Advanced Composites and Hybrid Materials最新文献

Albeit the abundance, renewability, and biodegradability of the polymer known as cellulose, the insolubility and poor dispersibility in most common organic solvents make it incredibly difficult to facilitate conversion into hydrogels without concomitant dissolution. It is known that Swift family birds construct strong and sturdy nests with saliva that acts to bind fibers and twigs. Inspired by this charming hierarchical architecture, protonated carboxymethyl cellulose and cellulose were exploited as “saliva” and “twigs,” respectively, and by a combination of freeze–thaw treatments, cellulose hydrogels can be successfully induced without pre-dissolution representing a striking advancement over what is currently known or predicted. The gel materials displayed considerable increases in storage modulus, viscoelastic behaviors, and thermal stability as the cellulose content increases and exhibited unique omniphilic behaviors. Moreover, this bioinspired strategy is much more universal than originally surmised as found by the gelation of bamboo fibers (additionally containing lignin and hemicellulose), illustrative of the versatility. As a bio-inspired strategy, the current work is the first report on a straightforward, simple, green, yet effective gelation protocol to prepare cellulose-based soft materials.

With the rapid development of wearable electronics and the advent of the Internet of Things (IoT) era, it is imperative to research and explore the basic components to meet the application scenarios. In particular, it is becoming increasingly difficult to impart suitable properties to individual materials and realize appropriate physical dimensions in order to satisfy increasing demands of multifunctionality for fundamental studies, device designs, and performance optimization. Therefore, these challenges and opportunities can be addressed by designing (optical) electronic and energy devices with unique functionality and versatility through the combined advantages of multidimensional integration or hybridization of inorganic semiconductors, especially inorganic two-dimensional semiconductor materials, with various types of organic materials with potentially novel functions and unique properties. Herein, a comprehensive review of emerging integration or hybridization of inorganic semiconductor materials with organic materials from their individual components, and assembly fabrication to their state-of-the-art electronic, optoelectronic, magnetic, and energy applications is presented. Future opportunities and challenges associated with these organic/inorganic hybrids are highlighted.

On the basis of high-efficiency electrostatic assembly, a type of ultralight, hydrophobic, hierarchically porous aerogels composed of metal–organic framework (MOF)-derived magnetic γ-Fe₂O₃@C/graphene are prepared via facile, scalable freeze-drying followed by annealing approach. The interaction between MOF and graphene oxide leads to the uniform dispersion of MOF-derived magnetic nanoparticles in the graphene-based cell walls, endowing the aerogels with high conductive and magnetic losses as well as polarization loss capacity derived from abundant heterogeneous interfaces. Both the core–shell microstructure of MOF derivative and the hierarchical pores of aerogels are instrumental in the multiple scattering of electromagnetic waves (EMWs), further promoting the EMW loss capability. Combined with the optimized impedance matching arising from the synergy between dielectric and magnetic components, an excellent EMW absorption performance of aerogel is achieved. At a filling ratio of merely 5 wt%, a minimum reflection loss of − 60.5 dB and a broad effective absorption bandwidth of 7.76 GHz covering the entire Ku-band are accomplished, significantly outperforming previously reported MOF- or graphene aerogel-based EMW absorbers. This work thus offers an efficient design strategy to prepare ultralight MOF-based aerogels for high-efficiency EMW absorbing materials in applications of electromagnetic compatibility and aerospace.

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Fabricating a functional heterogeneous interface to enhance catalytic performance is quite significant for developing high-efficiency electrocatalysts. Herein, a coral-like nickel phosphide@cerium oxide (Ni₂P@CeO₂) hybrid nanoarray on nickel foam was designed via selective-phosphorization of nickel hydroxide@cerium oxide (Ni(OH)₂@CeO₂). Benefiting from CeO₂ as the “electron pump,” it leads to electron transfer from Ni₂P to the CeO₂ side, and induces electron redistribution in the interface boundary, thereby optimizing the H* adsorption free energy in the hydrogen evolution reaction (HER) process. As hypothesized, the water molecules will preferentially adsorb on the CeO₂ side due to its better affinity for oxygen-containing species, and will readily break down into OH* and H* at a lower energy barrier. Subsequently, benefiting from the lower H* adsorption free energy of P sites, the generated H* will migrate to the Ni₂P side through the spillover process. Contributing to the synergistic effect of double-active sites, the Ni₂P@CeO₂/NF electrode exhibits brilliant catalytic performance for HER with 62 mV to attain 10 mA/cm² and exceptional durability over 100 h in alkaline solution at ~ 100 mA/cm². Meanwhile, attributing to the similar interface electron redistribution effect, the precursor Ni(OH)₂@CeO₂/NF likewise displays excellent oxygen evolution reaction (OER) electrocatalytic performance, which only requires 229 mV to arrive at 10 mA/cm², even better than benchmark ruthenium dioxide (RuO₂). Hence, the assembled Ni(OH)₂@CeO₂/NF||Ni₂P@CeO₂/NF system only needs 1.53 V to achieve 10 mA/cm² in alkaline solution. Moreover, the electrolyzer also presents brilliant electrocatalytic activity and stability in alkaline natural seawater electrolyte with higher reserves on earth.

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“Electrons pump” effect of CeO₂ ensures that interface-engineered Ni₂P@CeO₂ hybrid nanoarrays prepared via selective-phosphorization treatment present superior HER catalytic performance

Supercapacitor is an important energy storage device with rapid charge/discharge, long cycle life, and high-power density. The macron vertical channel structure in wood can provide an effective buffer space for the transport and storage of electrolyte ions. The transport kinetics of the electrolyte with wood-derived carbon electrode has an important effect on its capacitance performance. Herein, the wood branch of cedar is employed to construct supercapacitor electrode with high-rate performance by facile carbonization and KOH activation. The cedar demonstrates arranged pore structure and high specific surface area. The special pore structure is retained after carbonization. Furthermore, the carbonization temperature and carbonization process are explored. As the optimized, the wood-derived porous carbon electrode displays high specific capacitance of 108 F/g at a higher current rate of 15 A/g, implying its good rate capability. Moreover, after compounding MnO₂, the specific capacitance of composite electrode delivers 162.4 F/g at 0.5 A/g. The assembled symmetric supercapacitor shows high energy density of 3.01 Wh/kg at the power density of 250 W/kg. This work offers an idea for developing clean and efficient new energy technologies with high-rate performance.

To expand the application field of electromagnetic wave functional materials based on light, thin, and cost-effective, the integration of the structure and function of electromagnetic wave materials is the key research goal. In this work, hematite(Fe₂O₃)@carbon nanotubes (CNTs)/polyacrylamide hydrogel composites with good flexibility and biocompatibility were prepared, and the hydrogel composite exhibited excellent electromagnetic wave (EMW) absorption performance, even with a low load ratio of Fe₂O₃@CNTs (2,4,6 wt.%) achieved—the minimum reflection loss (RL_min) value of 2 wt.% Fe₂O₃@CNTs/polyacrylamide (PAM) is − 60.96 dB at 15.87 GHz with a matching thickness is 1.63 mm and a wide effective absorption bandwidth (EAB) of about 3.4 GHz. Furthermore, the RL_min values of 4 wt.% Fe₂O₃@CNTs/PAM reach − 55.65 dB at 14.15 GHz. In addition, when the thickness of the hydrogel composite is between 1.56 and 1.64 mm, almost all electromagnetic waves can be absorbed in the Ku band frequency. Therefore, the impedance matching of the hydrogel composite was optimized, and EMW absorption performance was improved by introducing Fe₂O₃@CNTs. This work provides a strategy for designing a structure–function integrated EMW absorber and a convenient method for preparing flexible and biocompatible EMW hydrogels, which will be conducive to the wider application of EMW functional materials in daily life.

Graphical Abstract

Excellent absorption performance is achieved at a low load ratio of Fe₂O₃@CNTs (2 wt.%), successfully designing hydrogel absorbers with good flexibility and biocompatibility

With the rapid development of the 5th-generation (5G) mobile communication technology, the applications of high-frequency and high-power electronic equipment are becoming increasingly broadened, which seriously affects the operation of electronic components and human health. Therefore, the research on high-performance electromagnetic interference (EMI) shielding materials is of great significance for the development and upgrading of 5G electronic equipment. In recent years, the transition metal carbides, nitrides, and carbonitrides (MXenes) have gradually received extensive attention from scholars due to ultra-high electrical conductivity, large specific surface area, and excellent hydrophilicity. This review introduces the preparation methods of MXenes and the latest research progress of MXene-based nanomaterials in the field of EMI shielding. In this review, the EMI shielding mechanism and the preparation methods of MXenes are briefly introduced first. Next, the research progress of MXene-based EMI shielding materials in recent years is reviewed, and various kinds of MXene-based EMI shielding materials are introduced in detail, especially the preparation of MXene/polymer EMI shielding composites with various structures. The key scientific and technical problems in the field of MXene-based EMI shielding materials are put forward, and the future development trend is prospected.

Living in the noisy environment for long time would cause various diseases and seriously harm physical and mental health of mankind. In this work, water-soluble polyamide acid was used to prepare the polyimide-polyvinylpyrrolidone (PI-PVP) aerogels with hierarchical cellular structures by homogeneous mixing with pore modifier of PVP, freeze-drying, and thermal treatment. PVP could adjust pore structures, widen pore size distribution, and improve sound absorption performances for PI aerogels in wide frequency range. When the amount of PVP is 45 wt%, PI-PVP aerogels exhibit excellent sound absorption, mechanical, thermal insulation, and heat resistances performance. The noise reduction coefficient is 0.34 and average sound absorption coefficient is over 0.9 in the frequency range of 2000 ~ 6300 Hz. Young’s modulus is 7.12 kPa. Stress loss and plastic deformation after 100 compression cycles (strain of 50%) are 14.7% and 3.2%, respectively. Meantime, the thermal conductivity coefficient and the initial thermal decomposition temperature in the air are 0.044 W/(m·K) and 420 °C, respectively. Our fabricated PI-PVP aerogels in this work own broad application prospects in the fields of engineering, construction, vehicle noise reduction, and personal protection.

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Sound absorption performance and mechanism of PI-PVP aerogels.

A facile technique was reported for fabricating high conductivity and improved strength of linear low-density polyethylene/multi-walled carbon nanotubes (LLDPE/MWNTs) composite films by the ultrasonication anchoring technique and compression molding treatment. Thermal property, mechanical property, electrical conductivity, microstructures, optical property, and organic vapor sensing behaviors of the MWNTs/LLDPE composite films were studied. The MWNTs are uniformly anchored onto the surface of LLDPE matrix, and the conductive networks are easily formed by the ultrasonication anchoring technique. After compression molding treatment, the incorporation of MWNTs causes an easier formation of LLDPE extended-chain, which is wrapped around of MWNTs shish. The MWNTs/LLDPE composite films exhibit an excellent conductivity of 2.79 × 10⁵ Ω∙cm with 0.15 wt % MWNTs. Meanwhile, the tensile strength of the composite films reaches 18.9 MPa. Interestingly, the transparency is not significantly reduced. The sensitivity and reproducibility of vapor sensing behaviors have been demonstrated during immersion-drying runs toward two representative solvents, i.e., acetone and xylene. This work opens up a new direction for the conductivity optimization of MWNTs/LLDPE composite films with a broad prospect in the field of vapor sensor.

Bioinspired nanosurfaces with hydrophobicity and multifunctionality have stimulated wide interests in both basic research of fundamental wetting theory and practical application arising from various intriguing phenomena in nature. 3D printing has become one of the most promising techniques for the manufacture of biomimetic materials with versatile applications because of the various advantages including easy accessibility and low cost. Here, a comprehensive review of recent progress on 3D-printed hydrophobic materials and their application was presented to summarize the achievement of the field and look forward to the future research perspective. First, classical models of hydrophobicity and theoretical progress related to the wetting phenomena are proposed. Moreover, diverse mechanism of 3D-printing techniques is systematically summarized following the classification of the methods to gain hydrophobicity in the 3D-printing process. Subsequently, bioinspired intriguing applications including drag reduction, water harvesting, oil-water separation, and 4D-printing are introduced from theory to practice. Finally, a general summary is drawn along with future guidelines for the fabrication of hydrophobic materials which fully utilize the advantage of 3D printing.

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Comprehensive review for hydrophobic 3D-printed material: theories, applications, and future prospects for oil-water separation, water harvesting, drag reduction, and 4D-printing.