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Ion doping strategy is a promising method to enhance the efficiency of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells, however, most of the reported works focus on studying the single ion doping in CZTSSe absorber layers. Here, Li+&Ag+ and Li+&Cd2+ double-ion-doping strategy are applied to improve the microstructure and device performances. We found that the double-ion-doping strategy can obviously increase the grain size, reduce the thickness of fine-grain layers and enhance the device performances. Furthermore, the PCEs of Li+&Ag+ and Li+&Cd2+ doped CZTSSe solar cells are up to 8.87% and 8.39%, respectively. It shows an encouraging improvement of over 43.5% and 35.8% enhancement compared with the traditional method (6.18%), and significantly higher than single ion doping strategy (7.60%, 7.99% and 7.11% for Li+, Ag+, and Cd2+ doped CZTSSe solar cells). This work provides a new solution to improve the microstructure and device performances of CZTSSe solar cells.

The improvement of recrystallization texture and magnetic properties in grain-oriented electrical steel with trace Bi addition processed by strip casting process was studied in this study. Low casting temperature and sufficient liquid steel flow during strip casting process enabled relatively homogeneous distribution of Bi in the as-cast strip, which accelerated the precipitation during solidification and cooling process. As a result, relatively high density of duplex MnS + AlN, MnS and AlN was formed at grain boundaries and inside grain. Due to the synergistic effect of continuous precipitation and fragmentation of coarse precipitates during cold rolling, the number density of precipitates was increased and mean size was decreased along the processing route. High density of precipitates is attributed to severe inhomogeneous plastic deformation, which promoted the formation of high density in-grain shear bands during cold rolling and recrystallization Goss texture during annealing. Homogeneous microstructure with average grain size of ~ 11.6 μm, strong Goss texture with intensity of 2.5 multiples of random distribution, fine precipitates with number density of ~ 1.9 × 109 /cm2 and mean size of ~ 49 nm were formed after primary recrystallization annealing. Furthermore, grain-oriented electrical steel with Bi addition experienced complete secondary recrystallization of exact Goss grains during high-temperature annealing, which is attributed to beneficial optimization of Goss texture and strong inhibition effect, and superior magnetic induction B8 of 1.91 T was obtained. It is expected that this study paves a new way for fabrication of high-performance grain-oriented electrical steel.

The scaling-up issue, mechanical instability, and possible packing capacity loss during pelletization remain as the major obstacles for the application of metal–organic frameworks (MOFs) in practic...

Stimulated by novel properties in topological insulators, experimentally realizing quantum phases of matter and employing control over their properties have become a central goal in condensed matte...

This article reports microstructural characterization of as-cast and as-extruded Zn-Fe alloys and their mechanical and corrosion properties. Specifically, 1 wt.%, 2 wt.% and 3 wt.% Fe was added into the Zn matrix to form respective Zn-Fe alloys using casting and indirect hot extrusion processes. As the Fe content increased within the range of 1–3 wt.%, the mechanical properties of as-cast and as-extruded Zn-Fe alloys improved. The as-extruded Zn-Fe alloys showed superior mechanical properties of hardness, ultimate tensile strength (UTS) and elongation to failure (EL) to the as-cast Zn-Fe alloys of the same composition. Specifically, the UTS for as-extruded Zn-Fe alloys was 138–170 MPa, whereas the UTS for as-cast Zn-Fe alloys was 89–125 MPa. The corrosion properties of the as-extruded Zn-Fe alloys were investigated using the electrochemical and immersion methods. The corrosion rate of the as-extruded Zn-Fe alloys ranged from 0.015 mm/year to 0.210 mm/year.

The crystal quality of Cu2ZnSn(S,Se)4 (CZTSSe) thin film is crucially important to the high-performance CZTSSe solar cell. After the selenization, a bi-layer CZTSSe thin film consisting of a large-...

Although many studies on luminescent metal–organic frameworks (MOFs) have been reported for chemical sensing applications, it has yet to be realized in MOFs the precise linearity control over photo...

State-of-the-art chemical sensors based on covalent organic frameworks (COFs) are restricted to the transduction mechanism relying on luminescence quenching and/or enhancement. Herein, we present an alternative methodology via a combination of in situ-grown COF films with interdigitated electrodes utilized for capacitive benzene detection. The resultant COF-based sensors exhibit highly sensitive and selective detection at room temperature toward benzene vapor over carbon dioxide, methane, and propane. Their benzene detection limit can reach 340 ppb, slightly inferior to those of the metal oxide semiconductor-based sensors, but with reduced power consumption and increased selectivity. Such a sensing behavior can be attributed to the large dielectric constant of the benzene molecule, distinctive adsorptivity of the chosen COF toward benzene, and structural distortion induced by the custom-made interaction pair, which is corroborated by sorption measurements and density functional theory (DFT) calculations. This study provides new perspectives for fabricating COF-based sensors with specific functionality targeted for selective gas detection.

This work reports a template-free wet chemical synthesis method for economical production of zinc oxide (ZnO) microrods by using an inexpensive polypropylene beaker as a reactor under atmospheric pressure. The morphology and crystal structure of the as-prepared ZnO microrods were investigated by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and Raman scattering. Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), Ultraviolet–visible (UV/Vis) spectroscopy and methylene blue photocatalytic degradation test were also conducted to study their physical and chemical properties. The results show that the as-prepared ZnO microrods have a hexagonal crystal structure. Under the optimal synthesis condition, they have a diameter of 0.8–2.6 μm and a length of 10–40 μm. Compared with commercial ZnO powders, the as-prepared ZnO microrods have a higher whiteness. Meanwhile, the as-prepared ZnO microrods have very low photocatalytic activity, indicating that they have good photostability and are unlikely to cause the photodegradation of polymers such as binders. As a result, they will be an excellent and economical white pigment with great potential in coating applications.

Fabricating flexible, stable and highly reproducible surface-enhanced Raman scattering (SERS) active substrates is very important in furthering the development of practical SERS sensors. Nevertheless, the fabrication of such SERS substrates is rather challenging in processing conditions for both noble metal and semiconductor substrates. In this study, highly sensitive SERS detection is achieved by fabricating novel textile-based SERS substrates with a structure of graphite/titanium/cotton which are prepared by sputtering cotton fabric with titanium and graphite for different lengths of time at room temperature. The resultant samples show excellent SERS with an enhancement factor of 1.6 × 104, limit of detection of 4 × 10−7 as well as outstanding flexibility. The optimal SERS active substrate in this study also shows promising application for conformal rapid detection in the field of food safety testing.

Articular cartilage has very poor intrinsic healing ability and its repair remains a significant clinical challenge. To promote neocartilage regeneration, we fabricated two collagen (Col) scaffolds functionalized with a porcine decellularized extracellular matrix (dECM) in the forms of particle and solution named pE-Col and sE-Col, respectively. Their differences were systematically compared, including the biochemical compositions, scaffold properties, cell-material interactions, and in situ cartilage regeneration. While it is demonstrated that both forms of dECM could enhance the cell recruitment, proliferation, and chondrogenesis of bone marrow stem cells (BMSCs) in vitro, better performance was seen in the sE-Col group, which could quickly provide a more favorable chondrogenic microenvironment for endogenous BMSCs. The superiority of sE-Col was also proved by our in vivo study, which showed that the sE-Col scaffold achieved better structural hyaline-like neocartilage formation and subchondral bone repair compared to the pE-Col scaffold, according to the gross morphology, biological assessment, and micro-CT imaging analysis. Together, this study suggests that the sE-Col scaffold holds great potential in developing the one-step microfracture-based strategy for cartilage repair and also reminds us that despite dECM being a promising biomaterial in tissue engineering, the optimization of the proper processing methodology would be a crucial consideration in the future design of dECM-based scaffolds in articular cartilage regeneration.

In order to investigate the effects of solid solution atoms, precipitated particles and cold deformation on the microstructures and properties of Al–Sc–Zr alloys, the Al–Sc–Zr alloys prepared by continuous rheo-extrusion were treated by thermomechanical treatment, analyzed for conductivity and mechanical properties by tensile and microhardness testing, and characterized using optical microscope, TEM and STEM. A mathematical model was established to quantitatively characterize the contribution of solid solution atoms, precipitates and cold deformation to the conductivity of the alloy. The results show that the strength of Al alloy can be significantly improved by solid solution, aging and cold deformation, and the quantitative impacts of solution atoms, precipitates and cold deformation on the conductivity of Al alloy are 10.5% (IACS), 2.3% (IACS) and 0.5% (IACS), respectively. Aging and cold deformation treatments are the keys to obtain high-strength and high-conductivity aluminum alloy wires.

Membrane technology has aroused great attention for gas separations due to its high energy efficiency, small capital investment, easy and continuous operation. Mixed matrix membranes (MMMs) constructed from a continuous polymer phase and a dispersed filler phase offer new opportunities to achieve a breakthrough in fabricating high-performance membranes. Metal–organic frameworks (MOFs) have been regarded as potential fillers to boost the MMM separation performance. However, MOFs occasionally exhibit limited compatibility with the polymer matrixes owing to their partially inorganic structure and tendency of agglomeration in the membranes. Here, an interfacial design strategy is demonstrated by coating size-selective MOF cores with covalent organic framework (COF) layers to construct MOF@COF hybrids as fillers in MMMs for enhanced polymer-filler compatibility. The pure organic COF layers exhibit high affinity to the polymer matrix, thereby preventing the formation of nonselective interfacial voids and alleviating filler agglomeration. With the incorporation of only 5 wt% of MOF@COF fillers, the resultant MMM exhibits 48% and 79% enhancements in CO2 permeability and CO2/CH4 selectivity, respectively, with better operational stability compared to that of the pure polymeric membrane. These results reveal a novel filler design strategy for the tailored synthesis of high-performance MMMs for natural gas and biogas purification.

Engineering metal–organic frameworks (MOFs) for adsorptive ethylene/ethane separation has shown bright prospects for replacing the energy-intensive cryogenic distillation process. Herein, we demons...

Mixed matrix membranes (MMMs) have long been considered as promising membrane types for industrial energy-intensive gas separation processes. Current MMMs are still facing grand challenges of poor filler dispersion and poor polymer-filler interfacial compatibility. The present study demonstrates that these challenges can be addressed by fabricating MMMs containing three-dimensional (3D) covalent organic framework (COF) fillers with ultrasmall size-selective pores. Two different polymer matrixes, including glassy 6FDA-DAM and rubbery Pebax, are explored to validate the effectiveness of 3D COF fillers in improving the membrane separation performance. The pure organic nature of COFs facilitates their high affinity with pure organic polymer matrixes, leading to good interfacial compatibility in the resultant MMMs. These porous COF-300 fillers can increase the membrane fractional free volume that enhances the membrane gas permeability. Besides, the ultrasmall pores of COF-300 fillers and the rigidified polymer chains at the filler surface can enhance the size discriminative processes, resulting in increased membrane gas pair selectivity. Moreover, the separation performance of COF-300 can be further improved by functionalizing it with polyethylenimine (PEI), enabling the design of advanced membranes suitable for industrial applications.

Mixed matrix membranes (MMMs) have gained great attention for the efficient CO2 removal from raw nature gas or biogas (CO2/CH4 separation) and flue gas (CO2/N2 separation). Nevertheless, the development of high-performance MMMs for industrial applications is largely limited by the lack of suitable porous fillers. Herein, a novel ionic covalent organic polymer (ICOP-1) consisting of gas selective pores and hollow cavities is facilely fabricated using a metal triflate catalyzed condensation reaction. Considering its unique structural properties, ICOP-1 is explored as a novel filler to enhance the gas separation properties of polysulfone (PSf) membranes. Defect-free MMMs are successfully prepared owing to the high polymer–filler affinity originating from the organic nature of these two phases. Besides, the large cavities and size-selective pores of ICOP-1 lead to a simultaneous increase in membrane CO2 permeability and CO2/CH4, CO2/N2 selectivities. With the addition of only 0.5 wt % of ICOP-1 fillers, the a...

Covalent organic frameworks (COFs) have emerged as promising crystalline porous materials with well-defined structures, high porosity, tunable topology, and functionalities suitable for various applications. However, studies of few-layered ultrathin two-dimensional (2D) COF nanosheets, which may lead to unprecedented properties and applications, are still limited. Herein, we report the targeted synthesis of three azine-linked and imine-linked 2D COFs named NUS 30–32 using monomers containing aggregation-induced emission (AIE) rotor-active tetraphenylethylene (TPE) moieties, affording micro- and meso-dual pores in NUS-30 and NUS-32 and triple pores in NUS-31. For the first time, we demonstrate that these isostructural bulk COF powders can be exfoliated into ultrathin 2D nanosheets (2–4 nm thickness) by a temperature-swing gas exfoliation approach. Compared with TPE monomers and COF model compounds, the AIE characteristic of NUS 30–32 nanosheets is distinctly suppressed because of the covalent restriction o...

Cap-like α-Fe2O3 films are fabricated and deposited onto quartz fabric by using radio frequency magnetron sputtering and annealing. The treated fabric sample in this study shows highly sensitive surface-enhanced Raman scattering (SERS) and excellent flexibility, reproducibility and stability. In addition, the sample can be recovered after a washing process with an organic solvent and repeatedly used. The sensitive SERS performance is attributed to chemical enhancement through a charge transfer process. Moreover, the SERS performance is also found to be dependent on the light coupling effect. When the light absorbance rate of the α-Fe2O3 films increases at a wavelength near that of laser light, the film shows excellent sensitivity due to light coupling effect.

Phase and porosity control in titanium dioxide (TiO2) is essential for the optimization of its photocatalytic activity. However, concurrent control over these two parameters remains challenging. Here, a novel metal-organic framework templating strategy is demonstrated for the preparation of highly microporous anatase TiO2. In situ encapsulation of Ti precursor in ZIF-8 cavities, followed by hydrolysis and etching, produces anatase TiO2 with a high Brunauer-Emmett-Teller surface area of 335 m2·g-1 and a micropore surface area ratio of 48%. Photocatalytic hydrogen generation catalyzed by the porous TiO2 can reach a rate of 2459 μmol·g-1·h-1. The measured photocatalytic activity is found to be positively correlated to the surface area, highlighting the importance of porosity control in heterogeneous photocatalysts.

Introducing nonvolatile liquid acids into porous solids is a promising solution to construct anhydrous proton-conducting electrolytes, but due to weak coordination or covalent bonds building these solids, they often suffer from structural instability in acidic environments. Herein, we report a series of steady conjugated microporous polymers (CMPs) linked by robust alkynyl bonds and functionalized with perfluoroalkyl groups and incorporate them with phosphoric acid. The resulting composite electrolyte exhibits high anhydrous proton conductivity at 30-120 °C (up to 4.39 × 10-3 S cm-1), and the activation energy is less than 0.4 eV. The excellent proton conductivity is attributed to the hydrophobic pores that provide nanospace for continuous proton transport, and the hydrogen bonding between phosphoric acid and perfluoroalkyl chains of CMPs promotes short-distance proton hopping from one side to the other.

A novel metagrating is proposed to achieve single order diffraction. The proposed unit has electric and magnetic hybrid response. The unit is composed of asymmetrical patch. By introducing magnetic response, the element will break the symmetry of diffraction. One of the first order diffraction is canceled and the energy is totally reflected into the other order at 10GHz. Besides, the diffraction efficiency is higher than 80% from 9.4GHz to 11.1GHz. The simulated far field pattern shows good agreement with prediction. The proposed design provide a highly efficient method to suppress 0 and +1 order diffraction and simplify the difficulty of design, paving the way for further applications of beam steering.

Ethylene glycol (EG)-based hybrid nanofluids containing graphene oxide–silver nanosheets (GO–Ag) were simply prepared without using any surfactant. The graphene oxide–silver composites were characterized using X-ray diffraction analysis, transmission electron microscope, infrared and UV–visible spectroscopy. The stability of GO–Ag nanofluids was estimated by UV–visible spectroscopy. The GO–Ag/EG hybrid nanofluids has good stability without significant sedimentation for 60 days. A few thermophysical properties of GO–Ag/EG nanofluids with 0.1, 0.2 and 0.3 wt% nanosheets were analysed experimentally at different temperatures ranging from 20 to 50°C.

Both humans and objects can emit infrared (IR) wavelengths which generate thermal emissions that can be detected with an IR camera. Therefore, highly IR reflective materials have been the subject of interest recently, for example, in achieving IR stealth. In this work, IR reflective coatings on polyester fabric in the form of a titanium dioxide/copper/titanium dioxide (TiO2/Cu/TiO2; TCT) sandwich-like structure are fabricated by using magnetron sputtering. The coated fabric samples are then examined by using an energy dispersive X-ray detector, a scanning electron microscope and an X-ray diffractometer. The reflection of IR wavelengths which range from 8 to 14 µm of the TCT coated fabric is evaluated. The bending stiffness, and mechanical and adhesion strengths of the coated fabric samples are also investigated. The results show that the TCT sandwich-like structure on the polyester fabric sputtered for 30 min with Cu which results in a Cu film of 200 nm in thickness is observed to have the maximum reflection of IR wavelengths. The color of the TCT coated polyester fabric samples sputtered for 5, 10, 20, and 30 min with Cu is green, yellow, brown and purple, respectively. The TCT coated fabric therefore has potential applications as IR protection textiles for military purposes.

In this paper, the microstructure and properties of as-cast Cu-Y-Zr alloys with different Zr content were studied in order to investigate whether the precipitates in copper alloys would interact with each other by adding Y and Zr simultaneously. As-cast Cu-0.5Y-xZr (wt.%, x = 0.05 and 0.1, nominal composition) alloys were prepared by vacuum melting in this study. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to observe the microstructure of the alloys. The mechanical properties of the alloys were tested by universal material testing machine at room temperature. The effects of Zr content on the microstructure and mechanical properties of the alloys were explored. As shown by the research results, in the as-cast Cu-0.5Y-xZr (wt.%) alloys, the precipitated phase was the Cu5Y/Cu5Zr phase and ranged from 10 nm to 70 nm in size, when the Zr content increased from 0.05 wt.% to 0.1 wt.%, both the tensile strength and elongation rate of the alloys increased, when the Zr content was 0.1 wt.%, the tensile strength was 225 MPa and the elongation rate was 22.5%.

Two-dimensional (2D) materials have attracted increasing attentions recently due to their unique physical and chemical properties. We herein report the synthesis of four chemically stable 2D covalent organic nanosheets (CONs) with large lateral sizes (up to 200 μm) and high aspect ratios (>20 000) at the air-water interface through the Langmuir-Blodgett method. These CONs exhibit good crystallinity proved by high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). In addition, the hydrophobicity of these CONs can be systematically adjusted by the introduction of various functional groups, making them suitable as functional coating and membrane materials.

In this paper chiral polymer R-P could be synthesized by click polymerization reaction of (R)-3,3′-diethynyl-2,2′-bis(octyloxy)-1,1′-binaphthalene (R-M-1) and 1,2-bis(4-azidophenyl)-1,2-diphenylethene (M-2), and S-P was obtained by click polymerization reaction of (S)-3,3′-diethynyl-2,2′-bis(octyloxy)-1,1′-binaphthalene (S-M-1) and M-2, respectively. R-/S-P enantiomers can show strong aggregation-induced circularly polarized luminescence (AICPL) emission signals in the aggregate and cast-spin film, and the dissymmetry factors (glum) can be up to 6.97 × 10−3 and 1.45 × 10−2, respectively. The SEM images further demonstrate that AICPL response behavior of R-/S-P can be attributed to the formation of the supramolecular self-assembled helical nanowires in the aggregation state at 90% of the fraction of water (fw).

In the present study, a numerical simulation of droplets wetting on surfaces with chemically heterogeneous stripes was performed by using many-body dissipative particle dynamics (MDPD). The effects of the ratio of periodicity width w to the contact length L of a 2D droplet (i.e., w / L ) on the contact angle were investigated to analyse the validity of Cassie-Baxter equation. With the simulated process about the droplets wetting on chemically heterogeneous surfaces, the results show that when the ratio is smaller than 0.118 (2/17), the numerical values of the static contact angles are in good agreement with the prediction of the Cassie-Baxter equation for droplets wetting on chemically heterogeneous substrates formed by alternative stripes in mesoscopic scale. While for the ratio larger than 0.118, the Cassie-Baxter equation will not be appropriate to accurately predict the apparent contact angles. This ratio may be considered as the critical value to apply Cassie-Baxter equation on these types of chemically heterogeneous substrates. Furthermore, a comparison between rear dynamic contact angles for different ratios was found in accordant with expected.

To understand the synergistic effect of TiAl3 and TiB2 particles on grain refinement of α-Al, equal-channel angular pressing (ECAP) of Al-5Ti-1B (wt%) alloy was carried out. The ECAPed Al-5Ti-1B (wt%) alloy was characterized by X-ray Diffraction (XRD), electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM). The results reveal that α-Al grains and TiAl3 phase of ECAPed Al-5Ti-1B (wt%) alloy were refined, while the average size of TiB2was marginally decreased. The tensile strength was increased from 128 MPa to 218 MPa, and the elongation was reduced from 26% to 20.6%. The transformation from dislocations to low-angle grain boundaries (LAGBs) and high-angle grain boundaries (HAGBs) resulted in continuous dynamic recrystallization (CDRX), which induced grain refinement during ECAP. From 3 to 6 passes of ECAP, CDRX occurred in the alloy, and as ECAP passes increased to 9, the rate of formation of LAGBs and the transformation rate from LAGBs to HAGBs reached a dynamic balance. The present study indicates that the second phase particles promote the formation of LAGBs but prolong complete-recrystallization time, such that complete-recrystallization leads to grain refinement. TiB2 particles are smaller than TiAl3 particles and this is caused by the composition of the alloy and its synthesis method, and compared with TiAl3, TiB2 with a smaller size had a more obvious influence on the formation of LAGBs and grain refinement.

Samples of the woven cotton fabric are first modified with a continuous polyvinyl alcohol (PVA) thin film by using the padding method and then coated with copper (Cu), titanium and stainless steel (SS) respectively, by using a magnetron sputtering system. The samples are then systematically characterized with energy dispersive X-ray spectroscope, X-ray diffractometer, and scanning electron microscope. The infrared (IR), ultraviolet and electromagnetic interference shielding properties of the samples are also well investigated, as well as the contact angle (CA), light transmittance and conductivity. The results show that pretreatment with PVA can enlarge the light transmittance of cotton fabric. The metal coated PVA/cotton samples show a better performance in electro-conductivity although there is a little bit decrease in other properties compared to the metal coated cotton fabric. The Cu coated PVA/cotton sample has a higher electromagnetic interference shielding effectiveness of − 30 dB, a lower electrical resistivity of 5.49 × 10−6 Ω m, while the Cu coated cotton sample presents a higher IR reflection rate about 25%, the SS coated cotton fabric show a higher CA of 128.2 °and UPF of 117.647. The excellent properties of the coated cotton fabric mean that it is a promising electro-conductive and multi-shielding textile for smart applications.

In previous studies, Mg-Sr alloys exhibited great biocompatibility with regard to test animals, and enhanced peri-implant bone formation. The objective of the present study was to investigate the effects of heat treatments on the mechanical and corrosion properties of Mg-Sr alloys. Various heat-treated Mg-xSr (x = 0.5, 1, and 2wt%, nominal composition) alloys were prepared using homogenization and aging treatments. Mechanical tests were performed at room temperature on the as-cast, homogenized, and peak-aged alloys. As the Sr content increased, the volume fraction of Mg17Sr2 phases within the as-cast alloys increased; in addition, the mechanical strength of the alloys initially increased and subsequently decreased, while the ductility decreased. Following the homogenization treatment, the mechanical strength of the alloys decreased, and the ductility increased. Nano-sized Mg17Sr2 phases were re-precipitated during the aging treatment. The age-hardening response at 160°C was enhanced as the Sr content increased. Following the aging treatment, there was an increase in the mechanical strength of the alloys; however, there was a slight reduction in the ductility. Immersion tests were conducted at 37°C for 360h, using Hank's buffered salt solution (HBSS), to study the degradation behavior of the alloys. As the Sr content of the Mg-Sr alloys increased, the corrosion rate (CR) increased owing to the galvanic effect. The homogenization treatment consequently reduced the CR dramatically, and the aging treatment had a slight effect on the CR. The peak-aged Mg-1Sr (wt%) alloy exhibited the best combination of properties. The tensile yield strength (TYS), ultimate tensile strength (UTS), elongation, compressive yield strength (CYS), ultimate compressive strength (UCS), compressibility, and CR of the as-cast Mg-1Sr (wt%) alloy were 56.0MPa, 92.67MPa, 1.27%, 171.4MPa, 243.6MPa, 22.3%, and 1.76mm/year, respectively. The respective results obtained for the peak-aged Mg-1Sr (wt%) alloys were 69.7MPa, 135.6MPa, 3.22%, 183.1MPa, 273.6MPa, 27.6%, and 1.33mm/year. Following immersion in HBSS, the primary corrosion products of the peak-aged Mg-1Sr (wt%) alloy were Mg(OH)2, MgO, MgCO3, Mg3(PO4)2, MgHPO4, and Mg(H2PO4)2, which enhanced the corrosion resistance by forming a composite corrosion film.

Microporous metal-organic frameworks (MOFs) as building materials for molecular sieving membranes offer unique opportunities to tuning the pore size and chemical property. The recently reported polycrystalline Zr-MOF membranes have greatly expanded their applications from gas separation to water treatment. However, Zr-MOFs are notoriously known for their intrinsic defects caused by ligand/cluster missing, which may greatly affect the molecular sieving property of Zr-MOF membranes. Herein, we present the mitigation of ligand-missing defects in polycrystalline UiO-66(Zr)-(OH)2 membranes by postsynthetic defect healing (PSDH), which can help in increasing the membranes’ Na+ rejection rate by 74.9%. Intriguingly, the membranes also exhibit excellent hydrothermal stability in aqueous solutions (>600 h). Our study proves the feasibility of PSDH in improving the performance of polycrystalline Zr-MOF membranes for water-treatment applications.

Strip-cast grain-oriented 4.5% Si steel was produced by short-term isochronal secondary annealing (15 min) and isothermal annealing (1000 °C) under hydrogen atmosphere. The relationship between the evolution of grain structure and magnetic properties was elucidated. It was observed that during isochronal annealing, abnormal grain growth occurred followed by normal grain growth with the increase of annealing temperature. Additionally, decreasing the primary annealing temperature accelerated the isochronal annealing kinetics, and near complete abnormal grain growth with optimal magnetic properties was obtained at lower temperature. Furthermore, during isothermal annealing, abnormal grain growth successfully occurred and magnetic properties were continuously improved with the increase of annealing time. The optimal magnetic properties were superior to those of isochronal annealing because of sharper secondary Goss texture and reduced retention of second-phase particles. The grain-oriented 4.5%Si steel in the present study indicated superior properties and better workability than the previously reported non-oriented 6.5%Si steel. Thus, grain-oriented 4.5%Si steel produced by short-term secondary annealing can potentially replace non-oriented 6.5%Si steel.

The competitiveness of reduced graphene oxide (GO) based composite can be significantly improved when the raw material of GO become the low-cost microcrystalline graphite mine. Herein, we first successfully fabricate high-quality microcrystalline graphite GO (MGO) with small size 3 O 4 @C/PrMGO composite is simply constructed by using porous reduced MGO (PrMGO) to support carbon coated Fe 3 O 4 nanoparticles (Fe 3 O 4 @C NPs). The Fe 3 O 4 @C/PrMGO composite exhibits high reversible capacity and excellent cyclic stability that a high reversible capacity of 1216 mA h g −1 is received after 392 cycles at 100 mA g −1 . Meanwhile, the composite possesses high rate retentions, superior structural and cycling stability, which are further revealed by rate test, SEM and EIS analyses. The significant advantages of Fe 3 O 4 @C/PrMGO composite (low cost, facile operation and high electrochemical performances) endow the composite to be practically promising anode material for next-generation LIBs. This research supplies a new strategy to fabricate low-cost and high performances MGO-based anode materials.

Zirconium carbide (ZrC) films are deposited onto polyester fabric through magnetron sputtering. The deposited films are then examined by using field scanning electron microscopy and energy dispersive X-ray spectroscopy. The photothermal conversion property, film thickness, infrared reflectance and transmittance, and thermal conductivity are also evaluated. The results show that the highest far-infrared emissivity of polyester fabric deposited with ZrC is 0.9379. The ZrC deposited samples showed a small increase in thermal conductivity with a difference of 0.0611W/m·K, and a higher photothermal conversion efficiency with a temperature increase of 27.5 °C in 100 s, when the thickness of the ZrC film is 1920 nm. These therefore indicate that coating fabrics with ZrC through magnetron sputtering is an environmentally friendly means to produce textiles with photo-thermal conversion and heat insulation properties.

Ultrathin mixed matrix membranes (MMMs) containing two-dimensional (2D) fillers are highly sought recently due to their good performance in gas separations. Here we report the preparation of PIM-1 based ultrathin MMMs containing 2D metal-organic framework (MOF) nanosheets using spin coating method. The lamellar structure of the 2D layered MOF filler (copper 1,4-benzenedicarboxylate nanosheets, CuBDC-ns) enlarges the contacting area between fillers and the polymer matrix, leading to the formation of dense MMMs. The centrifugal force generated during the spin coating process helps to horizontally align these CuBDC-ns, increasing the gas diffusion resistance across the membrane. The influence of membrane thickness and filler content on the separation performance of CO2/CH4 mixture is examined and discussed. Optimizing membrane thickness and filler content results in a 660 nm thick ultrathin MMM comprising 10 wt% CuBDC-ns, which exhibits a CO2/CH4 selectivity of 15.6 and CO2 permeance as high as 407 GPU, surpassing other PIM-1 based membranes. Besides, the long term stability test shows that the prepared ultrathin MMMs are stable up to 100 h. These results demonstrate that the ultrathin MMMs reported in this study are excellent candidates for CO2/CH4 separation, with potential applications in natural gas purification and biogas upgrading.

Thin film composite membranes (TFCMs) have displayed attractive CO2 capture performance, in which a critical gutter layer with small transport resistance is needed to prevent the penetration of the top separation layer into the bottom porous support for realizing high CO2 permeance. However, traditional and recently developed gutter layer materials face some issues such as physical aging, thickness-dependent permeability, instability, or poor compatibility. Herein, wholly organic, orientated, two-dimensional covalent organic framework (COF) films, for the first time, are used as the novel gutter layers due to the ideal pore size, intrinsic porosity, small transport resistance, good compatibility with polymer matrix, good anti-aging capability and high stability. Commercial or photo-initiated crosslinked polymer can be deposited compatiblely on the COF gutter layer with a thickness as thin as 55 nm, an ultrathin thickness that traditional gutter layers are challenging to attain. As a result, one optimized TFCM realizes high CO2 capture performance with CO2 permeance of 1843 gas permeation units (GPU) and CO2/N2 separation selectivity of 28.2, which displays unique advantages over other gutter layer-based TFCMs and meets the performance target for CO2 capture (CO2 permeance > 1000 GPU, CO2/N2 selectivity > 20).

Three types of Magneli phase anodes (Ti/Ti4O7, Ti/Ti4O7-PbO2-Ce, and Ti/Ti4O7 nanotube arrays (NTA)) were fabricated, characterized, and compared with other typical active and non-active anodes (i.e., BDD, Ti/Pt, Ti/RuO2-IrO2, and Ti/IrO2-Ta2O5) for electro-oxidation treatment of p-nitrophenol (PNP) solution and a real coal chemical concentrated brine in this study. Characterization results indicate a nanotube array structure of Ti/Ti4O7 NTA, and a compact coating of Ti4O7 microparticles and PbO2-Ce nanocrystals on the Ti substrate for Ti/Ti4O7 and Ti/Ti4O7-PbO2-Ce, respectively. The three anodes present relatively high oxygen evolution potentials (2.16–2.44 V vs SCE), showing good capacity of electro-generating reactive oxidative species for pollutant degradation. After 30 min of EO treatment, Ti/Ti4O7 NTA and Ti/Ti4O7 removed 89–92% of PNP, which were 10–60% higher than Ti/Pt, Ti/RuO2-IrO2, and Ti/IrO2-Ta2O5, and were almost comparable with BDD (95%). Furthermore, Ti/Ti4O7 NTA and Ti/Ti4O7 kept very efficient for mineralization of PNP solution and real coal chemical concentrated brine. For Ti/Ti4O7-PbO2-Ce, its degradation efficiency was lower than other two Magneli phase anodes, but still competitive compared with other active anodes. Thanks to their high removal efficiencies, the three Magneli phase anodes required relatively low energy demand for pollutant mineralization. Besides, operational parameters such as electrolyte and current density were also very significant for efficient pollutant removal. The results of this study suggest Magneli phase electrodes as promising and cost-effective anode materials for industrial wastewater treatment, with Ti/Ti4O7 NTA and Ti/Ti4O7 being more efficient options.

Copper (Cu) is deposited as a film onto polyamide-6 (PA-6) fibers with a magnetron sputtering technology by using a self-assembly machine with a winding unit. The Cu coated PA-6 fibers are characterized by using surface profiler, X-ray diffractometer and scanning electron microscope. The electrical conductivity, Raman spectra, tensile strain and tensile stress of Cu coated PA-6 fibers are also systematically investigated. The results show that the mean value of the electrical conductivity of Cu-coated PA-6 fibers increases with decrease of winding speeds and reaches 7.03 × 10−5 Ω m at 4.7 cm/min. The Cu coated PA-6 fibers are used as electric wires to light the LEDs. The Raman characteristic peak of PA-6 fiber in the spectra is influenced after coating. With the drop of winding speed, the tensile strain and tensile stress of coated PA-6 fibers both decrease after Cu deposition.

This is a successive study to our previous study published in this journal. In the present study, a further numerical study on the penetration of a droplet into non-wetting capillaries is carried out by using many-body dissipative particle dynamics (MDPD). The simulation results show the outer (outside of the capillary) and inner (inside of the capillary) curvatures of the droplet can cause two Laplace pressures. The difference between these two pressures forms a net pushing force which directly drives the droplet flowing into the non-wetting capillary. We give a detailed analysis on how the outer and inner curvatures change during the penetration process. To further show the effect of the Laplace pressure difference on the droplet movement, we also simulate a new droplet/capillary/film system. In this system, the droplet and liquid film are placed at both ends of a prefilled capillary. It is very interesting to find that the droplet penetrates even faster in lyophobic capillaries over lyophilic ones, and the spontaneous penetration does not pose any wettability restriction which is different from previous study in literatures. The present work is expected to provide new ideas for designing microfluidics or nanofluidics devices by utilizing the driving force from the droplet itself.

We herein report an optimal modulated hydrothermal (MHT) synthesis of a highly stable zirconium metal-organic framework (MOF) with an optimum aperture size of 3.93 A that is favorable for CO2 adsorption. It exhibits excellent CO2 uptake capacities of 2.50 and 5.63 mmol g−1 under 0.15 and 1 bar at 298 K, respectively, which are among the highest of all the pristine water-stable MOFs reported so far. In addition, we have designed a lab-scale breakthrough set-up to study its CO2 capture performance under both dry and wet conditions. The velocity at the exit of breakthrough column for mass balance accuracy is carefully measured using argon with a fixed flow rate as the internal reference. Other factors that may affect the breakthrough dynamics, such as pressure drop and its impact on the roll-up of the weaker component have been studied in details. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4103–4114, 2017

Covalent organic frameworks (COFs) represent a new class of crystalline porous organic materials with huge potential in gas storage and separation. Here we present three isoreticular COFs sharing identical two-dimensional layered structures but with different planarity of the building monomers, leading to various crystallinities, porosities and hydrocarbon uptake and separation performances. This study reveals the importance of monomer design in the long-range stacking of COFs, which can be used to tailor COFs with target functionalities for specific applications.

Herein, we report the synthesis of a new 1,4-dihydropyridine derivative containing 2,2-dimethyl-1,3-dioxane-4,6-dione and N,N-dimethylaniline. This compound exhibits aggregation-induced emission properties due to its highly twisted conformation and it has three crystalline polymorphs, which exhibit yellow (DHPM-y), orange (DHPM-o), and red (DHPM-r) fluorescence. The different emissions of the polymorphs mainly depend on their molecular conformations due to the weak intermolecular interactions, as revealed by single crystal structural analysis. More importantly, these three crystalline polymorphs show different mechanochromic phenomena under varying pressure. The fluorescent color changes in DHPM-o and DHPM-r upon gentle grinding are attributed to a crystal-to-crystal transformation which alters their molecular conformations, whereas those of DHPM-y and DHPM-o upon strong grinding are ascribed to the transformation from a crystalline state to an amorphous state. Additionally, DHPM-y and DHPM-o also display thermochromic properties. These results will provide useful information for obtaining intriguing multifunctional fluorescent materials by rational modification of classic luminogens.

The proton exchange membrane fuel cell (PEMFC) is an innovative technology for the realization of next-generation power sources, in which a polymer or blend membrane is used to separate the fuel from the oxidant and to transport protons. Although a variety of membranes have been synthesized and characterized by both experimental and molecular simulation methods in the past few decades, the underlying microscopic molecular mechanism is still unclear. In this article, a blend membrane composed of SPEEK and PVDF is investigated by dissipative particle dynamics (DPD) and molecular dynamics (MD) simulation methods. The results show that the blend of SPEEK and PVDF has preferable compatibility as the sulfonation degree is about 50%, and the compatibility is improved further by adding 10% PSSA grafting additive. For both 90/10 and 80/20 blending proportions, SPEEK and PVDF-g-PSSA mixed fairly well, and a proton exchange channel network is observed. What's more, as the PVDF-g-PSSA content increases from 5% to 20%, the hydrophilic clusters, which consist of sulfonate groups, water molecules and hydronium ions, are formed and aggregate inside the SPEEK membrane. In addition, the transport properties and proton conductivities of the blend membrane are also significantly improved by the increase of the content of PVDF-g-PSSA.

Grains of Al–1Si(wt%) alloy were refined by accumulative continuous extrusion forming (ACEF). Electron backscatter diffraction and transmission electron microscopy were used to analyze the microstructure evolution of the Al–1Si(wt%) alloy. The grain size of the alloy decreased from 54.36 to 2.59 μm after four passes of ACEF. The grain refinement was attributed to continuous dynamic recrystallization (CDRX). The enhanced effect of nanosized precipitates on CDRX was pronounced. Nanosized eutectic Si precipitates retained a high density of dislocations in the alloy by promoting their generation and pile-up, resulting in an increase in the driving force for CDRX and a consequent promotion of grain refinement. After 4 ACEF passes, the tensile yield strength of the alloy at room temperature increased from 102 MPa to 117 MPa. Further, the elongation of the alloy at room temperature decreased from 38 to 17 % after 3 ACEF passes and subsequently increased to 23 % after 4 ACEF passes.

Two pairs of thermally activated delayed fluorescence (TADF)-active chiral luminogens (R/S-1 and R/S-2) can be achieved by introducing D–A-type groups to chiral BINOL skeletons. The resulting chira...

Continuous preparation of high-conductivity and high-strength aluminium alloy cable remains a challenge. Here we reveal the scientific significance of high electrical conductivity Al-Ag-Sc-Zr alloy with ultrafine grains prepared by novel processing technologies, the combination of rheo-extrusion and accumulative continuous extrusion forming. Attributed to the continuous dynamic recrystallization during rheo-extrusion, equiaxial microstructure and significantly refined grains (2.8 ± 0.2 μm) were achieved. By means of partially replacing low conductive scandium and zirconium solute atoms with high conductive silver solute atoms, the processed alloy wires exhibit significant higher electrical conductivity (53.5 ± 0.4 %IACS) than the Al-Sc-Zr alloy with similar atomic concentration of alloying elements. Appropriate mechanical properties were also obtained due to the similar solution strengthening effects of silver atoms to scandium and zirconium atoms. These results highlight the potential of this high electrical conductivity Al-Ag-Sc-Zr alloy and its novel processing route.

To enhance the cycle stability of sulfur cathode for a high energy Li-S battery system, a novel sulfur@carbon nanocube (S@CNC) composite was prepared by encapsulating sulfur into micropores of CNCs by thermal treatment of a mixture of sublimed sulfur and CNCs. Electrochemical results demonstrated that encapsulating sulfur into individual insulated CNCs could effectively inhibit the aggregation of sulfur, eliminate excessive contact of sulfur species with the electrolyte and help confine the soluble lithium polysulfides. Additionally, the large surface area and thin shells of CNC hosts could facilitate rapid transport of Li+ ions and electrons to achieve superior rate capability and stable cycling performance.

The present work aims to unravel the effect of Ti microalloying on the refinement of co-precipitated nanoscale Cu and M2C carbides, and thereby the improvement of both strength and toughness of an ultrahigh-strength Fe-0.05C-1.3Cu steel. The co-precipitated Cu and M2C carbides in Ti-free and Ti-containing steels was characterized after quenching and aging treatment via atom probe tomography (APT), and their contribution to the yield strength was quantified. APT results show that after being aged at 550 °C for 1 h, nanoscale Cu particles and M2C carbides co-precipitated. And, the density of finer Cu was found to be higher in the Ti-containing steel than that in the Ti-free steel which can produce more nucleation sites for M2C carbides precipitation. After being aged at 550 °C for 1 h, the Ti-containing steel had a yield strength as high as 1055 MPa, and an impact toughness of 132 J at −40 °C, which was an improvement of 61 MPa and 27 J, respectively, in comparison to the Ti-free steel. The higher-density M2C carbides were found to contribute to precipitation strengthening enhancement. The co-precipitation strengthening contribution from the Cu-M2C precipitates of the Ti-containing steel was calculated to be 69 MPa higher than that of the Ti-free steel. This is similar to the difference of 61 MPa from the experiment. The high toughness of Ti-containing steel is attributed to a higher density of high angle grain boundaries and a smaller prior austenite grain size by deflecting crack propagation.