Advanced Fiber Materials最新文献

Although the bionic evaporative cooling mechanism is regarded as a key path to enhance the thermal management efficiency of the human body outdoors, the structural limitations of traditional fabrics and the bottleneck of heat transfer efficiency led to sweat retention, intensifying the skin’s heat load and restricting the realization of the goal of microenvironment comfort regulation. Here, a metafabric with unidirectional sweat transport and three cooling modes is innovatively fabricated by weaving core–shell yarns via mature weaving techniques. The gradient wetting structure formed in the fabric through the plasma treatment can pull liquid water out of the skin and diffuse it to the outer layer of the fabric for rapid evaporation (0.41 g h⁻¹), which is in a leading position in the field of sweat evaporation of cotton materials. Meanwhile, the addition of heat-conducting substances in shell nanofibers has improved the sweat cooling utilization rate of cotton fabrics, providing an additional skin temperature drop of 3.5 ℃ through sweat evaporation. In the outdoor experiment simulating human sweating, a temperature reduction of 7 ℃ is observed for skin-covered metafabric compared with skin-covered cotton fabric. Owing to its exceptional performance, the metafabric can provide promising design guidelines for developing a thermal-moisture comfort textile.

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Elastomers containing functional groups hold significant potential for soft tissue repair, particularly in vascular tissues; however, available materials of this type are scarce. In this study, we present a straightforward and easily synthesized biodegradable elastomer (named PGSCC), which was developed by incorporating citric acid and L-cysteine into the molecular structure of poly(glycerol sebacate) (PGS). This elastomer exhibits good elasticity, biocompatibility, and biodegradability comparable to PGS while also demonstrating enhanced reactivity due to the presence of two active functional groups: -COOH and -SH. This unique combination of exceptional properties endows PGSCC with significant potential for various biomedical applications, particularly for the bioactive modification of essential materials or implanted grafts. One notable example was the significantly improved effect of PGSCC-containing fibrous films on cell proliferation following appropriate modification through the PGSCC. By introducing PGSCC into our previously reported fibrous vascular graft, we obtained a new graft (M-Tri-layer tube) with functional groups that can be modified easily with vascular endothelial growth factor (VEGF) and heparin simultaneously. The VEGF/heparin dual-modified graft exhibited more favorable outcomes than the unmodified grafts in rabbits, particularly regarding neo-tissue formation and endothelialization during the early stages of implantation (within 16 weeks), demonstrating the excellent efficacy of PGSCC for vascular graft modification.

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After peripheral nerve injury, decreased nerve growth factor (NGF) levels and interrupted bioelectrical signal transmission are key factors leading to delayed nerve regeneration. However, the nerve conduits currently applied in clinical practice fail to simultaneously achieve sustained nutritional support and electrical activity maintenance for the injured microenvironment, limiting their repair effects. Herein, a dual-functional-layer nerve conduit loaded with NGF and exhibiting a high piezoelectric response was fabricated using electrospinning technology. The inner layer was composed of heparin-functionalized chitosan nanofibers loaded with NGF (CPHN), whereas the outer layer was formed from polyvinylidene fluoride (PVDF) nanofibers incorporated with ZnO nanoparticles (PZ). The results showed that the heparin-functionalized chitosan nanofibers significantly enhanced the loading density and stability of NGF. Additionally, PZ nanofibers with 1 wt% ZnO generated stable and appropriate endogenous electrical stimulation under controlled external stimulation. In vitro experiments demonstrated that the combination of PZ and CPHN (PZ@CPHN) could compensate for TrkA receptor desensitization, improve NGF pharmacodynamics, and activate the NGF/TrkA signaling pathway to regulate PC12 cells proliferation, differentiation, and motility. In the rat sciatic nerve defect model, transplantation of the PZ@CPHN conduit significantly promoted the reconstruction of regenerated nerve tissue and the recovery of muscle motor function after 12 weeks, achieving a repair outcome comparable to that of autologous nerve transplantation. In summary, a novel therapeutic strategy combining NGF administration with endogenous electrical stimulation is proposed to accelerate peripheral nerve regeneration.

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The rigid molecular structure and inherent golden color of polyimide fibers pose a significant challenge for its color construction. Traditional dyeing methods often come at the expense of mechanical properties due to the swelling effect. Here, the supercritical carbon dioxide (scCO₂) dyeing method was used to balance the contradictory relationship between color and mechanical properties of polyimide. Employing scCO₂ fluid as the dyeing medium leverages its unique dissolution and diffusion properties to drive the dye deep into the fiber, thereby imparting the satisfactory color to the polyimide fiber with the uptake ratio of 31.46 mg/g and the color fastness of up to grade 5. Furthermore, the swelling effect of the carrier on the fibers and the optimization and arrangement effect of the fluid on the molecular chains produce a synergistic effect, resulting in the tensile strength increased by about 20%. Given its streamlined process, eco-friendly nature and consistent results, we anticipate this prospective approach to be a formidable competitor in the field of color construction of polyimide fibers.

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The rapid development of intelligent electronic devices demands novel lightweight conducting wires with high ampacity. Carbon nanotube fibers (CNTFs) are regarded as an ideal candidate due to their low density, good stability, and excellent flexibility. However, because the carrier density of CNTFs is relatively low, their electrical properties need to be improved. Herein, a high vapor pressure squeezing method was developed to fill FeCl₃ into the inner hollow core and inter-tube nanovoids of highly-compacted double-wall CNT fibers (DWCNTFs) prepared by wet-spinning. It was found that the FeCl₃ nanoparticles not only provide sufficient carriers and increase the hole transfer efficiency, but also function in interlocking the aligned DWCNTs. As a result, the obtained fibers had a record-high electrical conductivity of 1.35 × 10⁷ S m^–1 and an ampacity of 1.57 × 10⁹ A m^–2, which are, respectively, 21% and 96% higher than the highest values reported for CNT fibers. The fibers also have a high tensile strength of 2.54 GPa, a high toughness of 177.2 MJ m^–3, and good stability during thermal shock cycles at temperatures of − 196 to 200 °C.

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The cold energy of the Universe can be harnessed through radiative cooling (RC) to achieve thermal comfort and energy conservation, representing a promising green thermal management strategy. However, most studies have focused on maximizing cooling power. The limitations of dynamic environmental changes in the RC performance have been overlooked. In this study, a Janus-structured polyimide composite nanofiber membrane was developed using electrospinning for efficient thermal management in various environments. The concept of mismatched charge transfer complexes was utilized to prepare fluorinated polyimides, which exhibit excellent RC performance and effectively address the issue of high solar absorption (average solar reflectance ((overline{R}_{{{text{solar}}}})) = 96.2%; average mid-infrared emissivity ((overline{varepsilon }_{{{text{MIR}}}})) = 89.7%). Moreover, lauric acid@fluorinated polyimide composite nanofibers with a core–shell structure were continuously deposited onto hollow polyimide nanofibers to construct a Janus-structured membrane that integrates RC, thermal shock resistance (melting enthalpy (ΔH_m) = 107.6 J g⁻¹ and crystallization enthalpy (ΔH_c) = 111.9 J g⁻¹), and thermal insulation. This structure exhibits excellent RC power (105.9 W m⁻²), temperature regulation ability (cooling of approximately 12.8 °C in summer and maintaining temperature for 2400 s without sunlight), and thermal insulation performance under complex weather changes. The thermal management mechanism and energy-saving principle of this structure in different environments were systematically summarized. Considering these advantages, this study provides design inspiration and theoretical support for the development of multifunctional integrated RC materials.

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The development of efficient fog-harvesting materials is of great significance for addressing freshwater scarcity. However, conventional materials with hydrophilic/hydrophobic regions frequently struggle with coordinating water droplet capture and transport, resulting in lower water collection efficiency. Herein, an integrated strategy based on the engineering of cellulose molecular modification for achieving high-performance fog harvesting is presented. The well-designed cellulose heterogeneous wettability surface (CWF-Cu), through the coordination of copper ions with nanofibrils and masking-assisted spray technique, significantly facilitates water capture and transport for fog harvesting. The copper ions are introduced into the cotton fabric, endowing it with high hydrophobicity (with a contact angle of approximately 130°) and polarity, which regulates wettability and increases potential nucleation sites. The as-prepared CWF-Cu fabric realizes a superior water collection rate (WCR) of 2672 mg·cm⁻²·h⁻¹, increasing by 70% compared with those of the conventional hydrophobic materials. Moreover, the CWF-Cu fabric demonstrates stable performance to withstand the impact of water and pollutant flushing, and enhanced mechanical strength and ultraviolet (UV) durability, which ensures the long-term usability of the material. This work provides an efficient route to achieving efficient fog harvesting that addresses water scarcity from the environment.

Gastroesophageal reflux disease (GERD) is a prevalent chronic condition that affects approximately 33% of the population and significantly increases the risk of esophageal cancer (5-year survival rate < 10%). Current pharmacological treatments cannot cure GERD, and surgical treatment often interferes with normal gastroesophageal physiology. Here, we developed a non-invasive transoral deliverable bioelectronic stent that enables real-time, closed-loop management of GERD without disrupting normal esophageal function. The stent is fabricated by an industrial weaving machine with functionalized fibers, followed by electroplating and chemical etching. It integrates vertically aligned multiple-channel pH/impedance fiber sensors for reflux detection and an electrical stimulator with pressure feedback. Owing to its shape-memory properties and low modulus, which is comparable to that of the woven structure of the esophagus, the stent is synchronized with esophageal motility without affecting physiological function. These sensing and electrical stimulation modules operate in a closed-loop fashion, where reflux-specific pH and impedance signals trigger LES stimulation, and the resulting contraction efficacy is immediately confirmed by a pressure sensor. In GERD animal models, the stent achieved 99.7% accuracy in reflux episode detection and successfully induced sphincter contraction in more than 95% of events, with negligible esophageal inflammation. This non-invasive, physiologically compatible, and closed-loop bioelectronic stent offers a novel solution for GERD management with real-time intervention for preventing disease progression and improving long-term outcomes.

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