Passive building thermal management requires materials that adapt to seasonal changes by modulating their spectral properties, yet conventional materials exhibit fixed optical properties. Here, we report Janus gradient porous membranes that enable switchable thermal regulation by simple flipping: radiative cooling for summer and solar heating for winter. The membranes are fabricated via a solvent template-assisted evaporation-induced phase separation (ST-EIPS) process combined with strategic carbon black (CB) modification. The resulting asymmetric architecture is endowed with hierarchical porosity spanning from nano- to microscale, which facilitates a tailored solar-thermal response. When the original white surface faces upward, the membrane exhibits 96.06% solar reflectance and 94.69% emissivity in atmospheric transparency window, achieving subambient cooling of 11.7 °C under solar irradiance of 1101.3 W/m2. Upon flipping to expose the carbon-modified black surface, solar absorptance reaches 97.07%, delivering a 22.5 °C temperature rise above ambient under winter conditions (923.2 W/m2). The Janus gradient porous membrane (JGPM) supports direct surface application with excellent mechanical robustness and strong component adhesion. Architectural prototype testing confirms the membrane's seasonal adaptability, demonstrating temperature reductions of 5.7 °C under high-temperature conditions and temperature increases of 10.3 °C in cool climates. The reliable performance across diverse environmental conditions underscores the potential of JGPM as a transformative solution for adaptive building thermal management.

Zirconium-based organic frameworks (MOFs) are effective in the decomposition of chemical warfare agents (CWAs), but current studies on protective equipment containing MOFs still face challenges in terms of the complexity of the preparation process, low loading of MOFs, and limited protective efficacy. Here, we report a UiO-66-NH2@ANF aerogel with low density, high specific surface area, high flexibility, and excellent mechanical properties by integrating UiO-66-NH2 into aramid nanofibers (ANFs) through nucleophilic substitution modification method. The resultant aerogel exhibits a high MOF loading of 205.67

Effective control of membrane water content is essential for increasing the space for ice formation during the cold start stage and enhancing the success rate of start-up. Shutdown purge can effectively lower the membrane water content following fuel cell operation. However, during the cooling and standing process after purge, the rapid change in saturated vapor pressure can result in the redistribution of membrane dissolved water, leading to an increase in its content and a reduction in the success rate of cold start. Therefore, this study establishes a multidimensional, multiphase simulation model to comprehensively and thoroughly analyze the redistribution mechanism after purging and investigates the relationship between membrane water content and cold start. This is achieved by identifying the maximum membrane water content boundary during the cold start process and ultimately improving the success rate of cold start through a secondary purge strategy. The research results indicate that the membrane water content of the fuel cell increases from 2.31 to 8.31 after redistribution. During the cold start stage, the cold start success of the fuel cell under different environmental temperatures exhibits relatively specific boundary conditions, with the cold start process being closely related to the load current density and initial membrane water content. After implementing the secondary purging strategy, the membrane water content of the fuel cell decreases again, displaying favorable cold start characteristics in the cold start stage and successfully starting at-10 degrees C. This study can provide a reliable basis for the development of purging strategies during shutdown and offer a theoretical foundation for the boundary identification process of cold start.

Organic dye wastewater produced by the dye industry contains a lot of harmful chemicals, making its treatment particularly challenging. Dichromate, as a commonly used mordant in the dyeing process, contains hexavalent chromium which is extremely toxic and is the main pollutant of dye wastewater. Although significant progress has been made in recent years in the removal of Cr (VI) and dyes, research on the treatment of mixed chromium-containing dye wastewater is still relatively scarce. Chitosan-based magnetic chitosan-polyacrylate sodium composite materials prepared by a crosslinking method possess the ability to adsorb hexavalent chromium and cationic dyes such as crystal violet. The study focused on screening the optimal ratio and refining the best preparation conditions using the crosslinking agent dosage, initiator dosage, and material ratio as indicators. Microscopic morphology, functional groups, and crystal structure of the adsorption material were analyzed through means such as Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD). Furthermore, the adsorption capacity and recyclability of the material were investigated using chromium-containing crystal violet wastewater as the target pollutant.

To overcome the critical challenges of low capacitance and poor cycling stability in yarn supercapacitors (YSCs), we propose a novel surface engineering strategy employing oxygen plasma modification. This technique significantly enhances interfacial adhesion between multi-walled carbon nanotubes (MWCNTs) and polypyrrole (PPy) on cotton yarn (CY) substrates by introducing oxygen-containing functional groups and strengthening it-conjugated interactions. The optimized PPy/modified-MWCNTs (PPy/m-MWCNTs)/CY composite electrode achieves a specific capacitance of 247.35 F g-1 at 5 mV s-1-representing an 882.72 % enhancement over the unmodified electrodes. Crucially, it exhibits exceptional cycling stability, retaining 96.1 % of its capacitance after 3000 cycles at 0.26 A g-1, a significant improvement compared to its non-modified counterpart (60.5 %). The assembled all-solid-state symmetric modified YSC (m-YSC) delivers an energy density of 2.04 Wh kg-1 and power density of 4.94 W kg-1 at 0.01 A g-1. Furthermore, the m-YSC maintains over 98 % capacitance under tensile, torsional, and folded states, demonstrating outstanding mechanical robustness. Practical applicability is validated by successfully powering an LED using four series-connected m-YSCs and seamless integration into wearable textiles. This work provides a scalable plasma-assisted interface design strategy for high-stability wearable energy storage devices.

Metal-organic frameworks (MOFs) show great potential applications in dealing with heavy metal pollution due to their unique large specific surface area, tunable pore size, and diverse active groups. However, the powder form of MOFs has suffered from the disadvantages of difficult recycling and secondary contamination after adsorption of heavy metals, which seriously limits their practical application. Therefore, in this work, we prepared a series of bifunctional zirconium-based MOFs cotton fabric composites (MCFC) via in situ growth of MOFs on carboxylated cotton fabric, exhibiting large specific surface area, adjustable pore size, and effective adsorption ability. The prepared CF-UiO-66-(OH)(2)-FA shows an excellent adsorption efficiency of Au(III) more than 99.990 %, and the saturated adsorption amount is up to 190.98 mg.g(-1) at 25 degrees C. Meanwhile, the kinetic experiment analysis demonstrated that the Au(III) adsorption behavior of MCFC follows pseudo-second-order (PSO) kinetic model. More importantly, it also exhibits great selectivity in adsorbing Au(III) from the mixture of multiple metal ions coexisted solution. The results of adsorption thermodynamics and adsorption isotherms indicate that adsorption is monolayer and a spontaneous, exothermic process. And the ideal adsorption and separation process could be finished by quickly filtrating with a single or multi-layer MCFC. Excellent adsorption performance even after four cycles of adsorption. Therefore, the fabricated MCFC shows great processability, flexibility, collectability and reusability in adsorbing and recycling precious metal ion from wastewater.

To improve the fire safety of polyacrylonitrile (PAN) and expand its application area, flame retardant and antibacterial PAN composite was prepared by a simple and environmentally friendly method. First, AgNO3 and NaBH4 solutions were added to the microcrystalline cellulose (MCC) aqueous suspension to prepare MCC loaded Ag nanoparticles (Ag NPs) (MCC/Ag) by in situ reduction. Then, MCC/Ag was mixed in PAN solution to prepare MCC/Ag/PAN composite, which was then phosphorylated by phytic acid (PA) to obtain flame retardant MCC/Ag/PAN composite (FR-MCC/Ag/PAN). FR-MCC/Ag/PAN could achieve self-extinguishing with limiting oxygen index (LOI) value of 36.8%. The thermogravimetric results showed that phosphorus-containing acids accelerated the char-forming ability of FR-MCC/Ag/PAN, and the final char residue was up to 29.76% in air atmosphere. Thermogravimetric coupled with Fourier transform infrared spectroscopy (TG-FTIR) and scanning electron microscope (SEM) showed that FR-MCC/Ag/PAN formed an expanded and dense char layer after combustion, suppressing the release of low molecular toxic gases. Moreover, FR-MCC/Ag/PAN showed favorable inhibition of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This work proposed a novel method for developing flame retardant and antibacterial PAN material, which broadened the application field of polyacrylonitrile.

为解决气凝胶的低密度带来的空间成本问题,将聚酰胺酸纳米纤维及芳纶纳米纤维通过水相分散、冷冻干燥、热亚胺化等过程制备了具有形状记忆特性的聚酰亚胺/芳纶复合纳米纤维气凝胶,并对其微观形貌、化学结构、力学性能、隔热性能和形状记忆性能进行了研究.结果表明:复合气凝胶表现为纳米纤维相互缠结的三维网络,体密度仅为0.0096g/cm3,具有优异的热稳定性和隔热性能,导热系数为0.031 7 W/(m·K);气凝胶表现出形状记忆特性,当温度大于140℃时,气凝胶开始从临时形状恢复至初始形状,其形状固定率和形状恢复率分别可达到84.5％和96.15％,在智能材料、高温隔热领域有广阔的前景.

Mxene-based fibrous supercapacitors show great application potential in wearable energy storage devices with large specific surface area, good electrical conductivity and higher power density. Here, we prepare a fiber supercapacitor based on MXene. MXene-PAN nanofibre@polypyrrole composite fiber electrode was prepared by electrostation-melt blowing device and chemical deposition method. The addition of CNT and MXene conductive nanoparticles increased the specific surface area of the fibers, which was beneficial to provide more conductive pathways. Compared with the CNT fiber, the specific capacitance, power density and energy density of the MXene-based fiber electrode are significantly increased. When the current density is 0.1 A g-1, the energy density and power density of the capacitor are 18.21 μWh cm-2 and 0.27 mW cm-2, respectively. In the application experiment, it also shows excellent stability, flexibility and stretchability. After 5000 cycles, the capacitor cycle retention rate is 65%.

纳米纤维凭借其优异的孔隙率和表面体积比成为了研究热点,成功地应用在电容器、过滤分离、伤口敷料、传感器等领域.近年来,人们提出了多种纳米纤维制备方法,如静电纺丝、熔喷法、离心纺丝法和溶液喷射法等.其中溶液喷射法具有成本低、可原位操作、纤维生产速率高等优点.这种制备工艺通过高速气流蒸发聚合物溶液的溶剂来吹塑纳米纤维.综述了溶液喷射纺纳米纤维的制备原理和技术,重点分析了聚合物溶液、喷嘴、气流场等工艺因素对溶液喷射纺纳米纤维的形态影响.分析了目前溶液喷射纺的各种应用,并对其未来发展进行了展望.

Aerogels are highly porous structures produced by replacing the liquid solvent of a gel with air without causing the collapse of the solid network.

There are several methods of preparing nanofiber yarns, but little work has been reported using a combination of electrospinning and solution blowing methods (i.e., electrostatic-solution blow spinning) to prepare nanofiber yarns. In this study, a response surface method (RSM) based on Box–Behnken design was used to investigate the relationship between the yarn parameters and yarn diameter, and the process was optimized. The yarn diameter was simulated by electrostatic voltage, air pressure, winding speed and funnel velocity. The correlation coefficients before and after adjustment were 0.97 and 0.95, respectively, through variance analysis, which verified the accuracy of the yarn diameter model. The results showed that the influence of each experimental factor on the yarn diameter was in descending order of winding speed, electrostatic voltage, airflow and funnel velocity, and there were interactions among the factors. The BDD response model was used to obtain the best experimental conditions, which provided a good theoretical reference for the preparation of polyacrylonitrile nanofibers. In addition, the effects of voltage and air pressure on the diameter of the nanofiber and yarn and the effects of the twist coefficient on the shape and mechanical properties of the yarn were studied. The results showed that with the increase of voltage and air pressure, the diameter of the nanofiber decreased, and the yarn diameter decreased first and then increased. When the twist factor was 100, the twist angle of the yarn was 49.91°, the breaking strength was 12.92 MPa and the elongation at break was 81.34%.

Aramid nanofiber (ANF) aerogels have received attentions as high-temperature insulators due to their highly porous structure, low thermal conductivity and excellent thermal stability. However, the common ANF fabrication methods still face drawbacks of low efficiency, high energy consumption and environmental pollution. Here, we report a novel, simple and aqueous-based treatment method in which aramid fibrils were fabricated by steam explosion of poly (p-phenylene terephthalamide) (PPTA) pulp. The obtained aramid fibrils have fine branches with a size smaller than micrometers. They can be evenly dispersed in water and the dispersion was directional frozen and freeze–dried to aramid fibril aerogels. The aerogel demonstrates abundant inter-fiber entanglement, large specific surface area with a specific surface area of 134.32 m 2 /g and high thermal insulation performance with thermal conductivity of 0.03137 W/m·K. Besides, aramid fibril presents high thermal stability over 500 °C. Taking advantage of these features, aramid fibril aerogels are expected to find potential applications in the fields of thermal insulation.

Palygorskite ( PG) adsorbent with superior adsorption property and ion-exchange ability is highly desired in the field of dye removal. However, it generates high amounts of precipitation due to the granular form, resulting in secondary pollution after adsorption. Herein, the novel high porosity PG-based nanofibers that are easy for operating and retrieving have been fabricated using effective solution blowing and subsequent calcination. The obtained highly efficient adsorption nanofibers exhibit large specific surface area about 170.50 m2/g with average diameter from 243 nm to 365 nm. Based on the abovementioned nanofibrous structure and negatively charged PG, the solution blowing of PG-based nanofibers (SBPNs) showed high adsorption capacity for methylene blue (MB) (112.36 mg/g). In addition, the adsorption of SBPNs is well described by the Langmuir isotherm model. This work provides new SBPNs forming process for the fields of dye removal, which may achieve the production of PG adsorbents at the industrial level.

Sponges with large protein adsorption capacity are highly desired in various fields such as biosensors, biofuel cells, biocatalysis, and protein chromatography. However, the use of environmentally friendly materials and mass production still face enormous challenges. Herein, a novel and facile method to fabricate an environmentally friendly monolithic cellulose/chitosan composite sponge (CECSS) with remarkable performance is designed using the mature viscose process. The obtained highly efficient adsorption sponge exhibits a hierarchical porous structure with open-pore structures with a diameter range of 200-1000 mu m and small micro/nanocellular structures (0.5-2 mu m), which endow it with remarkable porosity (62.95%) and water adsorption capacity (1409%). Based on the abovementioned unique porous structure and reactive groups of chitosan, the CECSS exhibits a high bovine serum albumin adsorption capacity of 200.56 mg/g at pH 5.5 for 10 h. In addition, the adsorption of the CECSS can be well described by the pseudo-second-order kinetic model and the Langmuir isotherm model. This work provides a new sponge-forming process for the fields of protein adsorption, which may achieve the production of natural protein adsorbents at the industrial level.

Fabricating a high-performance adsorbent as a desirable candidate for removing Pb2+ from aqueous water remains a challenge. Aramid nanofibers (ANFs) are promising building blocks that have realized multifunctional applications due to their intrinsic mechanical and chemical stability. Herein, an in situ loading strategy for preparing nanofiber composite aerogel was proposed by assembling ANFs into a 3D aerogel and applying it as host media for the in situ polymerization of pyrrole followed by facile redox reaction between the polypyrrole (PPy) and MnO4-1 to load manganese dioxide (MnO2). The idea was to fully exploit the structural advantages of ultra-low bulk density, large specific surface area, and high porosity of ANFs, and the possible chemical adsorption characteristics of MnO2 on the basis of ion exchange reaction. The adsorption capacity of 3D ANF/MnO2 composite aerogel was as large as 554.36 mg/g for Pb2+. The adsorption mechanism based on an exchange reaction between Pb2+ and protons on the surface of MnO2 was also investigated. The desorption results showed that the adsorption performance could remain up to 90% after five times of usage. In conclusion, this research provides promising insights into the preparation of high-performance lead adsorbent for water treatment. (C) 2021 Elsevier Inc. All rights reserved.

Metal-organic frameworks (MOFs) exhibit high proton conductivity, thermal stability, and offer immense flexibility in terms of tailoring their size. Owing to their unique characteristics, they are desirable candidates for proton conductors. Nevertheless, constructing ordered MOF proton channels in proton exchange membranes (PEMs) remains a formidable challenge. Herein, blend nanofibers of cellulose and UiO-66-NH2 (Cell-UiO-66-NH2) obtained via the electrospinning process were embedded in a sulfonated polysulfone matrix to obtain high-performance composite PEMs with an orderly arrangement of UiO-66-NH2. Comprehensive characterization and membrane performance tests reveal that composite membrane with 5 wt% (nominal) UiO-66-NH2 have revealed high proton conductivity of 0.196 S cm(-1) at 80 degrees C and 100% relative humidity. Meantime, the composite membrane exhibits a low methanol permeability coefficient (similar to 5.5 x 10(-7) cm(2) s(-1)). Moreover, the composite membrane exhibits a low swelling ratio (17.3%) even at 80 degrees C. The Cell-UiO-66-NH2 nanofibers exhibit strong potential for use as a proton-conducting nanofiller in fuelcell PEMs. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

High-performance yarn-shaped supercapacitor electrode materials are lightweight, compact, flexible, and low cost, making them ideal for developing flexible energy storage devices. In this paper, a low-cost and large-scale manufacturing method to build high-performance super-capacitor yarn electrodes was proposed. To construct a new polypyrrole (PPy)/PAN/cotton yarn electrode, the solution jet spinning technique was used to prepare PAN nanofiber-wrapped cotton core yarns; in situ polymerization was used to deposit PPy nanoparticles to prepare a high-performance yarn electrode, and flexible all-solid super-capacitors were assembled. The synergistic effect caused by the unique electrode structure greatly improves the electrochemical performance. The supercapacitor had a maximum area ratio capacitance of 341.67 mF cm(-2) (37.60 F cm(-3)) at a current density of 0.87 mA cm(-2). The maximum energy density was 0.047 mWh cm(-2) at a power density of 4.32 mW cm(-2). Supercapacitors had outstanding electrochemical stability and flexibility, which has broad application prospects in wearable smart textiles.

Proton-conducting nanofiber hybrid membranes (PC-NFHMs) as promising candidates, are widely used for proton exchange membrane fuel cells (PEMFCs), combining the properties and some synergism from interactions between nanofibers and the polymer matrix.