Advanced Composites and Hybrid Materials最新文献

Heteroatom doping represents an innovative strategy for finely tuning a catalyst’s electronic structure and kinetics for efficient water splitting. We synthesized a novel electrocatalyst of copper-doped zinc cobalt sulfide nanosheets (Cu-ZnCoS/NF) via a hexamethylenetetramine-assisted hydrothermal process. The resulting catalyst exhibits exceptional performance, with minimal overpotentials for both the hydrogen evolution reaction (HER 119/217 mV) and the oxygen evolution reaction (OER 210/280 mV) at 20 and 50 mA cm⁻², respectively, in an alkaline environment. The water electrolyzer/anion–exchange membrane (AEM) electrolyzer containing Cu-ZnCoS/NF as both cathode and anode operate at a low voltage of 1.51 V/1.88 V, respectively, for several hours. The density functional theory (DFT) and electrochemical tests reveal that modulation of the electronic structure optimizes intermediate adsorption energy, enhances electroactive centers, and facilitates charge transfer of the water-splitting process. These findings pave the way for exploring similar catalysts as robust electrocatalysts for practical electrolyzer devices.

Due to their great potential in saving weight, carbon fiber–reinforced epoxy composites are receiving great interests for the liquid oxygen (LOX) cryotank as the largest component in the spacecraft propulsion system. However, the application of epoxy resins as matrices in LOX composite cryotanks is severely constrained by their LOX incompatibility and poor cryogenic mechanical properties. To address these issues, two-dimensional MXene nanosheets as multifunctional fillers are introduced into an epoxy resin, and the effects of MXene on the cryogenic mechanical properties and liquid oxygen compatibility of the epoxy resin are comprehensively examined. It is interestingly observed that the mechanical properties at both room temperature (RT) and cryogenic temperature (90 K) of the epoxy resin, including tensile strength, elastic modulus, and fracture toughness, are significantly enhanced with the addition of low content MXene; and the MXene/epoxy nanocomposite with 0.10 wt.% MXene exhibits the optimal mechanical performances. MXene is also effective in enhancing the LOX compatibility of the epoxy, and the MXene/epoxy nanocomposite with 0.20 wt.% MXene completely passes the LOX impact test. In overall, the MXene/epoxy nanocomposite with simultaneously enhanced cryogenic mechanical properties and LOX compatibility is promising for applications in LOX composite tanks.

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Luminescent gold nanoparticles (L-AuNPs) with diameters exceeding 2 nm hold great promise for biomedical imaging due to their unique optical properties and excellent biocompatibility. However, they typically exhibit weak photoluminescence (PL) because of surface plasmon resonance (SPR) effects. Moreover, conventional synthesis of L-AuNPs, often through thermal or chemical reduction, tends to be complex and labor-intensive. It is crucial, therefore, to develop more straightforward synthesis methods that enhance PL emission efficiency. Herein, we introduce a facile photochemical method for synthesizing highly luminescent AuNPs coated with 2-n-hexylthio-1,3,4-thiadiazole-5-thiol (L-AuNP@HTT). These nanoparticles, with a diameter of 3.19 nm, exhibit outstanding optical properties, including a high quantum yield (φ ~ 12%), an extremely long luminescence lifetime (~ 1 µs), a symmetric PL spectrum, and a narrow full width at half maximum (FWHM ≤ 49 nm). They also feature an exceptionally large two-photon absorption cross-section (σ), reaching up to 8.0 × 10⁴ GM (1 GM = 10⁻⁵⁰ cm⁴ s photon⁻¹). Upon encapsulation in a polymer matrix (p-AuNPs), the TPA cross-sections were further enhanced to 1.1 × 10⁸ GM. These p-AuNPs demonstrated high photostability and efficient targeting to mitochondria, making them highly effective for mitochondrial-targeted two-photon excited luminescence (TPEL) imaging. Deep-tissue time-gated TPEL imaging and in vivo computed tomography (CT) imaging have also been achieved with p-AuNPs. This work establishes a straightforward synthesis route for highly luminescent gold nanoparticles larger than 2 nm, significantly broadening their potential in various bioimaging applications.

The fabrication of nano-materials with delicate microstructure design and suitable multicomponent allocation is considered as a promising approach to meet the requirements of lightweight, high efficiency, and broadband absorption for electromagnetic wave (EMW) absorbers. Toward this end, nickel/carbon@zirconium dioxide core–shell nanofibers composited with polyurethane were successfully prepared through flexible electrospinning, carbonization, and a subsequent resin curing process. Profiting from the synergistic coactions of constituents and unique morphology, the ternary nanocomposites displayed the minimum reflection loss of − 61.7 dB at 17.1 GHz, and an ultra-broad bandwidth up to 8.3 GHz. In-depth investigation through electromagnetic parameters analysis and electric field distribution simulation indicated that the introduction of zirconium dioxide brought about the optimal impedance matching, while the existence of nickel and abundant heterogeneous interfaces contributed to diverse attenuation pathways, including interface polarization, dipoles polarization, conductivity loss, and magnetic loss. Thus, this study paved new research avenues for the design and synthesis of one-dimensional high-performance microwave absorbing materials, and enriched the application range of polyurethane matrix composites.

A custom-made rotational coating system that can apply constant, uniform, and high force to nanosheets was made. Montmorillonite (MMT) nanosheets and polyvinyl alcohol (PVA) chains were coassembled onto a poly(ethylene terephthalate) (PET) substrate using a rotational coating process. Different concentrations and centripetal accelerations were explored to study their effects on coating properties. The nanocoating thickness was determined by a thin-film measurement system and a stylus profilometer. The turbidity of the coating layer was determined using ultraviolet–visible (UV–Vis) spectrophotometry and the Beer-Lambert law. The nanostructure of the coating was characterized by X-ray diffraction (XRD). Finally, the oxygen transmission rate was measured to determine the effects of processing conditions on permeability. Two statistical approaches were used to determine the degree to which each processing parameter has an impact on each coating property. Aside from the fundamental study on rotational coating, this coating technique can fabricate highly ordered nanocoatings with significantly improved barrier properties. Potential applications are envisioned in the fabrication of food packages, dielectric materials, and biomedical devices.

Multifunctional integrated flexible electronic skin (e-skin) is the essential medium for information exchange between humans and machines. Especially, the proximity/pressure/strain sensing has become a technological goal for various emerging wearable electronic devices, such as biomonitoring devices, smart electronics, augmented reality, and prosthetics. Herein, a stretchable hybrid electronic network-based e-skin is presented, fabricated by embedding 3D hollow MXene spheres/Ag NWs hybrid nanocomposite into PDMS, which can effectively avoid the electrode falling off due to stress concentration. This e-skin works in noncontact mode (proximity-negative capacitance) and contact mode (pressure-positive capacitance and strain-resistance) for multiplex detection of random external force stimuli without mutual interference. The macroscopic physical structure of stretchable electrodes and the microscopic hybrid three-dimensional conductive network jointly contribute to the good sensing performance of the device. This work provides an effective and universal strategy for the application of wearable intelligent electronic products that demand noncontact interaction and multimodal tactile perception.

Shape memory alloys are widely used in aerospace, biomedical engineering, flexible electronics, and smart actuators because of their excellent mechanical properties, good biocompatibility, and corrosion resistance. With the complexity and diversity of application scenarios, the demand for shape memory alloys with special structures and functions is becoming more and more obvious. However, the shape memory alloys prepared by traditional metallurgical technology generally suffer from impurity contamination, uneven composition, and structural defects and have certain limitations when designing special complex structures. 3D printing technology can better improve the compositional accuracy of shape memory alloys, reduce structural defects, and achieve the design of complex structures. The preparation of precise reliable and adaptable shape memory alloys plays an important role in medical devices, implants, and biosensors. This paper briefly reviews the research results of 3D-printed shape memory alloys in recent years in terms of molding process and biomedical engineering applications, and the future development of 3D-printed shape memory alloys is discussed with a view to providing valuable references for research and applications in this field.

Climate change and its impact on the environment and human health have become alarming concerns in recent years. The use of traditional energy sources such as coal, oil, and gas is a major contributor to the rise in carbon dioxide emissions, which is the primary driving force behind climate change. As a result, significant efforts have been made to develop more sustainable and efficient methods of using carbon-based resources to reduce net carbon dioxide emissions. This review delves into the latest advanced techniques for converting carbon dioxide into high-value chemical products and renewable energy. By employing these innovative approaches, remarkable progress can be made towards enhancing the environment and promoting economic growth, ultimately leading to carbon neutrality.

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Biopolymer composites are emerging as promising materials for smart sensors in the fields of civil engineering and intelligent cities. With enhanced mechanical properties, tailored sensitivity, and versatile fabrication methods, biopolymer composites provide a compelling solution for sustainable sensing technologies. The versatility of biopolymer composites with different electrical properties enables their applications in resistive, capacitive, and piezoelectric sensors, thus enhancing their potentials in healthcare, environmental monitoring, and consumer electronics. Here, we review an advancement of biopolymer composites in sensor technology, such as piezoresistive strain sensors used in structural health monitoring and a novel biochemical oxygen demand (BOD) biosensor for water monitoring. Integrating biopolymer composites into electrical biosensors has demonstrated promising results in detecting various substances, including moisture content in soil and model pollutants. Furthermore, their utilization in biopolymer-bound soil composites for building materials holds potential implications for sustainable construction practices. In summary, the incorporation of biopolymer composites in sensing applications paves the pathway towards developing smart and sustainable cities. As research continues, these materials are expected to play an increasingly significant role in sensor technology, providing eco-friendly solutions for challenges in civil engineering, environmental monitoring, and beyond. Furthermore, the potential for biopolymer composites to contribute to a more sustainable and interconnected world is considerable, making them a promising avenue for future sensor manufacturing and Internet of Things (IoT) applications.

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The advancement of sustainable biopolymer composites for sensors is comprehensively reviewed with their manufacturing and applications in smart cities.

Transition metal selenides are considered reliable anode materials for sodium-ion batteries (SIBs) on account of their commendable sodium storage capability. Yet they still face problems such as substantial volume amplification and unsatisfied conductivity which are detrimental to the circulation performance of the battery. In view of this, nitrogen-doped carbon (NC) packaged ZnSe/CoSe heterostructures (ZnSe/CoSe@NC) octahedron are rationally designed in this work. The NC capsulated heterostructures octahedron could substantially mitigate the issues of volume expansion and low conductivity for transition metal selenides. Additionally, the rich phase boundary derived from ZnSe/CoSe heterostructured interfaces yields numerous active sites for sodium ions and the formed electric field inside ZnSe/CoSe heterostructure can largely boost charge transfer. Most importantly, the unique heterostructure endows ZnSe/CoSe@NC with relatively stronger sodium adsorption, leading to long cycling stability with a reversible capacity of 289 mAh g⁻¹ underneath 900 cycles at 1 A g⁻¹. Given the pseudocapacitance effect of ZnSe/CoSe@NC in SIBs, a sodium ion capacitor (SIC) on the basis of ZnSe/CoSe@NC capacitor-type anode and Na₂FePO₄F (NFPF) battery-type cathode is rationally conceived and features high energy densities of 209.4 and 80.4 Wh kg⁻¹ at 240 and 4000 W kg⁻¹. The findings offer a promising pathway toward developing advanced energy storage devices with enhanced cycling stability and high energy density.