Aramid Nanofibers Research Articles

Fluorinated interface engineering targeting high-performance multifunctional composites of BN/aramid nanofibers

Aramid nanofibers (ANFs)-based composites have attracted considerable interest in electronic and electrical engineering due to their exceptional thermal stability, high strength, and superior insulating properties. However, the performance of ANFs-based composites is severely confined by interfacial issues. Accordingly, a novel strategy of fluorinated interface engineering is proposed herein, by which the fillers are grafted by the fluorine-containing functional groups. The introduction of interfacial fluorination yields a dense and compact composite structure which stems from the improved compatibility at the matrix-filler interfaces. The tensile strength and thermal conductivity are increased by 30% and 50%, respectively. Additionally, the band structure variation is observed in the fluorinated BNNs, where the electron trap states are formed at the interface. With the deepened deep trap depth and increased density, the breakdown strength is enhanced by 50%. The breakdown phase field simulations also indicate the high discharge energy consumption by the fluorination effect.

Large-Scale Fabrication of Tunable Sandwich-Structured Silver Nanowires and Aramid Nanofiber Films for Exceptional Electromagnetic Interference (EMI) Shielding.

The recent advancements in communication technology have facilitated the widespread deployment of electronic communication equipment globally, resulting in the pervasive presence of electromagnetic pollution. Consequently, there is an urgent necessity to develop a thin, lightweight, efficient, and durable electromagnetic interference (EMI) shielding material capable of withstanding severe environmental conditions. In this paper, we propose an innovative and scalable method for preparing EMI shielding films with a tunable sandwich structure. The film possesses a nylon mesh (NM) backbone, with AgNWs serving as the shielding coating and aramid nanofibers (ANFs) acting as the cladding layer. The prepared film was thin and flexible, with a thickness of only 0.13 mm. AgNWs can easily form a conductive network structure, and when the minimum addition amount was 0.2 mg/cm2, the EMI SE value reached 28.7 dB, effectively shielding 99.884% of electromagnetic waves and thereby meeting the commercial shielding requirement of 20 dB. With an increase in dosage up to 1.0 mg/cm2, the EMI SE value further improved to reach 50.6 dB. The NAAANF film demonstrated remarkable robustness in the face of complex usage environments as a result of the outstanding thermal, acid, and alkali resistance properties of aramid fibers. Such a thin, efficient, and environmentally resistant EMI shielding film provided new ideas for the broad EMI shielding market.

Folk arts-inspired twice-coagulated configuration-editable tough aerogels enabled by transformable gel precursors

Aerogels, as famous lightweight and porous nanomaterials, have attracted considerable attention in various emerging fields in recent decades, however, both low density and weak mechanical performance make their configuration-editing capability challenging. Inspired by folk arts, herein we establish a highly efficient twice-coagulated (TC) strategy to fabricate configuration-editable tough aerogels enabled by transformable gel precursors. As a proof of concept, aramid nanofibers (ANFs) and polyvinyl alcohol (PVA) are selected as the main components of aerogel, among which PVA forms a flexible configuration-editing gel network in the first coagulation process, and ANF forms a configuration-locking gel network in the second coagulation process. TC strategy guarantees the resulting aerogels with both high toughness and feasible configuration editing capability individually or simultaneously. Altogether, the resulting tough aerogels with special configuration through soft to hard modulation provide great opportunities to break through the performance limits of the aerogels and expand application areas of aerogels.

Aramid nanofiber‐reinforced poly(lactic acid) nanocomposites with enhanced thermal stability, melt‐crystallization rates, and mechanical toughness

AbstractThe main goal of this study is to investigate the impact of aramid nanofiber (ANF) on enhancing various properties of poly(lactic acid) (PLA), including thermal stability, crystallization rates, melt‐rheological behavior, and mechanical properties. To achieve this, ANF fillers were produced using a modified deprotonation process from commercial aramid fibers, and a masterbatch (PLA/ANF = 90/10 by wt%) was prepared through solution blending and drying. The masterbatch was then combined with neat PLA through melt‐blending to create a range of PLA nanocomposites containing 1–10 wt% ANF loadings. Microscopic and spectroscopic analyses confirmed the uniform dispersion and intermolecular interaction of ANFs within the PLA matrix, respectively. As a result, the nanocomposites exhibited a slight increase in glass transition temperature with higher ANF loading, while the cold‐crystallization temperature decreased due to ANFs acting as nucleating agents during PLA crystallization. Isothermal crystallization analysis confirmed accelerated melt‐crystallization rates in nanocomposites with greater ANF content. The introduction of ANFs enhanced the thermal degradation temperature of the PLA matrix and the 700°C residue of the nanocomposites, attributed to ANFs' barrier and flame retardant effects on PLA. Moreover, the nanocomposites with higher ANF loading demonstrated superior tensile strength, strain at break, toughness, and impact strength owing to the effective bonding interactions at the interfaces between the PLA matrix and the ANF fillers.Highlights ANF‐reinforced PLA nanocomposites are prepared by masterbatch melt‐compounding. Uniform dispersion of ANFs in PLA is attained via effective interfacial bonding. ANFs boost the melt‐crystallization of the PLA matrix. ANFs enhance the thermal stability of the PLA matrix. Tensile strength and toughness of PLA are improved with higher ANF content.

Light-enhanced osmotic energy generation with an aramid nanofiber membrane

Osmotic energy generation with reverse electrodialysis through membranes provides a worldwide free energy resource. Photo-driven proton transport in photosynthesis supplies basal energy for plants and living organisms on the planet. Here, we utilized aramid nanofiber (ANF) semiconductor-based membranes to enable light-driven proton transport for osmotic energy generation. Under unilateral illumination, the light-driven proton transport system converted light energy into electrical energy and showed wavelength- and intensity-dependent transmembrane potentials and currents. Interestingly, the synergistic effects of simultaneous illumination and pressure provided a five-fold increase in the voltage and a three-fold increase in the current relative to pressure alone. Density functional theory calculations and spectroscopic measurements demonstrated that the ANF and photoinduced electrons enabled proton transport during illumination and generated a transmembrane potential and current. The light-driven proton transport system supports the development of devices with flexible and stable ANF membranes.

Multifunctional Liquid Metal-Bridged Graphite Nanoplatelets/Aramid Nanofiber Film for Thermal Management.

Miniaturization of modern micro-electronic devices urges the development of multi-functional thermal management materials. Traditional polymer composite-based thermal management materials are promising candidates, but they suffer from single functionality, high cost, and low fire-resistance. Herein, a multifunctional liquid metal (LM)-bridged graphite nanoplatelets (GNPs)/ aramid nanofibers (ANFs) film is fabricated via a facile vacuum-assisted self-assembly approach followed by compression. ANFs serve as interfacial binders to link LM and GNPs together via hydrogen bondings and π-π interactions, while LM bridges the adjacent layer of GNPs to endow a fast thermal transport by phonons and electrons. The resultant composite films exhibit a high bidirectional thermal conductivity (In-plane: 29.5Wm-1K-1 and through-plane: 5.3Wm-1K-1), offering a reliable and effective cooling. Moreover, the as-fabricated composite films exhibit superior flame-retardance (peak of heat release rate of 4000Jg-1), outstanding Joule heating performance (200 °C at supplied voltage of 3.5V), and excellent electromagnetic interference shielding effectiveness (EMI SE of 62dB). This work provides an efficient avenue to fabricate multifuntional thermal management materials for micro-electronic devices, battery thermal management, and artificial intelligence.

Coordinated self-assembly of ultraporous 3D aramid nanofibrous separators with a poly(vinyl alcohol) sheath for lithium-metal batteries

Li-metal batteries with a low negative/positive electrode capacity ratio require significant improvement to ensure their practical implementation as high-energy-density batteries. In the present study, ultraporous aramid nanofiber (ANF) separators with a poly(vinyl alcohol) (PVA) sheath were fabricated using a coordinated self-assembly process to produce an ultrahigh bulk (>95 %) and surface (>48.6 %) porosity and a high ion affinity. In this process, sol films consisting of an optimized mixture of aramid nanoseed sols and PVA were sequentially immersed in ethanol and water to induce the formation of a 3D aramid network and the phase separation of PVA by their rate differences, followed by swelling-induced pore formation. The resulting separators exhibited an excellent ion conductivity and Li+ ion transference number of up to 2.73 mS cm−1 and 0.78, respectively, with the effective suppression of Li dendritic growth and the formation of a stable fluorine-rich solid electrolyte interphase (SEI) layer on the Li-metal surface. Li/Li half cells exhibited stable operation for up to 1500 cycles with a high current density of 10 mA cm–2 and an areal capacity of 1 mAh cm–2, with Li/Cu half cells operating for over 244 cycles even with a lithiophobic Cu current collector. LFP/Li full cells with a low N/P ratio (∼2.03) exhibited stable operation for 172 cycles with an average Coulombic efficiency of 99.6 %. NCM/Li full cell with extremely low N/P ratio (0.96) and lean electrolyte condition (4 g Ah–1) stably operated for 55 cycles with projected energy density of 350.7 Wh kg–1.

Bio‐Inspired Interfacial Engineering of MXene Fibers Toward Synergistic Improvement in Mechanical Strength and Electrochemical Performance

AbstractHigh‐performance fibrous materials urgently desired for fabricating energy storage devices to power wearable textile electronics are expected excellent mechanical properties, improved output capacitance, and rapid charge/discharge capability; nevertheless, their contradictory requirements in material design impose immense challenges. Inspired by the robust structure of higher plants that evolve over millions of years, herein, an interfacial engineering strategy is proposed for synergizing the mechanical strength and electrochemical performance of Ti3C2TX MXene fibers by selecting aramid (Kevlar) nanofibers and borate ions (B) as the enhancers. The intercalation of Kevlar nanofibers endows the nascent wet‐spun MXene gel fibers with a high stretchable ratio through physical interaction (hydrogen bonds), greatly aligning the orientation of MXene nanosheets. B‐cross‐links introduce covalent bonds between MXene nanosheets, which together with hydrogen bonds significantly enhance fiber strength. More importantly, optimal ion transport kinetics is achieved by synergizing the inverse impacts of Kevlar nanofibers and B‐cross‐link on interlayer spacing, guaranteeing excellent electrochemical performances. Benefiting from their excellent mechanical, electrical, and electrochemical performances, borate (B)‐cross‐linked MXene/Kevlar fibers (MKB) are simultaneously adopted as fibrous electrodes and receiving antennae for asymmetric supercapacitors with wireless charging functions. The proposed strategy provides an avenue for designing high‐performance functional fibers for future wearable applications.

Aramid nanofiber membrane decorated with monodispersed silver nanoparticles as robust and flexible SERS chips for trace detection of multiple toxic substances

Aramid nanofibers (ANFs) as an innovative nanoscale building block exhibit great potential for novel high-performance multifunctional membranes attributed to their extraordinary performance. However, the application of aramid nanofibers in the field of surface enhanced Raman scattering (SERS) sensing has been rarely reported. In this work, aramid nanofibers derived from commercial Kevlar fibers were synthesized by a facile dimethyl sulfoxide/potassium hydroxide (DMSO/KOH) solution treatment. The monodispersed silver nanoparticle-decorated aramid nanofiber (m-Ag@ANF) membranes were constructed by an efficient vacuum filtration technique. Taking advantages of unique intrinsic properties of ANF, the m-Ag@ANF substrates exhibit good flexibility, excellent mechanical properties and prominent thermal stability. Besides, due to the abundance of positively charged amino-group on the ANF substrates, the negatively charged m-AgNPs were uniformly and firmly deposited on the surface of ANF substrate through electrostatic interactions. As a result, the optimal flexible m-Ag-9@ANF SERS substrate exhibits high sensitivity of 10-9 M for methylene blue (MB) and excellent signal reproducibility (RSD = 6.37 %), as well as outstanding signal stability (up to 15 days). Besides, the 2D Raman mapping and FDTD simulations further reveal prominent signal homogeneity and strong electric field distribution for flexible m-Ag-9@ANF SERS substrate. Finally, it is demonstrated that the flexible m-Ag-9@ANF SERS substrate can also be used for detection of toxic molecules on irregular surfaces by a feasible paste-and-read process. The m-Ag@ANF paper exhibits potential applications as a flexible, low-cost, robust and stable SERS sensing platform for trace detection of toxic materials.

Efficient mechanochemically for the preparation of high performance aramid nanofibers and KOH/DMSO superbase

Although Aramid nanofibers (ANFs) exhibit exceptional mechanical strength, thermal stability, and chemical resistance, their extensive utilization is hindered by protracted preparation processes and inefficient production methods. In this study, we present an efficient mechanochemical approach to rapidly produce ANFs and KOH/DMSO superbase, yielding ANFs at concentrations of 0.2 %, 1.0 %, and 2.0 % within 25, 35, and 50 min, respectively. Furthermore, the analysis of UV–Vis, FTIR, and Raman spectra demonstrated the possible hydrogen-bonding transition mechanisms during the formation of ANFs. Ultimately, the obtained ANFs film (0.2 wt%) and aerogel (1.0 wt%) also demonstrated impressive mechanical properties (tensile strength of 236 MPa, elongation at break of 21 %, and toughness 33.13 MJ/m³) and large specific surface area (204 m²/g), respectively. This study offers an efficient and expeditious method for Kevlar fibers dissociation and introduces a novel approach to preparing highly active KOH/DMSO superbase.

Multilayered graphene fluoride and Ti3C2Tx MXene-based aramid nanofiber films with excellent thermal conductivity and electromagnetic interference shielding performance

Thermally conductive electromagnetic interference (EMI) shielding materials with excellent thermal conductivity, EMI shielding effectiveness (SE), and electrical insulation are pivotal for ensuring the operation and performance of next-generation electronic devices, safeguarding them against external electromagnetic waves and mitigating excessive heat generation. In this study, multilayered graphene fluoride (GF) and Ti3C2Tx MXene (MX)-based aramid nanofiber (ANF) films, in which the MX@ANF layer was sandwiched between GF@ANF layers, were fabricated using the alternating vacuum filtration method. The resultant multilayered films with increased GF and MX contents showed an upsurge in thermal conductivity and EMI SE while maintaining excellent electrical insulation, thermal stability, and mechanical flexibility. The GF50/MX75 film with 50 wt% GF content and 75 wt% MX content in each layer exhibited an excellent EMI SE of ∼41 dB in the X-band frequency, along with a superior specific shielding effectiveness of 3818 dB·cm2/g, an outstanding in-plane thermal conductivity of 85 W/m·K, and mechanical strength of 70 MPa. The notable properties of the GF/MX films are attributed to the well-ordered alignment of the GF and MX sheets and their strong interaction with ANF, which facilitates phonon and electron conduction. Furthermore, the multilayered GF/MX films exhibited excellent heat dissipation capabilities and flame retardancy. Owing to their exceptional performance, multilayered GF/MX films offer a compelling opportunity to advance EMI shielding and thermal management materials to the forefront of next-generation electronics.

Functionalized graphite carbon nitride nanofluid membranes for enhanced osmotic energy harvesting

Reverse electrodialysis is a promising technology that using ion exchange membrane to obtain electrical energy directly between seawater and river water. Current attempts that based on the ion exchange membrane are limited due to the channel size and low charge density. Graphitic carbon nitride (g-C3N4, GCN) is a type of graphite-layered polymer that combined with inherent nanopore structure and adjustable surface charge, which provides a shortcut for the preparation of highly selective ion exchange membrane. However, carbon nitride membranes still exhibit low power density. Herein, g-C3N4 was successfully functionalized with three different negatively charged molecules (carboxylation, polyacrylic acid (PAA) and poly (sodium 4-styrenesulfonare) (PSS)), which benefited from its rich nitrogen-containing groups. These functionalized g-C3N4 were combined with anodized aluminum oxide (AAO) membrane to form heterochannel membranes, which can transport counter-ions and harvest osmotic energy. The results showed that the surface charge density of functionalized g-C3N4 was obviously improved, which enhanced the output power density. Among them, the heterochannel membrane functionalized with PSS (PSS-CN/AAO) had the highest output power density of 31 mW/m2 (effective area 4.9 mm2), which was 3.1 times higher than that of the unfunctionalized heterochannel membrane (GCN/AAO, 9 mW/m2). In this base, two-dimensional PSS-CN/ANF membranes were designed by compositing PSS-functionalized g-C3N4 (PSS-CN) nanosheets with aramid nanofiber (ANF), which can maintain high output power density (50 mW/m2) and further improve the mechanical property of membrane, providing a guarantee for the long-term stable use of nanofluid membrane.

MXene‐Modified Aramid Aerogel for Advanced Solar Steam Generation

Developing solar‐driven desalination through interfacial steam generation is crucial to reducing global water shortages. However, traditional solar steam generation systems have faced efficiency, durability, cost, and complexity limitations. To overcome these issues, interfacial solar steam evaporators are fabricated using light‐absorbing materials with low thermal conductivity, high absorption capacity, and sufficient mechanical strength. Herein, an advanced 3D solar evaporator is developed by coating MXene onto the surface of the aramid nanofiber aerogels (MX@ANF aerogels). The MXene coating enhances the ANF aerogels' light absorption and thermal conversion capabilities. Additionally, the hydrophilicity of MXene complements the high porosity of the host aerogels, enhancing continuous water supply by improving the capillary action. Primarily, these MX@ANF aerogels show promising performance at the air–water interface, with an evaporation rate of 1.48 kg m−2 h−1 and steam conversion efficiency of 93.8% under 1 sun irradiation (1 kW m−2). These highlight the effectiveness of the MX@ANF aerogel as a material for solar‐driven desalination. Moreover, using MXene as a photothermal agent in composite materials paves new avenues toward efficient and cost‐effective solutions for addressing water scarcity through solar desalination.

Interfacial reinforcement of carbon fiber composites through a chlorinated aramid nanofiber interphase

Carbon fiber-reinforced polymers (CFRPs) rely on a strong interfacial bond between the reinforcing fibers and polymeric matrix to yield the high strength and toughness expected by a composite material. Poor interfacial strength leads to sub-optimal load transfer and introduces stress concentrations, which can reduce overall performance and result in catastrophic failure. Aramid nanofibers (ANFs) have shown significant promise for interfacial reinforcement in polymeric composite systems due to their high tensile strength, large specific surface area, and abundant polar functional groups. However, due to the chemically inert nature of carbon fibers, ANFs do not readily bond to their surface – thus limiting their application to CFRPs. In this work, we demonstrate that chlorination of ANFs and oxygen plasma treatment of carbon fibers enables the formation of a chlorinated ANF (Cl-ANF) interphase through chemical and physical adsorption using a simple dip-coating process, while fully preserving the tensile strength of the carbon fibers. The Cl-ANF interphase yielded a 79.8 % increase in interfacial shear strength and a 33.7 % increase in short beam strength. By enhancing the interfacial bond between fiber and matrix without degradation of the fiber's tensile strength, this method provides a rapid and reliable process to improve the mechanical properties of CFRP composites.

Compressible and conductive multi-scale composite aerogel elastomers for electromagnetic wave absorption, energy harvesting, and piezoresistive sensing

With the rapid development of electronic technology, wearable electronic devices have been widely used in the lives of people. However, integrating multiple functions, such as flexible sensing and electromagnetic protection, into a single device remains challenging. Herein, silver nanowires and cobalt-nickel@carbon were assembled into a conductive and magnetic composite aerogel enhanced by aramid nanofibers and cellulose nanofibrils by freeze-drying. It exhibited an excellent electromagnetic wave absorption ability with an optimal minimum reflection loss of −51.6 dB. Then, polydimethylsiloxane (PDMS) was introduced in the subsequent vacuum-assisted impregnation process to obtain a compressible aerogel elastomer with excellent mechanical and electrical properties. It was not only used as a piezoresistive sensor for different application scenes (e.g., human behavior monitoring, pressure array identification, and parking location recognition) but also as a triboelectric nanogenerator for high-performance energy harvesting. Such a unique and multifunctional composite aerogel elastomer will open up new potential applications for electromagnetic protection, blue energy harvesting, and piezoresistive sensing.

Preparation and Mechanical Properties of UV-Curable Epoxy Acrylate/Modified Aramid Nanofiber Nanocomposite Films.

In order to enhance the mechanical properties of UV-curable epoxy acrylate (EA)-based coatings, 3-(trimethoxysilyl)propyl methacrylate modified aramid nanofibers (T-ANFs) were synthesized and used as nanofillers to prepare EA/T-ANF nanocomposite films. The morphology of T-ANFs was characterized by transmission electron microscopy. The chemical structure of T-ANFs was analyzed via infrared spectroscopy, confirming successful grafting of methyl methacryloyloxy groups onto the surface of aramid nanofibers (ANFs). Real-time infrared spectroscopy was employed to investigate the influence of ANFs and T-ANFs on the photopolymerization kinetics of the EA film. The results revealed that the addition of ANFs and T-ANFs led to a decrease in the photopolymerization rate during the initial stage but had little impact on the final double bond conversion, with all samples exhibiting a conversion rate of over 83%. The incorporation of ANFs improved the tensile strength of the films while significantly reducing their Young's modulus. In contrast, the addition of T-ANFs led to a substantial increase in both tensile stress and Young's modulus of the films. For instance, the tensile strength and Young's modulus of the 0.1 wt% of T-ANF film increased by 52.7% and 41.6%, respectively, compared to the pure EA film. To further study the dispersion morphology and reinforcement mechanism, the cross-sectional morphology of the films was characterized by scanning electron microscopy.

Sulfone-functionalized metal–organic framework aerogels for selective CO2 capture from natural gas

The accumulation of CO2 in natural gas may reduce the heating value and even pose a risk of corrosion in transport pipelines, making the effective removal of CO2 highly essential. Metal–organic frameworks (MOFs), known for their high specific area and large porosity, show promising application in CO2 capture. However, a major obstacle is their intrinsic fragility and poor physicochemical stability. Herein, we present a sulfone-incorporated in-situ growth and fiber freeze-shaping strategy to develop lightweight, robust, and multiscale porous sulfone-functionalized UiO-67 (UiO-67-SO2) aerogels supported by aramid nanofibers. The resulting UiO-67-SO2 aerogels exhibit remarkable structural features, including a high MOF loading mass (64.39 wt%), low density (5.31 mg/cm3), high specific surface area (769.98 m2g−1), and large porosity (99.24 %). Moreover, owing to the introduction of CO2-philic sulfone groups, the UiO-67-SO2 aerogels exhibit high CO2 adsorption capacity (5.88 mmol/g), a high CO2/CH4 adsorption selectivity (43), and only a 2.77 % decline in their initial CO2 adsorption capacity after 10 cycles. The adsorption energy calculated by density functional theory method further confirms the strong interactions between UiO-67-SO2 aerogels and CO2 molecules. This work presents a promising direction for developing multiscale porous UiO-67-SO2 aerogels for the highly selective removal of CO2 from natural gas.

High fire safety thermal protective composite aerogel with efficient thermal insulation and reversible fire warning performance for firefighting clothing

High fire safety thermal protective aerogels serve as a thermal insulation barrier in firefighting clothing are urgently needed to improve personal protective technology. However, fabricating fire protection aerogels that can simultaneously hold efficient insulation and early fire warning capabilities to provide high fire safety for firefighters still remains grand challenging. Herein, a novel lightweight and high fire safety smart thermal protective composite aerogel (APFP) composed of aramid nanofibers (ANFs), polyethylene glycol (PEG), Fe3O4 NWs, and polyaniline (PANI) was fabricated via freeze-drying and a chemical in-situ polymerization method. The resultant APFP achieved an efficient thermal buffer performance in response to high temperature with a latent heat of 162.5 J/g due to the absorption and storage thermal capability of PEG.Furthermore, based on the resistance change of Fe3O4 NWs under high temperature and flame, adding 25 wt% Fe3O4 NWs to ANFs-based aerogel, APFP aerogel can achieve resistance sensitive transition from an electrically insulated state to a highly conductive state. Under a flame attack, the APFP demonstrated an ultrasensitive and repeatable fire warning response (1.3 s), which contributes to acquiring active fire protection for APFP before the thermal barrier layer malfunctions in fire. In addition, the APFP exhibited impressive flexibility, heat insulation, lightweight, and flame retardancy, which self-extinguished within 1.5 s after exposure to fire for 10 s. This work proposed an ingenious strategy for the construction of high fire safety and thermal insulation fireproof aerogels, which revealed enticing prospects as thermal insulation barrier in the field of firefighting clothing.

Aramid nanofibers/biochar nanosheets co-assembled composites for wastewater remediation under harsh environments

Nanoscale biochar is a promising material for the remediation of polluted water due to its low-cost sustainability, nevertheless, which still hindered by the self-aggregation and vulnerability issues in actual wastewater. In this work, biochar nanosheets (BCN) were successfully molded into membranes and aerogels with the help of aramid nanofibers (ANF) through a co-assembled process. Ascribing to the improved molecular sieving effects and electrostatic interactions of co-assembled membranes, as well as the superior chemical and thermal stabilities, the resultant ANF/BCNx membranes exhibited favorable dye separation performances toward rhodamine 6 G (R6G) even under high-temperature (e.g., ∼96.1 L·m−2·h−1·bar−1 and ∼97.4% at 80 °C) and strong acidic conditions (e.g., ∼84.1 L·m−2·h−1·bar−1 and ∼97.9% for 10 wt% H2SO4 solutions). Besides, due to the reduced vaporization enthalpy, the ANF/BCNx aerogels as solar steam generators also demonstrated promising capability for clean water production even in 5 wt% H2SO4 solutions (an evaporation rate of ∼1.0 kg·m−2·h−1 and an impressive efficiency of ∼89.9% under one sun illumination). Compared to conventional biochar materials, this work offered simple feasible morphology engineering designs to prepare multifunctional biochar-based composites with unique co-assemble structures, while also demonstrated great potential in wastewater remediation under extreme conditions.

Metal-grade laminated nanofiber films with outstanding EMI shielding performances and high-temperature resistance

With the growing demands in electronics, communications, and energy, conductive composites face a daunting challenge as criteria for conductivity and mechanical properties rise. Extensive search on nanocomposites and amorphous metals has been motivated by the quest for a conductive material that can enhance strength and deformability. However, finding conductive materials that can overcome the drawbacks of their conventional counterparts and exhibit great strength, toughness and quick charge transmission while accomplishing large-scale production remains a significant challenge. This paper describes an approach to high-temperature flexible conductive materials by utilizing composites composed of aramid nanofiber (ANF) and silver nanoparticles (Ag NPs). The ANF is derived from macro-aramid fibers and retains its excellent mechanical properties and heat resistance. Within the composite, Ag NPs effectively enter the special nanofiber matrix to build a tightly connected conductive pathway on the ANF, thus facilitating efficient charge transport. The resulting Ag-ANF composite films exhibit an impressive electrical conductivity of 36,989.68 S m−1 and a tensile strength of 30.3 MPa. Additionally, they provide outstanding EMI shielding with a value of 107.9 dB. This significant achievement opens up the possibility of metallizing the surface of insulated polymer fibers, thereby enabling effective EMI shielding applications even in challenging and extreme conditions.