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Polymer electrolyte with a controllable structure affords a unique opportunity to improve its ionic conductivity and lithium-ion transference number (tLi+) due to the precise design of its polymer ...

Chromium (Cr) is a common heavy metal that has severe impacts on the ecosystem and human health. Capacitive deionization (CDI) is an environment-friendly and energy-efficient electrochemical purification technology to remove Cr from polluted water. The performance of CDI systems relies primarily on the properties of electrodes. Carbon-nanotubes (CNTs) membranes are promising candidates in creating advanced CDI electrodes and processes. However, the low electrosorption capacity and high hydrophobicity of CNTs greatly impede their applications in water systems. In this study, we employ atomic layer deposition (ALD) to deposit TiO2 nanoparticulates on CNTs membranes for preparing electrodes with hydrophilicity. The TiO2-deposited CNTs membranes display preferable electrosorption performance and reusability in CDI processes after only 20 ALD cycles deposition. The total Cr and Cr(VI) removal efficiencies are significantly improved to 92.1% and 93.3%, respectively. This work demonstrates that ALD is a highly controllable and simple method to produce advanced CDI electrodes, and broadens the application of metal oxide/carbon composites in the electrochemical processes.

Solid adsorbents that simultaneously have high selectivity and uptake capacity are highly promising as alternatives to conventional cryogenic distillation of propene/propane (C3H6/C3H8) separation. Coordinatively unsaturated metal sites (CUS) plays a vital role in selective adsorption of olefins over paraffins. Ultrathin poly (triazine imide) (PTI) nanosheets can reach rapid gas adsorption equilibrium, due to its large surface-to-volume ratio. In this work, combining the advantages of the CUS and the PTI nanosheets, Li CUSs were introduced into the PTI nanosheets for C3H6/C3H8 separation. Density functional theory (DFT) calculations demonstrated the thermodynamic feasibility of incorporating Li CUSs into the PTI nanosheets. These highly exposed Li CUSs were predicted to have a higher adsorption affinity toward C3H6 than C3H8. Using the DFT-derived force field parameters, we further performed grand canonical Monte Carlo (GCMC) simulations to investigate C3H6/C3H8 adsorption on the Li−PTI complexes slit pore model with different pore widths (H). We found that the Li−PTI complexes display considerable C3H6/C3H8 selectivity (4.2∼7.9) under relevant conditions. Moreover, the Li−PTI complexes slit pore have large C3H6 working capacities (1.5∼4.0 mmol g-1), superior to those calculated for the most of adsorbent materials that have been reported. The Li−PTI complexes with slit pore architecture show potential as C3H6/C3H8 separation materials.

In this paper, a phase-field-based lattice Boltzmann model for ternary fluid flows is proposed, where the conservative Allen-Cahn equation for ternary fluids is employed to track the interface of fluids. A time derivative term is introduced to the LB equation for the conservative Allen-Cahn equation and a forcing distribution function is used to the LB equation for the Navier-Stokes equations. The computational accuracy and capability of this proposed model are verified by benchmark cases related to stationary droplets, spreading of a liquid lens, and phase separation of a ternary mixture fluid. Moreover, a wetting boundary scheme based on the framework of the lattice Boltzmann method applicable to ternary fluid flows is developed. This model performs well in eliminating the undesired numerical artifact after considering the wettability effect. Typical wettability problems are simulated to verify the applicability of the wetting boundary scheme, including the spreading of binary droplets and compound droplets on the surface. The numerical results of static contact angles and spreading length show a good fit of the data to the theoretical results within the scope of permissible error. Furthermore, the reliability of this wetting boundary condition for the dynamic case is verified by modelling the motion of the compound droplets subjected to the shear flow on the substrate. This boundary scheme performs well for the motion of ternary fluids with a small and large density ratio. In conclusion, the phase-field-based lattice Boltzmann model for ternary fluid flows considering the wetting effect has good applicability for modelling the ternary fluid flows at a density ratio of 1000.

The electrocatalytic nitrogen reduction reaction (NRR) has emerged as a promising renewable energy source and a feasible strategy as an alternative to Haber-Bosch ammonia (NH3) synthesis. However, finding an efficient and cost-effective robust catalyst to activate and cleave the extremely strong triple bond in nitrogen (N2) for electrocatalytic NRR is still a challenge. Herein, a FeNi@CNS nanocomposite as an efficient catalyst for N2 fixation under ambient conditions is designed. This FeNi@CNS nanocomposite was prepared by a simple water bath process and post-calcination. The FeNi@CNS is demonstrated to be a highly efficient NRR catalyst, which exhibits better NRR performance with exceptional Faradaic efficiency of 9.83% and an NH3 yield of 16.52 μg h − 1 cm−2 in 0.1 M Na2SO4 aqueous solution. Besides, high stability and reproducibility with consecutive 6 cycles for two hours are also demonstrated throughout the NRR electrocatalytic process for 12 h. Meanwhile, the FeNi@CNS catalyst encourages N2 adsorption and activation as well as effectively suppressing competitive HER. Therefore, this earth-abundant FeNi@CNS catalyst with a subtle balance of activity and stability has excellent potential in NRR industrial applications.

Summary Preparation of thermally stable metal single-atom catalysts (SACs) is a challenge in heterogeneous catalysis, especially on conventional supports that provide a weak metal-support interaction. In this work, we report that a modified support MgAl2O4 can stabilize Pt single atoms by a mechanism of vapor-phase self-assembly in a high-temperature treatment (800°C, air). The experimental results on the formation mechanism and the structure are validated by DFT and ab initio molecular dynamics simulations. We infer that stable triangular K3O3 structures help stabilize Pt single atoms at high temperatures in oxidizing conditions, exhibiting excellent reactivity for methane oxidation. The obtained Pt/K/MgAl2O4 SAC presents excellent stability in methane oxidation after steam treatment at elevated temperatures, whereas the Pt/MgAl2O4 nanocatalyst suffers from rapid deactivation due to Pt nanoparticle growth. This work paves the way for preparing thermally stable and highly active SACs using conventional high-surface-area supports, despite the weak metal-support interaction.

Zinc (Zn) metal anode, as a promising candidate for high-energy Zn-based batteries, is attracting more attention for its high specific capacity and safety. However, severe issues of uncontrollable side reactions and fatal Zn dendrites exhibit great limitations for practical application. Herein, a unique separator decorated with functional supramolecules (GF@SM) is constructed for guiding the uniform distribution of Zn ions and enhancing the electrochemical performance of the Zn metal anode. Plenty of zincophilic groups in supramolecules display a superior affinity with Zn ions, avoiding the accumulation of Zn ions on the electrode surface and suppressing the formation of dendritic Zn metal. When applied in the Zn metal batteries, GF@SM separators can effectively improve electrochemical performances. For the galvanostatic charging/discharging test, an ultralong lifespan of 2000 h with stable voltage polarization can be delivered by the symmetric cell with GF@SM. Zn|MnO2 full cell based on GF@SM composite separator exhibit a stable and high specific capacity of 159.8 mAh g−1 after 1000 cycles at 1 A g−1 and superior rate capability. The unusual design of this composite separator and its promising application provides helpful guidance for safe and high-performance Zn metal batteries.

The goal of the research was to investigate the profile control and oil displacement characteristics of the polymer nanoparticles after high temperature swelling. The displacement parameters showed considerable influence on the plugging effect of the high-temperature swelled polymer nanoparticles, such as the core permeability, concentration of nanoparticles in the suspension, swelling time and swelling temperature, which makes it flexible to control the plugging effect by controlling displacement experiments conditions. Experimental results show that polymer nanoparticles dispersion system with a concentration of 500 mg/L is suitable for cores plugging with a permeability of 30 × 10−3 - 150 × 10−3 μm2, even after aging at 150 °C for three months. The shunt flow experiments show that when the displacement factors are optimal values, the polymer nanoparticles after high temperature swelling to plug the high-permeability layer selectivity and almost do not clog the low-permeability layer. Oil recovery of homogeneous artificial core displacement experiment and a heterogeneous double-tube cores model are increased by 20% and 10.4% on the basis of water flooding. The polymer nanoparticles can be a great help for petroleum engineers to better apply this deep profile control and flooding technology.

With great superiorities in energy density, rate capability and structural stability, Na3V2(PO4)2F3 (NVPF) has attracted much attentions as cathode of sodium ion battery (SIB), but it also faces challenges on its poor intrinsic electronic conductivity and the controversial de/sodiation mechanism. Herein, a series of Zr-doped NVPF coated by N-doped carbon layer (~5 nm in thickness, homogenously) materials are fabricated by a sol–gel method, and the optimized heteroatom-doping amounts of Zr and N doping improve intrinsic properties on enlarging lattice distance and enhancing electronic conductivity, respectively. Specifically, among all samples of Na3V2−xZrx(PO4)2F3/NC (NVPF-Zr-x/NC, x = 0, 0.01, 0.02, 0.05, and 0.1), the optimized electrode of NVPF-Zr-0.02/NC delivers high reversible capacities (119.2 mAh g−1 at 0.5 C), superior rate capability (98.1 mA h g−1 at 20 C) and excellent cycling performance. The structural evolution of NVPF-Zr-0.02/NC electrode, in-situ monitored by X-ray diffractometer, follows a step-wise Na-extraction/intercalation mechanism with reversible multi-phase changes, not just a solid-solution-reaction one. Full cells of NVPF-Zr-0.02/NC//hard carbon demonstrate high capacity (99.8 mA h g−1 at 0.5 C), high out-put voltage (3.5 V) and good cycling stability. This work is favorable to accelerate the development of high-performance cathode materials and explore possible redox reaction mechanisms of SIBs.

Covalent organic frameworks (COFs) have been recognized as a new type of promising visible-light-driven photocatalysts for H2 evolution, while it still is a key point to facilitate the separation and transfer of photoinduced charges for further enhancing their activities. In this work, we fabricated a new type of ternary Pt/rGO/COF photocatalysts with Pt cocatalyst precisely anchored on rGO serving as electron collector for largely enhanced H2 evolution. A series of ternary hybrid materials were obtained via one-pot photoreduction of Pt4+ and GO under visible-light irradiation in a solution the same as photocatalytic H2 evolution reaction and simultaneous self-assembling of rGO/COF heterostructure. No need isolation, the synthetic system could be further used for photocatalytic H2 evolution reaction and the results show the H2 evolution rate of Pt/rGO(20%)/TpPa-1-COF hybrid material is 19.59 mmol·g−1·h−1, 6.51 times higher than that of Pt/TpPa-1-COF. The essential role of the exclusively distributed Pt nanoparticles on rGO to the high H2 evolution activity was confirmed by various comparisons of activity for the samples with diverse Pt distribution.

Two-dimensional covalent organic frameworks (COFs) with specific morphologies including nanofibers and nanoplates are highly desired in both nanoscience research and practical applications. Thus far, however, morphology engineering for COFs remains challenging because the mechanism underlying the morphology formation and evolution of COFs is not well understood. Herein, we propose a strategy of surfactant mediation coupled with acid adjustment to engineer the morphology of a β-ketoenamine-linked COF, TpPa, during solvothermal synthesis. The surfactants function as stabilizers that can encapsulate monomers and prepolymers to create micelles, enabling the formation of fiber-like and plate-like morphologies of TpPa rather than irregularly shaped aggregates. It is also found that acetic acid is important in regulating such morphologies, as the amino groups inside the prepolymers can be precisely protonated by acid adjustment, leading to an inhibited ripening process for the creation of specific morphologies. Benefitting from the synergistic enhancement of surfactant mediation and acid adjustment, TpPa nanofibers with a diameter down to ~20 nm along with a length of up to a few microns and TpPa nanoplates with a thickness of ~18 nm are created. Our work sheds light on the mechanism underlying the morphology formation and evolution of TpPa, providing some guidance for exquisite control over the growth of COFs, which is of great significance for their practical applications.

Graphene-based 2D materials have shown extraordinary promise in electrochemical energy storage, owing to their high electrochemical activity, fast carrier mobility, and large electronic conductivity. However, low specific capacity ( 5 mAh cm−2). The highly interpenetrating graphene oxide network in the HAGO/Co@CN electrode accelerates electronic transport. In addition, benefiting from the advanced layered architecture, the HAGO/Co@CN electrode exhibits excellent structural stability and thickness-independent electrochemical performances. By systematically adjusting the orientation of GO/Co@CN nanosheets inside electrode to optimize the electron/ion transmission to deliver high areal capacity and high-rate capability at high mass loading. More importantly, a designed full cell with NCM622 cathode and HAGO/Co@CN anode shows ultrahigh capacity retention of >98% at 1 C after 500 cycles with a commercial-level reversible capacity of 2.3 mAh cm−2.

Semiconductor-based photocatalysis represents a promising technology for removing antibiotic given its cost effectiveness and environmental compatibility. However, finding suitable photocatalysts and semiconductors for practical applications can be challenging. This work aims to investigate the photocatalytic performance of as-synthesized photocatalysts under broad-spectrum from visible (Vis) to near-infrared (NIR) sunlight. In this work, a step-scheme (S-scheme) heterojunction photocatalyst, i.e., CuS/S–C3N4, was prepared, employing a single-step hydrothermal route. The synthesized photocatalyst showed excellent crystallinity and high purity content. The CuS loading provided a better NIR light response-ability and improved photocatalytic activity for CuS/S–C3N4. The 2 wt% CuS/S–C3N4 produced the highest tetracycline (TC) photodegradation rate, up to about 95% efficiency under Vis + NIR light irradiation. The result also showed that the 2 wt% CuS/S–C3N4 sample had a first-order kinetic constant (k) that was 6.2-fold higher than the pure S–C3N4 sample under Vis + NIR light irradiation. However, too much CuS content led to the presence of inactive sites on S–C3N4, which hampered the light absorption ability, thus leading to inadequate photocatalytic activity. In addition, the 2 wt% CuS/S–C3N4 sample also showed high photocatalytic stability and insignificant change of the composite structure before and after the experiments. In short, we can enhance the CuS/S–C3N4 photocatalytic activity by increasing the light response range and the separation efficiency of light-induced electrons and holes. Consequently, we have developed a novel strategy and experimental basis for S-scheme heterojunction to be fully utilized under broad-spectrum sunlight.

Poor cycling stability and low volumetric capacity of sulfur cathode prevents practical application of Lithium-sulfur (Li-S) batteries. Herein, we demonstrate a strategy to address the two drawbacks of sulfur cathode by synthesizing a compact and flexible film cathode with bilayer structure using a two-step vacuum filtration method. Two layers make up the sulfur cathode, active layer (sulfur-acethlene black (S C) spheres) and barrier layer (three dimensional MnO2-graphene oxide-multi-walled carbon nanotubes (MnO2-GO-CNTs) composites), which are integrated together by reduced graphene oxide (rGO) through self-binding. The rGO sheets provide an electrical conductive framework and a stable architecture to accommodate volume changes of sulfur. S C spheres stacked orderly between the rGO layers facilitate fast Li+ storage and energy release. Polar MnO2-GO-CNTs composites with large specific surface area have not only afforded efficient sites for chemically binding polysulfides, but also provided fast electron transfer for accelerating polysulfides redox reaction. Consequently, the integrated film cathode exhibits an unprecedented cycling stability of ~0.0279% capacity decay per cycle over more than 600 cycles at 1C and high volumetric capacity of 1021.9 Ah L-1 at 2C. Meanwhile, a foldable Li-S battery based on this flexible cathode is fabricated and shows excellent mechanical and electrochemical properties. The integrated flexible sulfur cathode of this study sheds light on the design strategies for application in flexible high volumetric capacity system.

The suppression of high-intensity blob structures in the scrape-off layer (SOL) by ion-cyclotron range of frequencies (ICRF) power, leading to a decrease in the turbulent fluctuation level, is observed first in the Experimental Advanced Superconducting Tokamak (EAST) experiment. This suppression effect from ICRF power injection is global in the whole SOL at EAST, i.e. blob structures both in the regions that are magnetically connected to the active ICRF launcher and in the regions that are not connected to the active ICRF launcher could be suppressed by ICRF power. However, more ICRF power is required to reach the full blob structure suppression effect in the regions that are magnetically unconnected to the active launcher than in the regions that are magnetically connected to the active launcher. Studies show that a possible reason for the blob suppression could be the enhanced E r × B shear flow in the SOL, which is supported by the shaper radial gradient in the floating potential profiles sensed by the divertor probe arrays with increasing ICRF power. The local RF wave power unabsorbed by the core plasma is responsible for the modification of potential profiles in the SOL regions.

Purpose Although mock-ups have been widely used in dental esthetic rehabilitation, their accuracy has not been quantitatively evaluated, and the methods of fabricating mock-ups are various. This in vitro study investigated the thickness accuracy of mock-ups fabricated with different silicone matrices. Methods Mock-ups of maxillary anterior teeth were respectively fabricated by 72 silicone matrices that were equally divided into four groups (n=18 for each group) according to two variables of the silicone matrices: labial margin position (equigingival or cover labial gingiva for 1-2 mm) and palatal notches (with or without notches on the palatal side of silicone matrices). The thickness accuracy of the mock-ups was analyzed using 3D scanning and 3D deviation analysis techniques compared with diagnostic waxing. The thickness change ratios of the mock-ups were compared using a two-way analysis of variance (ANOVA). One-way ANOVA and Kruskal-Wallis tests were used to compare differences in thickness change ratios between different teeth in each group. Results The thickness accuracy of the mock-ups was significantly affected by the labial margin position and the palatal notches of the silicone matrices, respectively, in the labial area and the incisal area. The most accurate mock-ups were made using silicone matrices with equigingival labial margins and palatal notches. The thickness accuracy of the mock-ups was also inconsistent on different teeth. Conclusions The mock-ups fabricated by silicone matrices were thicker than the diagnostic waxing. The application of silicone matrices to equigingival labial margins and palatal notches was beneficial to the thickness accuracy of mock-ups.

Flexible freestanding electrodes, with high electrochemical performances and long-cycle stability, are the key units and urgently essential to realize flexible solid-state supercapacitors, fulfilling the demand for portable electronic equipment. Herein, we report hierarchical “tube-on-fiber” nanostructures synthesized via melamine-assisted carbonization and vulcanization process on electrospun fibers composed of zeolitic imidazolate framework-67 and polyacrylonitrile. The hierarchical nanostructure is devised to prevent agglomeration of Co mixed-cobalt sulfide nanoparticles and the in situ growth of Co-catalyzed carbon nanotubes (CNT) on carbon nanofibers is extremely acceptable to improve the electronic conductivity. Based on the above advantages, hierarchical nanostructured composite of carbon encapsulated metal sulfide (Co-S@CNF-CNT-3) presents a satisfied specific capacitance of 416.5 F g−1 at 0.2 A g−1. In addition, a quasi-solid-state asymmetric supercapacitor with Co-S@CNF-CNT-3 as the cathode and C@CNF-CNT-3 as the anode (defined as Co-S@CNF-CNT-3//C@CNF-CNT-3) is assembled. It exhibits a high energy density of 10.3 Wh kg-1 with a power density of 320 W kg-1 at 0.4 A g-1 or a superior power density of 8000 W kg-1 with an energy density of 7.56 Wh kg-1 at 10 A g-1. Furthermore, the assembled hybrid supercapacitor shows an outstanding capacitance retention of 96.9% after 10000 cycles at 5 A g-1 and good mechanical flexibility, illustrating its promising potential for practical flexible supercapacitors.

Auto-tandem catalysis that uses a single catalyst to bridge and discriminate different catalytic cycles in a one-pot process is highly desirable for obtaining a high degree of structural complexity...

OBJECTIVES: To evaluate the effects of different polyphenols and solvents on dentin collagen’s crosslinking interactions and biostabilization against MMPs and collagenase degradation. METHODS: Two polyphenols [proanthocyanidin (PA) and quercetin (QC)] with different water solubility were prepared as treatment solutions using ethanol (EtOH) or dimethyl sulfoxide (DMSO) as solvents. 6-um-thick dentin films were microtomed from dentin slabs of third molars. Following demineralization, films or slabs were subject to 60-s treatment (PA or QC) or no treatment (control) with subsequent extended-rinse with original solvent (EtOH or DMSO) or distilled water (DW). Collagen crosslinking interactions were assessed by FTIR. Biostability was assessed through endogenous MMPs activity via confocal laser scanning microscopy, and exogenous collagenase degradation via weight loss, hydroxyproline release and SEM. Finally, direct collagenase inactivation was also evaluated. Data were analyzed by three-way ANOVA and post-hoc tests (α=0.05%). RESULTS: Distinct effects of two polyphenols and solvents on collagen crosslinking and biostabilization were observed. Higher crosslinking and biostability efficacy occurred with PA than QC (p < 0.001) that demonstrated negligible collagen interactions. With DMSO solvent, efficacy results were significantly reduced with both polyphenols (p < 0.05). DMSO-rinse further weakened interactions of PA with collagen, diminishing biostability (p < 0.05). Low biostability was detected with QC and DW-rinse, suggesting direct enzymatic inhibition due to physical presence in collagen. SIGNIFICANCE: Collagen crosslinking interactions and biostability depend on polyphenol chemical characteristics. Treatment-solution solvents may affect interactions between polyphenols and collagen, specifically, DMSO showed detrimental effects on collagen crosslinking and biostability and should be used with caution.

Perovskite oxides have emerged as promising candidates for the oxygen evolution reaction (OER) electrocatalyst due to their flexible lattice structure, tunable electronic structure, superior stability, and cost-effectiveness. Recent research studies have mostly focused on the traditional methods to tune the OER performance, such as cation/anion doping, A-/B-site ordering, epitaxial strain, oxygen vacancy, and so forth, leading to reasonable yet still limited activity enhancement. Here, we report a novel strategy for promoting the OER activity for perovskite LaNiO3 by crystal phase engineering, which is realized by breaking long-range chemical bonding through amorphization. We provide the first and direct evidence that perovskite oxides with an amorphous structure can induce the self-adaptive process, which helps enhance the OER performance. This is evidenced by the fact that an amorphous LaNiO3 film on glassy carbon shows a 9-fold increase in the current density compared to that of an epitaxial LaNiO3 single crystalline film. The obtained current density of 1038 μΑ cm-2 (@ 1.6 vs RHE) is the largest value among the literature reported values. Our work thus offers a new protocol to boost the OER performance for perovskite oxides for future clean energy applications.

This paper assesses a number of direct strength methods (DSM) for thin-walled steel members under combined major axis bending and compression. These methods consist of two ways of calculating the compression – bending moment (P-M) interaction surface (plastic or first yield) of the cross-section, and the following three methods of operating on the P-M surface: using a compound value of the surface; converting a beam-column to an equivalent beam; and converting a beam-column to an equivalent column. The aim of this research is to identify the most consistently accurate and easy to implement DSM equations to calculate the resistance of thin-walled steel beam-column members, by comparison against numerical simulation results, obtained using a validated ABAQUS model. The numerical simulations investigated the effects of changing different design parameters to ensure a sufficient dataset for each failure mode, including section size, member length, flange restraint, load eccentricity and yield strength. Based on an evaluation of the mean and standard deviation of ratios of the calculated resistances to ABAQUS simulation results, it has been found that for global buckling, any of the methods can produce accurate results. For local buckling, the standard deviation values for all the methods are similar, about 0.05. However, when judging the mean values, the best methods are the equivalent beam method using plastic P-M surface, with a mean value of 0.995. For distortional buckling, upon modification of the existing DSM equations for pure bending using the plastic P-M surface, the equivalent beam method gave an average of 0.998 and a standard deviation of 0.102. Overall, the equivalent beam method using the plastic P-M surface is the most consistently accurate method.

Sea water resources are extensive and can be used to extinguish fires, but their corrosiveness is a major problem. Using the method of electrochemical workstation, the electrochemical corrosion behavior of aluminum sheet in artificial sea water solution and silica-coated artificial seawater was studied; by analyzing the surface morphology, polarization curve and electrochemical impedance spectroscopy, the electrochemical corrosion behavior of aluminum sheets under different immersion times and different immersion media is obtained. The conclusion is that the coating of nanosilica powder has a certain corrosion protection effect on artificial seawater.

Supramolecular adhesives that enable debonding on-demand are of significant research interest for the development of adaptive and smart materials, yet, biodegrable supramolecular adhesives have been rarely exploited. Herein, telechelic, three-armed and four-armed CO2-based polyols with close molecular weights and various CO2 content (or carbonate unite content) have been synthesized via a zinc-cobalt double metal cyanide complex catalyzed ring-opening copolymerization of CO2 and propylene oxide, and further exploited as sustainable and biodegradable building blocks for supramolecular polymers (SMPs) with 2-ureido-4[1H]-pyrimidinone (UPy) motifs. Notably, the orthogonal modulation of the CO2 content and the topology of CO2-based polyols provide a unique opportunity to fine-tune the surface energy as well as the cohesive strength of the resulting CO2-based SMPs. Notably, a three-armed SMP with 44% CO2 (3UPy-CO2-44%) can well balance the trade-off between surface energy and cohesive strength, therefore bestowing a high adhesive strength of 7.5 and 9.7 MPa towards stainless steel and wood substrates respectively by testing the corresponding single lap joints. Moreover, the light-responsive adhesion property of 3UPy-CO2-44% has been demonstrated exemplarily by blending with a UV sensitizer.

Fe-based nanocrystalline alloys obtained through isothermal annealing of their amorphous counterparts have emerged as an indispensable soft magnetic material. The development of Fe-based nanocrystalline alloys with excellent soft magnetic properties and good corrosion resistance is highly desirable. In this study, the magnetic properties and corrosion resistance of Fe75.8Si12B8Nb2.6Cu0.6P1 alloys are investigated a function of the annealing temperature. Upon crystallization, the permeability (μ) and coercivity (Hc) of the alloy gradually improve with an increase in the annealing temperature owing to the formation of homogeneous and fine α-Fe(Si) grains. However, excessively high temperatures promote the precipitation of Fe2B and Fe23B6 phases, significantly deteriorating the soft magnetic properties. The alloy annealed at 843 K exhibits excellent magnetic softness with a high saturation magnetization of 1.41 T, a good μ of 2.7 × 104 at 1 kHz and a low Hc of 0.8 A/m. On the other hand, the corrosion resistance of the alloy is sensitive to the annealing temperature, and the higher the annealing temperature, the better the corrosion resistance will be. The improved corrosion resistance is due to the increase in the crystalline volume fraction resulting in the formation of an insoluble protective layer rich in Si and Nb oxides. This study further reveals the relationship between the annealing temperature and alloy properties and can facilitate the development of soft magnetic nanocrystalline alloys with good corrosion resistance.

CdS has a wide visible-light response range and suitable energy band structure; it has been spotlighted in the field of photocatalysis. Nevertheless, its poor photogenerated carriers separation eff...

An ultra-low carbon bainitic steel is developed through nanoprecipitation of high-density Mn/Fe-rich intermetallic B2-NiAl. A high yield strength of ~ 1.3 GPa and a good total elongation of ~ 13 pct are attained via minimal lattice misfit nanoprecipitation. Atom probe tomography and high-resolution transmission electron microscope were applied to characterize nanoscale precipitates. An increment of 544 MPa in yield strength is achieved after an aging process, predominantly attributed to the order strengthening mechanism.

In catalysis science, the electronic structure of the active site determines the structure-activity relationship of the catalyst to a large extent. Therefore, modulating the electronic structure has become a main route for the rational design of metal-based catalyst materials. In this work, we prepared a LaCoSiHx material that has more electronegativity and a lower workfunction than traditional supported Co-based catalysts. Using CO2 methanation as a model catalytic reaction, the facile dissociation of CO2 and CO (a key reaction intermediate) on the surface of the LaCoSiHx catalyst is observed by various experimental methods (e.g., in situ Raman and FTIR) at room temperature. Moreover, theoretical calculation results further show that LaCoSiHx has a much stronger capacity for carbon-oxygen bond activation than the Co surface. The intrinsic mechanism is attributed to the marked electron transfer from catalysts into the antibonding orbital of CO2 and CO.

The four-dimensional (4D) printing technology, as a combination of additive manufacturing and smart materials, has attracted increasing research interest in recent years. The bilayer structures printed with smart materials using this technology can realize complicated deformation under some special stimuli due to the material properties. The deformation prediction of bilayer structures can make the design process more rapid and thus is of great importance. However, the previous works on deformation prediction of bilayer structures rarely study the complicated deformations or the influence of the printing process on deformation. Thus, this paper proposes a new method to predict the complicated deformations of temperature-sensitive 4D printed bilayer structures, in particular to the bilayer structures based on temperature-driven shape-memory polymers (SMPs) and fabricated using the fused deposition modeling (FDM) technology. The programming process to the material during printing is revealed and considered in the simulation model. Simulation results are compared with experiments to verify the validity of the method. The advantages of this method are stable convergence and high efficiency, as the three-dimensional (3D) problem is converted to a two-dimensional (2D) problem. The simulation parameters in the model can be further associated with the printing parameters, which shows good application prospect in 4D printed bilayer structure design.

The treatment of emissions from natural gas engines is an important area of research since methane is a potent greenhouse gas. The benchmark catalysts, based on Pd, still face challenges such as water poisoning and long-term stability. Here we report an approach for catalyst synthesis that relies on the trapping of metal single atoms on the support surface, in thermally stable form, to modify the nature of further deposited metal/metal oxide. By anchoring Pt ions on a catalyst support we can tailor the morphology of the deposited phase. In particular, two-dimensional (2D) rafts of PdOx are formed, resulting in higher reaction rates and improved water tolerance during methane oxidation. The results show that modifying the support by trapping single atoms could provide an important addition to the toolkit of catalyst designers for controlling the nucleation and growth of metal and metal oxide clusters in heterogeneous catalysts. Despite its importance in the context of natural gas engines emissions treatment, methane oxidation remains challenging. Now, the authors introduce an approach to stabilize PdOx rafts on ceria by trapping Pt single atoms in the support resulting in a superior catalyst for this transformation.

The widely used alkyd resin suffers not only the flammability but also the autoignition of resin waste. Its autoignition should result from the air-drying exothermic effect due to autoxidation and conversion of double bond. However, the air-drying exothermic effect is seldom studied. In this study, five soybean oil-based alkyd resins were synthesized. The content of double bond measured by the titration method increased linearly with increasing the molar fraction of maleic anhydride. After air-drying, the infrared spectroscopy absorption peak for the double bond disappeared. Considering that the curing originated from the conversion of chemical bonds, the exothermic effect was theoretically analyzed to be 1163–1455 kJ mol−1 double bond based on the air-drying mechanisms and the differences among chemical bond energies. According to thermodynamics principles, the air-drying exothermic effect was also derived from the measured heat of combustion. When the content of double bond increased from 2.19 mol kg−1 resin to 2.56 mol kg−1 resin, the exothermic effect linearly increased from 1352 kJ mol−1 double bond or 2.96 kJ g−1 resin to 2508 kJ mol−1 double bond or 6.42 kJ g−1 resin. The steady and unsteady autoignition theoretical analyses implied that due to the air-drying exothermic effect the alkyd resin waste with a certain thickness would catch fire within one working day.

Membranes based on covalent organic frameworks (COFs) have demonstrated huge potential to resolve the long-standing bottlenecks in separation fields due to their structural and functional attributes. Herein, a three-dimensional COF featuring interpenetrated apertures, 3D-OH-COF, is rationally synthesized on polyimide supports to generate flexible, robust membranes. The resultant 3D-OH-COF presents excellent crystallinity, prominent porosity, and exceptional solvent resistance, enabling the produced membrane a sharp and durable selectivity to small molecules in water and organic solvents. Impressively, the membrane also exhibits excellent flexibility and robustness as verified by the well-maintained performances after serious bending and solvent soaking under elevated temperatures. We further chemically convert 3D-OH-COF into the carboxyl-decorated 3D-COOH-COF by a postsynthetic strategy. The 3D-COOH-COF retains high crystallinity, and the converted membrane receives a remarkable capture ability for targeted multivalent ions over other competing ions. This study exploits a viable avenue to produce practical 3D COF membranes toward ultimate separations under extreme conditions.

Graphene oxide (GO) is receiving tremendous attention in membrane separation; however, its desalination performances remain suboptimal because of excessive swelling and tortuous transport pathways. Herein, we chemically joint GO nanosheets and phenolic nanomeshes together to form laminated membranes comprising through-plane nanopores and stabilized nanochannels. GO and phenolic/polyether nanosheets are mixed to form stacked structures and then treated in H2SO4 to remove polyether to produce nanomeshes and to chemically joint GO with phenolic nanomeshes. Thus-synthesized laminated membranes possess enhanced interlayer interactions and narrowed interlayer spacings down to 6.4 A. They exhibit water permeance up to 165.6 L/(m2 h bar) and Na2SO4 rejection of 97%, outperforming most GO-based membranes reported so far. Moreover, the membranes are exceptionally stable in water because the chemically jointed laminates suppress the swelling of GO. This work reports hybrid laminated structures of GO and phenolic nanomeshes, which are highly desired in desalination and other applications.

When ethanol and water are mixed into gasoline, the dielectric properties of gasoline will change. Based on this characteristic, we propose an antenna sensor and study its radiation and sensing performance in detection of ethanol gasoline in 6-7GHz band. In order to avoid the corrosion of the oil sample on the antenna, the antenna adopts a multilayer dielectric substrate structure. A $2\times 2$ artificial magnetic conductor (AMC) array is loaded on the bottom of the antenna to increase the gain of the sensor and reduce the return loss. The antenna sensor has good radiation pattern with a peak gain of 4 dB and high quality factor(Q) up to 69. Furthermore, the antenna sensor shows the advantages of high sensitivity and wide detection range on the detection of oil-water mixture and ethanol gasoline concentration. In order to verify the simulated results, the radiation and sensing performance of the antenna were measured, and the measured results were basically consistent with the simulated ones. Therefore, the proposed antenna sensor can be used for real-time wireless detection in ethanol gasoline transportation.

Two-dimensional graphene oxide (GO) membranes exhibit great potential for environmental aqueous separation and purification. However, their viability and performance are greatly limited under cross-flow conditions due to the enlargement of interlayer spacing and peeling of stacked GO laminates in aqueous environments. Herein, inspired by natural nacre structure, we present a dual-functional and ultra-stable β-cyclodextrin (β-CD) -polyacrylic acid (PAA) -GO composite membrane, with a constant d-spacing in both wet and dry states. Nanosheets and chain polymers construct a typical “brick-mortar” structural configuration, which exhibits great anti-swelling property compared with other reported GO membranes. By rationally optimizing and tuning the membrane structures, the ultrathin GO membrane (∼50 nm) exhibits outstanding stability in cross-flow and long-term filtration. Moreover, the designed membrane shows dual functions (high-throughput enantioselectivity and excellent dyes rejection) with the increase of molecular size. This strategy boosts the ongoing research in designing robust lamellar membrane materials for practical engineering applications in aqueous environments.

Metal/oxide interface is of fundamental significance to heterogeneous catalysis because the seemingly “inert” oxide support can modulate the morphology, atomic and electronic structures of the metal catalyst through the interface. The interfacial effects are well studied over a bulk oxide support but remain elusive for nanometer-sized systems like clusters, arising from the challenges associated with chemical synthesis and structural elucidation of such hybrid clusters. We hereby demonstrate the essential catalytic roles of a nanometer metal/oxide interface constructed by a hybrid Pd/Bi2O3 cluster ensemble, which is fabricated by a facile stepwise photochemical method. The Pd/Bi2O3 cluster, of which the hybrid structure is elucidated by combined electron microscopy and microanalysis, features a small Pd-Pd coordination number and more importantly a Pd-Bi spatial correlation ascribed to the heterografting between Pd and Bi terminated Bi2O3 clusters. The intra-cluster electron transfer towards Pd across the as-formed nanometer metal/oxide interface significantly weakens the ethylene adsorption without compromising the hydrogen activation. As a result, a 91% selectivity of ethylene and 90% conversion of acetylene can be achieved in a front-end hydrogenation process with a temperature as low as 44 °C., Metal/oxide interface is of fundamental significance to heterogeneous catalysis. Here, the authors construct a nanometer Pd/Bi2O3 interface by grafting Pd clusters onto Bi2O3 clusters and demonstrate its essential roles in the low-temperature semi-hydrogenation of acetylene.

Response surface methodology (RSM) was used to optimize the preparation conditions of nano-hybrid wood/polymer composites with montmorillonite (MMT) and furfuryl alcohol (FA). The effects of MMT amount, impregnation pressure and impregnation time on weigh percent gain (WPG) of treated samples were evaluated with Box-Behnken design (BBD) of a 3-level-3-factor from RSM. The predictive model for the response was extremely significant (p < 0.01). The determination coefficient (√R2) and the adjusted determination coefficient (VR2) of this model were 0.9651 and 0.9203, respectively. The optimal preparation conditions obtained by RSM design with the assistance of Design Expert were determined as follows: 4 wt% MMT amount, 0.8 MPa impregnation pressure, and 80 min impregnation time. It could be concluded from the SEM images that MMT and FA coated the cell walls and filled cell lumens. Moreover, the thermal stability was also investigated. The effects of preparation conditions were further validated by analyzing the water uptake ratio (WU), modulus of elasticity (MOE) and modulus of rupture (MOR) of the pristine samples and the treated samples prepared under optimized conditions.

The novel keyhole gas tungsten arc (K-TIG) welding technique was applied to weld 2205 duplex stainless steel (DSS) with a thickness of 8 mm. The effects of welding parameters on both stability time of keyhole and profile of fusion zone were discussed. And the influence of heat input on microstructure and mechanical properties of welded joints was investigated. The results showed that both quasi-steady keyhole and single-pass full-penetration welding joint were obtained by optimizing welding parameters. The welding current is a crucial factor for the formation of a quasi-steady keyhole. Furthermore, the weld metal (WM) with a heat input of 1.57 kJ/mm has more content of intragranular austenite (IGA) as well as low content of hard Cr2N and exhibits an excellent mechanical property. Refined IGA grains, including large amounts of recrystallized grains (RGs) and high angle grain boundaries (HAGBs), could improve the strength of the welded joint and hinder the propagation of microcracks. Besides, the rod-like precipitate Cr2N plays a pernicious role in impact toughness because it could be the microcracks origins. With an increase in heat input, the hardness of WM increases, which is owing to the growing content of both hard Cr2N and the semi-shear Widmanstatten austenite (WA).

Laboratory experiment and thermodynamic calculation for the Ti-containing 24 mass pct Cr ferritic stainless steel with a CaO-SiO2-Al2O3-MgO system slag were performed to investigate the effect of slag addition on the inclusion characteristics in molten steel. The morphology, composition, and size evolution of inclusions in steel samples were analyzed in three-dimensional by the electrolytic extraction method and in two-dimensional by the automatic analysis method. The results showed that the Ti content significantly decreased after the slag addition. However, the change of the Si content showed an opposite tendency. The decrease of the Ti content in steel was due to the reduction of SiO2 and Al2O3 in the slag by dissolved Ti in steel. An increase of the TiO2 content in the slag can decrease the Ti loss in steel based on the slag-steel kinetic analysis. The total O content in the steel melt decreased from 62 to 26 ppm, and the steel cleanliness was improved, since the number density of inclusions decreased after the slag refining. The results of a kinetic analysis showed that the rate-determining step of the oxidation of Ti in the steel and the reduction of SiO2 in the slag were the mass transfer on the slag side. In addition, high Ti2O3-containing inclusions were found to be transformed to Cr2O3-Ti2O3-Al2O3 and Cr2O3-Ti2O3-SiO2 system inclusions after the slag addition. The Al2O3 contents in inclusions increased while the Ti2O3 contents decreased with time. However, there were some amount of high melting point inclusions with high Al2O3 content, which were not what we expected. When plotted on logarcxithmic scales, the mole ratio $$X_{{{\text{Al}}_{2} {\text{O}}_{3} }} /(X_{{{\text{Ti}}_2 {\text{O}}_{3} }} \cdot X_{{{\text{Cr}}_{2} {\text{O}}_{3} }} )$$ X Al 2 O 3 / ( X Ti 2 O 3 · X Cr 2 O 3 ) values of the inclusions were expressed as a linear function of the $$a_{\text{Al}}^{2} /(a_{Ti}^{2} \cdot a_{\text{Cr}}^{2} \cdot a_{\text{O}}^{3} )$$ a Al 2 / ( a Ti 2 · a Cr 2 · a O 3 ) values of the steel melts with a slope of unity, which was theoretically expected.

The effect of Al content on the microstructure and ductile-brittle transition temperature (DBTT) of 18Cr–Al–Si ferritic heat-resistant stainless steel have been studied by Charpy impact testing over temperatures ranging from 20 to 90 ℃. Charpy impact test results show that DBTT increased with increasing Al content. Meanwhile, fracture morphology changed with increasing Al content, where the amount of dimples decreased and cleavage facets increased, indicating increases in the tendency for brittle fracture. Furthermore, ferrite grain size, volume fraction and size of (Cr, Fe)23C6 carbides increased with increasing Al content, which led to decreasing toughness and increasing DBTT.

Solid polymer electrolytes (SPEs), with improved energy densities and operational safety, have replaced liquid electrolytes in next-generation Li metal batteries (LMBs). However, the detrimental ef...

A single-atom Pt1 /CeO2 catalyst formed by atom trapping (AT, 800 °C in air) shows excellent thermal stability but is inactive for CO oxidation at low temperatures owing to over-stabilization of Pt2+ in a highly symmetric square-planar Pt1 O4 coordination environment. Reductive activation to form Pt nanoparticles (NPs) results in enhanced activity; however, the NPs are easily oxidized, leading to drastic activity loss. Herein we show that tailoring the local environment of isolated Pt2+ by thermal-shock (TS) synthesis leads to a highly active and thermally stable Pt1 /CeO2 catalyst. Ultrafast shockwaves (>1200 °C) in an inert atmosphere induced surface reconstruction of CeO2 to generate Pt single atoms in an asymmetric Pt1 O4 configuration. Owing to this unique coordination, Pt1 δ+ in a partially reduced state dynamically evolves during CO oxidation, resulting in exceptional low-temperature performance. CO oxidation reactivity on the Pt1 /CeO2 _TS catalyst was retained under oxidizing conditions.