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Localized corrosion sometimes brings about unanticipated and catastrophic damages in petrochemical pipelines and pressure vessels. For localized corrosion modeling, multicomponent reactive transport and corrosion morphology evolution are two arduous problems that involve multi–physical‐(electro) chemical processes along with multi–temporal and spatial scales. In this study, the lattice Boltzmann method (LBM) is employed to shed some light on the evolution of localized corrosion on a heterogeneous surface focusing on the effects of electrolyte ohmic resistance and diffusion. The corrosion pit is always initiated at the junction of anode and cathode sites; however, quite different morphologies are prompted under ohmic control or ohmic‐diffusion control. Under ohmic control, the pit propagates along the interface of the anode and cathode. Under ohmic‐diffusion control, the pathway of reactive species is broadened, and the corrosion morphology is developed into a more regular shape, like a flattened semicircle in 2‐D modeling. This work presents the huge potential of LBM in long‐term corrosion modeling. [ABSTRACT FROM AUTHOR]

Although the layer‐by‐layer (LBL) processing can usually achieve an optimal bulk‐heterojunction morphology for high‐performance Organic photovoltaics (OPVs), the unambiguous working principles governing the morphology evolution are still lacking. To address this issue, here the phase‐separation kinetics of LBL processing are comprehensively studied using in situ spectroscopies, which are very sensitive to the intermolecular interactions, e.g. the molecular packing and D:A phase‐separation. Upon casting the nonfullerene acceptor (i.e., the BTP‐eC9) solution on top of the polymer donor, i.e., PM6, it is found that 1) the solvent will first swell the polymer and induce a polymer gel, 2) following the polymer gelation, the NFAs will immediately permeate into the cavities of polymer gel and form a molecular‐level D:A mixing, and 3) with the evaporation of the solvent, phase‐separation between the donor and acceptor occurs and results in a bulk‐heterojunction morphology as those achieved with blend‐cast processing. With these understandings, more diverse processing conditions have been purposely utilized to dictate the phase evolution process precisely. As a result, a high efficiency of 19.7% is reached, representing one of the best among binary OPVs. Therefore, this work deciphers phase‐separation kinetics of LBL processing and should pave the way toward advanced morphology control for high‐performance OPVs. [ABSTRACT FROM AUTHOR]

Despite extensive studies of deposited carbon in Fischer–Tropsch synthesis (FTS), an atomic-level comprehension of the effect of carbon on the morphology of cobalt-based FTS catalysts remains elusive. The adsorption configurations of carbon atoms on different crystal facets of hexagonal close-packed (hcp) Co nanoparticles were studied using density functional theory (DFT) calculations to explore the interaction mechanism between C and Co surfaces. The weaker adsorption strength of C atoms on Co(0001), Co(10-10), and Co(11-20) surfaces accounted for lower diffusion energy, leading to the facile formation of C dimers. Electronic property analysis shows that more electrons are transferred from Co surfaces to C atoms on corrugated facets than on flat facets. The deposition of carbon atoms on Co nanoparticles affects surface energy by forming strong Co-C bonds, which causes the system to reach a more energetically favorable morphology with an increased proportion of exposed Co(10-12) and Co(11-20) areas as the carbon content increases slightly. This transformation in morphology implies that C deposition plays a crucial role in determining the facet proportion and stability of exposed Co surfaces, contributing to the optimization of cobalt-based catalysts with improved performance. [ABSTRACT FROM AUTHOR]

This work systematically investigated the coarsening, dissolution, and morphological evolution behavior of γ′ precipitates in GH4742 superalloy through carefully designed heat treatment experiments. During long-term aging processes at 650 °C, 750 °C, and 850 °C, the coarsening model of γ′ precipitates followed the classic function of r3 vs. t, consistent with the classical Lifshitz-Slyozov-Wagner (LSW) coarsening model (diffusion-controlled). Due to higher diffusion coefficients of γ′ forming elements at higher temperatures, the coarsening rate K increased with aging temperature. The dynamical models for the dissolution of primary γ′ precipitates were established during sub-solvus (1080 °C) and super-solvus (1120 °C) heat treatment processes. The results indicated rapid dissolution of primary γ′ precipitates in the initial stages of solution heat treatment, with the dissolution rate gradually decreasing as the treatment time extended, approaching the γ′ precipitate size at thermodynamic equilibrium. During subsequent slow cooling at 14 °C/min after super-solvus (1120 °C) heat treatment, irregular-shaped γ′ precipitates formed through “aggregation” of adjacent γ′ precipitates, followed by “splitting” into smaller γ′ precipitates during growing up. Conversely, during subsequent slow cooling at 14 °C/min after sub-solvus (1080 °C) heat treatment, irregular-shaped γ′ precipitates were mainly controlled by unstable growth and “splitting” of cubic-shaped γ′ precipitates. For individual γ′ precipitates, the portion undergoing unstable growth (protrusions) did not undergo further splitting.

A phase-field model combined with CALPHAD thermodynamic database was employed to investigate the microstructure evolution of δ-hydride in Zr alloys during isothermal aging. The results showed that under the elastic strain energy, a small δ-hydride forms a plate-like structure which deviates from the (0001)α base plane 39°. With the δ-hydride growth, the competition between elastic strain energy and interfacial energy gradually reaches a balance. The tilt angle between δ-hydride and the basal plane decreases to ∼15°, which is consistent with experimental results. As the hydrogen content increases, the volume fraction and number density of the δ-hydrides increase, while their size decrease. Increasing temperature results in a decrease in volume fraction and number density of the δ-hydrides, but an increase in their size. As the shear stress around the δ-hydride increases, the hydrogen-depleted region gradually expands from the tips of δ-hydride to the surrounding of the entire δ-hydride. The elastic interaction energy between different δ-hydride variants is the main factor leading to the formation of different stacking structures and coarsening structures in the experimental results.

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A high Fe content easily produces Fe-rich phases with a harmful morphology, resulting in a huge detrimental effect on the properties and recycling ability of Al-Si alloys. Therefore, finding ways to effectively transform Fe-rich phases to form a beneficial phase or shape is of great significance. Accordingly, Al-Si-based alloys with Fe contents ranging from 0.1 wt.% to 2.0 wt.% were modified by different Mn additions. Moreover, experiments combined with simulations were utilized to comprehensively analyze the mechanism of Mn on the morphology and microstructural evolution of Fe-rich phases from different perspectives. The current findings determine that adding different Fe contents changes the phase-transition reactions in alloys. Without Mn, and by increasing the Fe content from 0.1 wt.% to 2.0 wt.%, the Fe-rich phases gradually convert from a skeleton-shaped α-Al8Fe2Si (<0.25 wt.%) to β-Al9Fe2Si2 with a fibrous (0.5 wt.%), needle-like (1.0 wt.%) and plate-like shape without curvatures (2.0 wt.%). The maximum length and mean aspect ratio increase from 12.01 μm to 655.66 μm and from 1.96 to 84.05, while the mean curvature decreases from 8.66 × 10−2 μm−1 to 8.25 × 10−4 μm−1. The addition of 0.35 wt.% Mn promotes a new Chinese-character and petal-shaped α-Al15(FeMn)3Si2, with an atomic ratio of Fe and Mn of 1:1 when the Fe content is lower than 0.5 wt.%, while it transforms to β-Al15(FeMn)3Si2 with an atomic ratio of 5:1, presenting as a refined plate-like shape with a certain curvature, as the Fe content increases to 2.0 wt.%. Mn alters the phase reactions and increases the threshold of the Fe content required for β-Al15(FeMn)3Si2, limiting the formation and growth of them simultaneously in time and space. The enrichment of Mn atoms and solute diffusion at the growth front of β-Al15(FeMn)3Si2, as well as the strong atomic-binding ability, can deflect the growth direction of β-Al15(FeMn)3Si2 for it to have a certain curvature. Additionally, the enriched Mn atoms easily form α-Al15(FeMn)3Si2 and cause the long β-Al15(FeMn)3Si2 to be broken and refined to further reduce the damages caused to the alloy's performance. Ultimately, the maximum length and mean aspect ratio can be effectively reduced to 46.2% and 42.0%, respectively, while the mean curvature can be noticeably increased by 3.27 times with the addition of Mn. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) is chemically modified with maleic anhydride (MAH) and cross-linked with zinc oxide at different concentrations by melt mixing. The grafting process is conducted at two different temperatures, 150 °C and 180 °C. Using relatively high concentrations of initiator a grafting degree sufficient for cross-linking is achieved. FTIR spectroscopy confirms that a lower processing temperature leads to a significantly higher grafting efficiency. The concentration of stearic acid influences the neutralization degree of the cyclic anhydride grafts significantly, and, therefore, a mechanism has been proposed to explain this behaviour. The DSC thermograms of the grafted samples reveal secondary melting points at lower temperatures attributable to the interactions between the polar grafts. Samples grafted at the lower processing temperature undergo long-chain branching and exhibit complex thermal behaviour. Rheological analysis shows that ionic cross-linking has improved the melt properties; the analysis also reveals the formation of a dual-phase morphology developed with cross-linking and supports the proposed mechanism. Dynamic-mechanical thermal analysis proves the mechanical stability at elevated temperatures and reveals the cross-linked samples' ion-hopping temperatures. Tensile testing is also performed to evaluate the mechanical properties of cross-linked samples. [ABSTRACT FROM AUTHOR]

In the present work, the modification effect of Te and the corresponding growth process of Mg2Si were clarified. With 0.5 wt% Te addition, the dendritic primary Mg2Si transformed to polygons, accompanied by a reduction in size from over ∼165 μm–∼18 μm. However, 2.0 wt% Te addition resulted in degradation of modification effect, and the morphology of Mg2Si changed to dendrite. Three-dimensional morphology of primary Mg2Si indicated that Te altered the morphology of primary Mg2Si from dendrites to polyhedrons surrounded by {111} and {100}. The modification mechanism of Te can be attributed to the heterogeneous nucleation and the doping of Te during the growth process of primary Mg2Si, which greatly contributed to dimension decrease and morphology evolution of primary Mg2Si respectively. With Te corporation, the relative surface energy between the {100} and {111} (r) drops, contributing to the exposure of {100}. Our work shows that the solute concentration under non-equilibrium solidification plays an important role in determining the final morphology of Mg2Si. The local segregation of Mg and Si solutes results in the degradation of dendrite arms along certain directions during the initial stage of crystal growth. Combined with the modifying effect of Te, which alters the surface energy of the crystal, the final crystal morphology deviates from its equilibrium state. Our study demonstrates that ultimate morphology and dimensions of primary Mg2Si can be determined simultaneously with the addition of certain modifiers, which can be achieved by regulating the growth and nucleation of Mg2Si at the same time.

A facile, one-step nitridation–decomposition method was developed for the synthesis of nanosized tungsten powder with a high surface area. This approach involved the nitridation of WO3 in NH3 to form mesoporous tungsten nitride (W2N), followed by in situ decomposition of W2N to directly yield single-phase W particles. The phase and morphology evolution during the synthesis were systematically investigated and compared with the carbothermal reduction of WO3. It was revealed that powdered tungsten product with single-phase particles was obtained after nitridation at 800 °C combined with in situ decomposition at 1000 °C, displaying an average particle size of 15 nm and a large specific surface area of 6.52 m2/g. Furthermore, the proposed method avoided the limitations associated with intermediate phase formation and coarsening observed in carbothermal reduction, which resulted in the growth of W particles up to ~4.4 μm in size. This work demonstrates the potential of the nitridation–decomposition approach for the scalable and efficient synthesis of high-quality, fine-grained tungsten powder.

Hydroxyapatite (HAp) nanoparticles organically modified with citrate group are fabricated via a simple wet chemical precipitation method. The as-synthesized nanoparticles are structurally characterized by TEM, XRD, FT-IR, EDAX and dynamic light scattering (DLS) to investigate in detail the influence of surface coating ligand i.e. citrate on HAp morphology, crystal structure, phase and colloidal stability of the particles. Production of single phase with hexagonal crystal structure is evident by XRD analysis. The work shows mesoporous structure could be synthesized under the influence of citrate as confirmed by TEM image and N2 adsorption−desorption isotherm. The experimental results indicate that citrate strongly influences HAp crystallization giving reduced particle size and uniform distribution. BET and BJH analysis indicate large surface area 135.74 m2/g and pore diameter of 9.86 nm with a total pore volume of 0.41 cm3/g respectively for 1 : 1 citrate to calcium ion molar ratio. The appropriate surface area and pore entrance significantly indicate potentiality to apply into biomedical fields as drug loading/delivery application. [ABSTRACT FROM AUTHOR]

A facile, one-step nitridation–decomposition method was developed for the synthesis of nanosized tungsten powder with a high surface area. This approach involved the nitridation of WO3 in NH3 to form mesoporous tungsten nitride (W2N), followed by in situ decomposition of W2N to directly yield single-phase W particles. The phase and morphology evolution during the synthesis were systematically investigated and compared with the carbothermal reduction of WO3. It was revealed that powdered tungsten product with single-phase particles was obtained after nitridation at 800 °C combined with in situ decomposition at 1000 °C, displaying an average particle size of 15 nm and a large specific surface area of 6.52 m2/g. Furthermore, the proposed method avoided the limitations associated with intermediate phase formation and coarsening observed in carbothermal reduction, which resulted in the growth of W particles up to ~4.4 μm in size. This work demonstrates the potential of the nitridation–decomposition approach for the scalable and efficient synthesis of high-quality, fine-grained tungsten powder. [ABSTRACT FROM AUTHOR]

The complex thermo-fluid dynamics of the molten pool determine the dimension accuracy and mechanical properties of laser directed energy deposition (L-DED) components. In this work, a three-dimensional (3D) multiphase computational fluid dynamics (CFD) model based on the Volume of Fluid (VOF) method was proposed to establish the relationship between the thermo-fluid dynamics and the molten pool morphology evolution of René N5 nickel-based superalloy in L-DED. The single-track and ten-layer deposition processes under unidirectional and bidirectional scanning strategies were studied. Results show that the predicted deposition morphology and dimensions are in good agreement with the experimental samples. The heat accumulation in the multilayer deposition process increases the size of the molten pool, thereby increasing the width of the deposit. Different from the single-layer deposition driven by the Marangoni force, gravity is the key factor in the multilayer deposition process without the side support. The hump structure at the starting position under unidirectional scanning is attributed to the backward flow of the melt of the molten pool, while the decline structure at the end position is enhanced by the forward flow of the melt. At the starting position of each layer under bidirectional scanning, the expansion of the molten pool resulted from the heat accumulation and mass addition increases the width of the two ends and compensates for the deposition height. This work can provide a theoretical basis for understanding the uneven morphology characteristics and the dimensional accuracy control in L-DED.

The reactive molecular dynamics method was employed to examine the thermal decomposition process of aluminized hydride (AlH3) containing explosive nanoparticles with a core–shell structure under high temperature. The core was composed of the explosives RDX, HMX, and CL-20, while the shell was composed of AlH3. It was demonstrated that the CL-20@AlH3 NPs decomposed at a faster rate than the other NPs, and elevated temperatures could accelerate the initial decomposition of the explosive molecules. The incorporation of aluminized hydride shells did not change the initial decomposition mechanism of the three explosives. The yields of the main products (NO, NO2, N2, H2O, H2, and CO2) were investigated. There was a large number of solid aluminized clusters produced during the decomposition, mainly AlmOn and AlmCn clusters, together with AlmNn clusters dispersed in the AlmOn clusters.

Despite extensive studies of deposited carbon in Fischer–Tropsch synthesis (FTS), an atomic-level comprehension of the effect of carbon on the morphology of cobalt-based FTS catalysts remains elusive. The adsorption configurations of carbon atoms on different crystal facets of hexagonal close-packed (hcp) Co nanoparticles were studied using density functional theory (DFT) calculations to explore the interaction mechanism between C and Co surfaces. The weaker adsorption strength of C atoms on Co(0001), Co(10-10), and Co(11-20) surfaces accounted for lower diffusion energy, leading to the facile formation of C dimers. Electronic property analysis shows that more electrons are transferred from Co surfaces to C atoms on corrugated facets than on flat facets. The deposition of carbon atoms on Co nanoparticles affects surface energy by forming strong Co-C bonds, which causes the system to reach a more energetically favorable morphology with an increased proportion of exposed Co(10-12) and Co(11-20) areas as the carbon content increases slightly. This transformation in morphology implies that C deposition plays a crucial role in determining the facet proportion and stability of exposed Co surfaces, contributing to the optimization of cobalt-based catalysts with improved performance.

Liquid crystalline nanoparticles (LC NPs) are a kind of polymer NPs with LC mesogens, which can form special anisotropic morphologies due to the influence of LC ordering. Owing to the stimuli‐responsiveness of the LC blocks, LC NPs show abundant morphology evolution behaviors in response to external regulation. LC NPs have great application potential in nano‐devices, drug delivery, special fibers and other fields. Polymerization‐induced self‐assembly (PISA) method can synthesize LC NPs at high solid content, reducing the harsh demand for reaction solvent of the LC polymers, being a better choice for large‐scale production. In this review, we introduced recent research progress of PISA‐LC NPs by dividing them into several parts according to the LC mesogen, and discussed the improvement of experimental conditions and the potential application of these polymers. [ABSTRACT FROM AUTHOR]

NiFe‐layered double hydroxide (NiFe‐LDH) as electrode materials for supercapacitors are successfully prepared by green and one‐step hydrothermal method without template. The controllable structure–performance relation of NiFe‐LDH nanoflower clusters (NCs) for green energy storage is realized by regulating reaction time. The morphology evolution of NiFe‐LDH is elucidated. NiFe‐LDH‐24 h offers a unique NC structure and has specific capacitance of 635.8 F g−1 at 1 A g−1, which is larger than one of the reported pure NiFe‐LDHs so far. The improved electrochemical performance of NiFe‐LDH‐24 h NCs is due to its unique structure and synergistic effect between components that cause the larger specific surface area and more electroactive sites for Faradic reaction. The reaction kinetics reveals the electrochemical energy storage mechanism of the NiFe‐LDH‐24 h NCs. The energy storage is contributed by diffusion and surface capacitance. The electrochemical performance of NiFe‐LDH‐24 h NCs is further modified for the first time by doping F, and the specific capacitance of F‐doped NiFe‐LDH‐24 h NCs (1942 F g−1) is increased by 3 times higher than that of NiFe‐LDH‐24 h NCs. This work provides a more solid theoretical basis for green energy storage through morphology control and doping modification strategies. [ABSTRACT FROM AUTHOR]

The morphologies of the keyhole and molten pool during the laser welding process are highly related to weld formation process, which affects the weld quality further. To investigate the influence of the oscillation amplitude on the morphology evolution processes of the keyhole and molten pool during the oscillating laser stake welding of dissimilar materials T-joints, a three-dimensional multiphase flow numerical model is developed. The circular shaped oscillating laser stake welding processes of dissimilar materials T-joints under different oscillation amplitudes are calculated and analyzed in detail. The results show that the depth of the keyhole decreases and the widths of the molten pool and weld at the interface increase with the increase in the oscillation amplitude during the circular shaped oscillating laser stake welding of dissimilar materials T-joints. The periodical expansion and contraction of the keyhole are formed during the welding process. The collapse of the keyhole may cause bubbles in the molten pool due to the instability of the keyhole, and these bubbles also can be captured by the keyhole later. [ABSTRACT FROM AUTHOR]

The low efficiency of upconversion luminescence hinders the pratical applications in many optical fields. During the past years, much attention have focused on the fluorides, reports of lanthanum vanadate (LaVO 4) in oxides are scarce. Herein, a series of LaVO 4 :Yb3+/Er3+ crystals codoping with Ba2+ ions are synthesized through one-pot facile hydrothermal route. Many instruments, such as XRD, ICP, TEM equipped with EDS, luminescence spectroscopy are applied to characterize the products. By optimizing the impurity doping content to 15 mol%, the upconversion luminescence intensities of the green and red emissions are enhanced by 23 and 25 times, respectively. A formation mechanism for morphology evolution is proposed. The enhancement of upconversion performance are systematacially investigated upon the grain size, crystal structure symmetry and doping concentration. Moreover, additional operations are carried out by DFT calculations to confirm the experimental result. This work will guide to enhance upconversion performance based on lanthanum vanadate nanocrystals through impurity doping, which may realize the prospective applications in many fields. [ABSTRACT FROM AUTHOR]

Interesting nanoscopic morphologies which can support nanoparticles in order to generate heterogeneous catalysts are highly useful in various catalytic organic transformations. Herein, we report the design and synthesis of phosphate-based nanocontainers promoting the catalytic activity of Pd nanoparticles generated in situ from Pd-(II) salts. The polymers were synthesized via a time- and cost-efficient, less rigorous synthetic route (i.e., 30 min stirring at room temperature). Based on the linker length in these phosphate-based polymers, the morphological changes were observed from a sphere-rich morphology to more a bowl-like morphology. Interestingly, the precursor/POCl3 ratio contributed to the drastic change in the morphology. The bowl-shaped morphology could load Pd nanoparticles as high as 36.46%, while only 12.46% loading was observed for the spheres. The as-synthesized Pd nanoparticle-loaded organic polymer networks were channelized as a robust catalytic platform for C–C cross-coupling reactions with isolated yields up to 99% and recyclability for five runs without a rigorous protocol. The bowl-shaped morphologies performed better in catalytic C–C coupling reactions as compared to the spherical ones due to the higher Pd nanoparticle loading in the former. Apart from that, a theoretical study elucidated the pivotal role of phosphate moieties in stabilizing the in situ generated Pd nanoparticles. The prepared catalysts were robust and air stable, which make them an alternative to expensive, air-sensitive, commercial Pd catalysts. [ABSTRACT FROM AUTHOR]

The thermal decomposition processes of CL-20 nanoparticle (NP), core-shell structured CL-20@Al NP, and CL-20@AlO NP were studied through reactive molecular dynamics simulations. The results are as follows: (1) the CL-20@Al and CL-20@AlO NPs decomposed earlier than the CL-20 NP; (2) the Al shell experienced the melting-aggregation process and gradually changed from a shell structure to block aluminized clusters; (3) different in the decomposition of the CL-20 NP, N2 appeared first in the decomposition of the CL-20@Al and CL-20@AlO NPs, indicating that Al changed the initial decomposition process of CL-20; (4) the quantities of NO2, NO, and CO2 produced during the decompositions of the CL-20@Al and CL-20@AlO NPs were much lower than those produced during the decomposition of CL-20 NP. This occurred because the Al atoms had high activity at high temperature and attacked these products to produce massive aluminized substances; (5) Al significantly promoted the movement of H and N atoms but impeded that of O and C atoms in the three systems. This study will present fundamental information about the interfacial behaviors of aluminized explosives.

Hangzhou Bay is a world-famous strong tidal estuary with an irregular coastline, unique topography, numerous human activities, and complex hydro-sedimentological environment. The Daishan-Yangshan Sea-Crossing Transport Corridor (DSTC) project is located at the mouth of Hangzhou Bay, which is composed of multiple sea-crossing bridges, an underground tube tunnel, and several man-made islands. The large-scale engineering of DSTC fully connects the cities of Shanghai, Yangshan, Daishan, Zhoushan, and Ningbo. This article discusses the morphodynamic responses due to the construction of the DSTC based on a state-of-art numerical model system from the perspective of its impacts on the hydro-sedimentological environment of Hangzhou Bay, as well as on adjacent projects. This study proved that the variation range of tide level in Hangzhou Bay is mostly within 2 cm after the implementation of the DSTC, while that of the man-made island and piers is only within 6 cm. The tidal prism decrease percentage of Hangzhou Bay is less than 0.5%. It does not significantly change the current field and underwater topography in Hangzhou Bay, except near the man-made islands and the bridge. The effect of the DSTC on surrounding ports and channels is small and limited. That is, the proposed DSTC engineering is feasible from the perspective of morphodynamic responses. The conclusions provide a useful reference for similar large-scale estuary construction projects. [ABSTRACT FROM AUTHOR]

All‐polymer solar cells (all‐PSCs) have achieved impressive progress by employing acceptors polymerized from well performing small‐molecule non‐fullerene acceptors. Herein, the device performance and morphology evolution in blade‐coated all‐PSCs based on PBDBT:PF5–Y5 blends prepared from two different solvents, chlorobenzene (CB), and ortho‐xylene (o‐XY) are studied. The absorption spectra in CB solution indicate more ordered conformation for PF5–Y5. The drying process of PBDBT:PF5–Y5 blends is monitored by in situ multifunctional spectroscopy and the final film morphology is characterized with ex situ techniques. Finer‐mixed donor/acceptor nanostructures are obtained in CB‐cast film than that in o‐XY‐cast ones, corresponding to more efficient charge generation in the solar cells. More importantly, the conformation of polymers in solution determines the overall film morphology and the device performance. The relatively more ordered structure in CB‐cast films is beneficial for charge transport and reduced non‐radiative energy loss. Therefore, to achieve high‐performance all‐PSCs with small energy loss, it is crucial to gain favorable aggregation in the initial stage in solution. [ABSTRACT FROM AUTHOR]

One of the hugely focused areas of research for addressing the world's energy and environmental challenges is electrochemical water oxidation. Morphological modulation of nanomaterials is essential for producing efficient electrocatalysts to achieve the required results. The purpose can be achieved by controlling synthesis parameters, and this is a key factor which greatly influences the oxygen evolution reaction (OER) performance during electrochemical water splitting. In this study, synthesis of cobalt molybdate (CoMoO4) through a simple and low-cost hydrothermal/solvothermal strategy with tunable morphology is demonstrated. Different morphologies, namely rods-like, buds-like, and sheets-like, referred to as R-CMO, B-CMO, and S-CMO, respectively, have been obtained by systematically varying the solvent media. Their catalytic activity towards OER was investigated in 1.0 M aqueous KOH medium. R-CMO nanoparticles synthesized in an aqueous medium demonstrated the lowest overpotential value of 349 mV to achieve a current density of 10 mA cm−2 compared with other as-prepared catalysts. In contrast, the B-CMO and S-CMO exhibited overpotential values of 369 mV and 384 mV, respectively. Furthermore, R-CMO demonstrated an exceptional electrochemical stability for up to 12 h. [ABSTRACT FROM AUTHOR]

Nanoporous Au (NPG) prepared by dealloying is one of the most used substrates for surface-enhanced Raman scattering (SERS). The morphology tailoring of the NPG to obtain both ultrafine pores and suitable Au/Ag ratio is of great importance for the acquiring of enhanced SERS performance. Compared with the chemical dealloying, the electrochemical dealloying can tailor the NPG to be more flexible by the additional adjustment of dealloying voltage and current. Thus, further understanding on the morphology evolution of NPG during the electrochemical dealloying to obtain enhanced SERS performance is of great importance. In the presented work, the morphology and composition evolution of the NPG film during the electrochemical dealloying was investigated. NPG films with a stable pore diameter of approximately 11 nm as well as diverse compositions were obtained by electrochemical dealloying an Au-Ag alloy film. The prepared NPG film exhibits an enhanced SERS activity with an enhancement factor (EF) of 7.3 × 106 and an excellent detection limit of 10−9 M. This work provides insights into the morphology and composition evolution of the NPG during the electrochemical dealloying process to obtain enhanced SERS performance. [ABSTRACT FROM AUTHOR]

The preparation of two-dimensional magnetic materials is a key process to their applications and the study of their structure and morphology plays an important role in the growth of high-quality thin films. Here, the growth, structure, and morphology of Cr1+δTe2 films grown by molecular beam epitaxy on mica with variations of Te/Cr flux ratio, growth temperature, and film thickness have been systematically investigated by scanning tunneling microscopy, reflection high-energy electron diffraction, scanning electron microscope, and X-ray photoelectron spectroscopy. We find that a structural change from multiple phases to a single phase occurs with the increase in growth temperature, irrespective of the Cr/Te flux ratios, which is attributed to the desorption difference of Te atoms at different temperatures, and that the surface morphology of the films grown at relatively high growth temperatures (≥ 300 °C) exhibits a quasi-hexagonal mesh-like structure, which consists of nano-islands with bending surface induced by the screw dislocations, as well as that the films would undergo a growth-mode change from 2D at the initial stage in a small film thickness (2 nm) to 3D at the later stage in thick thicknesses (12 nm and 24 nm). This work provides a general model for the study of pseudo-layered materials grown on flexible layered substrates. [ABSTRACT FROM AUTHOR]

The authors prepared multilayered Si‐based Ge quantum dots (Ge/Si QDs) by using the magnetron sputtering technique and reported the corresponding morphology evolution by atomic force microscope (AFM), scanning electron micrograph (SEM), X‐ray photoelectron spectroscopy (XPS), Raman and X‐ray diffraction (XRD) tests. The increased temperature can improve the Si‐isolated‐layer crystallinity and Ge atom mobility to increase the density, size, and spatial distribution uniformity of top‐layer QDs. The morphology and vertical correlation between the layers of QDs at different temperatures exhibited different phenomena or laws, and had been explained in this paper. The authors' work made it possible to control the quality of multilayer QDs by high‐rate deposition technology and laid a foundation for the industrial production of multilayer QDs in the future. [ABSTRACT FROM AUTHOR]

A novel KNO 3 in-situ etching-activation strategy is demonstrated towards evolution of carbon sheet to carbon spindle, fold-carbon-spheres and then to regular carbon spheres via changing the amount of KNO 3. The fold-carbon-spheres shows more excellent electrochemical performance than regular carbon sheets, spindle and spheres. [Display omitted] Carbonaceous materials with diverse morphologies have shown unique and excellent performance in many fields, such as catalysis, adsorption, separation and energy storage. However, regulating the structural changes of these morphologies accurately using simple approaches is a difficult process. In this study, porous carbon materials with a morphology that changed from carbon spindles to fold-carbon spheres and then to regular carbon spheres were prepared assisted by in-situ activator of KNO 3 in co-assembly of resorcinol/phenol resin and 1-alkyl-3-methylimidazolium bromide. The activation of KNO 3 greatly improves the hydrophily, pore volume and surface area of the inert carbon skeleton, and increases heteroatom defects for the carbon framework. As electrode materials of supercapacitors, the influence of different structures on energy storage performance was studied. The obtained fold-carbon spheres showed a higher capacitance (405 F g−1) than flake, spindle and spherical porous carbon, which is due to convenient electrolyte transmission and completely available active sites. [ABSTRACT FROM AUTHOR]

Various TiO2 nanofilms with nanosheet, nanosheet–nanowire hybrid, and nanowire nanostructures were successfully achieved through an in situ hydrothermal alkali-etching method. The effects of the TiO2 film structures on their photoelectrochemical cathodic protection performance against 304 stainless steel corrosion were evaluated. Characterization results show that the as-prepared TiO2 films exist mainly as anatase crystals and that TiO2 nanowire films display high light absorption intensity, low fluorescence intensity, and great carrier density. After coupling with TiO2 nanowire films, the corrosion potential of 340SS presents the most negative shift from − 0.216 V vs. SCE to − 0.306 V vs. SCE, and the photopotential and the photocurrent density display the largest response of − 0.284 V and 0.22 mA cm−2. The nanowire structure enhances light scattering and trapping for efficient solar light harvesting. [ABSTRACT FROM AUTHOR]

• The adsorption strength of Co n (n = 1–5) clusters with same size on three ZrO 2 surfaces follows the order: m- ZrO 2 (−111) > t -ZrO 2 (101) > c -ZrO 2 (111). • It is thermodynamically favourable for the nucleation of Co n clusters on c -ZrO 2 (111) and t -ZrO 2 (101) surfaces, but it is opposite on m -ZrO 2 (−111) surface. • More Co-Zr bonds and electron transfer of the Co 5 cluster on m -ZrO 2 (−111) surface lead to overlap between Co d-orbital and Zr d-orbital. • The AIMD simulations not only confirmed the stable Co 5 structures of DFT calculation, but also predicted the morphology of large Co 13 clusters on ZrO 2 surfaces under realistic reaction conditions, consistent with the experimental SAM images. The optimization of structure-dependent activity of supported metal catalysts has driven the dynamic determination of the morphology of Co nanoparticles on ZrO 2 using atomic-level simulations. Density functional theory (DFT) calculations combined with ab initio molecular dynamics (AIMD) simulations were used to investigate the surface structure, nucleation mechanism and morphology evolution of Co n clusters supported on different ZrO 2 facets. As the size of the Co n (n = 1–5) cluster increases, the competition between Co-Co bonding and the interaction of Co n clusters with the ZrO 2 surface further promotes the nucleation of larger clusters. Co atoms prefer to nucleate into large clusters on both c -ZrO 2 (111) and t -ZrO 2 (101) surfaces, but this behavior is unfavorable on the m- ZrO 2 (-111) surface. The analysis of electric properties suggests that the types of hybrid orbitals and the number of electron transfer accounts for the difference in energies of Co n clusters on ZrO 2 surfaces. Further, the AIMD simulations verified the stable structure of small Co 5 cluster obtained by DFT, and predicted the morphology of large Co 13 clusters on ZrO 2 surfaces under realistic reaction conditions, consistent with the experimental SAM images. Our work provides an intuitive understanding of structure and morphology evolution of catalysts for the targeted design of catalysts to achieve the desired activity and explore more reaction possibilities. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • In-situ observations of the apatite ring evolution in oolitic hematite by HT-CLSM was proposed. • This study focused on insight into phosphorus migration mechanism for efficient separation of iron and phosphorus. • Dissolution of apatite was affected by Fe/(Al + Si) molar ratio in the melt. • Rate-limiting step of apatite melting was the diffusion of phosphorus. Oolitic hematite is a promising alternative resource, in facing the iron ore downgrading. As oolitic hematite is often rich in phosphorus, an efficient separation of iron and phosphorus is necessary, in terms of utilizing both elements. Therefore, a close insight into the transformation of phosphorus-bearing minerals in the unique oolitic structure during the reduction process is important. To capture the real-time transformation of the apatite ring in the oolitic structure, in-situ observations under roasting, and CO/carbon reducing conditions were adopted by high-temperature confocal laser scanning microscopy. The results indicated that the apatite ring was transformed by four stages during the roasting process from 25 °C to 1400 °C: stabilization, defluorination, partial melting, and complete melting, which was: Ca 5 (PO 4) 3 F → Ca 3 (PO 4) 2 → Ca 3 (PO 4) 2 + P 2 O 5 liquid → P 2 O 5 liquid. Under the CO reduction, the partial reduction of the phosphate at 1400 °C generated a Fe-P low alloy. While the carbon reduction promoted iron phase absorption of phosphorus, forming Fe-P high alloy at 1400 °C. In addition, interfacial phenomena between apatite and slag melt were observed, and the dissolution of apatite (Ca/P molar ratio) into the slag melt was affected by the Fe/(Al + Si) molar ratio of the slag. Finally, using inverse error function methods, the diffusion coefficients of P and Ca increased significantly from the roasting to CO reduction and then to carbon reduction. These findings can benefit to understand phosphorus migration mechanisms, improving effective dephosphorization strategies for high-phosphorus oolitic hematite. [ABSTRACT FROM AUTHOR]

[Display omitted] • A cross-scale transient model for direct-ammonia SOFCs was developed. • The influence of electrode morphology evolution on cell performance was discussed. • DA-SOFCs can achieve performance output comparable to hydrogen fuel cells. • A long-term performance optimization strategy for direct-ammonia SOFC was proposed. Direct-ammonia solid oxide fuel cells (DA-SOFCs) represents a highly promising energy conversion technology, enabling direct utilization of ammonia (NH 3) as fuel. However, the industrial-scale deployment of SOFCs has been hindered by issues related to poor device durability, notably performance degradation resulting from electrode morphology evolution during long-term operation. In this study, a cross-scale trainset model is established, linking the pore scale with the macroscopic scale, thereby elucidating the mechanisms by which electrode morphology evolution affects performance degradation over long-term operation. Additionally, long-term performance optimization strategies are proposed. The model effectively captures the impact of electrode morphology evolution on NH 3 decomposition and long-term performance. The parametric analysis is conducted to explore the effects of various combinations of operating conditions, flow configurations, and microstructures on the Ni-pore interface area, active three-phase boundary length, NH 3 decomposition and cell performance over time. The findings indicate that the DA-SOFCs exhibits enhanced thermal stability at the cost of a slight reduction in performance relative to its H 2 -fueled counterpart. Lowering the operating temperature can alleviate the performance degradation rate, but it also has a profound impact on the cell's overall performance throughout its lifespan. Based on the parametric analysis results, the optimal set of solutions that satisfy different maximum temperature gradient constraints are obtained using a data-driven multi-objective optimization algorithm. The optimal solutions ensure sufficient thermomechanical stability (degradation rate < 0.26 % kh-1) while meeting the long-term performance requirements. [ABSTRACT FROM AUTHOR]

Ferrophosphorus (Fe–P alloy), a byproduct in the carbothermal reduction of phosphorite for yellow phosphorus production, has remarkable potential application as foundational precursors to prepare advanced catalysts and energy materials. However, the gas-solid-liquid equilibrium in the reduction smelting of phosphorite and hematite is intricate, and the reduction, volatilization, and alloying mechanisms of Fe and P at higher temperatures should be given close attention to optimize the production of yellow phosphorus vapor and Fe–P alloy. In this study, the reduction smelting behaviors of fluorapatite and hematite in the phosphorite ore were investigated. Carbothermic reduction reactions of Ca 5 (PO 4) 3 F with and without Fe 2 O 3 are calculated, establishing theoretical fundamentals. The phase and microstructure evolutions of Ca 5 (PO 4) 3 F and Fe 2 O 3 are researched. This work also emphasizes the interfacial element migration to clarify the reduction, volatilization, and alloying of Fe and P by considering the solid-solid interface of Ca 5 (PO 4) 3 F–Fe 2 O 3 and the gas-liquid interface of P 2 vapor-metallic Fe. The phase and microstructure evolutions of fluorapatite with and without Fe 2 O 3 are compared. It's demonstrated the Fe 2 O 3 facilitates the reduction of fluorapatite. The liquid-solid-gas interfaces among Ca 5 (PO 4) 3 F–Fe–P systems are studied to clarify the reduction, volatilization, and alloying mechanisms. [Display omitted] • P distributions in the gas, slag, and alloy phases during reduction smelting are determined. • Phase and microstructure evolutions of fluorapatite with and without Fe 2 O 3 are compared. • Fe 2 O 3 facilitates the reduction of fluorapatite. • Liquid-solid-gas interfaces among Ca 5 (PO 4) 3 F–Fe–P systems are discussed. • Reduction, volatilization, and alloying mechanisms of P are clarified. [ABSTRACT FROM AUTHOR]

The combination of SiO 2 and CaO has an interdisciplinary significance in the practical application of thermal conversion of organic wastes. In this work, the influence of CaO/SiO 2 on pyrolysis behavior and morphology evolution of cellulose pyrolytic char pellets were explored in a high-frequency heating furnace. Results showed that, the addition of these two oxides obviously regulated the content and composition of pyrolytic products. The further cracking of pyrolytic oil was promoted and the gas yield was increased. Besides, SiO 2 and CaO were found in the forms of sharp splinters and aggregates in pyrolytic char, which inhibited the shrinkage of pellets and improved their reactivity. Moreover, a series of synergistic effects were observed, which had influence on both the oil and gas composition, the char reactivity and the microcrystalline structure. [Display omitted] • SiO 2 /CaO was proved to regulate the content and composition of pyrolytic products. • Oxide content and existential form could directly affect the pellet shrinkage. • Reactivity of pyrolytic char was improved and cross-linked structures increased. • A series of synergistic effects of SiO 2 /CaO were observed and an overall mechanism proposed. [ABSTRACT FROM AUTHOR]

The Cu(111) surface is an important substrate for catalysis and the growth of 2D materials, but a comprehensive understanding of the preparation and formation of well-ordered and atomically clean Cu(111) surfaces is still lacking. In this work, the morphology and structure changes of the Cu(111) surface after treatment by ion bombardment and annealing with a temperature range of 300–720 °C are investigated systematically by using in situ low-temperature scanning tunneling microscopy. With the increase of annealing temperature, the surface morphology changes from corrugation to straight edge, the number of screw dislocations changes from none to numerous, and the surface atomic structure changes from disordered to ordered structures (with many reconstructions). In addition, the changing trend of step width and step height in different stages is different (first increased and then decreased). A perfect Cu(111) surface with a step height of one atom layer (0.21 nm) and a width of more than 150 nm was obtained. In addition, two interesting superstructures and a new surface phase with a large number of line defects were found. This work serves as a strong foundation for understanding the properties of Cu(111) surface, and it also provides important guidance for the effective pretreatment of Cu(111) substrates, which are widely used. [ABSTRACT FROM AUTHOR]

The reactive molecular dynamics method was employed to examine the thermal decomposition process of aluminized hydride (AlH 3 ) containing explosive nanoparticles with a core-shell structure under high temperature. The core was composed of the explosives RDX, HMX, and CL-20, while the shell was composed of AlH 3 . It was demonstrated that the CL-20@AlH 3 NPs decomposed at a faster rate than the other NPs, and elevated temperatures could accelerate the initial decomposition of the explosive molecules. The incorporation of aluminized hydride shells did not change the initial decomposition mechanism of the three explosives. The yields of the main products (NO, NO 2 , N 2 , H 2 O, H 2 , and CO 2 ) were investigated. There was a large number of solid aluminized clusters produced during the decomposition, mainly Al m O n and Al m C n clusters, together with Al m N n clusters dispersed in the Al m O n clusters.

In the present work, the modification effect of Te and the corresponding growth process of Mg 2 Si were clarified. With 0.5 wt% Te addition, the dendritic primary Mg 2 Si transformed to polygons, accompanied by a reduction in size from over ∼165 μm-∼18 μm. However, 2.0 wt% Te addition resulted in degradation of modification effect, and the morphology of Mg 2 Si changed to dendrite. Three-dimensional morphology of primary Mg 2 Si indicated that Te altered the morphology of primary Mg 2 Si from dendrites to polyhedrons surrounded by {111} and {100}. The modification mechanism of Te can be attributed to the heterogeneous nucleation and the doping of Te during the growth process of primary Mg 2 Si, which greatly contributed to dimension decrease and morphology evolution of primary Mg 2 Si respectively. With Te corporation, the relative surface energy between the {100} and {111} (r) drops, contributing to the exposure of {100}. Our work shows that the solute concentration under non-equilibrium solidification plays an important role in determining the final morphology of Mg 2 Si. The local segregation of Mg and Si solutes results in the degradation of dendrite arms along certain directions during the initial stage of crystal growth. Combined with the modifying effect of Te, which alters the surface energy of the crystal, the final crystal morphology deviates from its equilibrium state. Our study demonstrates that ultimate morphology and dimensions of primary Mg 2 Si can be determined simultaneously with the addition of certain modifiers, which can be achieved by regulating the growth and nucleation of Mg 2 Si at the same time., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Published by Elsevier Ltd.)

Abstract High‐performance perovskite solar cells (PVSCs) with low energy consumption and green processing are highly desired, but constrained by the difficulty in morphology control and the poor understanding on morphology evolution mechanisms. To address this issue, here we studied the effect of antisolvents on the perovskite film formation. We found that both the antisolvents and the perovskite composition affect the perovskite film morphology greatly via influencing the intermediate phase, and different perovskite compositions require different antisolvents to reach the optimal morphology. This provides the opportunity to achieve high‐performance PVSCs with green antisolvent, that is, isopropanol (iPA) by changing the perovskite compositions, and leads to a power conversion efficiency (PCE) of 21.50% for PVSCs based on MA0.6FA0.4PbI3. Further, we fabricated “fully green” PVSCs with all layers prepared by green solvents, and the optimal PCE can reach 19%, which represents the highest among PVSCs with full‐green processing. This work provides insight into the perovskite morphology evolution and paves the way toward “green” processing PVSCs.

The incorporation of solid additive has been considered as an effective strategy for developing organic photovoltaics with multi‐components, which is independent of dynamics, playing unique roles in morphology adjustment. However, their complex working mechanisms involving specific chemical structures are selective to material systems, hence limiting their university and flexibility in application. Herein, an inert small‐molecular compound naphtho[1,2‐c:5,6‐c′]bis[1,2,5]thiadiazole (NT) is introduced into the bulk‐heterojunction blend as the solid additive, which can function with various material systems and solvents, depending on its simple π‐conjugated structure and S⋯N interaction for adjusting molecular alignment. It is interesting to note that the introduced NT can not only improve device performance, but also simplify complicated pre‐ or post‐processing methods, reduce impact from batch‐to‐batch differences, construct sufficient energy transfer channel as well as improve device stability. The resulting devices based on PTzBI‐dF:Y6‐BO system show an impressive power conversion efficiency of 17.4% with obviously enhanced T80 lifetime of >1200 h. These findings provide useful guidelines for exploring potential universal solid additives benefitting toward commercial application. [ABSTRACT FROM AUTHOR]

NaNbO 3 (NN) is a well-known perovskite-type dielectric material. However, its phase transition is a complex process and the phase transition mechanism is insufficiently investigated yet. Therefore, in the work, the NN superfine particles were synthesized by a hydrothermal method with the assistance of K+ and the microstructures of NN were carefully investigated to understand the strain-driven phase transition and morphology evolution of NN. The results suggest that K+ leads to strong planar bending of NbO 6 by influencing the Na + vibration, which accounts for the O-R phase transition as the K+ increases. Once the R phase is triggered, the O-R phase transition proceeds spontaneously based on phonon calculations of orthorhombic (O) NN and R NN. The antiferroelectric nature of rhombohedral (R) NN with the space group R–3H is confirmed through charge density distribution. Additionally, the morphology evolution is deduced on the TEM analysis basis. [ABSTRACT FROM AUTHOR]

Heterostructures integrated by diverse material featuring nanocrystals (NCs) tunable properties and functions are of great interest. However, to rationally design and precisely control the heterostructures in multiple shapes still remains a tremendous challenge. In this work, the nucleation of SiO2 nanoparticles is manipulated via a kinetics‐controlled water–hexane interfacial reaction system to construct Cs3Cu2I5/SiO2 heterostructures, which can be well controlled in Janus and patchy morphology. In this interfacial reaction, the evolution of Cs3Cu2I5 NCs and the intrinsic formation mechanism of the heterostructures are investigated. It is observed that the Cs3Cu2I5 NCs on the interface undergo a morphology transformation driven by ligand loss and exposed facets evolution. Increased wettability between Cs3Cu2I5 and SiO2 favors the formation of Cs3Cu2I5/SiO2 heterostructures. The key to this strategy is to break the rule of thermodynamic domination in reaction by kinetics manipulation when constructing the patchy heterostructure. To be noted, an increased stability is conferred on the resultant heterostructure product compared to naked perovskite NCs. This work enables to better control the complicated heterostructure configurations and understand their formation mechanism. [ABSTRACT FROM AUTHOR]

• High-energy pulsed lasers can effectively strip the anti-erosion coatings. • The laser fabrication parameters greatly affect the post-stripping surface morphology. • Asymmetric structures can be induced by overlapped laser spots in stripping. • Recoil pressure and capillary forces drive the morphological evolution process. Laser stripping has emerged as a pivotal technique for repairing anti-erosion coatings in the aviation and armored vehicle industries. This process entails complex thermodynamic interactions that remain incompletely explored. Unraveling the intricacies of the stripping mechanism, especially the evolution of surface morphology, is essential for advancing its industrial utility. This study characterizes the laser stripping effect on TiN anti-erosion coatings using confocal microscopy, scanning electron microscopy, and energy dispersive spectrometer. Notably, at an energy density threshold of approximately 102 J/cm2, pulsed lasers are observed to induce a distinctive hydrodynamic surface morphology, marked by parallel asymmetric grooves. This phenomenon is accompanied by a redistribution of surface elements and a decrease in nitrogen content. To dissect the underlying mechanisms, we have developed simulation models that integrate principles of heat transfer and fluid dynamics. These models reveal that the high-temperature decomposition and vaporization of TiN, coupled with the ejection of molten material due to vapor recoil pressure, are central to the stripping process. Additionally, the formation of asymmetric groove profiles is predominantly attributed to the nonlinear superposition effect from overlapping laser spots. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) have excellent ability to capture CO 2 due to their unique properties. The observation on the evolution process of solid-supported IL nanomembranes at the nanoscale benefits understanding the interaction between IL nanomembranes and CO 2. In this work, we have investigated the CO 2 -induced evolution process of solid-supported nanomembranes formed by the imidazolium-based ILs with alkyl chains of different lengths but with a common anion by in-situ atomic force microscopy (AFM). The morphology evolution and mechanical properties of the IL nanomembranes have been quantitatively analyzed. The results show that similar phenomena were observed for the three IL nanomembranes, i.e., the absorption of CO 2 presents a maximal impact on the innermost layer of the solid-supported IL nanomembranes. The innermost layer of IL nanomembranes becomes fragmented and tends to re-assemble into a multi-layer structure, while the area of the multi-layer IL nanomembranes expands due to the incorporation of some small regions. In addition, the morphology changes of IL nanomembranes are dependent on the length of cation alkyl side chain. For the [BMI][TFSI] nanomembrane, the morphology change is faster than the other two IL nanomembranes in the preliminary stage of CO 2 absorption and reaches a stable state in a shorter time. AFM quantitative nanomechanical measurements show that Young's moduli of the three IL nanomembranes significantly decrease after CO 2 absorption, which supports that CO 2 molecules could weaken the interaction among IL anions, cations and mica, and thus lead to the morphology changes of the three solid-supported IL nanomembranes. Our work provides microscopic insights into the process of CO 2 absorption by ILs, which lays a foundation for further studying the interaction between CO 2 and solid-supported IL nanomembranes. The morphology evolutions of three IL nanomembranes have been investigated by in-situ atomic force microscopy (AFM). The results shows that the innermost layer becomes fragmented and tends to re-assemble into a multi-layer structure while the area of the multi-layer expands due to the incorporation of CO 2. [Display omitted] • The absorption of CO 2 presents a maximal impact on the innermost layer of the solid-supported IL nanomembranes. • The [BMI][TFSI] nanomembrane's morphological transformation is rapid initially during CO 2 absorption, stabilizing quickly. • CO 2 absorption markedly reduces the Young's Moduli of nanomembranes, suggesting that CO 2 disrupts IL ion interactions with mica. [ABSTRACT FROM AUTHOR]

Herein, the evolution of reduction process of ultrafine tungsten powder in industrial conditions was investigated. The transition process of morphology and composition was examined via SEM, XRD, and calcination experiments. The results show that the reduction sequence of WO2.9 was WO2.9 → WO2.72 → WO2 → W on the surface, but WO2.9 → WO2 → W inside the oxide particles. With the aid of chemical vapor transport of WOx(OH)y, surface morphology transformed into rod-like, star-shaped cracking, floret, irregularly fibrous structure, and finally, spherical tungsten particles.

The morphology of supramolecular polymer aggregates evolved during normal aging from thin 25-nm-wide nanoribbons into 1-µm-wide nanoribbons and nanotubes thanks to hydrophobic interactions between phenylalanine residues exposed on the edges of nanoribbons. [Display omitted] • Benzene-1,3,5-tricarboxamide decorated with diphenylalanine self-assemble into micrometer-long nanoribbons immediately after dissolution. • Nanoribbons interact laterally via "sticky edges" and gradually merge over the entire length. • After reaching a critical width nanoribbons self-merge, irreversibly forming nanotubes. • Mechanical perturbations cause nanotube fracture and fragmentation similar to analogous inorganic materials. During the aging of supramolecular systems, new stable materials with different morphologies, molecular packing, and hierarchical organization may form from the initial assembly. Understanding the mechanisms and pathways accompanying age-related changes may allow for the controlled synthesis of multiple materials from a single molecule in a nature-inspired manner. Herein, we demonstrate the multi-stage evolution of a single solution of C3-symmetric peptide amphiphile containing diphenylalanine fragment and benzyl-1,3,5-tricarboxamide core. Transmission electron microscopy reveals the rapid formation of 20–40 nm wide nanoribbons in an aqueous solution within 60 s after preparation. The lateral edges of nanoribbons contain solvent-exposed aromatic residues that tend to merge via an unconventional edge-to-edge zipping mechanism, leading to the nanoribbon's growth in width. After reaching a critical width and flexibility, "sticky edges" on the same nanoribbon may merge via a self-zipping mechanism, forming rigid nanotubes. Eventually, mechanical perturbations cause buckling and fracture of nanotubes into shorter nanotubes via flexural or tensile failure. This work reports new evolution pathways in soft 2D assemblies and introduces solution ageing as a promising method to control morphology of peptide amphiphiles. [ABSTRACT FROM AUTHOR]

• The hydrate formed free gas (WHC) was coarse and porous hydrate crystals. • The growth of WHC was related to the gas–water interface and water migration. • Hydrate formed from dissolved gas (SHC) was transparent polyhedral crystals. • The growth rate of SHC was determined by the concentration of methane in water. The distribution characteristics of gas hydrates in the pores of sediments are critical to predict the macroscopic properties of hydrate reservoirs and the efficient production of gas hydrates. In this study, the experiments of methane hydrate formation were conducted in a glass micromodel, and the morphology evolution of hydrate formed from the free gas and dissolved gas in the pores were observed through a video microscope. Observation results showed that the hydrate formed from free gas grew preferentially along the gas–water interface and subsequently toward the center of the gas phase. For the hydrate formed from dissolved gas, it was preferentially occurred on the surface of the hydrate crust formed from free gas and gradually grew toward the water phase. The hydrate formation rate was determined by the concentration of methane molecules in surroundings water. The hydrate formed from free gas was porous structure and composed of many tiny hydrate crystals, and the hydrate formed from dissolved gas was smooth and transparent polyhedral hydrate crystal. For the hydrate formed by free gas, the occurrence pattern of hydrate in the pores might change from the grain-cementing to the contact-cementing or the patchy. The occurrence pattern of the hydrate formed from dissolved gas could be the pore-filling or the load-bearing. This study could be helpful for explaining the phenomenon of macro-experiments, the model construction for the macro-properties of hydrate-bearing sediments, and the exploring of gas hydrates reservoirs. [ABSTRACT FROM AUTHOR]

The paper is focused on the growth of polystyrene particles followed by optical microscopy during dispersion polymerization (DP) in the absence of crosslinking agents. In particular, we compared the growth kinetics of the particles and their tendency to coagulation in alcoholic media in the presence of a steric stabilizer, chosen from one of the following: polyvinylpyrrolidone (PVP-40, PVP-10, PVP-360), hydroxypropyl cellulose (HPC), poly(acrylic acid) (PAA), and polyvinyl alcohol (PVA). The particle size distributions from the optical microscopy images were obtained using trained neural network. To predict the particles' growth at the first few hours after microphase separation, we suggest to adopt a simple model describing the coalescence of liquid drops in immiscible fluids. Based on this model, we discuss the possible approaches for the preparation routes of the particles with non-spherical morphology. [ABSTRACT FROM AUTHOR]

The microstructural characteristics of the high pressure die casting (HPDC) AlSiMgMnCu alloys in the skin layer, segregation band and the central zone were investigated in three dimensions by serial block-face scanning electron microscopy (SBFSEM). The results present that the volume fractions of α-Al15(Fe, Mn)3Si (α-Fe phase), β-Mg2Si (β phase) and Q-Al5Cu2Mg8Si6 (Q phase) in the skin layer and the central zone are higher than those in the segregation band zone. The volume fractions and sizes of the θ-Al2Cu phase (θ phase) in the skin layer and the central zone are lower than those in the segregation band zone. In the skin layer, the preferential growth orientation of the α-Fe phase with plate-like morphology is parallel to the heat transfer direction, while the other phases exhibit a complex seaweed-like morphology. In the central zone and the segregation band zone, the shearing stress and turbulent flow during the filling process lead to the morphology of α-Fe and β-Mg2Si relatively regular. However, the morphology of Q-Al5Cu2Mg8Si6 and θ-Al2Cu phases are irregular owing to their lower solidification temperatures. The distribution and morphology of β-Mg2Si, Q-Al5Cu2Mg8Si6 and θ-Al2Cu in the segregation band zone mainly determined the distribution and morphology of the α-Fe phase.