furthermore, the addition of aramid fibrid greatly enhanced the moisture resistance, which expands the potential for mica‐based composites. Thus, we successfully fabricated a mica‐based composite for electrical insulation with good mechanical properties, high end‐use temperature and excellent moisture resistance by adding hybrid aramid fibers. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In the present study, a C/SiFeN(O)-based ceramic paper with in situ generated hierarchical micro/nano-morphology was prepared upon thermal treatment of a cellulose-base paper surface-modified with a polymeric single-source precursor prepared from perhydropolysilazane (PHPS) and iron(II) acetylacetonate (Fe(acac) 2 ). The ammonolysis at 1000 °C of the paper/precursor hybrid materials leads to a C/SiFeN(O)-based ceramic paper which exhibits the same morphology as that of the cellulose paper. Subsequent annealing of the ceramic paper in nitrogen atmosphere at temperatures from 1200 to 1400 °C results in the in-situ generation of ultra-long silicon nitride nanowires with aspect ratios in the range of 10 3 on the surface and in the macropores of the ceramic paper. The nanowires exhibit round Fe 3 Si tips at the end, indicating that the growth occurred via iron-catalyzed VLS (vapor-liquid-solid) mechanism. The combination of single-source precursor, porous template and in situ VLS growth of 1D nanostructures provides a convenient one-pot synthesis approach to produce ceramic nanocomposites with hierarchical morphologies. [ABSTRACT FROM AUTHOR]

We investigated the filling process of cellulose-based paper with natural clay nanotubes and their mixtures with hydroxypropyl cellulose (HPC) that is commonly used as glue and consolidant for degraded paper. A comprehensive characterization of the materials was carried out through morphology, wettability, thermal degradation, and tensile properties. The treatment with halloysite nanotubes generated a decrease of the paper mechanical performance and did not alter the thermal properties. The co-presence of HPC and nanoparticles generated a more uniform nanotubes distribution in the paper fibrous structure and a significant enhancement of both the mechanical properties and the surface hydrophobicity with respect to the HPC treatment. This work proposes the use of halloysite/HPC mixture in a new protocol for paper consolidation and represents a starting point to develop, with a biocompatible approach, smart composite material in which the nanotube cavity is filled with active species for paper protection or active response to external stimuli. [ABSTRACT FROM AUTHOR]

Tin-based compounds are potential anode materials for high performance lithium-ion batteries (LIBs). Due to the low melting point of metallic Sn, it is hard to maintain the crystal morphology of Sn during the as-follow process of carbon coating for high performance anode. In this work, the core@shell composite of SnO x @carbon (SnO x @C) is successfully fabricated on the substrate of carbon paper (CP) through electrodeposition and carbonization based on the precursor of Sn nanoparticles. A passivation shell is essentially grown onto Sn particles to obtain a stable structure of SnO x @C, otherwise the Sn particles will be pulverized and fell off the substrate of CP during the subsequent process of carbonization. The as-produced CP/SnO x @C film has excellent flexibility and mechanical stability to be directly served as electrode for LIBs. Carbon shell prevents the detachment and agglomeration of the active particles during lithiation/delithiation processes and maintains the stability of the conductive network. After 100th cycles, CP/SnO x @C electrode delivers 0.8 mAh cm −2 , much higher than the capacity 0.37 mAh cm −2 of CP/Sn electrode operated at the current density of 0.1 mA cm −2 . These features enable the flexible film of CP/SnO x @C to be attractive applications in energy storage devices. [ABSTRACT FROM AUTHOR]

This paper presents a discussion of the paper published by Lv et al. in Cement and Concrete Composites, 2016, 66: 1–9. The discussion is mainly focused on whether or not graphene oxide (GO) nanosheets can regulate formation of flower-like cement hydration crystals. Lv et al. in their paper proposed a regulation mechanism stating that GO nanosheets can control ettringite (AFt), monosulfate (AFm) and calcium hydroxide (CH) to form the flower-like and polyhedron crystals, whilst our experimental results show that there might be a possible pitfall in sample preparation for SEM analysis. It is here suggested that the main chemical components of flower-like and polyhedron crystals are calcium carbonates, which are not the products from cement hydration but from carbonation of cementitious hydrates. It is therefore suggested that further study is needed to verify the regulation mechanism of GO on cement hydration crystals proposed by Lv et al. in the discussed paper. [ABSTRACT FROM AUTHOR]

A simple and facile method for the synthesis of paper-based porous gold (PAu) with large surface area using gold nanoparticles (AuNPs) and filter paper is proposed. Morphology of palladium (Pd) deposited on PAu electrode was adjusted with applied potential, and Pd-dendrite/PAu and Pd-dot/PAu were obtained by electrodeposition. The reduction of 4-nitrophenol (4-NP) into 4-aminophenol was chosen as a model reaction and Pd-dendrite/PAu showed high catalytic activity. Even when the reduction potential of 4-NP solution with Pd-dendrite/PAu electrode was applied to the electrode, the reduction rate was enhanced 2.6 times. [ABSTRACT FROM AUTHOR]

Highlights: [•] NiCo2O4 nanowires and nanosheets have been grown on carbon fiber paper by a facile solvothermal route. [•] The solvent plays a key role in control the morphology of NiCo2O4. [•] The nanosheets reveal better pseudocapacitive performances than nanowires. [Copyright &y& Elsevier]

Abstract: Cerium-doped yttrium aluminum garnet phosphors with laminar structure were synthesized by a very simple method using filter paper as the structure template at 1100°C. Three thin plate samples with different morphology were prepared via the different preparation procedures. The crystalline phase, composition, surface morphology and luminescence property of the synthesized samples are investigated by X-ray diffraction, energy dispersive X-ray analysis, scanning electron microscopy, and photoluminescence spectrum. Results indicate that the metal cations are combined with the filter paper templates and are self-assembled on the surface of filter paper. The self-assembly induced the growth of YAG: Ce crystal and the formation of the plate-like YAG: Ce samples. These plate-like bulky grains are composed of YAG: Ce nanoparticles (about 30nm), and they show yellow–green fluorescent emissions. The YAG: Ce with laminar structure facilitates the increase of PL intensity. [Copyright &y& Elsevier]

Crystallization is important to the pharmaceutical, the chemical, and the materials fields, where the morphology of crystals is one of the key factors affecting the quality of crystallization. High-throughput screening based on microfluidic droplets is a potent technique to accelerate the discovery and development of new crystal morphologies with active pharmaceutical ingredients. However, massive crystal morphologies' datum needs to be identified completely and accurately, which is time-consuming and labor-intensive. Therefore, effective morphologies' detection and small-target tracking are essential for high-efficiency experiments. In this paper, a new improved algorithm YOLOv8 (YOLO-PBESW) for detecting indomethacin crystals with different morphologies is proposed. We enhanced its capability in detecting small targets through the integration of a high-resolution feature layer P2, and the adoption of a BiFPN structure. Additionally, in this paper, adding the EMA mechanism before the P2 detection head was implemented to improve network attention towards global features. Furthermore, we utilized SimSPPF to replace SPPF to mitigate computational costs and reduce inference time. Lastly, the CIoU loss function was substituted with WIoUv3 to improve detection performance. The experimental findings indicate that the enhanced YOLOv8 model attained advancements, achieving AP metrics of 93.3%, 77.6%, 80.2%, and 99.5% for crystal wire, crystal rod, crystal sheet, and jelly-like phases, respectively. The model also achieved a precision of 85.2%, a recall of 83.8%, and an F1 score of 84.5%, with a mAP of 87.6%. In terms of computational efficiency, the model's dimensions and operational efficiency are reported as 5.46 MB, and it took 12.89 ms to process each image with a speed of 77.52 FPS. Compared with state-of-the-art lightweight small object detection models such as the FFCA-YOLO series, our proposed YOLO-PBESW model achieved improvements in detecting indomethacin crystal morphologies, particularly for crystal sheets and crystal rods. The model demonstrated AP values that exceeded L-FFCA-YOLO by 7.4% for crystal sheets and 3.9% for crystal rods, while also delivering a superior F1-score. Furthermore, YOLO-PBESW maintained a lower computational complexity, with parameters of only 11.8 GFLOPs and 2.65 M, and achieved a higher FPS. These outcomes collectively demonstrate that our method achieved a balance between precision and computational speed. [ABSTRACT FROM AUTHOR]

A HKUST-1 metal-organic framework membrane was constructed on the high voidage three-dimensional paper-like stainless steel fibers (PSSF) and was applied for the catalytic wet peroxide oxidation (CWPO) of phenol in a structured fixed bed for the first time. The chemical structure, surface areas, thermal stability of the obtained HKUST-1 membrane/PSSF support were characterized by using SEM, XRD, XPS, TGA and FT-IR. The results indicated that the HKUST-1 membrane/PSSF showed an intact morphology with octahedron crystal and a specific surface area of 376.72 m2 g−1, and it was stable in the air before 320 °C. The effects of the temperature, the catalyst bed height, and the feed flow rate on the catalytic performance of the membrane were investigated by monitoring the conversion of phenol, TOC, H 2 O 2 , respectively. Under the optimum condition of 3 cm bed height, 80 °C of catalytic temperature, 2 mL min −1 of the feed flow rate, the conversion of phenol and TOC could reach to 100% and 70%, respectively. The HKUST-1 membrane/PSSF could maintain a phenol conversion of 80% and a TOC conversion of 39% after being used for three times. Image 1 • HKUST-1 membrane was successfully prepared and systematically characterized. • The copper based HKUST-1 membrane/PSSF was firstly used in a fixed bed reactor. • High conversion of phenol (100%) and TOC (70%) were obtained in phenol oxidation. [ABSTRACT FROM AUTHOR]

Epidermal wax is strategically situated at the interface between plants and air; therefore, it plays a key role in plants' interactions with their surroundings. It is also unstable and susceptible to light intensity. Hosta plants are shade-loving herbs with admirable flowers and leaves. Hosta 'Halcyon' and Hosta ensata F. Maek. are two species of Hosta with a glaucous and a glossy appearance, respectively. Light intensity can affect the composition of epicuticular wax on the leaf surface, which influences the leaf color phenotype and ornamental value. In this paper, the crystal micromorphology, content, and components of epicuticular wax on the leaves of two species of Hosta under different light conditions (10%-, 30%-, 50%-, 70%-, and 100%-intensity sunlight, relative light intensity (RLI)) have been studied using pot experiments. The results indicate that the epicuticular wax crystals of H. 'Halcyon' and H. ensata are tubular and platelet-like, respectively. The wax crystals of H. 'Halcyon' melted and formed a thick crust under 100% RLI, and those of H. ensata melted and formed a thick crust under 70% and 100% RLI conditions. The primary ingredients of the epicuticular wax of the two species of Hosta contained primary alcohols, alkanes, fatty acids, and esters; β-diketones were only detected in H. 'Halcyon'. The quantity of epicuticular wax of H. 'Halcyon' reduced at first and then increased with an RLI increase, achieving its lowest value at 50% RLI, but that of H. ensata declined little by little. The amounts of C28 primary alcohols, C31 alkanes, and C18 fatty acids were significantly higher than those of other carbon atoms in the two genotypes of Hosta. The C31β-diketones content decreased with the increase in light intensity, which caused the white frost phenotype to gradually weaken in H. 'Halcyon'. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Synthetic Crystals is the property of Journal of Synthetic Crystals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The non-uniformity of a single crystal can sometimes be found in biominerals, where surrounding biomacromolecules are incorporated into the growing crystals. This unique composite structure, combining heterogeneity and long-range ordering, enables the functionalization of single crystals. Polymer gel media are often used to prepare composite single crystals, in which the growing crystals incorporate gel networks and form a bi-continuous interpenetrating structure without any disruption to single crystallinity. Moreover, dyes and many kinds of nanoparticles can be occluded into single crystals under the guidance of gel incorporation. On this basis, the bio-inspired method has been applied in crystal morphology control, crystal dyeing, mechanical reinforcement, and organic bulk heterojunction-based optoelectronics. In this paper, the composite structure, the incorporation mechanisms, and the multiple functions of gel-incorporated single crystals are reviewed. [ABSTRACT FROM AUTHOR]

In the process of pharmaceutical crystallization, the automatic detection of crystal shapes in images is important since controlling the morphology of the crystals improves the quality of pharmaceutical crystals. In this paper, a novel image detection method called RECDet is proposed. It leverages an automatically adapted binary image to bypass background regions, thereby reducing the detection field. In addition, the method greatly reduces the training time while improving the detection accuracy by using a specially designed detection box for the crystal shape. The performance of our model is evaluated through experimental analysis on a publicly available glutamate crystal dataset and a self-made entecavir pharmaceutical crystal dataset. Experimental results show that RECDet improves the accuracy of prediction bounding boxes by more than 2% compared to other popular models and achieves a classification accuracy of 98%. It can be used as a promising tool in the application of pharmaceutical crystallization control. [ABSTRACT FROM AUTHOR]

In this paper, the influence of process parameters on the morphological properties of fine precipitated hydrate was examined. The research was conducted with the aim of synthesizing fine precipitated aluminum hydroxide from the aluminate solution obtained by the Bayer process. Fine precipitated hydrates obtained in this way are mostly used in the non-metallurgical industry. The synthesized fine precipitated hydrate should comply with certain quality requirements such as granulometry (average particle diameter), purity, specific surface area, whiteness, etc. This paper shows the influence of certain technological parameters, namely the initial precipitation temperature, the amount and specific surface area of the seed, the influence of the NaOH/Al(OH)3 molar ratio on the characteristics of the synthesized fine precipitated hydrate in terms of the specific surface area, mean diameter and morphology of the obtained particles. [ABSTRACT FROM AUTHOR]

This paper proposes a technique for producing underground backfilling materials using enzyme-induced calcium carbonate precipitation (EICP) technology to address the growing ecological security concerns caused by coal mining. To augment the mineralization impact of EICP, diverse levels of organic substances, including yeast extract, peptone, and skimmed milk powder, were incorporated into the cementing solution to offer a greater number of nucleation sites for the precipitation of calcium carbonate. The results indicate that (1) based on visual observations, all the sand columns remained intact after cementation, demonstrating a good cementation effect; (2) unconfined compressive strength (UCS) test findings demonstrated that the introduction of organic components effectively augmented the strength of EICP. Among these materials, skimmed milk powder exhibited the most significant effect, resulting in a 66.01% increase in the UCS of EICP at a concentration of 6 g/L. Peptone also showed a positive impact, albeit to a lesser extent, while yeast powder had a relatively lower effect; (3) The utilization of scanning electron microscopy (SEM) revealed a significant diversification in the crystal morphology of calcium carbonate when combined with organic materials through the EICP process. An X-ray diffraction (XRD) test confirmed the presence of calcite and vaterite. This finding implies that the molecular structure of calcium carbonate is enhanced by the inclusion of organic materials. [ABSTRACT FROM AUTHOR]

This paper describes, for the first time, the application of an Elastodynamic Boundary Element Method (BEM) in Laplace Domain for the Structural Health Monitoring (SHM) of poly-crystalline materials. The study focuses on Ultrasonic Guided Wave (UGW) propagation and investigates the wave–material interactions at micro-scale. The study aims to investigate the interaction of UGWs with assessing micro-structural features such as grain size, morphology, degradation, and flaws. Numerical simulations of the most common micro-structural features demonstrate the accuracy and validity of the proposed method. Particular attention is paid to the study of porosity and its influence on material macro-properties. Different crystal morphologies such as cubic, rhombic, and truncated octahedral are considered. The detection of voids based on the changes in the amplitude and Time of Arrival (ToA) of the backscattered signal is investigated. The study also considers inter-granular cracks, which cause laceration, and examines flaw position/orientation, length, and distance from a specific reference. Furthermore, a framework is proposed for generating Probability of Detection (PoD) curves using numerical simulations. Experimental tests in pristine conditions are shown to be in good agreement with the numerical simulations in terms of ToA, signal amplitude, and wave velocity. The numerical simulations provide insights into wave propagation and wave–material interactions, including different types of defects at the micro-scale. Overall, the BEM and UGW methods are shown to be effective tools for better understanding micro-structural features and their influence on the macro-structural properties of poly-crystalline materials. [ABSTRACT FROM AUTHOR]

NbSe2 nanoparticles, the representative member of the VB TMDCs group, have garnered significant attention due to their unique structural and optical properties, which make them promising candidates for various applications in nanoelectronics and optoelectronics. In this paper, the authors report on the synthesis of NbSe2 nanoparticles via the sonochemical method at ambient temperature with controlled size, well-defined crystal structure, and desirable optical properties. The investigation of the compositional and structural analysis revealed that the synthesized nanoparticles are well-defined, near stoichiometry, with a hexagonal crystal structure belonging to the space group P63mmc. The other morphological and optical characteristics of the synthesized nanoparticles studied through scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), UV-VIS NIR spectroscopy, etc., were discussed here. [ABSTRACT FROM AUTHOR]

Recent advances in nucleation and crystal growth have revolutionized our understanding and control of crystallization processes. This paper highlights key developments in this field and the processes and technologies involved in its continuous growth. Advanced computational models have allowed for precise prediction of nucleation rates and crystal morphologies, facilitating the rational design of materials with desired properties. Innovative strategies have also emerged, enabling enhanced control over crystal growth kinetics and crystallographic orientations. Process intensification strategies, including microreactors and membrane crystallization, enhance nucleation rates and crystal growth. Advances in the potential-driven growth of metal crystals from ionic liquids, including protic ionic liquids (PILs) and solvate ionic liquids (SILs), are discussed. Lastly, current research gaps and future prospects in the field of nucleation and crystal formation are highlighted. The integration of cutting-edge experimental techniques, computational modeling, and novel strategies will drive the understanding of nucleation and crystal growth processes, allowing for the development of materials with tailored properties and enhanced functionality across multiple disciplines. [ABSTRACT FROM AUTHOR]

Enzyme-induced carbonate precipitation (EICP) is an emerging and environment-friendly geotechnical technique for soil improvement. Despite the extensive amount of previous studies focusing on the mechanical properties of biocemented samples with varying calcium carbonate content, less is known about the cementitious property of calcium carbonate crystals generated in the EICP process. This paper presents a systematic study on the effect of cementation solution concentration (CCS) on cementitious property of calcium carbonate crystals. Solution tests were conducted to ascertain the dominant factor causing the retarding effect of CCS. Glass slide tests and ultrasonic oscillation tests were performed to evaluate the cementitious property of calcium carbonate crystal. The results of solution tests indicated that the higher CCS would affect calcium carbonate production and calcium conversion efficiency, which is mainly caused by the concentration of CaCl2 rather than urea. The increase in CCS will cause calcium conversion efficiency to decrease significantly, and calcium carbonate production will also decrease once CCS exceeds a threshold value. The higher CCS contributes to formation of larger calcium carbonate crystals and has little effect on the morphological characteristics of the crystal. Glass slide tests showed that mineral composition is controlled by the CCS of EICP solution. Increasing the CCS results in the increased vaterite content, which affects the cementitious property of calcium carbonate crystal, especially for CCS is higher than 1.0 M. The results are expected to help identify the retarding effect of CCS and to provide a reference for optimizing the cementitious property of calcium carbonate crystals. [ABSTRACT FROM AUTHOR]

This paper provides a detailed technological characterization of the Roman opus sectile glasses (second century AD) coming from the renowned Gorga collection. Nine glass samples corresponding to imitations of the porfido verde antico, cipollino rosso, rosso antico, giallo antico, diaspro nero e giallo, semesanto and agate/alabaster stones were studied. The aim of this study was twofold: (i) archaeometric, i.e., to provide valuable data on the production, raw materials and techniques of these refined Roman glasses that mimic precious stones and (ii) methodological, i.e., to highlight the good performance of combining polished thin sections and local probe measurements for the study of glassy microstructures. Based on the nature of the flux used, the glasses from the samples were classified as either natron-type or mixed-type (natron/plant ash). The latter stem from remelted glasses and contain relict grains of wollastonite that were not found in the pure natron samples. Relict wollastonite crystals appear to be a proficient petrographic marker to spot recycled glasses along with the commonly used chemical fingerprints. Different production and colouring techniques were identified, even for a given type of imitated stone. Metallic Cu, Ca antimonates and Pb-Fe antimonates were the three opacifiers used for the opaque glasses. Based on the crystal morphologies, metallic Cu and Ca antimoniates were possibly synthesized in situ simultaneously with the glass, whilst the Pb-Fe antimonates were prepared ex situ. The working temperatures for these glasses were estimated within the 900–1100 °C range based on the presence and known thermal stability of some identified crystal phases. [ABSTRACT FROM AUTHOR]

The conventional solid-phase sintering method for the preparation of Ln 2 Ti 2 O 7 ceramics using oxides as reactants generally requires higher temperature, larger pressure, and greater energy consumption. In this paper, we synthesize a Eu 2 Ti 2 O 7 ceramic powder in relatively low-temperature molten salt (KCl–NaCl) using Eu 2 O 3 powder and TiO 2 powder as reactants at 1000 °C. The results of XRD, SEM, and element mapping indicate that the product have high phase purity, good crystal morphology and uniform chemical composition. Moreover, Eu 2 Ti 2 O 7 -based glass-ceramics are obtained by sintering with different contents of borosilicate glass. The SEM images of glass-ceramic show that almost no obvious defects or voids are found on the surface of the samples. The values of water absorption for all glass-ceramic waste forms are less than 0.5 %. With the increase of ceramic embedding rate, the hardness of the glass-ceramics first increases and then decreases, while the density gradually increases. When the embedding rate increased to 30 wt%, the hardness of glass-ceramic reaches a maximum of 19.53 GPa. The glass-ceramic waste form embedded with 30 wt% Eu 2 Ti 2 O 7 exhibits very stable chemical durability with a low leaching rate of 1.42 × 10−8 g m−2 d−1 at 90 °C even after 28 days. [ABSTRACT FROM AUTHOR]

The cation exchange reaction is a powerful method for generating nanomaterials with unique structures because of the easy control of the size, morphology, composition, and crystal structure of the nanoparticles. This study investigated the kinetically controlled morphology and composition of colloidal nanoparticles (NPs) through cation exchange reactions, specifically focusing on variations from copper sulfide to transition metal sulfides, including Co, Fe, Zn, and Mn sulfides. In the cation exchange reaction, Co exhibited the fastest exchange rate, followed by Fe,Mn, and Zn. The difference in kinetics rates affected the change in morphology; Co, with the fastest rate, was immediately and uniformly distributed in the NPs. For Fe, a sandwich structure was initially formed and this gradually transformed into a solid-solution phase. After exchanging Cu with Mn and Zn, a heterostructure was formed, which became increasingly clear as the reaction progressed. The transformation of the morphology and crystal structure were confirmed using XRD, TEM, and SEM analyses. The findings of this study suggest that the morphology and distinct structures of the exchanged particles can be controlled by manipulating the kinetics rates of cations through cation exchange reactions. This process offers a powerful tool for the tailored synthesis of colloidal nanoparticles and provides a design principle for enabling predictable outcomes through cation exchange reactions. [ABSTRACT FROM AUTHOR]

In this manuscript, a simple one-pot heat-up method has been used to prepare multi-component copper-tin-sulfur nanomaterials, including binary Cu1.94S, ternary Cu4SnS4, and Cu1.94S/Cu4SnS4 nanocrystals by varying the reaction temperature, reaction time, and the type of copper source. Post-synthetic ligand exchange (LE) has further been introduced to replace the long-chain ligands originating from 1-dodecanethiol. It has been found that the LE process not only changes the surface ligands but also significantly affects the crystal structure and optical properties of nanocrystals. After LE, the crystal structures of Cu1.94S and Cu4SnS4 transformed to Cu7S4 and Cu3SnS4, respectively, with the Cu1.94S/Cu4SnS4 nanocrystals showing the same trend. This phenomenon could be ascribed to the loss of Cu+ originating from the strong complexation of Cu+ and ammonia with the formation of [Cu(NH3)n]2+ ions under aerobic conditions. Proton nuclear magnetic resonance (1H NMR) has been used to characterize the ligands on the surface before and after LE, which further demonstrated that the -SH was replaced during LE. Meanwhile, the band gaps of the obtained nanocrystals after LE show an obvious shift in the near-infrared region due to the evolution of crystal structures. This study will provide useful guidance for the LE of nanocrystals and the application of copper-based sulfide nanomaterials in optoelectronics and other fields. [ABSTRACT FROM AUTHOR]

Highlights In this paper, the reasons for the improved wear resistance of irradiation‐modified Polytetrafluoroethylene (RM‐PTFE) and its composites above the melting point were investigated from the microcrystalline point of view by using methods such as crystallization kinetics, and it was found that the linear wear rate of RM‐PTFE was only 0.3 um/km, with a 1000 times increase in wear resistance, which was due to the transformation of its crystals from flake crystals that were easily dislodged to spherical crystals that were more resistant to abrasion. It was also found that the linear wear rate of Polytetrafluoroethylene (PTFE) with coke and graphite was 0.2 and 0.1 μm/km, respectively, and the abrasion resistance was further improved, which was attributed to the lowering of spherical crystal grain size by coke and graphite, which had better mechanical properties. These studies lay the foundation for future research on the frictional wear mechanism of RM‐PTFE above the melting point. Irradiation‐modified PTFE above the melting point Wear resistance of PTFE increases 1000 times Changes in crystal morphology dramatically increase wear resistance Use of crystallization kinetics to study the crystalline form of PTFE Small grain size improves wear resistance [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is currently the largest volume of production and application of synthetic biodegradable polymer via bio-derived materials. However, the relaxation characteristics and very low crystallization rate determined by the hand- structure of PLA chains result in low heat-resistance temperature and troublesome demold behavior for fast extrusion and/ or injection molding process. It is well known, by introducing of nucleating agent and crystal growing accelerator, the crystallization properties of PLA materials can be improved efficiently. In the paper, the isothermal crystallization behaviors of PLA, which include the rate and temperature of crystallization, crystallinity, crystals morphologies, were systemically shown. Meanwhile, a serious of regulation strategies of isothermal crystallization kinetics of PLA materials, such as adding of biodegradable polymers, different dimension of fillers, various chain-reconstruct for PLA, processing flow fields and post-treatment, were comprehensively summarized. Additionally, the regularity strategies and next study points for PLA isothermal crystallization behavior were also presented. [ABSTRACT FROM AUTHOR]

Silica-rich Y (FAU topology) and EMC-2 (EMT topology) zeolites have been obtained in the presence of the tetraethylammonium (TEA+) cation as a structure-directing molecule and the corresponding protonic zeolites as seeds. In the presence of USY seeds, Y zeolites were fully crystallized after a few hours at 130 °C but they were unstable and rapidly converted into chabazite, a zeolite with CHA topology. Their stability could nonetheless be greatly improved by decreasing the temperature to 110 °C without significantly modifying the morphology of the crystals and the composition of the framework. Framework SiO2/Al2O3 ratios up to 13 could be obtained, which is the highest value ever reported for Y zeolites synthesized with TEA+ cations as the sole organic molecule. The use of H-EMC-2 as seeds generally led to FAU–EMT intergrowths in which the relative proportion of EMT depended on the composition of the seeds. However, a pure EMT zeolite could be obtained under specific conditions. With a framework SiO2/Al2O3 ratio of 11.2, it constitutes the first example of Si-rich EMT obtained in the absence of crown ether from conventional silica and alumina sources. [ABSTRACT FROM AUTHOR]

Context: Ammonium perchlorate (NH4ClO4, abbreviated as AP) has the advantages of high oxygen content, high density, and good compatibility, and has significant application prospects in the field of energetic materials. The crystal morphology has a great influence on the properties and sensibility of energetic materials, and a single experimental means is difficult in exploring the crystals; therefore, the crystal morphology of AP is investigated using molecular dynamics simulation complemented with experiments, to theoretically analyze the differences in AP crystal habit and the interactions between solvent molecules and the main growing crystal surfaces of AP. The results show that AP crystal is mainly composed of five independent crystal surfaces (0 0 1), (0 1 0), (1 0 0), (1 0 1), and (1 0 −1) in vacuum using the BFDH laws, with (0 0 1) surface being the main growth crystal surface. In contrast, in H2O solvent, the (1 0 1) and (1 0 −1) surfaces disappear, and the AP mainly consists of (0 0 1), (0 1 0), and (1 0 0) surfaces with a rectangular shape. The crystal morphology obtained from theoretical prediction is in good agreement with that obtained from experimental culture. This paper can provide a new idea for the cultivation and preparation of AP large crystals, and promote the application of AP crystals in energetic materials. Methods: The crystal morphologies of AP in vacuum and H2O solvent under Dreiding force field were predicted based on attachment energy model by using molecular dynamics method in Materials Studio 2019 software. The entire molecular dynamics simulation was carried out under the NTV system, the temperature control method was selected as Anderson, and the system temperature was set to 298 K. The simulation time was set to 40 ps, the step size was set to 1 fs, and the data were outputted every 5000 steps. [ABSTRACT FROM AUTHOR]

Oiling‐out is a common phenomenon in industrial crystallization processes that not only prolongs the total operating time but also leads to undesirable crystal morphology, making it challenging to control crystallization paths. This review provides a comprehensive overview of the oiling‐out phenomenon in organic small molecule crystallization. First, the formation mechanisms of oiling‐out are summarized from both thermodynamic and dynamic perspectives, providing the theoretical foundation for understanding the phenomenon. Then, the universal characterization methods for studying the oiling‐out phenomenon of organic small molecules are introduced in detail, covering both offline and online analytical tools. Moreover, the regulation strategy for oiling‐out, including solvents, impurities, seeding, temperature, and mixing methods are discussed. This paper also focuses on the application of oiling‐out in co‐assembly and crystal shape modulation. Finally, future opportunities and challenges are presented to address the current shortcomings and application bottlenecks in the study of organic small molecule oiling‐out phenomena. This review aims to provide valuable insights and guidance for researchers working on the crystallization of organic small molecules, particularly in the pharmaceutical industry, to better understand, control, and utilize the oiling‐out phenomenon. [ABSTRACT FROM AUTHOR]

Context: Ammonium perchlorate (NH4ClO4, abbreviated as AP) has the advantages of high oxygen content, high density, and good compatibility, and has significant application prospects in the field of energetic materials. The crystal morphology has a great influence on the properties and sensibility of energetic materials, and a single experimental means is difficult in exploring the crystals; therefore, the crystal morphology of AP is investigated using molecular dynamics simulation complemented with experiments, to theoretically analyze the differences in AP crystal habit and the interactions between solvent molecules and the main growing crystal surfaces of AP. The results show that AP crystal is mainly composed of five independent crystal surfaces (0 0 1), (0 1 0), (1 0 0), (1 0 1), and (1 0 −1) in vacuum using the BFDH laws, with (0 0 1) surface being the main growth crystal surface. In contrast, in H2O solvent, the (1 0 1) and (1 0 −1) surfaces disappear, and the AP mainly consists of (0 0 1), (0 1 0), and (1 0 0) surfaces with a rectangular shape. The crystal morphology obtained from theoretical prediction is in good agreement with that obtained from experimental culture. This paper can provide a new idea for the cultivation and preparation of AP large crystals, and promote the application of AP crystals in energetic materials. Methods: The crystal morphologies of AP in vacuum and H2O solvent under Dreiding force field were predicted based on attachment energy model by using molecular dynamics method in Materials Studio 2019 software. The entire molecular dynamics simulation was carried out under the NTV system, the temperature control method was selected as Anderson, and the system temperature was set to 298 K. The simulation time was set to 40 ps, the step size was set to 1 fs, and the data were outputted every 5000 steps. [ABSTRACT FROM AUTHOR]

In this work, the effect of catalyst viscosity on diamond growth was studied by simulating and analyzing the catalyst convection field in a diamond synthesis chamber in different viscous catalyst systems. The results showed that the low-viscosity catalyst had a high convection velocity, fast carbon flow, and large crystal growth volume, but it easily produced defects during long growth times. The convection velocity in the high-viscosity catalyst was slow, the precipitation rate of carbon was moderate, and the crystal quality was good. It is suitable for growing high-quality large-sized diamond single crystals. The structural properties of the synthesized samples were characterized by optical microscopy and Raman spectroscopy. The synthesis experiment and simulation results were consistent. In this experiment, a new viscosity concept is proposed to control the quality of diamond crystals, in which the crystal morphology is controlled by adjusting the flow field in the catalyst. This is not limited to controlling the synthesis of crystals with different morphologies by changing the temperature gradient in the diamond synthesis chamber. Therefore, this paper establishes the characteristics of a convection field suitable for the growth of diamond crystals using different viscous catalysts and provides an important theoretical reference for cavity optimization and the design of flow fields for new catalysts. [ABSTRACT FROM AUTHOR]

Nanocrystals of VO2(B) have attracted significant attention for their promising performance in electrochemical energy storage applications. Phase-purity and nanocrystal morphology are both crucial factors for the performance of these materials, but given the large number of crystal polymorphs available to VO2, achieving simultaneous control over crystal phase and nanocrystal size is a significant synthetic challenge. This paper describes the impact of water concentration on the synthesis of VO2(B) nanocrystals via solvothermal reaction of a molecular V(IV) precursor in toluene. Using controlled, stoichiometric amounts of water (20 equivalents per vanadium centre) enables access to short nanorods of VO2(B) whose lengths follow a Gaussian distribution with an average and standard deviation of 110 ± 30 nm. Decreasing the amount of water present to two or four equivalents results in formation of VO2(A) nanocrystals and eliminating it entirely results in no reaction. Increasing the amount of water to more than 20 equivalents increases the average length of the VO2(B) nanorods and causes the distribution in rod lengths to evolve from Gaussian to lognormal. This evolution in the size distribution is consistent with changes in a model Gaussian distribution observed upon simulated end-to-end oriented attachment events. These results demonstrate that control over the concentration of water is a useful strategy for tuning the morphology and crystal phase of VO2 nanocrystals. [ABSTRACT FROM AUTHOR]

The increasing demand for cost-efficient, high-quality machined products has led to a requirement for cutting tools that are able to provide a long tool life even when operating under extreme cutting conditions. Hard thin-film coatings deposited on tool substrates have been at the forefront of dealing with such demands. Such coatings provide cutting tools with properties like increased hardness, wear resistance, oxidation resistance, resistance to thermo-mechanical shocks, lower friction coefficient, etc. Vapour deposition techniques are widely used to deposit these thin films. Any variation in process parameters during deposition affects the properties of a coating and hence is a crucial factor to be considered. This review paper discusses some of the commercially used deposition methods, their effects on the crystal morphology, and the thermal and mechanical properties obtained in these coatings. Finally, this paper will also cover some of the recent advancements in hybrid coating technology, nanostructured coatings, and the prospects of sustainable machining. [ABSTRACT FROM AUTHOR]

In era of modern technology, light-weight, flexible, low-cost and environmentally safe substrates/electrodes are highly feasible for application in disposable electronics and energy storage devices. This study presents morphological and dielectric characteristics of naked and polyaniline (PANI) coated lignocelluloses fibers, directly collected from self-growing plant, Typha Angustifolia. Impedance spectroscopy measurements performed in frequency range from 0.1 Hz to 10 MHz revealed increase of six orders magnitude in conductive properties of lignocelluloses fibers coated with polyaniline. Dielectric constant of polyaniline coated lignocelluloses fibers also increased by three to five orders magnitude and revealed weak frequency dependence. Presented morphological and dielectric investigations of directly collected and PANI coated lignocelluloses fibers will open possibilities to develop facile, low-cost, flexible and environment friendly paper substrates for energy storage and disposable electronic applications. [ABSTRACT FROM AUTHOR]

We consider the interfacial growth morphologies of crystals growing in contact in crystal mushes, with a specific application to those formed by the solidification of basaltic magma. We focus on the particular case of an augite (pyroxene) crystal growing between two plagioclase crystals. The augite is treated as an equant unfaceted crystal, whereas the plagioclase is faceted, and our treatment applies generally to such combinations. The resulting three-grain junctions in natural rock samples are commonly of two distinct types. In one, the two augite–plagioclase interfaces grow towards each other with opposite curvatures, whereas in the second the curvatures of the interfaces have the same sign, giving a distinctive morphology which we have called an eagle's beak. This paper provides a theoretical framework to provide explanations for both of these morphologies, based on the kinetics of interfacial growth. [ABSTRACT FROM AUTHOR]