Fibers and Polymers最新文献

Laminated composites frequently fail because of delamination, mainly owing to their characteristically weak resistance to interlaminar fractures. Enhancing the interlaminar fracture toughness of these materials remains a critical challenge in composite engineering. This study investigated the influence of incorporating glass nonwoven interlayer on the Mode I and Mode II fracture toughness of glass/epoxy laminated composites utilizing the double cantilever beam (DCB) and end-notched flexure (ENF) tests, respectively. For the fabrication of the composite specimens, woven glass fabrics with three distinct areal weights (200, 400, and 600 g/m²) were utilized along with glass nonwoven interlayers featuring two different areal weights (150 and 300 g/m²). The results revealed a significant enhancement in the fracture resistance of samples compared with the control samples without the interlayer. Specifically, the Mode I fracture toughness improved from 0.21 to 1.32 times, depending on the specific combination of layers. Similarly, including the nonwoven interlayer increased the Mode II fracture resistance from 1.44 to 10.55 times in the ENF test.

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Electrospinning is one of the techniques used for nanofiber fabrication, enabling the precise production of ultrafine nanofibers ranging from nanometers to micrometers in size. Compared to other nanofiber fabrication methods, electrospinning offers advantages such as a simple process, cost-effectiveness, and the ability to utilize a wide range of materials, making it highly versatile. Electrospun nanofibers exhibit a high surface area-to-volume ratio, a highly porous structure, tunable alignment and surface properties, and a structure that naturally mimics the extracellular matrix. These properties enhance their compatibility with biological environments, making them highly effective for biomedical engineering applications. Furthermore, the incorporation of nanoparticles and crosslinking agents can further enhance their mechanical strength, flexibility, biocompatibility, and antimicrobial properties, leading to extensive research in biomedical engineering fields. This review discusses the principles of electrospinning and provides a comprehensive overview of recent studies on the biomedical engineering applications of electrospun nanofibers, focusing on tissue engineering, wound dressing, drug delivery, and biosensors, while also exploring potential future research directions.

In this study, nanocomposite scaffolds were developed to regenerate full-thickness skin wounds. New bilayer fibrous constructs were fabricated using polylactic acid (PLA) as the outer layer and gelatin/honey blend (GH) containing different masses of selenium nanoparticles (0 µg, 1 µg, 10 µg, and 40 µg) as the inner layer of wound dressings. Nanocomposite wound dressings were evaluated by SEM, ATR–FTIR, surface wettability, swelling, degradation rate, and mechanical tests. The biocompatibility of nano constructs was evaluated by MTT assay after rat mesenchymal stem cells seeding onto the wound dressings. The full-thickness skin wounds were created on the back of rats, and the nanocomposite fibers were implanted. The PLA/GH/40 µg was a functional wound dressing and accelerated skin regeneration.

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Synthesis of selenium nanoparticles (A), fabrication of bilayer fibrous scaffolds by electrospinning technique (B), characterization tests of scaffolds (C), and animal study of electrospun fibrous scaffolds on a rat model. The PLA/GH/40 µg Se scaffold successfully regenerated skin injury in the rat model. PLA Polylactic acid

This study aimed to optimize the one-bath dyeing process for polyester/wool (80/20) fabrics using natural annatto (Bixa orellana) dye by examining the effects of temperature and dye concentration on colorimetric properties and fastness. Dyeing was carried out at 90 °C, 110 °C, and 130 °C for 30 min with dye concentrations from 1 to 30% owf, using water-soluble norbixin extracted from annatto seeds at pH 5. Color parameters (CIELab, K/S) and fastness properties (wash, light, sublimation) were assessed using standard methods. Results showed a strong interaction between temperature and dye concentration. At 90 °C, wool exhibited high dye uptake, but polyester absorption was limited, resulting in poor wash fastness despite high K/S values. At 130 °C, polyester dye penetration improved and light fastness increased, but high concentrations caused partial dye degradation and reduced color depth. The best overall results were achieved at 110 °C with 5–10% owf, balancing polyester dye uptake, wool dye retention, and dye stability while maintaining acceptable wash and light fastness. The findings highlight that the optimal dyeing conditions for polyester–wool blends with annatto differ from those for each fiber dyed separately, reflecting a compromise between polyester’s higher thermal requirement and wool’s lower heat tolerance. This work contributes to sustainable textile dyeing by demonstrating the potential of annatto to produce commercially acceptable shades on blended fabrics and by identifying light fastness as a key limitation to be addressed in future research.

Thermoplastic composites can be a solution for the circular economy of the wind industry. Some studies have focused on addressing the challenges of reusing raw materials and reducing both the economic costs and environmental damage. Thermoset composites have been crucial in increasing the size of wind turbines (WT), achieving longer and structurally more resistant blades, but they are difficult to recycle at the end of life and sometimes end up in landfills. Thermoplastic composites are being tested as an alternative to thermoset composites because of their similar structural properties and substantial advantages, such as ease of recycling. This article presents the results of the structural properties of a 2-m-long thermoplastic WT blade manufactured with a new thermoplastic resin called Akelite to obtain progress in the implementation of thermoplastic composites in this type of product. The new blade has been compared to an epoxy WT blade built with the same procedure. Property, static, and fatigue tests were performed on these blades to characterize them. The results of this comparison were quite similar, with less than 5% displacement in the static tests and a sensitivity change of less than 2% after the fatigue tests. Future studies should be conducted to extend this study to larger-scale blades.

This scoping review systematically explores recent advancements in polymeric piezoelectric nanofiber membranes for energy harvesting applications, with particular focus on the potential of multilayered piezoelectric structures to enhance energy efficiency. Following the PRISMA-ScR and Arksey & O’Malley frameworks, a structured search of Web of Science and ScienceDirect from 2018 to the present was conducted using predefined keywords, and eligible studies were screened and analyzed. After applying eligibility criteria, 35 studies with high piezoelectric output and effective designs were included in the review, of which only nine investigated multilayered piezoelectric structures. These studies demonstrated that stacked configurations, functional dopants, and innovative amplification designs significantly improved voltage and current outputs compared with single-layer systems. Among the multilayered approaches, six studies employed PVDF-based electrospun nanofibers, while three investigated hybrid designs incorporating piezoelectric ceramics. Although these multilayered designs showed considerable potential, challenges remain in terms of design complexity, scalability, long-term stability, and translation to real-world applications. Overall, this review highlights multilayered polymeric piezoelectric membranes as a promising strategy for sustainable energy harvesting, but also identifies critical gaps in the literature, particularly the limited number of studies on multilayered structures (six) and energy harvesting tower configurations (three), underscoring the need for further research to enable practical implementation.

Polyester–viscose blended knitted fabrics are widely used in the textile industry due to their exceptional wearing performance and cost-effectiveness. However, their easy pilling problems limit the long-term usability. This study adopts octadecyl dimethyl benzyl ammonium chloride (ODBAC), sodium hydroxide, benzyl alcohol, and sodium chloride for fiber surface modification, investigating the effects of finishing agent, impregnation temperature, and time on anti-pilling performance of these fabrics. The results indicated that when ODBAC concentration was set at 5 g/L, sodium hydroxide at 0.3 g/L, benzyl alcohol at 1.2 g/L, and sodium chloride at 1.2 g/L, a pilling grade of 5 can be achieved through an impregnation treatment conducted at 80 °C for 60 min. Furthermore, with a friction coefficient of polyester fiber ranging from 0.35 to 0.4 and the strength between 3.5 and 3.8 cN/dtex, the fabric exhibits reduced susceptibility to pilling. The treatment significantly enhances anti-pilling performance of the fabrics while preserving their air permeability, moisture permeability, warmth retention, and top-breaking strength. Additionally, it has been found to provide excellent anti-pilling durability under 50 washing cycles and cyclic temperature conditions for 120 h. The findings reveal the regulation of fiber surface by multi-component synergistic action under low alkali conditions and provide an efficient and durable industrial solution for the anti-pilling treatment of polyester–viscose blended knitted fabrics.

The growing demand for sustainable, lightweight, and high-performance materials in industries such as automotive, aerospace, and construction necessitates innovative production processes. This study introduces a novel, entirely dry manufacturing method for lightweight reinforced thermoplastic (LWRT) panels, thereby offering an environmentally friendly and cost-effective alternative to conventional wet processes. Nonwoven fabrics with areal weights of 150 and 250 gsm, comprising a 50 wt% glass fiber (GF)-reinforced polypropylene (PP) matrix, were fabricated using a double carding technique, with the effect of subsequent needle punching on fiber bonding and homogeneity systematically investigated. A mixture of expandable microsphere foaming agent and PP powder was applied onto nonwoven fabrics; lamination was performed to induce foam formation at 220 °C and 1 m/min conveyor belt speed. SEM and microscopic analysis confirmed the impregnation of PP and the successful formation of microcellular structures through the foaming process, leading to a decrease in the panel density. Tensile and flexural strength were affected by the needle punching process and fabric areal weight. Panels made with 250 gsm nonwoven fabrics yielded mechanical properties similar to those of the commercial reference panel.

Water contamination by dyes and anionic pollutants poses a significant global challenge. Among various organic dyes, azo dyes with azo groups are particularly hazardous. The elimination of methyl orange (MO) dye, nitrate, and phosphate by formaldehyde-modified chitosan is examined in this work, and the adsorbent was characterized by FTIR, SEM, TGA, and XRD spectroscopy. The effects of pH, amount of adsorbent, adsorption time, initial dye or anion concentration, and temperature were assessed on adsorption by batch studies. Under optimal conditions (pH 7 and 30 °C), modified chitosan achieved maximum removal efficiencies of 90.12% for MO, 76.19% for NO₃⁻¹, and 94.49% for PO₄⁻³. Results demonstrated rapid adsorption by the modified chitosan, which was 68.39, 54.83, and 50.44% for MO, NO₃⁻¹, and PO₄⁻³, respectively, within the first 10 min only at room temperature. As the temperature rose, the adsorbent’s capacity decreased. According to kinetic investigations, the pseudo-second-order model best describes the adsorption processes. The values of the isotherm parameters were determined using the Freundlich, Dubinin–Radushkevich, and Langmuir isotherms. Equilibrium data were well-fitted by the Langmuir isotherm. The low mean values of adsorption energy (0.909 to 4.463 kJ/mol) demonstrated the physisorption technique. Thermodynamic analysis revealed the adsorption to be exothermic (-∆H°), spontaneous (-∆G°), highly ordered (-∆S°), and feasible under the investigated conditions. Furthermore, the modified chitosan exhibited good reusability with adsorption–desorption capabilities over four cycles. This paper discusses the demonstration of modified chitosan as a profitable and efficient adsorbent for eliminating MO dye, nitrate, and phosphate from wastewater.

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An eco-friendly approach to dyeing high-performance polyetherimide (PEI) fibers is presented to avoid the toxic effects of diffusion accelerator (carriers) and disperse dyes used in the conventional high-temperature dyeing processes. Natural oils are investigated as bio-based carriers for natural turmeric dying of PEI fabric with microwave-assisted dyeing technology. This study evaluated 21 different natural oils as carriers to optimize the turmeric dyeing performance of PEI fabrics. A systematic evaluation of 21 natural oils identified optimal carriers, with vanilla oil (6 g/L) demonstrating the highest color strength (K/S) and minimal tensile loss. Sage and lavender oils also showed favorable performance at specific concentrations. Statistical analysis, color fastness evaluation, and advanced characterization (FTIR, SEM) validated the efficacy of these carriers. This study demonstrates that essential oil types can be used as natural carriers in the dyeing processes of high-performance fibers, and at the same time, it enables the adoption of renewable resources and environmentally friendly processes in material innovation, contributing to the advancement of sustainable textile dyeing applications. To balance tensile strength and color performance, this study also emphasizes how important it is to choose and optimize essential oil types and concentrations. When taken as a whole, these findings support the development of environmentally friendly textile dyeing techniques and the encouraging possibilities of natural-dyed PEI textiles for high-performance uses in fashion, interior design, automotive, and aerospace industries.