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We propose and investigate a novel coherent laser array design based on laterally coupled photonic crystal surface-emitting lasers (PCSELs). As a new type of semiconductor laser technology, PCSELs have field confinement in a planar cavity and laser beam emission in the surface normal direction. By engineering lateral couplings between PCSELs with heterostructure photonic crystal designs, we can achieve coherent operations from an array of PCSELs. In this paper, we demonstrate coherent operation from a passively coupled PCSEL array design. We fabricated PCSEL array devices on a GaAs-based quantum well heterostructure at a target wavelength of 1040 nm. Experimental results show that the 2-by-2 PCSEL arrays have spectral linewidth of 0.14–0.22 nm. Beam combining performance was characterized by self-interference experiments. Similar coherency between the PCSEL array and single PCSEL device was observed. Our compact PCSEL array designs by passive lateral coupling have potential applications in fields of on-chip photonic computing, quantum, and information processing. [ABSTRACT FROM AUTHOR]

Continuum- or discrete-polarizable models for the study of optoelectronic processes in embedded subsystems rely mostly on the restriction of the surrounding electronic dielectric response to its low frequency limit. Such a description hinges on the assumption that the electrons in the surrounding medium react instantaneously to any excitation in the central subsystem, thus treating the environment in the adiabatic limit. Exploiting a recently developed embedded GW formalism with an environment described at the fully ab initio level, we assess the merits of the adiabatic limit with respect to an environment where the full dynamics of the dielectric response are considered. Furthermore, we show how to properly take the static limit of the environment's susceptibility by introducing the so-called Coulomb-hole and screened-exchange contributions to the reaction field. As a first application, we consider a C60 molecule at the surface of a C60 crystal, namely, a case where the dynamics of the embedded and embedding subsystems are similar. The common adiabatic assumption, when properly treated, generates errors below 10% on the polarization energy associated with frontier energy levels and associated energy gaps. Finally, we consider a water molecule inside a metallic nanotube, the worst case for the environment's adiabatic limit. The error on the gap polarization energy remains below 10%, even though the error on the frontier orbital polarization energies can reach a few tenths of an electronvolt. [ABSTRACT FROM AUTHOR]

The surface optical (SO) phonon replica in photoluminescence (PL) spectroscopy of nitride nanowires (NWs) was theoretically investigated in this study. The dispersive relationships of SO phonon mode in anisotropic wurtzite (WZ) and isotropic zinc-blende (ZB) crystal structure NWs with circular and square cross sections (CSs) were derived within the framework of the dielectric continuum model. Based on the energy and momentum conservation laws, a constraint relationship between the frequency and wave-number was constructed for SO phonon-assisted excitonic PL spectra in the NW structure. By combining the dispersive and constraint relationships, the frequency and wave-number of the SO phonon replica in the PL spectra could be determined. The WZ and ZB crystal structures of nitride semiconductor were considered. The influences of surface factors including the CS shape, dielectric medium, and environment temperature on the frequency and photon wavelength of the band-edge emission of the SO phonon replica were studied in detail. Numerical results reveal that the crystal structure, surface factors, and environment temperature greatly affect the frequency and photon wavelength of the band-edge emission of the SO phonon replica. The calculated results for the photon wavelength agree well with the experimental values of the SO phonon replica in AlN NWs. The results of the dielectric effect obtained here are also supported by previous experimental and theoretical results for nitrides and other semiconductor NWs. The present theoretical scheme and numerical results can be used to analyze and design the SO phonon replica in PL spectra of nanostructures. [ABSTRACT FROM AUTHOR]

Controlling triplet states is crucial to improve the efficiency and lifetime of organic room temperature phosphorescence (ORTP). Although the intrinsic factors from intramolecular radiative and non-radiative decay have been intensively investigated, the extrinsic factors that affect triplet exciton quenching are rarely reported. Diffusion to the defect sites inside the crystal or at the crystal surface may bring about quenching of triplet exciton. Here, the phosphorescence lifetime is found to have a negative correlation with the triplet exciton diffusion coefficient based on the density functional theory (DFT)/time-dependent density functional theory (TD-DFT) calculations on a series of ORTP materials. For systems with a weak charge transfer (CT) characteristic, close π–π stacking will lead to strong triplet coupling and fast triplet exciton diffusion in most cases, which is detrimental to the phosphorescence lifetime. Notably, for intramolcular donor–acceptor (D–A) type systems with a CT characteristic, intermolecular D–A stacking results in ultra-small triplet coupling, thus contributing to slow triplet diffusion and long phosphorescence lifetime. These findings shed some light on molecular design toward high-efficiency long persistent ORTP. [ABSTRACT FROM AUTHOR]

To qualify the nature of a SiO2 film grown on a Si single crystal substrate by surface oxidation, we originally propose a quartz–cristobalite (Q–C) alloy-like model of SiO2 film growth on a Si (100) substrate. We treat two types of Si–SiO2 transformations as reactions when oxidizing a Si wafer surface: Si–quartz transformation with Si emissions and Si–cristobalite transformation without Si emission. Expanding into a Q–C alloy-like model using the Hakoniwa method enables us to estimate both the ratio of Si emitting from the SiO2/Si interface among involved Si atoms in the thermally oxidized Si wafer surface and molecular volume expansion ratio from Si to SiO2. In addition, SiO2 film stress generated during oxidation is also discussed. [ABSTRACT FROM AUTHOR]

Experimental and simulation studies were conducted for surface segregation-limited kinetics of nitrogen incorporation into a 4H-SiC crystal during physical vapor transport (PVT) crystal growth. It was revealed that the nitrogen incorporation is kinetically limited by the step-flow velocity on the growing crystal surface of a 4H-SiC crystal; in this study, the surface step-flow velocity at the growth front was deduced from the local inclination angle of the growth front measured from the (000 1 ¯) plane, assuming a uniform growth rate along the c-axis (crystal growth direction) across the growth front, and the nitrogen concentration across the growth front was measured using Raman scattering microscopy. The step-flow velocity dependence of nitrogen incorporation was theoretically analyzed using a two-site-exchange model, and the simulated dependence using the model was in good agreement with the experimental data. On the basis of these experimental and simulation results, kinematical and energetical aspects of nitrogen incorporation at the growth front of a 4H-SiC crystal during PVT growth are discussed. [ABSTRACT FROM AUTHOR]

The facet-dependent adsorption of CO on oxidized and reduced CeO2 single crystal surfaces is reviewed, with emphasis on the effect of CO coverage and the ability of state-of-the-art quantum-mechanical methods to provide reliable energies and an accurate description of the IR vibrational frequency of CO. Comparison with detailed, high-resolution experimental infrared reflection absorption spectroscopy data obtained for single crystal samples allows the assignment of the different CO vibrational bands observed on all three low-index ceria surfaces. Good agreement is achieved with the hybrid density functional theory approach with the HSE06 functional and with saturation coverage. It is shown that CO is very sensitive to the structure of cerium oxide surfaces and to the presence of oxygen vacancies. The combined theoretical-experimental approach offers new opportunities for a better characterization of ceria nanoparticles and for unraveling changes occurring during reactions involving CO at higher pressures. [ABSTRACT FROM AUTHOR]

Salt solubility is generally determined under isotropic stress conditions. Yet, in the context of salt weathering of porous media, mechanical constraints on the in-pore growth of salt crystals are likely to be orientation-dependent, resulting in an anisotropic stress state on the crystal. In this paper, we determine by molecular simulation the solubility of NaCl in water when the crystal is subjected to anisotropic stress. Such anisotropy causes the chemical potential of the crystal to be orientation-dependent, and proper thermodynamic formulation requires describing the chemical potential as a tensor. The solute and crystal chemical potentials are computed from free energy calculations using Hamiltonian thermodynamic integration, and the usual condition of solubility is reformulated to account for the tensorial nature of the crystal chemical potential. We investigate in detail how the uniaxial compression of the crystal affects its solubility. The molecular simulation results led to revisiting the Correns law under anisotropic stress. Regarding the solute, the non-ideal behavior of the liquid phase is captured using Pitzer's ion interaction approach up to high concentrations of interest for in-pore crystallization and beyond the concentrations addressed in the existing literature. Regarding NaCl crystals, the validity of the generalized Gibbs–Duhem equation for a tensorial chemical potential is carefully verified, and it is found that crystallization progresses almost orthogonally to the crystal surface even under high shear stresses. Comparing uniaxial and isotropic compression highlights the major differences in solubility caused by stress anisotropy, and the revisited Correns law offers an appropriate framework to capture this phenomenon. [ABSTRACT FROM AUTHOR]

Recently, metal-free organic materials that change their luster color in response to external stimuli have been reported. The development of such materials could have a significant impact on applications in the decorative and ink industries. Here we report a reversible change in luster color from pale yellow to wine red in microcrystalline film by using a photochromic diarylethene having thiazole rings and a naphthyl group. The diarylethene used can easily form thin plate-like crystals by recrystallization. In using these crystals, they were stacked in the same plane, forming a microcrystalline film. The combination of specular reflections from the surface of the plate-like crystals and multiple reflections from their stacked structure brings about a pale yellow luster effect. This film showed a reversible change in luster color from pale yellow to wine red due to the photocyclization--cycloreversion reactions of diarylethene. Such metallicappearing luster materials, which reversibly control the luster color in widely different color coordinates depending on the light, could have a significant impact on decorative and ink applications. [ABSTRACT FROM AUTHOR]

Photoactive black‐phase formamidinium lead triiodide (α‐FAPbI3) perovskite has dominated the prevailing high‐performance perovskite solar cells (PSCs), normally for those spin‐coated, conventional n‐i‐p structured devices. Unfortunately, α‐FAPbI3 has not been made full use of its advantages in inverted p‐i‐n structured PSCs fabricated via blade‐coating techniques owing to uncontrollable crystallization kinetics and complicated phase evolution of FAPbI3 perovskites during film formation. Herein, a customized crystal surface energy regulation strategy has been innovatively developed by incorporating 0.5 mol % of N‐aminoethylpiperazine hydroiodide (NAPI) additive into α‐FAPbI3 crystal‐derived perovskite ink, which enabled the formation of highly‐oriented α‐FAPbI3 films. We deciphered the phase transformation mechanisms and crystallization kinetics of blade‐coated α‐FAPbI3 perovskite films via combining a series of in‐situ characterizations and theoretical calculations. Interestingly, the strong chemical interactions between the NAPI and inorganic Pb−I framework help to reduce the surface energy of (100) crystal plane by 42 %, retard the crystallization rate and lower the formation energy of α‐FAPbI3. Benefited from multifaceted advantages of promoted charge extraction and suppressed non‐radiative recombination, the resultant blade‐coated inverted PSCs based on (100)‐oriented α‐FAPbI3 perovskite films realized promising efficiencies up to 24.16 % (~26.5 % higher than that of the randomly‐oriented counterparts), accompanied by improved operational stability. This result represented one of the best performances reported to date for FAPbI3‐based inverted PSCs fabricated via scalable deposition methods. [ABSTRACT FROM AUTHOR]

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

Metal halide perovskite single crystals are promising for photovoltaic applications due to their outstanding properties. However, the high surface trap density causes severe nonradiative recombination and ion migration, hindering device performance and stability. Herein, mitigation of the deficient crystal surface is reported by optimized polishing engineering, resulting in stoichiometric lead‐iodine ratio with reduced iodide ion vacancies, increased ion migration activation energy, and suppressed nonradiative recombination. As a result, Cs0.05FA0.95PbI3 (FA = formamidinium) devices exhibit an impressive efficiency of 23.1%, which is one of the highest values for single‐crystal perovskite solar cells (PSCs). Moreover, multiple recycling of the degraded single‐crystal PSCs with higher efficiency and stability is achieved by removing the deteriorated surface, validating crystal surface dominates device degradation while the role of bulk and buried interface is negligible, which is different from polycrystalline devices. The T85 lifetime (remain 85% of initial efficiency) of Cs0.05FA0.95PbI3 devices increases to 1150 h after the recycling process, which is much better than that of previously reported single‐crystal PSCs. Since deficient crystal surface and ion migration are universal issues of perovskite materials, this work will promote the development of stable single‐crystal PSCs and other optoelectronic devices, such as X‐ray detectors, light‐emitting diodes, etc. [ABSTRACT FROM AUTHOR]

We studied the effect of femtosecond laser irradiation on the incorporation of n-type forming ions (phosphorus ions, P + and nitrogen ions, N+) into diamond. The (001) surface of a diamond crystal was irradiated by using a femtosecond laser to draw a zigzag pattern in two areas in which the spacing between irradiation lines was controlled to be 2 μm and 1 μm. One half of the crystal surface was P+-implanted and the other half was N+-implanted, both at 600 °C. Electron diffraction patterns obtained from thinned samples showed that the crystallinity of diamond was lost in the densely laser-irradiated area. For both ions, the ion concentration in the laser-irradiated area was higher than that in the nonirradiated area. The highest ion concentration ratio was approximately 5 for the P+-implanted region and greater than 10 for the N+-implanted region. These results support the idea that femtosecond-laser-induced surface modifications can enhance incorporation of n-type forming ions into diamond, with the effect varying according to ion mass. [ABSTRACT FROM AUTHOR]

The generation of sub-grains during the preparation of AlN crystals by physical vapor transport (PVT) method can reduce crystal quality, and even lead to the development of polycrystallization. In this paper, the generation and evolution of sub-grains were studied by adjusting the thermodynamic and kinetic growth conditions, and effective suppression methods were proposed to regulate crystal growth mode. The experimental results show that the large temperature fluctuation leads to the large fluctuation of the gaseous substances supersaturation on the crystal surface. It promotes the formation probability of highindex facets, which are difficult to achieve perfect coalescence due to non-uniformity. The influence of the transport path of gaseous substances on the crystal growth mode under the condition of a stable temperature field was also studied. The experimental and simulation results show that during the crystal growth under the traditional crucible structure, the transmission path of gaseous substances migrates from the edge to the center on the crystal surface, which is opposite to the direction of the growth step. The crystal surface is prone to forming step clusters and evolving into Stranski-Krastanov growth mode. A novel crucible was designed to enable the migration of gaseous substances along the crystal growth step direction, which met the basic conditions of layer-by-layer growth. The experimental results of growth temperature from 2 200 ℃ to 2 300 ℃ show that as the decrease of temperature, crystal growth exhibits c-axis dominant growth, and lateral expansion capability decreases. As the temperature increases, the lateral expansion capability increases, but the probability of the formation of high-index crystal facets increases continuously. When the temperature is about 2 250 ℃, the two reach a balance, which is suitable for the suppression and elimination of sub-grains. Combined with BCF theory analysis, reducing the supersaturation enhances the two-dimensional tiling ability of screw dislocation-driven growth, and increases the growth step width, which is conducive to dispersing sub-grain boundaries into step flow. The optimized experimental results show that the Stranski-Krastanov growth mode gradually changes to a screw dislocation-driven growth mode, and the sub-grains are gradually annihilated. The high-quality AlN crystals were obtained, with an X-ray single crystal rocking curve full width at half maximum values of 58″ on AlN (0002) surface, a Raman spectrum E2 (High) full width at half maximum value of 3. 3 cm-1, and a dislocation density on the crystal surface of 2. 87 ×103 cm-2. [ABSTRACT FROM AUTHOR]

The dissolution behavior of the largest exposed crystal face of Baloxavir marboxil Form I crystal, an anti-influenza drug, was investigated by in-situ atomic force microscopy (AFM) at near molecular scale in water. The largest exposed crystal surface is the (020) face, the microstructure features of layered steps and spiral dislocations appear before dissolution. The in-situ AFM tests show that there are two main dissolution mechanisms: step retreat and pit expansion dissolution. The step retreat dissolution mechanism mainly occurs at the crystal faces where growth steps remain, and the dissolution is promoted by gradual retreat of layered steps. There are two forms of pits in pit expansion dissolution mechanism: regular pits and inverted spiral dislocation pits. The formation of inverted spiral dislocation pits is related to the defect initiated-dissolution at the spiral dislocation sites; the regular quadrilateral pits mainly appear at the relatively smooth and perfect crystal faces, because this characteristic crystal surface can only promote the dissolution process through spontaneous pitting nucleation. When the crystal face is dissolved by the regular pit dissolution mechanism, the critical size of the pit-dissolution exists, meaning only pits above a certain size can promote dissolution. [ABSTRACT FROM AUTHOR]

The chirality of biopolymers remains one of the mysteries of Life. For such objects, the phenomenon of supramolecular chirality (SMC) is vital. Enantiomers can be recognized by the adsorption on surfaces with SMC. However, the mechanisms of such chiral recognition are still unknown. In this work, the adsorption kinetics of menthol test enantiomers on the surfaces of γ‐glycine and NiSO4•6H2O chiral crystals was studied. It was found that the difference in adsorption was observed in nonequilibrium state more often than in equilibrium. If the enantioselectivity in equilibrium state was observed, the enantioselectivity coefficient α at nonequilibrium conditions was higher. The maximum α in nonequilibrium state was 2.44 for γ‐glycine crystals and 2.12 for NiSO4•6H2O crystals. Even if no differences in adsorption were observed under adsorption–desorption equilibrium conditions, a significant enantioselectivity at nonequilibrium conditions was found. This has proved the possibility of chiral recognition on surfaces with SMC by the differences in adsorption rates. Such novel chiral recognition mechanism can provide enhanced enantioselectivity in adsorption, catalysis, chromatographic separation, and chemical sensing. [ABSTRACT FROM AUTHOR]

A surfactant's equilibrium spreading pressure (ESP) is the maximum decrease in surface tension achievable at equilibrium below the Krafft point. Difficulties in measuring the ESP have been noted previously but no well-established experimental protocols to overcome them exist. We present a case study of three solid amphiphiles with different propensities to spread on the air–water interface. Starting with the partially water soluble n-dodecanol (C12H25OH), which spreads instantaneously. The strong Marangoni flows associated with the spreading result in the dislocating of the Wilhelmy plate or crystals attaching to it. A temporary mechanical barrier in front of the spreading crystals mitigates the flows disturbing the plate. Presaturating the subphase with the amphiphile prevents the establishment of dynamic steady states, reduces the standard error by a factor of three and causes faster equilibration. The perfluoroalkylated analog of dodecanol (11:1 fluorotelomer alcohol, C11F23CH2OH) is slow spreading. With surfactant crystals on the interface, the surface pressure reaches a pre-equilibrium plateau within an hour, followed by equilibration on day-long timescales. We show that it is better to estimate the ESP by averaging the values of multiple pre-equilibrium plateaus rather than waiting for equilibrium to be established. Finally, the nonspreading amphiphile DPPC exhibits a large barrier for the mass transfer from the DPPC crystal to the aqueous surface. This was overcome by introducing a volatile, water-immiscible solvent deposited on the surface next to the crystals to facilitate the spreading process and leave behind a monolayer. [ABSTRACT FROM AUTHOR]

Achieving diffraction‐limited performance in fourth‐generation synchrotron radiation sources demands monochromator crystals that can preserve the wavefront across an unprecedented extensive range. There is an urgent need for techniques of absolute crystal diffraction wavefront measurement. At the Beijing Synchrotron Radiation Facility (BSRF), a novel edge scan wavefront metrology technique has been developed. This technique employs a double‐edge tracking method, making diffraction‐limited level absolute crystal diffraction wavefront measurement a reality. The results demonstrate an equivalent diffraction surface slope error below 70 nrad (corresponding to a wavefront phase error of 4.57% λ) r.m.s. within a nearly 6 mm range for a flat crystal in the crystal surface coordinate. The double‐edge structure contributes to exceptional measurement precision for slope error reproducibility, achieving levels below 15 nrad (phase error reproducibility < λ/100) even at a first‐generation synchrotron radiation source. Currently, the measurement termed double‐edge scan (DES) has already been regarded as a critical feedback mechanism in the fabrication of next‐generation crystals. [ABSTRACT FROM AUTHOR]

We present direct evidence, for the first time, for the flash‐induced generation of crystal defects in single‐crystal cubic zirconia. The defects are characterized by multiple techniques. The crystals were flashed and then cooled down to ambient temperature in Ar atmosphere to preserve the electronic conductivity from the steady state of flash. Transmission electron microscopy revealed colonies of defects. The crystal structure, the non‐stoichiometry, and the electronic structure of oxygen ions within these colonies were characterized. They consist of oxygen‐depleted compositions. Selected area electron diffraction revealed the structure of these zirconia suboxides to be epitaxially coherent with the parent cubic structure but with a smaller lattice parameter. Electron energy loss spectroscopy spectra showed the peak near 25 mV to shift toward metallic zirconium. The electronic conductivity of the flashed cubic zirconia is attributed to this suboxide phase. The phase also gave rise to new peaks in Raman spectroscopy. A surprising finding was the presence of a distinct, ∼30 nm thick layer of the suboxide on the surface of the crystal. The surface layer showed a high degree of oxygen deficiency. It was also epitaxial, but with an even smaller lattice parameter than the defect colonies underneath the surface. Mechanical polishing of the crystal to remove this surface layer gave a broad view of the interconnected network of defects across the entire specimen; the length scale of this network was about 0.2 mm. Recent work, where an overlay of a magnetic field caused the flash to migrate from a flashing surface into a free‐standing workpiece, suggests the presence of evanescent plasma, which may have a connection to this surface layer. [ABSTRACT FROM AUTHOR]

The article presents a model of the thickness of the surface layer of YBCO crystals, from which its domain structure follows. It is shown that in the surface nanolayer, the temperature of the transition to the superconducting state increases by 2 times compared to the bulk phase. Lamels in the monodomain are determined as Abrikosov vortices, and there are 15 of them in the surface layer of YBCO. [ABSTRACT FROM AUTHOR]

Organic solvents host the synthesis of high-value crystals used as pharmaceuticals and optical devices, among other applications. A knowledge gap persists on how replacing the hydrogen bonds and polar attraction that dominate aqueous environments with the weaker van der Waals forces affects the growth mechanism, including its defining feature, whether crystals grow classically or nonclassically. Here we demonstrate a rare dual growth mode of etioporphyrin I crystals, enabled by liquid precursors that associate with crystal surfaces to generate stacks of layers, which then grow laterally by incorporating solute molecules. Our findings reveal the precursors as mesoscopic solute-rich clusters, a unique phase favored by weak bonds such as those between organic solutes. The lateral spreading of the precursor-initiated stacks of layers crucially relies on abundant solute supply directly from the solution, bypassing diffusion along the crystal surface; the direct incorporation pathway may, again, be unique to organic solvents. Clusters that evolve to amorphous particles do not seamlessly integrate into crystal lattices. Crystals growing fast and mostly nonclassically at high supersaturations are not excessively strained. Our findings demonstrate that the weak interactions typical of organic systems promote nonclassical growth modes by supporting liquid precursors and enabling the spreading of multilayer stacks. Organic solvents are used to produce high-value crystals such as pharmaceuticals, organic semiconductors, and optical devices, but our understanding of the fundamental processes of crystal growth from organic solutions is limited. Here, the authors use time-resolved in situ atomic force microscopy to show a nonclassical, dual growth mode of etioporphyrin I crystals from mesoscopic solute-rich clusters. [ABSTRACT FROM AUTHOR]

As one of the most promising anodes for aqueous batteries, Zn metal faces uncontrollable side reactions and deleterious dendrite growth, which drastically compromise its cycle life and coulombic efficiency (CE). In this work, a bi‐functional and environmentally‐friendly high‐performance electrolyte is prepared by introducing maleic anhydride (MA) as an additive. In situ/ex situ experiments and simulation indicate that MA can enter the Zn2+ solvated sheath to replace the distribution of some water molecules and form a cross‐linked hydrogen bond network with H2O to inhibit the side reactions caused by the decomposition of active water molecules. In addition, MA can induce uniform deposition of Zn by adsorption on Zn (002) crystal surface and inhibit dendrite growth. The symmetric cells assembled with MA as the electrolyte additive have a long cycle life of 4000 h at 25 °C and can be stably cycled for >400 h at −8 °C (1 mA cm−2/1 mAh cm−2). In the presence of MA in the electrolyte, Zn//MnO2 full cell shows good cycle stability over 200 cycles (N/P = 4.1). This study reports a simple and effective strategy for promoting the commercial application of aqueous zinc‐ion batteries (AZIBs). [ABSTRACT FROM AUTHOR]

Stimulated by the increasing interest in ion adsorption effects on electrocatalytic reactions and by recent more detailed reports on the potential dependent adlayer structures formed on Ru(0001) in pure HClO4 and H2SO4 electrolytes, we revisited the oxygen reduction reaction (ORR) on structurally well‐defined Ru(0001) single crystal surfaces prepared under ultrahigh vacuum conditions. We demonstrate that the complex, potential‐dependent activity both for the ORR and for H2O2 formation is closely related to potential‐dependent changes in the composition and structure of the adlayer. Our results demonstrate the enormous effects adsorbed species can have on the ORR reaction characteristics, either by surface blocking, e. g., by (co‐)adsorbed bisulfate species, or by participation in the reaction, e. g., by *H transfer from adsorbed H or OH to O2. The comparison with results obtained on polycrystalline Ru, which differ significantly from Ru(0001) data, furthermore underlines the importance of using structurally well‐defined surfaces as a reference system for future theoretical studies. [ABSTRACT FROM AUTHOR]

Aqueous Zn metal batteries (ZMBs) are largely hampered by the poor stability of zinc (Zn) anode in aqueous electrolyte due to uncontrollable deposition behavior and parasitic reactions. Hence, a stable Glu@Zn anode via acid etching is developed that simultaneously exposes (002) plane and modifies exposed grain boundaries. The surface‐preferred (002) plane is achieved by minimizing its surface energy. And the exposed grain boundaries are also modified by decomposition products of acid etching, which can greatly reduce the adverse effects caused by highly active grain boundaries. These features favor Glu@Zn anode by accrediting a long‐term cycle lifespan exceeding 4400 h with a high average coulombic efficiency (CE) of 98.9%. Surprisingly, Glu@Zn anode can run for more than 250 h with 50% Zn utilization. The assembled Glu@Zn//NH4V4O10 full batteries deliver a specific capacity of 291.6 mAh g−1 after 400 cycles even at a low current density of 0.5 A g−1. It can also obtain a stable cycling performance up to 2000 cycles. To further verify its stability, a pouch cell is constructed that can preserve stable 400 cycles with 5 mAh. This study sheds light on surface energy regulation exposing preferred crystal plane to develop highly stable and reversible cycling aqueous ZMBs. [ABSTRACT FROM AUTHOR]

Nd,Y:SrF2 crystal is considered a promising laser gain material in high-energy laser systems owing to its advantages of long emission lifetime, low nonlinear refractive index and high thermal conductivity. In this study, photothermal weak absorption and laser-induced damage at 1064 nm on the surface of NYSF crystals were characterized. Based on 3D damage morphologies of cracking and bending, thermoelastic effects were considered as the damage mechanism. By analyzing weak absorption values and laser-induced damage thresholds, the exponential-Chapman quantitative relationship between laser fluence and weak absorption was observed. Additionally, the relationship between the laser fluence and growth behavior of the damaged area was investigated, indicating that the damaged area grew exponentially with an increase in fluence, and the area damaged by a secondary laser pulse was one order of magnitude larger than the primary damaged area. [ABSTRACT FROM AUTHOR]

We study the shape evolution of pores with calcite surfaces that dissolve with rates linearly varying along the pore length due to saturation gradients. A reaction–diffusion equation predicts that the walls have uniform slope along the pore length, which corresponds to walls with equally separated monolayer steps in a microscopic scale. We also study a nanoscale model that represents the detachment of individual molecules from the pore surface with rates obeying the same linear dependence on the position. Kinetic Monte Carlo simulations performed with two different conditions of the crystal surfaces at the pore ends show wall profiles very different from those of the reaction–diffusion equation. These profiles are controlled by the formation of surface steps at points of low saturation and by dominant step propagation to the saturated region. When crystal edges are present at the pore ends, there is fast widening at the unsaturated side, formation of step trains, and their propagation along the inner and outer surfaces. The hydrodynamic interpretation of the process in the light of the Kardar–Parisi–Zhang theory explains why the initially sharp edges acquire an approximately circular shape in a few seconds of dissolution. Instead, when a flat wall condition is imposed at the pore ends, surface steps are slowly formed at the unsaturated side, propagate to the saturated region, and accumulate there in a phenomenon of step bunching. A stationary shape with flat (rough) walls at the unsaturated (saturated) side is attained typically after some tens of minutes and is approximately predicted by a hydrodynamic approach assuming an inverse proportionality between step density and local dissolution rate. Thus, the consequences of the molecular scale model can be explained by upscaled treatments of the kinetics of step generation and propagation and have a potential to improve multiscale approaches. [ABSTRACT FROM AUTHOR]

The electronic nose aims to emulate the olfactory capabilities of osmatic animals, utilizing olfactory sensing array with different sensing characteristics to perceive odors. However, the separate precursors and preparation methods of sensing materials pose challenges in the fabrication of an olfactory sensing array. In this work, the customization of the surface crystal phase of Sr─Fe─O materials (SFO) is demonstrated through the control of annealing temperature, enabling the simple fabrication of an olfactory sensing array using a single precursor. Significantly, the SFO materials exhibit diverse proportions of surface crystal phases, showcasing varied selective characteristics toward volatile organic compounds (VOCs). The materials also demonstrate remarkable responsiveness, linearity, and response/recovery times. Furthermore, this study unraveles the intricate gas‐sensor mechanism through first principle calculations, revealing that Fe spin‐down d band center of Sr3Fe2O7, located near the Fermi level, significantly enhances the binding strength of intermediates, leading to a higher response specifically to certain VOCs. Integrating these materials into a unified device, the sensor array quantitatively and discriminatively detected different VOCs. The results indicate that SFO materials hold tremendous potential as a promising and easily manufacturable olfactory material system. [ABSTRACT FROM AUTHOR]

Crystal size engineering allows tailoring of flexible metal–organic frameworks (MOFs) to achieve new properties. The gating type flexibility of the DUT-8(Zn) ([Zn2(2,6-ndc)2(dabco)]n, 2,6-ndc = 2,6-naphthalene dicarboxylate, dabco = 1,4-diazabicyclo-[2.2.2]-octane) compound is known to be extremely particle size sensitive. Here, the physisorption of ethanol vapor gives rise to so-called shape-memory effect, leading to rigidification and flexibility suppression. According to powder X-ray diffraction and nitrogen physisorption experiments, the open pore phase is retained selectively after desorption of alcohols, which could be attributed to the nano-structuring and surface deformation of the crystals as a result of exposure to alcohols. [ABSTRACT FROM AUTHOR]

Two ionic hydrogen‐bonded organic frameworks (iHOFs) assembled from 4‐cyano‐N‐(4‐cyanobenzyl)pyridinium, have been crystallized with Br− and antimony(III) pentabromide, [SbBr5]2−, as counter‐ions and characterized. These are 4‐cyano‐N‐(4‐cyanobenzyl)pyridinium bromide, C14H10N3+·Br−, and bis[4‐cyano‐N‐(4‐cyanobenzyl)pyridinium] antimony(III) pentabromide, (C14H10N3)2[SbBr5]. The CH...NC interactions induced by templating anions construct disparate frameworks. Hirshfeld surface analysis indicated that these crystals exhibit two types of hydrogen‐bonding interactions, specifically CH...NC and CH...Br. Consecutive reverse‐parallel CH...NC hydrogen‐bonding interactions in these crystals induced the formation of a large number of CH...NC bonds which exhibit both cis and trans configurations. [ABSTRACT FROM AUTHOR]

Starting from [Mn(C5H4Br)(PPh3)(CO)2] (1a), the cymantrenyl thioethers [Mn(C5H4SMe)(PPh3)(CO)2] (1b) and [Mn{C5H4–nBr(SMe)n}(PPh3)(CO)2] (n = 1 for compound 2, n = 2 for 3 and n = 3 for 4) were obtained, using either n‐butyllithium (n‐BuLi), lithium diisopropylamide (LDA) or lithium tetramethylpiperidide (LiTMP) as base, followed by electrophilic quenching with MeSSMe. Stepwise consecutive reaction of [Mn(C5Br5)(PPh3)(CO)2] with n‐BuLi and MeSSMe led finally to [Mn{C5(SMe)5}(PPh3)(CO)2] (11), only the fifth complex to be reported containing a perthiolated cyclopentadienyl ring. The molecular and crystal structures of 1b, 3, 4 and 11 were determined and were studied for the occurrence of S...S and S...Br interactions. It turned out that although some interactions of this type occurred, they were of minor importance for the arrangement of the molecules in the crystal. [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]

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]

Phosphoric acid etching combined with hydrothermal treatment was used to construct a Sc2O3-ZnO coating on the Zn anode surface to tune the content of Zn (002) crystal surface. The (002) crystalline surface of Zn surface became the preferred crystal face for the H3PO4 etching time of 7 min and hydrothermal reaction for 2 h at 160°C. The polarization curve results showed that in 2 M of ZnSO4 solution, the corrosion potential of Zn anode with (002) crystallographically optimal orientation was positively shifted by 663 mV and the corrosion current density was reduced by about four orders of magnitude compared with the bare Zn. The results of LSV and XRD showed that the Zn anode with (002) preferred crystal face possessed a more negative hydrogen evolution potential, which effectively hindered the occurrence of the H2 evolution side reaction and significantly inhibited the corrosion of metal Zn and the generation of alkaline zinc sulfate hydrate as a byproduct. Dense Sc2O3-ZnO coatings composed of crosslinked nanofibers provided a long-lasting and effective shielding protection. The coating facilitated the induction of Zn (002) crystal face oriented deposition, and the bonding of N or P enhanced the stability of coating, which significantly enhanced the corrosion resistance. [ABSTRACT FROM AUTHOR]

Starting from [Mn(C5H4Br)(PPh3)(CO)2] (1a), the cymantrenyl thioethers [Mn(C5H4SMe)(PPh3)(CO)2] (1b) and [Mn{C5H4–nBr(SMe)n}(PPh3)(CO)2] (n = 1 for compound 2, n = 2 for 3 and n = 3 for 4) were obtained, using either n‐butyllithium (n‐BuLi), lithium diisopropylamide (LDA) or lithium tetramethylpiperidide (LiTMP) as base, followed by electrophilic quenching with MeSSMe. Stepwise consecutive reaction of [Mn(C5Br5)(PPh3)(CO)2] with n‐BuLi and MeSSMe led finally to [Mn{C5(SMe)5}(PPh3)(CO)2] (11), only the fifth complex to be reported containing a perthiolated cyclopentadienyl ring. The molecular and crystal structures of 1b, 3, 4 and 11 were determined and were studied for the occurrence of S...S and S...Br interactions. It turned out that although some interactions of this type occurred, they were of minor importance for the arrangement of the molecules in the crystal. [ABSTRACT FROM AUTHOR]

The premelting layer on crystal surfaces significantly affects the stability, surface reactivity, and phase transition behaviors of crystals. Traditional methods for studying this layer—experimental techniques, classical simulations, and even first-principle simulations—have significant limitations in accuracy and scalability. To overcome these challenges, we employ molecular dynamic simulations based on neural network potentials to investigate the structural and dynamic behavior of the premelting layer on ice. This approach matches the accuracy of first-principle calculations while greatly improving computational efficiency, allowing us to simulate the ice–vapor interface on a much larger scale. In this study, we conducted a one-nanosecond simulation of the ice–vapor interface involving 1024 water molecules. This significantly exceeds the time and size scales of previous first-principle studies. Our simulation results indicate complete surface melting. Furthermore, our simulation results reveal dynamic heterogeneity within the premelting layer, with molecules segregated into clusters of low and high mobility. [ABSTRACT FROM AUTHOR]

Radiation detection is being revolutionized by integrating photonic elements into scintillators. In this study, a scalable and cost‐effective method is proposed to achieve tuneable emission enhancement across the visible spectrum by colloidal self‐assembly of photonic crystals on scintillator surfaces. This concept is demonstrated for Eu3+/Tb3+‐doped Gd and Ta oxides. Widely available and affordable colloidal nanospheres of SiO2 or polymethyl methacrylate are self‐assembled on these scintillators. The size of the nanospheres is carefully optimized to match the desired emission lines of Eu3+/Tb3+. The result is homogeneous and closely‐packed structures with clear photonic bandgap in the visible range. Under X‐ray excitation, the scintillators covered with the photonic layers exhibit enhanced light extraction in the direction perpendicular to the surface, compared to isotropic emission in the bare scintillator. Such scintillation directionality, when optically matched with a proper detector, will result in higher efficiency of the overall detection system. Moreover, X‐ray imaging demonstrates an enhancement of 25% in system resolution of the scintillator supplemented with the photonic layer compared to unmodified scintillators. The proposed method is scintillator‐ and nanosphere‐agnostic, thus offering a promising versatile approach for directing the scintillation light toward a photodetector and increasing detection system performance, including high‐resolution imaging applications. [ABSTRACT FROM AUTHOR]

In this study, a novel MgO–C refractory, fabricated through high–temperature nitriding, was developed by incorporating Si–Al 4 SiC 4 to in–situ form plate–like Mg–sialon ceramic bonding phase in situ. The influences of Al 4 SiC 4 content and nitriding temperature on the phase transformation, microstructure, and mechanical properties of MgO–C refractories were examined. The synergistic effect of Si co–existed with Al 4 SiC 4 promoted the in–situ formation of plate–like Mg–sialon, thereby accelerating the densification of MgO–C refractories. The primary crystal growth surface for Mg–sialon was identified as the (100) facet. The plate–like Mg–sialon was integrally bonded within the matrix, enhancing the interfacial bonding with MgO particles, rather than merely adhering to the surface. The incorporation of 2 wt% Al 4 SiC 4 significantly optimized the microstructure of MgO–C refractories, culminating in superior mechanical properties when nitrided at 1400 °C. Furthermore, the formation mechanism and morphological evolution of the plate–like Mg–sialon in MgO–C refractories were explored. • Novel in–situ Mg–sialon enhanced low–carbon MgO–C refractories have been developed. • The coexistence of Si with Al 4 SiC 4 synergistically facilitated the in-situ formation of plate-like Mg-sialon. • The addition of 3 wt% Si and 2 wt% Al 4 SiC 4 demonstrated optimal properties for the novel refractories. • The thermodynamics of the nitridation process was simulated and calculated. • Mg–sialon formation occurs predominantly through a solution–precipitation mechanism. [ABSTRACT FROM AUTHOR]

In this research work, surface-modified nano zerovalent copper (nZVC) was prepared using a simple borohydride reduction method. The spectroscopic and crystallographic results revealed the successful synthesis of surface-modified nano zerovalent copper (nZVC) using solvents such as ethanol (ETOH), ethylene glycol (EG) and tween80 (T80). The as-synthesized material was fully characterized for morphological surface and crystal structural properties. The results indicated that EG provides an excellent synthesis environment to nZVC compared to ETOH and T80 in terms of good dispersion, high surface area and excellent catalytic properties. The catalytic efficiency of nZVC/EG was investigated alone and with peroxymonosulphate (PMS) in the absence of light. The degradation results demonstrated that the involvement of PMS synergistically boosted the catalytic efficiency of synthesized nZVC/EG material. Furthermore, the degradation products (DPs) of CBZ were determined by GC−MS and subsequently, the degradation pathways were proposed. The ecotoxicity analysis of the DPs was also explored. The proposed (nZVC/EG/PMS) system is economical and efficient and thus could be applied for the degradation of CBZ from an aquatic system after altering the degradation pathways in such a way that results in harmless products. [ABSTRACT FROM AUTHOR]

CeO2 has high elastic modulus and thermal stability, as well as good surface effects, making it ideal as a reinforcement for aluminum matrix composites. In this paper, the interfacial relationships between Al and CeO2 was studied by first-principles calculation, and the nucleation mechanism of aluminum matrix growth on CeO2 substrate was discussed. First, the Al/CeO2 interface matching crystal surface was identified as the Al(111)/CeO2(111) interface. Then, the surface work function was calculated for all surfaces constituting the Al(111)/CeO2(111) interface, and the results showed that the Al(111) loses charge more easily than CeO2(111). Subsequently, the interface energy and work of adhesion of the Al(111)/CeO2(111) interface were calculated, and the results showed that the interface energy of O1–Al was the smallest (0.07 J/m2), the work of adhesion of O2 interface energy of O1–Al was the smallest (0.07 J/m2), the work of adhesion of O2–Al was the largest (9.36 J/m2)Al was the largest (9.36 J/m2). Finally, the combined properties of the Al(111)/CeO2(111) interface were analyzed by the electronic properties at the interface, and the results showed that The Al(111)/CeO2(111) interface is a mixture of ionic and covalent bonds. Therefore, the calculated results confirm that the effectiveness of CeO2 as a heterogeneous nucleation substrate for Al. This study provides a theoretical basis for the nucleation mechanism of the heterogeneous nucleation interface between CeO2 and aluminum matrix. [ABSTRACT FROM AUTHOR]

Direct recycling is a key technology for enabling a circular economy of spent lithium ion batteries (LIBs). For cathode active materials (CAMs), it is regarded as the tightest closed‐loop and most efficient approach among current recycling techniques as it simply proceeds via re‐lithiation and reconstruction of aged CAMs instead of separating them into elemental components. In this work, spent, i.e., morphologically and structurally decomposed CAM based on LiNi0.83Co0.12Mn0.05O2 (NCM‐831205) is restored by mimicking conditions of original CAM synthesis. After evaluating and optimizing the high‐temperature duration for CAM restoration and subsequent washing procedure, the recycled CAM is shown to maintain poly‐crystallinity and tap density, successfully recover specific surface area, lithium content, crystal structure in surface and bulk, while, however, only partly the original secondary particle size and shape. Though, comparable in initial 100 charge/discharge cycles with pristine CAM in lithium ion‐cells, the subsequent increase in resistance and capacity fading remains a challenge. High temperature during recycling can be regarded as a key challenge on material level, as it not only promotes detrimental surface carbonate species from residual carbon black but also enhances cation disorder and micro‐/nanoscopic porosity through oxygen release, likely in de‐lithiated, thus less thermally stable regions of cycled NCM. [ABSTRACT FROM AUTHOR]

Hysteresis related to first-order phase transformation in shape memory alloys, which is the macroscopic manifestation of energy dissipation, is detrimental to the precise control of actuation and causes structural and functional fatigue of components. It is of vital importance to explore high-performance shape memory alloys with low stress-hysteresis, large superelasticity, and wide temperature range operation in practical applications. Here, we have developed a Ni-Mn-Fe-In shape memory microwire, exhibiting an ultra-low stress-hysteresis and huge tensile superelasticity in a wide temperature range. The microwire shows a smooth surface and a single crystal structure (with ⟨001⟩A-oriented along the axial direction of microwire), and the microstructure of the microwire contains austenite matrix and sparsely distributed precipitates with an average size of 20–80 nm, all of which may be beneficial to obtain low hysteresis and large strains in the microwire. As a result, the microwire exhibits a minimum stress-hysteresis of as low as 8.5 MPa (with overall strain of 15.3%) and corresponding energy dissipation as low as 1.44 MJ/m3. The microwire always shows a low stress-hysteresis (less than 24 MPa) and low energy dissipation (less than 2.86 MJ/m3) above room temperature. The microwire shows a huge superelasticity with recoverable strains higher than 15% in the wide temperature range from 218 to 418 K. Together with the advantages of easy fabrication and no post-processing required, this microwire shows a tremendous potential for cyclic actuators and energy conversion devices under multi-field coupling. [ABSTRACT FROM AUTHOR]

The second formation stage of a surface martensite (SM) crystal is associated with a layer-by-layer extension of its faces. A dynamic pattern of every layer formation is similar to a rapid crystal growth in the first stage. The role of dislocation nucleation centers belongs to the dislocations framing the crystal-face surfaces. By the example of the (10-1) face it is shown that the proposed dynamic mechanism is compatible with the observed polar growth of the SM crystal trace on the (100) surface of the sample and the range of its visually observed growth. [ABSTRACT FROM AUTHOR]

This study aims to understand the influence of pore size on the compositional, morphological, and functional group characteristics of dicalcium phosphate dihydrate (DCPD)-coated porous β-tricalcium phosphate (β-TCP) granules. This study produced 300–600 μm granular sizes of porous β-TCP granules with various pore diameters. This was achieved by combining dry powders of DCPD and calcium carbonate (CaCO3) [Ca/P ratio: 1.5] with varied quantities of 10%, 20%, 30%, and 40% of sodium chloride (NaCl) powders to obtain mixtures composed of weight percentages (wt%) ratios of 90:10, 80:20, 70:30, and 60:40, respectively. Post-sintering, the porous β-TCP granules fabricated were soaked in an acidic calcium phosphate solution for 30 min to coat the surfaces with DCPD crystals formation via a dissolution-precipitation reaction. Subsequently, the specimens were examined with scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR). The morphological observations demonstrated that increasing NaCl powder up to 40% with a mixture of CaCO3 and DCPD enhanced the β-TCP granules' pore size. Furthermore, The formation of DCPD on and inside the porous β-TCP granules has been accelerated due to the presence of large pores. Conversely, dissolution-precipitation reactions were incomplete on granules with 2.8, 4.9, and 6.91 μm pore sizes. The major XRD peaks of the DCPD and β-TCP phases with 2.8, 4.9, and 6.91 μm pores were also slightly shifted to the right, while granules with 7.53 μm pores demonstrated DCPD and β-TCP peaks aligned with pure β-TCP and DCPD phases. This study's findings are expected to offer insight into the role of pore size in influencing the dissolution-precipitation process that affects the morphological, compositional, and functional group characteristics of DCPD-coated β-TCP granules. [ABSTRACT FROM AUTHOR]

Crystalline active pharmaceutical ingredients with comparable size and surface area can demonstrate surface anisotropy induced during crystallization or downstream unit operations such as milling. To the extent that varying surface properties impacts bulk powder properties, the final drug product performance such as stability, dissolution rates, flowability, and dispersibility can be predicted by understanding surface properties such as surface chemistry, energetics, and wettability. Here, we investigate the surface properties of different batches of Odanacatib prepared through either jet milling or fast precipitation from various solvent systems, all of which meet the particle size specification established to ensure equivalent biopharmaceutical performance. This work highlights the use of orthogonal surface techniques such as Inverse Gas Chromatography (IGC), Brunauer–Emmett–Teller (BET) surface area, contact angle, and X-ray Photoelectron Spectroscopy (XPS) to demonstrate the effect of processing history on particle surface properties to explain differences in bulk powder properties. [ABSTRACT FROM AUTHOR]

3,4-Dinitrofurazanfuroxan (DNTF) is widely used in fusion-cast-based explosive carriers owing to its low melting point, high energy, and excellent stability. To reduce the susceptibility of DNTF and improve the thermal properties, core–shell composites (DNTF@PDA@HTPB) were synthesized using the oxidative self-polymerization reaction of dopamine. The results showed that hydroxyl-terminated polybutadiene (HTPB) was tightly coated on the surface of DNTF@PDA crystals, and the crystal structure of the high-energy crystals did not experience any significant changes during the encapsulation process. Compared with the raw DNTF, the thermal decomposition of DNTF in the DNTF@PDA and DNTF@PDA are delayed by 13.3℃ and 17.1℃, respectively. This phenomenon indicates that the thermal stability of DNTF@PDA and DNTF@PDA@HTPB composites is improved. The ignition speed of DNTF@PDA@HTPB is faster, and the flame activity is more vigorous. Meanwhile, the friction susceptibility of DNTF@PDA@HTPB is reduced by 44% compared to DNTF, and the impact susceptibility is significantly reduced by 75%. This study provides a new idea to improve fused-cast explosives' structure and combustion performance. [ABSTRACT FROM AUTHOR]

Polyamide-6 (PA6), or nylon-6, is a widely used low-cost polymer material for various applications. Manufacturing PA6 into fibers involves a spinning process which orients the polymer chains into a semicrystalline structure. The most economical spinning process for PA6 fibers is melt extrusion. When stretching the produced fibers to high strains, the PA6 fibers transition the metastable γ phase back into the stable α phase. The effects of these large stretches on mechanical properties have not been explored after the stretch has been released. In this study, the effects on mechanical properties were studied by stretching the PA6 fibers from 10 to 50% tensile strain and subsequently releasing the fibers. The stretched fibers were characterized by X-ray diffraction and atomic force microscopy to determine the changes to the crystal structure and surface roughness. The stretched fibers were then tensile tested to failure and the tensile properties were examined. The stress-strain curves on the post-stretched PA6 fibers showed clear softening in the fibers with lower initial moduli after 30% stretching. These results may hold a clue to softening of fibers in applications with repeated loading and have implications for mechanical stability and fatigue of this polymeric material. [ABSTRACT FROM AUTHOR]

High-quality, 3D-shaped, SiO2 colloidal photonic crystals (ellipsoids, hyperboloids, and others) were fabricated by self-assembly. They possess a quadratic surface and are wide-angle-independent, direction-dependent, diffractive reflection crystals. Their size varies between 1 and 5 mm and can be achieved as mechanical-resistant, free-standing, thick (hundreds of ordered layers) objects. High-quality, 3D-shaped, polystyrene inverse-opal photonic superstructures (highly similar to diatom frustules) were synthesized by using an inside infiltration method as wide-angle-independent, reflective diffraction objects. They possess multiple reflection bands given by their special architecture (a torus on the top of an ellipsoid) and by their different sized holes (384 nm and 264 nm). Our hanging-drop self-assembly approach uses setups which deform the shape of an ordinary spherical drop; thus, the colloidal self-assembly takes place on a non-axisymmetric liquid/air interface. The deformed drop surface is a kind of topological interface which changes its shape in time, remaining as a quality template for the self-assembly process. Three-dimensional-shaped colloidal photonic crystals might be used as devices for future spectrophotometers, aspheric or freeform diffracting mirrors, or metasurfaces for experiments regarding space-time curvature analogy. [ABSTRACT FROM AUTHOR]

Reaction of thorium(IV) nitrate with 2-[(4-phenyl-1H-1,2,3-triazol-1-yl)meth­yl]pyridine (L) yielded (LH)2[Th(NO3)6] or (C14H13N4)2[Th(NO3)6] (1), instead of the expected mixed-ligand complex [Th(NO3)4L2], which was detected in the mass spectrum of 1. In the structure, the [Th(NO3)6]2- anions display an icosa­hedral coordination geometry and are connected by LH+ cations through C--H...O hydrogen bonds. The LH+ cations inter­act via N--H...N hydrogen bonds. Hirshfeld surface analysis indicates that the most important inter­actions are O...H/H...O hydrogen-bonding inter­actions, which represent a 55.2% contribution. [ABSTRACT FROM AUTHOR]

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