Advanced Fiber Materials最新文献

Spiral fibers with high energy storage and high output efficiency are highly desirable for soft robots and actuators. However, it is still a great challenge to achieve spiral fibers with excellent water actuation performance, structural stability, and high scalability in a low-cost strategy. A coaxial spiral structure is reported for the fabrication of high-performance fiber actuators. The developed shell–core helical fiber actuators were based on alginate/poly(ethylene glycol) acrylate shell and alginate/GO core with green and excellent spinnability. Owing to the high water-absorbing-swelling capacity and energy storage of the shell, the prepared spiral fibers are characterized by fast response, high energy output, and good repeatability of cycling. On the other hand, the core endows the spiral fibers with the additional features of strong force retention and photothermal response. The shell–core spiral structure promotes the output efficiency of the twisted fiber actuator with a large rotation (2500°/cm), untwisting speed (2250 rpm), and recovery speed (2700 rpm). In addition, the tertiary spiral structure based on TAPG fibers exhibits excellent humidity and photothermal response efficiency. The application of fibers to smart textiles enables efficient human epidermal thermal management.

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Developing an advanced individual protection cloth is a pivotal factor in combating global pathogen epidemics. However, formidable challenges are posed by the triangularity imbalance effect, necessitating the simultaneous fulfillment of requirements for high comfort, high safety, and mass production. In this study, a mass-producible hybrid polytetrafluoroethylene nanofiber mat (HPNFM) was developed by integrating technologies of organic–inorganic hybridization and membrane asynchronous stretching. Exceptional comfort was attained by conferring waterproofing and breathability attributes, achieved through the radial island-chain architecture exhibiting hydrophobicity and nanoporosity. Furthermore, through the incorporation of high-efficiency anti-pathogen nanoparticles, the HPNFM ensures high safety, demonstrating active antibacterial and antiviral effects. This is achieved through the synergistic effects of electrostatic induction and reactive oxygen species-based pathogen inactivation. More significantly, an HPNFM-based individual protective suit is designed and manufactured, which successfully encapsulates the advantages of high comfort, safety, and mass production, displaying competitiveness as a commercial product. Positioned as a viable strategy, this work holds substantial potential for practical applications in responding to future epidemics.

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Graphene composite yarns have demonstrated significant potential in the development of multifunctional wearable electronics, showcasing exceptional conductivity, mechanical properties, flexibility, and lightweight design. However, their performance is limited by the weak interfacial interaction between the fibers and graphene. Herein, a polydopamine–reduced graphene oxide (PDA–RGO) interfacial modulation strategy is proposed to prepare graphene-coated cotton yarns with high electrical conductivity and strength. PDA–RGO serves as an interfacial bonding molecule that interacts with the cotton yarn (CY) substrate to establish a hydrogen interface, while interconnecting with highly conductive graphene through π–π interactions. The developed interface-designed graphene-coated yarn demonstrates an impressive average electrical conductivity of (856.27 ± 7.02) S/m (i.e., average resistance of (57.57 ± 5.35) Ω). Simultaneously, the obtained conductive yarn demonstrates an exceptional average tensile strength of (172.03 ± 8.03) MPa, surpassing that of primitive CY by approximately 1.59 times. The conductive yarns can be further used as low-voltage flexible wearable heaters and high-sensitivity pressure sensors, thus showcasing their remarkable potential for high-performance and multifunctional wearable devices in real-world applications.

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Cellulose has sparked considerable interest in the advancement of biodegradable functional materials owing to its abundant natural sources and exceptional biocompatibility. This review offers a comprehensive review of the latest research and development concerning cellulose-based films, with a specific emphasis on their classification, properties, and applications. Specifically, this review classifies cellulose according to the various morphologies of cellulose (e.g., nanocrystals, nanospheres, and hollow ring cellulose) and cellulose derivatives (e.g., methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, and cellulose acetate). The subsequent section presents an analysis of cellulose-based films with improved mechanical properties, antibacterial characteristics, gas regulation, and hydrophobicity. A detailed discussion of the mechanisms that underlie these properties is provided. Additionally, representative applications of cellulosic composites, such as food packaging, medical supplies, and electronic devices, are summarized. Finally, the challenges faced by cellulosic materials are outlined, and a novel and feasible prospect is proposed to accelerate the future development of this material.

Fiber-based material systems are emerging as key elements for next-generation wearable devices due to their remarkable advantages, including large mechanical deformability, breathability, and high durability. Recently, greatly improved mechanical stability has been established in functional fiber systems by introducing atomic-thick two-dimensional (2D) materials. Further development of intelligent fibers that can respond to various external stimuli is strongly needed for versatile applications. In this work, helical-shaped semiconductive fibers capable of multifunctional sensing are obtained by wet-spinning MoS₂ liquid crystal (LC) dispersions. The mechanical properties of the MoS₂ fibers were improved by exploiting high-purity LC dispersions consisting of uniformly-sized MoS₂ nanoflakes. Notably, three-dimensional (3D) helical fibers with structural chirality were successfully constructed by controlling the wet-spinning process parameters. The helical fibers exhibited multifunctional sensing characteristics, including (1) photodetection, (2) pH monitoring, (3) gas detection, and (4) 3D strain sensing. 2D materials with semiconducting properties as well as abundant surface reactive sites enable smart multifunctionalities in one-dimensional (1D) and helical fiber geometry, which is potentially useful for diverse applications such as wearable internet of things (IoT) devices and soft robotics.

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Absorption-dominated electromagnetic interference (EMI) shielding fabrics are urgently needed to address the increasingly severe electromagnetic radiation pollution, especially the secondary radiation problem. In this study, we design novel core-sheath CNT@MXene fibers with a gradient conductive structure and corresponding fabrics to realize absorption-dominated EMI shielding performances. This coaxial structure utilizes carbon nanotubes (CNTs) as the sheath and MXene as the core and is constructed through a wet spinning technique. By virtue of the core-sheath structure, the conductive gradient structure in the fibers is easily optimized by adjusting the core MXene and sheath CNT content. This gradient conductive network of fiber effectively facilitates the incidence of electromagnetic waves and strong interactions between electromagnetic waves and the composites, resulting in excellent EMI absorption ability. Within the X-band frequency range, the fabric exhibits an electromagnetic interference shielding effectiveness of 23.40 dB and an absorption coefficient of 0.63. Due to the protection of polymer, the fiber’s electrical conductivity remains stable under conditions such as multi-cycle bending, stretching, and ultrasonic treatment, and in high relative humidity environments. Additionally, the fabric also demonstrates EMI shielding stability in indoor environments. This work indicates the great potential of the gradient structured fibers to achieve an absorption-dominated mechanism for next-generation eco-friendly EMI shielding fabrics.

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Improving the osteogenic properties of bone grafts plays a critical role in the repair and functional restoration of critical-sized bone defects. The endogenous electric field, one of the most crucial physiological signals, has been confirmed to maintain physiological function and reconstruct the structure of bone, which is inadequate in bone defect sites. Strategies for the development of electroactive osteogenic biomaterials arise to remodel and promote the electrophysiological microenvironment. Among the electroactive materials, electret biomaterials can provide a stable and persistent endogenous electrical stimulation, which better conforms to the physiological microenvironment and has long-term effectiveness in the bone repair process. Herein, an electret hybrid electrospun fibrous mat (EHFM) was developed to mimic the structure of the natural extracellular matrix (ECM) with a suitable and persistent electrophysiological microenvironment. The EHFM was constructed with a core–shell structure, in which silicon dioxide electrets were loaded in the core-layer to remodel and maintain the electrical microenvironment over the long term. The EHFM significantly promoted the osteogenesis of bone mesenchymal stem cells (BMSCs) in vitro and showed remarkable ability in bone repair, which was three times better than that of the control group in a critical-sized rat calvarial defect model. Furthermore, it was verified that EHFM-derived osteogenesis was related to the activation of the calcium ion-sensing receptor (CaSR), while increasing intracellular calcium ion concentration of BMSCs. This study puts forward a novel engineering strategy to promote bone defect repair by remodeling a stable and persistent electrophysiological microenvironment, showing potential for clinical applications.

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NdFeB magnets are third-generation permanent magnets that are employed as indispensable components in various industries. Notably, rare-earth elements (REEs) such as Dy and Nd must be efficiently recovered from end-of-life magnets to enable resource circulation and reinforce unstable supply chains. To that end, this paper reports synergistically performing core/shell-structured composite fibers (CSCFs) containing sodium polyacrylate and nanoporous zeolitic imidazolate framework-8 (NPZIF-8) nanocrystals as a readily recoverable adsorbent with an exceptional REE-adsorbing ability. The CSCF core forms an NPZIF-8 nanocrystal shell on the fiber surface as well as draws REEs using its dense sodium carboxylate groups into the NPZIF-8 nanocrystal lattice with high specific surface area. The CSCFs exhibit significantly higher maximum adsorption capacities (468.60 and 435.13 mg·g⁻¹) and kinetic rate constants (2.02 and 1.92 min⁻¹) for the Nd³⁺ and Dy³⁺ REEs than those of previously reported REE adsorbents. Additionally, the simple application of the CSCFs to an adsorption reactor considerably mitigates the adsorbent-shape-induced pressure drop, thereby directly influencing the energy efficiency of the recovery. Moreover, the high REE-recovery ability, tractability, and recyclability of the CSCFs offers a pragmatic pathway to achieving cost-effective REE recovery. Overall, this study provides new insights into designing synergistically performing core/shell architectures for feasible REE recovery.

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Carbon fiber (CF) has emerged as a promising candidate for microwave absorbers to resolve the escalating electromagnetic wave (EMW) pollution issue, not just serving as a structural reinforcement. However, the drawbacks, such as high conductivity, limit its ability to strongly absorb EMWs over a wide bandwidth. To address these challenges, graphite wrapped FeNi₃/Co with carbon nanotubes (CNTs) anchored on MgO@CF heterostructures were synthesized by introducing MgO nanofilms on a CF surface and subsequent chemical vapor deposition catalyzed by two-phase catalysts. The synthesis of MgO suppresses the etching of CF during the experimental processes, effectively maintaining the inherent structure of CF, which is conducive to constructing rich conductive networks and developing excellent mechanical properties. By modulating the catalyst concentration, deposited CNTs with appropriate defects increase the conduction loss and stimulate defect polarization loss. The abundant interfaces formed by multiple components lead to fulfilling interface polarization, while the doping of O heteroatoms causes dipole polarization. In addition, the introduction of FeNi₃/Co generates effective magnetic loss and optimizes electromagnetic parameters to form more matching impedance conditions. At a low filler loading of 23 wt%, the stable sample obtains a remarkable minimum reflection loss of up to − 72.08 dB at merely 1.38 mm with an effective absorption bandwidth reaching 4.88 GHz at only 1.44 mm, which is superior to that of numerous distinguished carbon-based composites in regard to being “thin, light, wide and strong”. CST simulation reveals that the maximum radar cross section reduction acquires 26.88 dBm², ascertaining the radar stealth capability of the distinctive heterostructure. Moreover, great mechanical and electromagnetic interference shielding performance is demonstrated by epoxy composites. Henceforth, this study proposes profound insights into the intricate relationship between the structure and EMW absorbing mechanism, and elucidates an attractive strategy for mass-producing modified CF-based hybrids for versatile applications.

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Owing to the high flexibility, low thermal conductivity, and tunable electrical transport property, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) exhibits promising potential for designing flexible thermoelectric devices in the form of films or fibers. However, the low Seebeck coefficient and power factor of PEDOT:PSS have restricted its practical applications. Here, we sequentially employ triple post-treatments with concentrated sulfuric acid (H₂SO₄), sodium borohydride (NaBH₄), and 1-ethyl-3-methylimidazolium dichloroacetate (EMIM:DCA) to enhance the thermoelectric performance of flexible PEDOT:PSS fibers with a high power factor of (55.4 ± 1.8) μW m⁻¹ K⁻² at 25 °C. Comprehensive characterizations confirm that excess insulating PSS can be selectively removed after H₂SO₄ and EMIM:DCA treatments, which induces conformational changes to increase charge carrier mobility, leading to enhanced electrical conductivity. Simultaneously, NaBH₄ treatment is employed to adjust the oxidation level, further optimizing the Seebeck coefficient. Additionally, the assembled flexible fiber thermoelectric devices show an output power density of (60.18 ± 2.79) nW cm⁻² at a temperature difference of 10 K, proving the superior performance and usability of the optimized fibers. This work provides insights into developing high-performance organic thermoelectric materials by modulating polymer chains.

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