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In this study, a hydrogel adsorbent was successfully synthesized using hydroxyapatite/acrylamide/β-cyclodextrin to adsorb heavy metal ions and dyes in water. In the study, different contents of hydroxyapatite were added to the hydrogel, and then the mechanical properties and adsorption properties of the material were studied. The results show that the compressive strength of hydrogel added with hydroxyapatite increased by 37.1%. According to the adsorption isotherm model, the maximum adsorption capacity is 300mg/g. In addition, the preparation process of the composite hydrogel is simple, and can be used at a lower pH value, and can be used multiple times. Therefore, the material is of great significance to the treatment of pollutants.

In order to prepare a new high-performance and flexibility stab-resistant composite material, one type of high-toughness and high-strength hydrogel is combined with aramid fabric. In this paper, the nanocomposite (NC) hydrogels are prepared using Pluronic F127 Diacrylate (PF127DA) as the crosslinking agent, acrylamide as the monomer and nano-silica as nano additive. The influence of the addition amount of nano-silica on the toughness and strength of nano-composite hydrogels is discussed. The strength and toughness of the NC hydrogels with nano silica are higher than that of the acrylamide hydrogel without nano particles. The NC hydrogel with the best strength is made as a composite with aramid fabric and the effect of nanocomposite hydrogel on the stab resistance of the stab-resistant composite material is studied. The research shows that the stab resistance performance of the composite material prepared by aramid fabric and nanocomposite hydrogel is effectively improved in comparison with aramid fabric, and the yarn pulling force is also improved. The composite material with high stab resistance can be used as the stab-resistant layer of armor, cut-resistant gloves and stab-resistant base material of shoes. This work provided a possibility for preparing a kind of lightweight composite material with high stab resistance.

We fabricated the HfZrO2 (HZO) ferroelectric fin field-effect transistors (Fe-FinFET) with fin width of 60 nm and gate length of 100 nm for ferroelectric nonvolatile memory operations. The fabricated Fe-FinFET exhibited a large memory window (MW) of 1.5 V and high (100 ns) program/erase speeds at ±5 V. After $10^{{5}}$ program/erase cycles, the MW was maintained at 1.09 V and the retention time was measured up to $10^{{4}}$ s with no degradation. The fabricated HZO Fe-FinFET is compatible with the current FinFET process and has a high MW, a fast program/erase speed, and excellent reliability. Therefore, the fabricated Fe-FinFET is a promising candidate for high-density ferroelectric field-effect transistor memory applications.

Pt-based alloy nanomaterials with nanodendrites (NDs) structures are efficient electrocatalysts for methanol oxidation reaction (MOR), however their durability is greatly limited by the issue of transition metals dissolution. In this work, a facile trace Ir-doping strategy was proposed to fabricate Ir-PtZn and Ir-PtCu alloy NDs catalysts in aqueous medium, which significantly improved the electrocatalytic activity and durability for MOR. The as-prepared Ir-PtZn/Cu NDs catalysts showed distinct dendrites structures with the averaged diameter of 4.1 nm, and trace Ir doping subsequently improved the utilization of Pt atoms and promoted the oxidation efficiency of methanol. The electrochemical characterizations further demonstrated that the obtained Ir-PtZn/Cu NDs possessed enhanced mass activities of nearly 1.23 and 1.28-fold higher than those of undoped PtZn and PtCu, and approximately 2.35 and 2.67-fold higher than that of Pt/C in acid medium. More excitingly, after long-term durability test, the proposed Ir-PtZn and Ir-PtCu NDs still retained about 88.9% and 91.6% of its initial mass activities, which further highlights the key role of Ir-doping in determining catalyst performance. This work suggests that trace Ir-doping engineering could be a promising way to develop advanced electrocatalysts toward MOR for direct methanol fuel cell (DMFC) applications.

In the work, a kind of composite material with excellent stab/puncture resistance was prepared by resin bonded Kevlar fabric. Water-borne epoxy resin (PAEK), polyacrylamide (APAM), fatty alcohol polyoxyethylene phosphate potassium salt (TFPK) are formulated to form a novel sizing agent that can be used for the sizing Kevlar fabrics. The effects of the sizing agent on the mechanical and stab/puncture resistance are examined. A field emission scanning electron microscopy (SEM), an ultra-depth of field 3d microscope, and a universal testing machine were used to observe and evaluate the morphology of sizing fabrics, the stab/puncture morphology, mechanical properties, and quasi-static stabbing properties, respectively. The test results show that the puncture resistance of the sizing Kevlar fabrics increases first and then decreases with the increase of sizing agent concentration. Compared with non-sizing fabrics, the Kevlar fabrics that are treated with a sizing agent at a concentration of 10 wt% have 524 % higher puncture resistance, 301 % higher stab resistance, and a 6.9-fold increase in the burst strength. Because the fiber bundles in the sizing fabrics are confined due to the resin saturation, the friction among fibers is enhanced and thus better resists an external force and contributes a greater resistance against sharp objects.

The Si-based n- and p-FeFET with 5-nm ferroelectric (FE) HfZrOx(HZO) and high-k AlON interfacial layer (IL) were fabricated for the comparison of memory characteristics and reliability. The memory window (MW) of 1.37 V and 1.25 V are obtained by the n- and p-FeFET respectively by applying pulses of ±3.8 V/ $50~\mu $ s. The typical MW asymmetry for both types of FeFETs is significantly reduced which is attributed to the reduced remanent polarization ( $\text{P}_{\text {r}}$ ) from the highly scaled HZO and the enhanced voltage drop across the HZO as well as the improved interfacial quality from the AlON IL. In addition, the p-FeFET demonstrates a MW of 1.02 V up to $10^{{5}}$ cycles with a long pulse $10^{-{4}}\text{s}$ , superior to that of the n-FeFET due to the mitigated hot-electrons induced hole generation. Furthermore, the p-FeFET shows comparable retention performance with the n-FeFET. These results indicate that the p-FeFET possesses the competence of future memory applications without adding process complexity and introducing new substrate material.

Epitaxial GeSn (epi-GeSn) shows the capability to form ferroelectric capacitors (FeCAPs) with a higher remanent polarization (Pr) than epi-Ge. With the interface engineering by a high-k AlON, the reliability of the epi-GeSn-based FeCAPs is enhanced. Using the highly reliable FeCAP in series with a resistor as the synapse and axon, a simplified neuromorphic network based on a differentiator circuit is proposed. The network not only holds the leaky integrate-and-fire (LIF) function but is also capable of recognizing the spatiotemporal features, which sets it apart from other LIF neurons arising from the FeCAP-modulated leaky behavior of the potential on the axon by spiking-time-dependent plasticity. Furthermore, it is more energy efficient to operate, nondestructive to read, and simpler to fabricate by employing FeCAPs, making it eligible for emergent spiking neural network hardware accelerators.

This article proposes a compact and high precision capacitive absolute angular position sensor based on time grating. The sensor consists of a stator and a rotor with three concentric capacitor structures forming primary and auxiliary angular displacement measurement components. The primary component combines a single middle-row capacitive structure with an outer-row capacitive structure to obtain high-precision displacement measurements composed of N measurement periods. The auxiliary component employs a single inner-row capacitive structure with a single spatial period over the 360° measurement range of the sensor in conjunction with a remodulation scheme to obtain displacement measurements composed of N − 1 measurement periods. Combining the measurements of the primary and auxiliary components in a manner similar to vernier calipers yields high-precision absolute angular position measurements. The sensor design and remodulation scheme facilitate good sensor compactness. The measurement performance of the proposed design is evaluated via tests of a prototype sensor with an outer diameter of 60 mm fabricated by printed circuit board technology. The prototype sensor is demonstrated to obtain a measurement resolution of 3" and a measurement accuracy of ±10" over the 360° measurement range of the sensor, indicating that the proposed sensor design has considerable potential for high precision applications.

For the pursuit of conductive textiles with high electromagnetic shielding performance, specified yarns are processed with a special spinning feeding device with twist counts of 40 T, 50 T, 60 T, 70 T, 80 T, and 90 T, for Next, the optimal yarns from each group are made into SS/Pc-70 and Cu/Pc-80 conductive woven fabrics with a plain weave structure design. In addition, the surface resistivity, electromagnetic shielding effectiveness measurement and air permeability of the two conductive woven fabrics were tested and analyzed. Regarding the electromagnetic shielding performance test, the effects of the complete shielding network, the lamination layers of fabric, and lamination angle on the electromagnetic shielding performance are discussed. The test results indicate that Cu/Pc-80 woven fabrics has the lowest surface resistivity, which means it has the best electrical conductivity; Moreover, different types of metal wires provide the conductive fabrics with different levels of surface resistance. The variations in the lamination angles help attain a complete conductive network that significantly enhances the EMSE, and Cu/Pc-80 have a greater average shielding value comparatively and thus greater EMSE. For both types of conductive woven fabrics, one-layered conductive woven fabrics exhibit the maximal air permeability. As the air permeability of conductive woven fabrics is correlated with the thickness of fabrics, the greater the number of lamination layers, the lower the air permeability of the conductive fabrics.

Oil and organic pollutants removal becomes an efficient solution to dispose of industrial oily and textile dye wastewater. This study proposes a lotus leaf-like bionic nanofibrous membrane with underwater superoleophobic for highly efficient oil-water separation. Papillary structure of the bionic membrane is formed by electrospraying of PVDF and TiO2 solutions on the surface of beaded-structure PVDF/TiO2 membrane. Dopamine is then decorated on the resultant PVDF/TiO2 membrane by in situ polymerization to be with hydrophilic-underwater oleophobic property for highly efficient oil-water separation. This bionic membrane has > 99 % oil-water separation efficiency, and high flux of 1389 ± 67 L m−2 h−1. Its contact angle of underwater petroleum ether and dichlomethane reaches 155° and 152°, respectively. Moreover, it has excellent water transport capacity, photocatalytic property, as well as high separation efficiency and flux even after 5-cycle filtration. This bionic nanofibrous membrane will become a promising candidate in clean production, industrial oil/water separation, water purification and efficient liquid transmission.

TiN/amorphous HfO x /ferroelectric-HfZrO x (HZO)/TiN was explored to accomplish switchable diode behavior with desirable memory characteristics in terms of high ${R}_{{\mathrm {HRS}}}/{R}_{{\mathrm {LRS}}}$ ratio of ~2600 and retention up to ten years at 25 °C. The bias-controlled direction of the built-in diode was studied to be dominated by the polarization of HfZrO x while good retention can be achieved by stacking HfO x which is beneficial to suppress leakage current. More importantly, 16 Boolean functions can be realized in a single device which is easier to implement multiplier and adder. The prominent nonvolatile memory and computation performance make it a promising device for logic-in-memory (LiM) applications. Besides electrical properties, it well outperforms other LiM devices due to simple structure and fab-friendly materials, inspiring a new approach to capitalize on the salient features of ferroelectric HZO for LiM applications.

Ultra-violet laser thermal annealing (LTA) is proposed to form contact TiSix for sub-10 nm FinFETs. Compared to conventional rapid thermal annealing (RTA), LTA process leads to reduced total series resistance (RTotal) by 10.1∼16.1% and 13.0∼15.3% which corresponds to enhanced transconductance (gm) by 7.7∼9.8% and 5.9∼9.0% for N-/P-FinFETs respectively due to improved contact resistivity (ρc) by 69% arising from more orderly local Ti-Si bonds and smoother TiSix/Si interface. There is also no concern of LTA process in terms of comparable off-state/junction leakage and reliability by hot carrier stress. In addition, LTA is VLSI-compatible without adding any process complexity. These promising properties enable LTA to further unleash the performance of FinFETs.

Aluminosilicate mesoporous materials were synthesized using F108 template (polyethylene glycol-polypropylene glycolpolyethylene glycol) at a concentration of 0.034 g/ml and the molar ratio of Al2O3 to SiO2 was 0.09. The products were then characterized using nitrogen adsorption/desorption tests, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The effects of various crystallization temperatures as well as sodium hydroxide concentrations on the average diameter, pore volume, surface area, and morphology of the synthetic material were analyzed. Results showed that a sodium hydroxide concentration of 11 mol/L and a crystallization temperature of 130 °C produced a synthetic material with regular pore size and homogeneous arrangement including a specific surface area of 137.62 m2/g, an average pore volume of 0.27 cm3/g, along with an average pore size of 15.33 nm.

To simply and effectively enhance the conversion capability of wearable thermoelectric textiles, a two-step in situ method is adopted to fabricate dual-shell photothermoelectric textiles which is made of polypropylene fibers with a photo-thermal layer (PPy) and a thermoelectric layer (PEDOT:Tos). The PPy is tailored to achieve high temperature and photothermoelectric effects. The PPy layer can significantly increase the photothermal conversion efficiencies of as-prepared fabric. The optimized photothermoelectric fabric can improve the generated voltage output from 294.13 to 536.47 μV under the infrared light, and its power density is up to 13.76 nW·m-2. A flexible photothermoelectric strip composed of as-prepared fabric coated with Ag particles and textile substrates with low thermal conductivity shows a voltage output of 2.25, 0.677, and 0.183 mV and a power output of 0.7031, 0.0636, and 0.0049 nW under IR light, sunlight, and on the arm, respectively. The photothermoelectric fabrics display potential as to a new smart wearable device for converting light and electricity.

The use of regular wound dressings commonly brings about excessively retained wound exudate between the dressing and the wound, which is detrimental to the healing. This study manages to control the biofluid around wounds effectively. To begin with, silk fibroin (SF) is extracted from silk. Next, SF and PCL are mixed and electrospun into multiscale hydrophobic nanofibers on the surface of the dopamine (PDA)-treated hydrophilic PVA nanofibrous membranes, thereby forming asymmetric wetability composite membranes with one-way water conduction. Moreover, PVA nanofibrous membranes are immersed in a PDA solution with an attempt to have a greater surface chemical activity and thus demonstrate an 85% greater wicking height and an air permeability being 90 mm/s. A 20% (w/v) SF solution and an 8% (w/v) PCL solution with a feeding rate being 1:3 provide the resulting SF/PCL nanofibrous membranes with greater hydrophobic properties, namely a water contact angle being 112°. In addition, the ultimate asymmetric wetability composite membranes exhibit an excellent wetting gradient, which benefits the directional transmission of moisture. The moisture management test results indicate that when the electrospinning time for PVA and SF/PCL layers is separately 30 min and 5 min, the resulting composite membranes attain the effect of one-way water conduction. In vitro analysis confirmed that the composite membrane produced were non-toxic. This unique wound dressing with one-way water conduction has a giant potential to serve as new type wound dressings for clinical use.

Pt-based catalysts are still most attractive and could be the major driving force for facile electrochemical reactions in direct methanol fuel cells (DMFCs). In this work, a Pt3Mn nanowire network structures (NWNs) catalyst was successfully synthesized by a soft template (CTAB) method. The morphology and elemental composition of the Pt3Mn NWNs were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-optical emission spectroscopy (ICP-OES). The electrocatalytic behavior of the synthesized Pt3Mn NWNs catalyst towards methanol oxidation reaction (MOR) was studied by cyclic voltammetry (CV) and chronoamperometry (CA). The results reveal that the Pt3Mn NWNs has superior MOR activity and durability compared to Pt NWNs and commercial Pt/C. The mass and specific activities of Pt3Mn NWNs are 0.843 A mg−1 and 1.8 mA cm−2 respectively, which are twice that of commercial Pt/C. Additionally, the results of CA test indicate that the Pt3Mn NWNs possesses better durability than Pt NWNs and commercial Pt/C catalysts in acidic media, which is expected to be a new alternative anode material in DMFCs.

The present work proposes a compact capacitive absolute angular displacement sensor design that adopts a stator and rotor configuration with a double capacitive ring structure, where the outer ring is composed of n measurement periods that function as a fine measurement component, providing high precision measurements. The inner ring is composed of a single measurement period that functions as a coarse measurement component, thereby providing an absolute position measurement. High measurement accuracy is obtained by adopting single-row excitation electrodes with induction electrodes that adopt a differential sensing structure to eliminate common-mode interference. In addition to the double-ring structure, the compact size of the proposed sensor is facilitated by integrating the electrodes of the stator and rotor and the peripheral circuits required for their respective signal processing using printed circuit board technology. A prototype of the proposed sensor is fabricated with outer and inner radii, and aggregate thickness dimensions of 30 mm, 7 mm, and less than 10 mm, respectively. The sensor design is optimized accordingly by increasing the radial interval between the outer and inner rings and adding shielding. Finally, the experimental results show that the optimized sensor design achieves a precision of $12^{\prime \prime }$ and resolution of $0.31^{\prime \prime }$ over the full measurement range of 0° to 360°. As such, the proposed sensor design is demonstrated to realize the small mechanical dimensions suffered by absolute angular displacement sensors. Accordingly, the relatively low cost and low power consumption of the proposed sensor have excellent potential for a wide variety of applications.

In this work, the trimetallic PtPdCr nanoparticles with low platinum loading (~5 wt%) supported on Vulcan carbon (PtPdCr/C) were synthesized through a facile two-step co-reduction method and showed superior methanol oxidation activity. The particle size distribution, morphology and elemental composition of the PtPdCr/C were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. The electrochemical performance for methanol oxidation of the PtPdCr/C was found to be higher with the mass activity of 969 mA·mg−1Pt compared to Pt/C (581 mA·mg−1 Pt) and PtRu/C (725 mA·mg−1 Pt). Moreover, the stability studies confirmed the enhanced durability of PtPdCr/C over Pt/C and PtRu/C catalysts after the accelerated durability test (ADT) and chronoamperometry (CA) analysis. The increased methanol oxidation activity and durability of the trimetallic PtPdCr/C in acid medium can be attributed to the change in binding energy of Pt and the induced synergistic effect from Pd and Cr atoms to Pt, which demonstrated a promising strategy for the preparation and utilization of ternary alloy catalysts towards methanol electrooxidation.

Developing inexpensive, noble metal-free, efficient, stable, and bifunctional electrocatalysts has attracted significant research interest in electrocatalysis and air battery-based energy storage d...

This study explores the influences of needle punching and a shear-thickening fluid (STF) on the stab resistance sandwich-structured composites made of nylon nonwoven and aramid fabrics. Needle punching and different treatments of aramid fabric are conducted to obtain the composites. The effects of needle punching and different treatments of aramid fabrics on the sandwich-structured composites were examined using quasi-static puncture resistance, quasi-static stab resistance, dynamic puncture resistance, and bursting property tests. Results show that needle punching and incorporation of STF positively influence the stab resistance of the composites. This study provides an innovative method to reduce the number of lamination layers and decrease the weight.

In this study, electrospun polyvinylidene fluoride (PVDF)-based nanofibrous membranes embedding TiO2 were prepared and used for photocatalytic degradation and oil/water separation. The nanofibrous membranes were characterized by scanning electron microscopy (SEM), transmission electronic microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) spectroscopy, thermal performance analysis, and oil/water separation analysis. And the degradation of rhodamine B dye was also investigated. Results showed that the fiber diameter and thermal stability of the membranes decreased with the increasing of TiO2. Meanwhile, the fiber surface roughness and specific surface area increased. The analysis of TEM, XRD and FTIR indicated that TiO2 existed in the PVDF membranes. When the TiO2 content was 12 %, the fiber diameter of the membranes was about 110 nm, and the photocatalytic degradation of rhodamine B dye efficiency was up to 97 %. The reaction rate constant was 0.02057 min−1. At 0.01 MPa vacuum, oil separated from water effectively, which proves that separation can be easily conducted with a low energy cost. Thus, the prepared membranes have a very high application prospect in the purification of reclaimed water and separation of oil and water.

With the significant advances in electronic products, materials with good flexibility, corrosion resistance, high electrical conductivity and minimal thickness are urgently needed. Herein, we demonstrate the biomimetic core–shell structure of lightweight, flexible, self-cleaning nanofiber films for high-performance electromagnetic interference (EMI) shielding by tuning the deposition of Ag nanoparticles (AgNPs). With a thickness of 0.06 mm, PAN@TiO2@AgNPs composite films (PTA films) exhibit an average EMI shielding effectiveness (SE) of 82.60 dB. After further processing with fluorine-containing molecules, the PTA-4 film becomes superhydrophobic and anticorrosive. After a hydrophobic treatment, composite films have average SE, specific SE (SSE) and SSE/t being 79.57 dB, 360.86 dB cm3 g−1, and 60143.33 dB cm2 g−1, respectively. In particular, conductive films that undergo UV radiation and bending cycles retain a stabilized electrical conductivity. This tuning bio-inspired fabrication method provides the films with UV-resistance, superhydrophobicity and EMI SE that fit the practical applications of wearable and flexible sensors.

In order to make conductive woven fabrics with electromagnetic shielding effectiveness (EMSE) and flame retardance, polysufonamide (PSA)/stainless steel (SS) core yarn are used as the weft yarns and PSA yarns are used as the warp yarns. The conductive woven fabrics are denoted as SS-60, SS-80, SS-100, SS-120, and SS-140 according to the twist counts of the core yarn, and evaluated in terms of mechanical properties, flame retardance, surface resistivity. The test results show that the best twist of the core yarn is 120 turns/10 cm. SS-60 has the maximum burnt length, while SS-140 has the minimum burnt length. Moreover, the surface resistivity of the PSA/SS woven fabrics is proportional to the twist counts, and the surface resistivity along the warp direction is higher than that along the weft direction. Changing the fabric lamination angle can form a complete shielding network, and the EMSE is significantly increased. For SS-80, SS-100, and SS-120, when they are composed of 4–6 layers with lamination angles of 0°/45°/90°/-45°/0°/45° and 0°/90°/0°/90°/0°/90°, the EMSE is above 40 dB and the shielding effect is above 99.99 % against the incident waves at 2000–3000 MHz. Specifically, SS-120 has the maximum EMSE of 64 dB against incident waves at 2844 MHz.

Geosynthetic clay liners (GCLs) are commonly used in engineering to prevent seepage. These liners’ surface fabric often suffers damage, especially in toxic environments and under high pressure. To mechanically strengthen the GCLs, this study proposes reinforcement by using needle bonding and glass geogrid to establish glass-geogrid-reinforced GCLs (i.e., GGCLs), consisting of glass geogrid, bentonite layer, and 0.3 mm thick melt-blown nonwoven fabric. Tensile durability of GGCLs was determined by exposing them to thermal oxidation and UV degradation. Hydraulic conductivity and heavy metal ions adsorption of GGCLs was explored to simulate the damage caused by garbage leachate. Tensile strengths of polyamide (PA)- and polyethylene terephthalate (PET)-contained GGCLs retained greater than 73% and 90%, respectively, even after 20 h thermal oxidation at 100°C and 60 h UV degradation. Improvement of hydraulic conductivity after 2 h adsorptions of Cu2+, Ni2+, and Pb2+ reached 51.09, 51.04, and 45.56%. The absorptions of Cu2+ and Ni2+ conformed to the quasi-secondary dynamics model, but that of Pb2+ followed both the quasi-first-order and quasi-secondary dynamics models. The mechanical properties and impermeability of the resulting GGCLs declined under the simulated conditions. This study provides a basic theory to predict the durability and adsorption of heavy metal ion of landfill GGCLs under natural and severe weather conditions.

In this paper, the shear-thickening fluids(STFs) are prepared by 0.5 µm and 12 nm silica particles. The STFs rheological properties and the performance of stab resistance are studied. SiO2 particles with two sizes (12 nm and 0.5 µm) are mixed at different weight ratios to form shear thickening fluids and its rheological behaviors are tested. Next, the quasi-static spike and knife stab resistances, dynamic impact strength, and yarn pull-out of shear thickening fluid-impregnated Kevlar fabrics are tested. The investigation showed that the micro- and nano-sized particles of silica are present in the compound shear thickening fluid, and the rheological behavior was positively improved. Regardless of whether shear thickening fluid is composed of mono-sized or binary particle-sized SiO2 particles, the presence of shear thickening fluids can significantly strengthen Kevlar fabrics in terms of the quasi-static spike and knife stab resistances, dynamic impact strength, and promote the friction force of inter-yarn. In particular, shear thickening fluid-impregnated Kevlar fabrics have better performances when being composed of 12 nm and 0.5 µm SiO2 particles at ratios of 2:1, 1:1, and 1:2 than when being made of only micro-sized or nano-sized particles.

Bio-ceramic hydroxyapatite (HA) coating has been commonly used to repair the bones or as the functionalized surface of bone substitutes due to its excellent biocompatibility, superior osteo-inductivity, and great corrosion resistance. Among many other methods for synthesizing HA coating, coating via the electrochemical deposition has a high degree of crystallinity and purity, which fits the nonlinear, complex, and rugged substrates. Furthermore, HA coating can be adjusted in terms of coating morphology, thickness, and chemical component via changing the parameters, such as electrolyte ion concentration, electrolyte composition, deposition current density, and deposition time, etc. Nevertheless, the properties of electrodeposited HA coating highly pertain to the bubbles generated by water electrolysis on the substrate surface as well as the concentration polarization of electrolyte ions near the cathode during the electrodeposition process. In this study, the critical factors and mechanisms of HA coating using the electrochemical deposition method are comprehensively evaluated, thereby examining the effects of parameter optimization (i.e., current mode, ultrasonic treatment, and postprocessing). Finally, the influences of ion substitution and HA composite coating on the surface structure and properties of the HA-based coatings are also discussed.

Environmental pollution, especially air pollution, seriously endangers public health globally. Due to severe air pollution, air filters still face many challenges, especially in terms of filtration...

This paper presents a high-precision absolute capacitive angular position sensor based on time grating. The sensor includes two single ring incremental type sensors arranged as outer and inner rings of capacitive arrays forming $N$ and $N-1$ measurement periods, respectively. The outer ring incremental sensor is employed as a fine measurement component to provide high-precision angular displacement values. The phase difference between the two incremental sensors is employed as a coarse measurement component to achieve absolute angular positioning according to a measurement principle similar to that of a vernier caliper. The proposed design is validated and optimized via tests conducted for a prototype sensor with $N\,\,=180$ and a diameter of 154 mm fabricated using standard printed circuit board manufacturing technology. Based on these results, a differential induction electrode structure is proposed to greatly reduce the magnitude of crosstalk interference signals captured by the induction electrodes of one array produced by the lead wires of the excitation electrodes of the other array. The optimized sensor achieves absolute angular position measurements with an original measurement accuracy of ±2” over a full 360° measurement range. The proposed sensor has advantages of low cost, high measurement precision, simple positioning method, and ease of manufacture.

Printing electronic components by screen printing with its excellent printing quality, high efficiency, and green environmental protection have broad application prospects in additive manufacturing. However, efficiency and quality of printing were decreased as conductive-ink blocking screen in the actual process of printing. Thus, it is pivotal that exploring factors of adhesion from the interaction of conductive-ink and screen. Herein, the functional relationship between adhesion and factors of adhesion and influence trend of adhesion on ink residue was obtained via the establishment of liquid-bridge adhesion model between two plates according to screen printing ink transfer process, solid-liquid wetting theory, and adhesion mechanism, which was verified by software Fluent. In order to justify the accuracy of the model and simulation, the adhesion and ink residue were tested on the surface-modified glass sheet as the result that the model and simulation were consistent with the experimental record. It was demonstrated that solid-liquid contact angle, tensile distance, and liquid volume are the main factors affecting the change of solid-liquid adhesion. With the increase of tensile distance and contact angle, the adhesion force decreases, which causes the decline of the residual amount of liquid on the solid surface. By means of screen modification, the adhesion between conductive-ink and screen can be reduced, as meanwhile the efficiency and quality of printed products can be improved.

The effect of polyaluminum chloride (PAC) on the durability, microstructure, and corrosion sensitivity of slag–cement pastes was investigated in this research. Various experimental tests we...

Poly(vinylidene fluoride-hexafluoropropylene) [P(VDF-HFP)] and bisphenol A epoxy resin (EP) composite films were prepared by solution casting. The tensile strength of the composite film was enhanced by adjusting the curing conditions of the EP. The results showed that EP dispersed in the form of particles, and at higher content, EP particles mixed with P(VDF-HFP) to form an enrichment zone. A special structure of P(VDF-HFP) epitaxial crystals formed around the enrichment zone. Fourier-transform infrared spectroscopy and x-ray diffraction analyses showed that parts of the non-polar α phase transformed to the weak polarity γ phase after the addition of EP. With the addition of EP, the breakdown strength of the composite film was significantly improved. The energy loss of the composite film was greatly reduced, and the discharge efficiency was remarkably improved.

Compacted soil is widely used in road and railway subgrade, while alternation of seasons can cause fluctuations in moisture content of soil (i.e., wetting-drying cycles) and influence the performance of soil. In order to research the effect of wetting-drying cycles on mechanical behaviour and electrical resistivity of compacted unsaturated subgrade soil, wetting-drying tests considering different number and cyclic amplitude were conducted on compacted unsaturated clay specimens, and the electrical resistivity and unconfined compressive strength of soil were measured in this study. The AC (alternative current) two-electrode method was applied in the resistivity measurement. The experimental results show that increasing number and cyclic amplitude of wetting-drying cycles can both reduce the strength and electrical resistivity of the compacted unsaturated specimens. After 3-4 wetting-drying cycles, the strength and electrical resistivity tend to be constant value. The change of pore structure can be the key factor leading to the reduction of electrical resistivity of soil subjected to wetting-drying cycles and consequently causing the decrease of soil strength in the present study. Thus, the electrical resistivity can be adopted to indirectly assess the mechanical behaviour of unsaturated compacted soil after wetting-drying cycles.

Glass geotextile reinforcement and needle-punch bonding are applied to compensate for the low mechanical strength of a geotextile clay liner (GCL) and reduce damage under complicated service condit...

Luminescent liquid crystalline polymers (LLCPs) show extensive application potentials, such as liquid crystal displays and circularly polarized luminescence. In this work, we employ a hydrogen-bonding strategy different from the traditional covalent-bonding method to fabricate LLCPs. First, the acceptor and donor of hydrogen bonding, (4,4′-dibutanoxy tetraphenylethylene)-1-pyridine (PTPEC4) and poly(2-vinyl terephthalic acid) (PPA), respectively, are successfully synthesized. Then, mixtures with different molar ratios (x’s) of PTPEC4 to PPA are used to prepare a series of LLCPs [denoted as PPA(PTPEC4)x]. The resultant LLCPs show a smectic A phase (x ≥ 0.8), a columnar nematic phase (0.6 ≤ x ≤ 0.05), and an amorphous state (x = 0.025), depending on the x value. Meanwhile, all polymers exhibit typical aggregation-induced emission behavior. More interestingly, with the variation of the PTPEC4 content, the series of LLCPs show different colors, that is, the emission peak red shifts from 510 nm (x = 1.0) to 55...

Terrorist attacks occur constantly, which subsequently arouses awareness of self-protection. In order to alleviate the harm caused by sharp objects of knives and daggers, a design of flexible stab-resistant materials that are impregnated with the shear thickening fluid (STF)/multi-walled carbon nanotubes (MWCNTs) system and different texture of fabrics is presented. STF/MWCNTs are composed of polyethylene glycol (PEG 200) as the dispersion medium and silica (SiO2) of 12 nm and 75 nm as disperse phase as well as MWCNTs as supplementary reinforcement, in expectation to provide the aramid fabrics with high strengths, low critical shear rate, and a short thickening response time. The textures of aramid fabrics—plain (P), twill (T), satin (S), or basket (B) weave—are saturated in the STF/MWCNTs system. The synergetic influences of silica size and texture on tensile strength, quasi-static knife, and spike stab resistances of the STF/MWCNTs-impregnated aramid fabrics are examined. Results show that the plain aramid fabric immersed in the STF/MWCNTs system containing 12 nm SiO2(SM12) exhibit the maximum tensile strength and quasi-static knife stab resistance, 14.7 MPa and 8.9 MPa, respectively, which is 1.15 and 1.43 times higher than pure aramid fabrics. Moreover, the basket-weave aramid fabric immersed in the STF/MWCNTs system containing 12 nm SiO2have the maximum quasi-static spike stab resistance of 17.12 MPa compared to other textures of fabrics, which is 1.05 times higher than those immersed in the 75 nm SiO2STF/MWCNTs (SM75) system and 1.33 times higher than that of pure basket aramid fabrics.

In order to deeply explore the fiber characteristics influencing on stab resistance of shear thickening fluid (STF)- impregnated fabrics, two different weaving fabrics, ultra-high molecular weight polyethylene (UHMWPE) fabric and Kevlar fabrics are saturate the various concentrations and particle size of STFs. Result shows that, SiO2/PEG-200 blends demonstrate quick shear-thickening property, and the critical shear rate lowers to 1.2-45 s-1 with higher concentration of 75 nm SiO2. STF concentration and particle size significantly affect spike puncture resistance property, but the knife stab resistance mainly depends on fiber characteristics. Comparatively, STF-UHMWPE composite fabrics exhibit better knife stab resistance but weaker spike puncture resistance than STF-Kevlar fabrics. This study can provide an optimization for structure design of stab resistance armors in the future.

The SnO–SnO2–Sb2O3 films were deposited by simultaneous RF and DC magnetron sputtering. Increasing the ratio of O2/Ar pressure raised the intensity of the (311) peak of cubic Sb2O3 and the (200) peak of tetragonal SnO2, but clearly reduced the intensity of the (101) peak of tetragonal SnO2. According to visible-photoluminescence analyses, the blue shift of the PL peak can be attributed to the combination of smaller grains and higher compressive strain in the SnO–SnO2–Sb2O3 films. The nonlinear refractive indices of SnO–SnO2–Sb2O3 films deposited in a pure Ar or a mixed Ar–O2 atmosphere were measured by Moire deflectometry, and were of the order of 10−8 cm2 W−1. At a higher ratio of O2/Ar pressure, a transparent SnO–SnO2–Sb2O3 film exhibited a lower surface roughness, better hydrophilicity, a higher linear refractive index and a lower extinction coefficient.

Previously, benzotrithiophene (BTT)-based hole-transporting materials (HTMs) had to be doped with three chemical agents for high-efficiency perovskite solar cells (PSC). This work describes significant progress by which the first dopant-free BTT core-based HTM (YKP03) with EDOT spacers was readily accessed by step-saving direct C–H arylation. PSCs with dopant-free YKP03 showed promising efficiencies of up to 16.15% with potential long-term storage stability.

In projects, mixed soil slurry between cut-off wall and coarse-grained soil always exists. It may influence on or change mechanical properties of interface between coarse-grained soil and structure. The mechanical behaviors of the interface between coarse-grained soil and concrete were investigated by simple shear tests under mixed soil slurry. The significant dilatancy and stress-strain softening can be achieved through the results, which also indicate that the cement content play an important role in the shear strength of the interface. The peak strength and the position when the dilatancy occurs are related to both normal stress and cement content. An elasto-plastic constitutive model for interface considering mixed soil slurry was formulated in the framework of generalized potential theory. The entire model parameters can be identified by experimental tests. Finally, the predictions of the model have been compared with experimental results, and results show the model is reasonable and practical.

Particulate matter 2.5 (PM2.5) has become a public hazard to people&rsquo, s lives and health. Traditional melt-blown membranes cannot filter dangerous particles due to their limited diameter, and ultra-fine electrospinning fibers are vulnerable to external forces. Therefore, creating highly efficient air filters by using an innovative technique and structure has become necessary. In this study, a combination of polypropylene (PP) melt-blown and polyvinyl alcohol (PVA)/zeolite imidazole frameworks-8 (ZIF-8) electrospinning technique is employed to construct a PP/PVA/ZIF-8 membrane with a hierarchical fibrous structure. The synergistic effect of hierarchical fibrous structure and ZIF-8 effectively captures PM2.5. The PP/PVA composite membrane loaded with 2.5% loading ZIF-8 has an average filtration efficacy reaching as high as 96.5% for PM2.5 and quality factor (Qf) of 0.099 Pa&minus, 1. The resultant membrane resists 33.34 N tensile strength and has a low pressure drop, excellent filtration efficiency, and mechanical strength. This work presents a facile preparation method that is suitable for mass production and the application of membranes to be used as air filters for highly efficient filtration of PM2.5.

With the increase of electromagnetic radiation pollution, there is an urgent need to develop lightweight, ultra-thin, and high electromagnetic shielding composite film to eliminate unwanted electromagnetic interference. Herein, based on the layer-by-layer assembly strategy, a simple solution dip coating method was used to achieve the combination of two-dimensional transition metal (MXene) and nanofiber film, thereby constructing a conductive composite film with a unique undulating structure. The silicon-containing hydrophobic layer imparted excellent hydrophobic properties to the composite film while maintained the stability of the sandwich structure. The contact angle (CA) of the composite film with ultra-thin thickness (29um) was 125.49° and the conductivity was as high as 71.91 S/cm. The hydrophobic treatment would not damage the flexibility and mechanical properties of the composite film. In particular, the average shielding effectiveness (SE) and SSE/t could as high as 28.82 dB and 12422.41 dB cm2g−1, due to the layered structure formed by the connection of countless MXene nanosheets is beneficial to promote multiple absorption and reflection. This layer-by-layer assembly strategy provides a facile route in fabricating light-weight, flexible and ultrathin composite film for high-performance electromagnetic shielding, which is of great significance for broadening the practical application of MXene-based conductive materials.

In order to improve the stab resistance of fabrics, needle-punching processing technology is adopted to combine the aramid fabric and the nonwoven fabric. The shear thickening fluid (STF) and Thermoplastic polyurethanes (TPU) are used to compound the sandwich structure stab-resistant composite in different combinations. The stab resistance performance, bursting performance and flexibility of stab-resistant composites have been studied. Studies have shown that the stab-resistant composite impregnated with STF and the stab-resistant composite impregnated with STF and then combined with the TPU coating have a more obvious improvement effect on the stab resistance performance while the flexibility is less reduced. The puncture process is accompanied by the shear thickening effect of STF. The stab-resistant composite impregnated with STF and coated with TPU has a tighter bond between the fibers.

Chitosan (CS) combined with hydroxyapatite (HA) was injected into a composite braid, and a hierarchical pore structure scaffold was obtained by freeze drying and cold atmospheric plasma (CAP) technology. The CS/HA/braid scaffold with hierarchical pore structure was analyzed and characterized by scanning electronic microscopy, Fourier transform infrared spectroscopy, true color confocal microscopy, improved liquid replacement method, and phosphate buffer solution immersion. The mechanical properties and degradation ability of the scaffold were evaluated through compression test and degradation test. Results showed that HA addition endowed the core of the scaffold with macroscopic pore sizes of 80-180 μm, and CAP treatment endowed the shell of the scaffold with microscopic pore sizes ≤10 μm. All scaffolds exhibited high porosity and swelling rates of ≥80 % and ≥300 %, respectively. The scaffold with a hierarchical pore structure had good mechanical properties and twice the degradation rate. In addition, the treated scaffold precipitated intact spherical HA crystals. Under the synergistic effect of HA and CAP treatment, scaffolds achieved 277.6 % cell viability compared with pure CS scaffold. Overall, this method was feasible for preparing bone scaffolds with hierarchical pore structure for potential bone tissue engineering.

The Pt–Fe2O3 nanoparticles embedded over N, P-doped carbon (Pt–Fe2O3/NPC) was successfully synthesized by chemical reduction method demonstrating an enhanced electrocatalytic efficacy in alkaline media toward oxygen reduction reaction (ORR). The surface morphology of Pt–Fe2O3/NPC has been characterized by electron microscopy scanning, X-ray diffraction, electron microscopy transmission, Raman spectra, and X-ray photoelectron spectroscopy. The ORR electrocatalytic activity of Pt–Fe2O3/NPC was found to be the superior mass activity of 0.120 mA µg−1, which are almost twice higher than those for Pt–Fe2O3/VC (0.068 mA µg−1) and Pt/C (0.061 mA µg−1) catalysts. The durability tests revealed that the Pt–Fe2O3/NPC exhibited enhanced stability observed from the order of electrochemical active surface area (ECA) loss determined as Pt–Fe2O3/NPC (45.67%)

This study reports a novel adsorbent structure and shows the satisfactory removal performance of Pb(II) and Ni(II). The fabric structure increases the strength of the hydrogel. The hydrogel plays a major role in the composite structure as a matrix, while the fabric bears the applied load and protects the structure from mechanical damage. The double-network composite hydrogel is reinforced by plasma grafted polylactic acid melt-blown non-woven fabric and polyethylene glycol dimaleate, and its compressive strength reaches 40.6 kPa at 60% strain. The interface substantially improves the compression strength by 42.9%. Through the adsorption isotherm model, the adsorption capacity of the hydrogel for Pb(II) and Ni(II) reaches 233.12 and 165.06 mg/g, respectively, and the removal rate of heavy metal ions in water at low concentrations exceeds 95%, showing the excellent removal rate of heavy metals. Even after the fifth cycle, the removal efficiency barely declines, indicating the feasibility of repeatedly use. Cost analysis reveals that the adsorbent is relatively low cost, solving the problems of difficult recovery, low strength, and easy damage of hydrogel adsorbents, and promoting the industrial application of hydrogels as adsorbents.