Fibers and Polymers最新文献

In recent years, driven by the pressing demand for sustainable energy solutions, polyvinylidene fluoride (PVDF), a promising piezoelectric material, has garnered considerable attention for its application in energy-harvesting devices. PVDF stands out as the material of choice in piezoelectric generator technology owing to its remarkable flexibility, superior processability, long-term stability, and biocompatibility. Nevertheless, PVDF-based generators exhibit inferior piezoelectric responses compared to traditional piezoelectric ceramic materials, thereby constraining their performance in large-scale deployments. To address this limitation, researchers have been exploring innovative strategies to enhance the piezoelectric properties of PVDF. Among these, electrospinning technology emerges as a pivotal approach due to its ability to impart mechanical stretching and in situ polarization to the polymer during fabrication. This paper comprehensively reviews recent advancements in optimizing the output performance of PVDF-based piezoelectric nanofiber membranes through the integration of filler doping technology with electrospinning. We delve into the effects of various filler types on the properties of electrospun PVDF-based piezoelectric nanofiber membranes and explore their underlying mechanisms. These fillers significantly bolster the output performance of PVDF-based piezoelectric devices by augmenting PVDF's piezoelectric activity, fostering dipole orientation, and elevating the dielectric constant. Notably, the incorporation of fillers not only elevates the piezoelectric coefficient but also optimizes the microstructure, facilitating an efficient conversion between mechanical and electrical energy. Furthermore, we envision the promising application prospects of PVDF piezoelectric nanofibers in cutting-edge fields, such as health monitoring, environmental monitoring, and energy-harvesting systems. These domains urgently require piezoelectric materials that combine high sensitivity, stability, and cost-effectiveness, where PVDF-based piezoelectric nanofibers, with their distinctive advantages, are poised to demonstrate significant application potential and societal value.

The catalytic activity of FeCo alloy nanoparticles (NPs) supported on nitrogen-doped mesoporous carbon spheres (FeCo/NMCS) was evaluated for hydrogen evolution and reduction of various organic dyes. The NMCS was spherical, with an average diameter of 488.1 nm, while the FeCo alloy NPs were evenly distributed across the NMCS, with an average diameter of 8.2 nm. The nitrogen content in FeCo/NMCS was found to be 3.91 wt%. The FeCo/NMCS displayed remarkable efficiency in hydrogen evolution through the hydrolysis of ammonia borane (AB), characterized by an activation energy of 23.49 kJ/mol. The FeCo/NMCS also demonstrated superior catalytic activity in reducing 4-nitrophenol (4-NP), with a reduction rate constant of 0.468 min⁻¹ using 5 mg of FeCo/NMCS and 20 mg of AB. This rate places the FeCo/NMCS among the highest-performing catalysts for 4-NP reduction. Further, the catalyst efficiently reduced crystal violet, methylene blue, and rhodamine B under the same conditions. Azo dyes, including tartrazine, methyl orange, Red 195, and Yellow 145, underwent faster reduction than other tested dyes. The FeCo/NMCS maintained its integrity and activity even after four hydrogen generation cycles. These results highlight FeCo/NMCS’s potential as a multifunctional, magnetically separable, and reusable catalyst for efficient hydrogen production and environmental remediation applications.

Thermo-regulating textiles incorporating Phase-Change Materials (PCMs) have emerged as innovative substances that automatically adapt to changes in environmental and body temperature. This paper presents an approach to develop a PCM-loaded composite yarn for potential use in medical textiles. Paraffin wax-based PCM nanocapsules were synthesized and integrated into cotton fibers during the ring spinning process. Subsequently, a composite core–shell-structured yarn was fabricated using electrospinning, comprising a cotton/PCM core and a poly (l-lactic acid) (PLLA)/PCM nanofibrous shell. Morphological analysis confirmed the successful formation of the core–shell structure and the uniform distribution of PCM nanocapsules within the fibers. The composite yarns exhibited reduced diameters with increasing PCM nanocapsule content. Thermal analysis revealed that the incorporation of PCMs resulted in decreased glass transition and cold crystallization temperatures of the PLLA nanofibers. Additionally, the presence of PCMs increased the crystallinity of PLLA fibers. According to the thermoregulation test results, the presence of PCM in its structure affected the heating and cooling behavior of the yarns. The composite yarns were further functionalized by incorporating Vancomycin as an antibiotic agent for medical dressing applications. This progress signifies an improved thermoregulation, offering potential applications in wound care and other medical settings.

Graphical Abstract

Natural products extracted from plants with excellent dyeing properties are widely explored due to greener and sustainable dyeing methods. The current study is concerned with applying natural dye extracted from dewberry fruit by using T. chebula (black acacia) and A.mearnsii (myrobalan) as a source of bio-mordant. The results proved that dewberry fruit extract could be an excellent natural dye source for the coloration of tencel and other cellulosic textiles. Using bio-mordants like T.chebula and A.mearnsii has improved the color properties, producing vibrant shades of color with high color strength. The color fastness ratings tested by ISO standards showed improvement after using bio-mordant. Additionally, using the AATCC 100–1999 (The American Association of Textile Chemists and Colorist) test methodology, the bio-mordanted tencel samples showed excellent bacterial reduction against S.aureus and E.coli bacteria. Hence, it is concluded that the dye extracted from dewberry fruit has huge potential to impart color on tencel fabric, producing vibrant shades of color and making the dyeing process greener and sustainable using bio-mordants.

This inspection explores the potential of 4-nitroaniline’s potential as a novel diazo component in synthesizing azo dyes, highlighting the research’s novelty. Two new azo dyes, designated 4-(4-nitrophenylazo) salicylic acid (SS) and 4-(4-nitrophenylazo) catechol (OH), were prepared by diazotization of 4-nitroaniline followed by coupling with salicylic acid and catechol, respectively. Fourier transform infrared spectroscopy and other analytical techniques confirmed the structural integrity of the dyes before and after application to cotton, wool, acrylic, and polyester fabrics. The dyes exhibited the best color strength (K/S) and fastness properties on cotton. The exhaustion and fixation of the dyes onto cotton fibers improved with increasing temperature, reaching optimal efficiencies (83.92 and 80.34% for SS and 89 and 84.36% for OH) at 95 °C. Furthermore, the study investigates a sustainable method for removing the dyes from textile wastewater. Sugarcane bagasse, a cost-effectiveness and environmentally friendly sorbent, achieved effectual dye elimination from wastewater after sulfuric acid pre-treatment (superior to formaldehyde). This treatment achieved a remarkable 99.34% removal efficiency under optimal conditions (2.5 g, 50 ppm, pH 9, 200 rpm, 120 min). Adsorption exhibited characteristics of both Langmuir isotherm and pseudo-second order kinetics. Diffusion studies revealed intraparticle diffusion as the rate-controlling step, with film diffusion likely governing the adsorption. Regression modeling yielded an R² of 93.89% between process factors and dye removal. The effectiveness was further validated by treating real-world, highly polluted textile wastewater obtained from an Egyptian factory. The sugarcane bagasse treatment effectively removed dyes (almost 98.8%) under optimal conditions, demonstrating its reusability after multiple dye-removal cycles.

Environmental concerns drive the demand for sustainable alternatives to synthetic materials, as high synthetic usage leads to waste and toxic emissions, while natural fibers offer biodegradability, low cost, and lightness. In this study, Mariscus ligularis fiber, developed into bidirectional mats with orientations of ±45°, ±60°, and 0°/90° (A, B, and C), was reinforced with epoxy resin LY556 and hardener HY951. Nine composite laminates with 20, 30, and 40% fiber weight fractions were fabricated using hand lay-up techniques. The mechanical, viscoelastic, thermal, heat distortion temperature (HDT), Vicat softening temperature (VST), and water absorption properties were characterized according to ASTM standards. The mechanical characterization reveals that the 0°/90° laminate with 40% fiber (C40) exhibited the best tensile strength (22.97 MPa) and flexural strength (45.31 MPa). The ±60° laminate with 40% fiber (B40) had the highest impact strength (8 J) and hardness (93.25). The viscoelastic studies indicated that the C40 composite exhibited the most elevated storage modulus (Eʹ) and loss modulus (Eʺ), and the highest glass transition temperature (T_g), signifying strong interfacial bonding and effective stress transfer. The thermal stability of the composites is up to 270 °C. C40 had an HDT of 60.2 °C, a VST of 75.3 °C, and a minimal water absorption of 4.5% after 24 h. The microstructural study confirmed favorable fiber-matrix adhesion and structural properties, making these composites suitable for automotive interior panels and lightweight applications.

In recent years, the interest in using natural dyes for coloring fabrics has surged due to their eco-friendliness and lower impact on human health. As a sustainable alternative to synthetic dyes, which pose environmental concerns, natural dyes are gaining significance in the textile industry. Therefore, developing more efficient extraction methods for natural dyes from plant materials for various applications, including food, cosmetics, and textiles, is essential. This study investigates the extraction and dyeing of a novel natural dye derived from Hypericum triquetrifolium. It examines the impact of supercritical CO₂ (ScCO₂) extraction compared to traditional aqueous methods. The extraction process was analyzed using gravimetric analysis, FTIR, and HPLC chromatography. The findings revealed that ScCO₂ significantly improved the extraction efficiency of the dyes. Additionally, initial assessments were conducted to evaluate the dyeing capabilities of the extracts obtained through both aqueous and ScCO₂ methods on multifiber samples using various dyeing techniques.

To develop thermal regulation nanofibers, this work used polyethylene glycol (PEG) solution and polylactic acid (PLA) solution as the inner and outer spinning fluids and developed PLA/PEG (P_oP_i) nanofibers using coaxial electrospinning process. Through XRD, FTIR, and water contact angle analysis, it was confirmed that the PLA of P_oP_i has a certain encapsulation effect on the inner layer of PEG, but the encapsulation effect decreases with the increase of PEG spinning solution concentration. PEG20 with a PEG spinning solution concentration of 20 wt% obtained smaller average diameters, while PEG40 with a PEG spinning solution concentration of 40 wt% showed a significant decrease in fiber formability and hydrophobicity. PEG significantly improved the mechanical properties of P_oP_i, and the Young’s modulus, yield stress, breaking stress, and breaking strain of PEG30 were increased by 18.24 MPa, 2.13 MPa, 3.54 MPa, and 41.65%, respectively, compared to pure PLA. The DSC curves of P_oP_i show a melting endothermic peak attributed to PEG, and the peak temperature gradually decreases with increasing PEG concentration. The P_oP_i exhibits temperature hysteresis during both heating and cooling processes, with PEG30 experiencing delays of 7.6 °C and 6.8 °C compared to pure PLA after heating and cooling for 5 s, respectively, indicating excellent thermal regulation ability. This work investigated the effect of PEG spinning solution concentration on inner and outer layer differences and the performance of P_oP_i, providing a theoretical basis for the development of coaxial electrospinning nanofibers for thermal regulation based on low-molecular-weight PEG.