Fibers and Polymers最新文献

Drilling of unidirectional carbon fiber reinforced polymer sheets often leads to damage around the hole, compromising the mechanical integrity of composite structures. To address this challenge, a deep learning framework was developed to predict drilling-induced damage images using process parameters as inputs. A convolutional autoencoder (CAE) was first employed to augment the limited experimental dataset by generating synthetic grayscale damage images. Subsequently, a multi-layer perceptron (MLP) decoder model was trained to predict damage images based on spindle speed and feed rate. Three CAE architectures were evaluated, with CAE Type I achieving the lowest reconstruction error in the damage area, with an error of 10.14% and an R² value of 0.9862. Four MLP-Decoder models were tested using different combinations of original and CAE-generated images. The model trained with both original and CAE Type I images (MLP-Decoder Type B) showed the highest prediction accuracy, with an MSE of 1.13 and a predicted damage area of 36.92 mm², which is closer to the validation data. Comparative analysis against experimentally validated images demonstrated that the proposed framework can effectively estimate drilling damage patterns.

This study explores the eco-friendly use of ground coffee pomace, an abundant biomass, as a natural dye source for wool and polyamide fabrics. Dyeing performance was evaluated under varying pH, time, and temperature conditions. The results show that acidic conditions (particularly pH 3), elevated temperatures (up to 100 °C), and extended dyeing times (up to 60 min) significantly enhance color yield (K/S values) and deepen fabric shades. The results underscore that ground coffee pomace, a byproduct rich in polyphenolic compounds, represents a viable and environmentally sustainable alternative to conventional synthetic dyes. Its natural dyeing properties offer significant potential for integration into eco-conscious textile manufacturing processes, aligning with the principles of circular economy and green innovation.

Using a Box–Behnken design approach, the study achieved a high coefficient of determination (R² ≈ 0.98) for the K/S models developed for wool and polyamide substrates. These results demonstrate the models' strong predictive capability for new dyeing datasets.

Highly protective clothing requiring minimal maintenance is essential for outdoor workers who face prolonged exposure to ultraviolet (UV) radiation and encounter chemical and biological pollutants. In this study, a self-cleaning and UV-protective coating was developed on cellulose fabric via the green in situ synthesis of zinc oxide nanoparticles (ZnO NPs) and subsequent modification with stearic acid. The self-cleaning effect of the fabric is attributed to its superhydrophobic, water-repellency-induced particulate removal and antibacterial properties. The solution-immersion method was employed for fabric modification, utilizing zinc (Zn) acetate, Aloe vera leaf skin extract, and stearic acid. XRD and SEM–EDX analyses confirmed the formation of amorphous, irregularly shaped ZnO NPs after the in situ synthesis. This led to excellent UV protection and effective antibacterial activity. Further modification resulted in a superhydrophobic fabric due to the precipitation of stearic acid crystals on the surface. The fabrics exhibited good washing durability and excellent UV protection, even with prolonged sun exposure. Overall, the study demonstrates a viable method for producing a UV-protective and self-cleaning cellulose fabric using environmentally friendly materials and processes.

The current study outlines the use of a bioreduction process to synthesize copper nanoparticles. Copper sulfate pentahydrate serves as a precursor salt, while lemon leaf extract acts as an eco-friendly bio-reducing agent for synthesizing copper nanoparticles. The formation of copper nanoparticles was characterized by UV–visible spectroscopy, Transmission Electron Microscopy (TEM), and Attenuated Total Reflectance–Fourier-Transform Infrared spectroscopy (ATR-FTIR). UV–visible spectroscopy revealed surface plasmon resonance at 320 nm. The size and shape of the CuNPs were evaluated through TEM investigations, which showed that the typical particle size ranged from 3 to 11 nm. The minimum inhibitory concentration of the biosynthesized CuNPs was analyzed using the broth dilution method against four microbial cultures: Staphylococcus aureus ATCC 6835, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, and Pseudomonas aeruginosa ATCC 10145. Using the Pad-Dry-Cure technique, these biosynthesized CuNPs were applied to cotton fabric. The developed CuNP-finished cotton fabrics were then evaluated in terms of SEM–EDX, antimicrobial activity, in vitro cytotoxicity (direct method), and UV protection. The antimicrobial activity showed 99.93% antiviral effectiveness against the SARS-CoV-2 virus and over 95% bacterial reduction against Klebsiella pneumoniae and Staphylococcus aureus after 20 washes. The cytotoxicity and UV protection results for the CuNP-finished fabric indicated mild cytotoxicity and very good UV-protective properties, ensuring the commercial viability of the finished fabric for various applications.

The fabrication of PTFE micron filaments with superior mechanical properties remains both a key research focus and a considerable challenge in the field of engineering technology. In this study, the PTFE micron filaments were successfully prepared via wet spinning and molding process by optimizing the concentration of the carrier polyethylene oxide (PEO) aqueous solution, molecular weight of the coagulation bath poly-(ethylene glycol) PEG, mass ratio of PTFE to PEO, and sintering temperature. Due to its higher hygroscopicity and surface tension compared to the spinning solution, PEG provided favorable conditions for the solidification of the PTFE/PEO primary filaments. Elemental analysis results confirmed the complete removal of PEO and PEG from the PTFE fibers after sintering. When the mass fraction of PEO is 4%, the mass ratio of PTFE to PEO is 4:1, PEG molecular weight is 200 Da, and the sintering temperature is 370 ℃, the resulting PTFE fibers display a smooth and compact Surface, with a diameter of 27.50 ± 0.66 μm. Furthermore, tensile testing reveals that the PTFE filaments achieved a tensile strength of 133.02 ± 5.39 MPa and an elongation at break of 567.77 ± 93.67%. These findings demonstrate a feasible and efficient approach for the fabrication of high-performance PTFE micron filaments.

Polypyrrole nanobelts (PNBs) were synthesized through an organic single-crystal surface-induced polymerization (OCSP) method utilizing single crystals of 5-sulfoisophthalic acid sodium salt (5-SINa) in acetonitrile, a polar aprotic organic solvent. The OCSP technique enables the polypyrrole to grow along the surface of the organic crystals, replicating their needle-like morphology. This shape-copying approach results in highly anisotropic PNBs with significantly improved structural order and surface area. Compared to conventionally synthesized polypyrrole, the PNBs exhibited enhanced π − stacking interactions and a higher doping level, which collectively contributed to a notable electrical conductivity of 21.3 S/cm, approximately seven times higher than that of polypyrrole fabricated without the use of organic single crystals. The OCSP process in acetonitrile also offers advantages such as a fast reaction rate, low processing cost, and high product yield, making it suitable for scalable manufacturing. To evaluate their electrochemical performance, the PNBs were employed as counter electrodes in dye-sensitized solar cells (DSSCs). The resulting devices demonstrated high optical transmittance and an overall energy conversion efficiency reaching 75% of the standard platinum-based cells. These findings highlight the potential of PNBs as a cost-effective and flexible alternative to noble metal-based materials for next-generation optoelectronic and energy devices.

Melt-blown (MB) nonwoven fabrics are made by mixing thick poly(ethylene terephthalate) (PET) fibers with polypropylene fibers to induce special functionality. However, their production is complex. In this study, a simpler process in which PET and polypropylene were extruded simultaneously from large and small nozzle holes, respectively, was developed. The resulting nonwoven was annealed for 5–15 min. The effects of the PET fibers and the annealing time on the structure and physical properties of the nonwoven were investigated. The proportion of the fibers with a diameter greater than 30 µm increased, indicating that the extruded PET produces thick fibers. The PET crystallinity increased from 6 to 45% with annealing time. Furthermore, the compressibility of the nonwoven decreased and its compression–recovery rate slightly increased with annealing time. The above changes in compression ability appear to be caused by the increase in the initial elastic modulus of the PET fibers owing to the increase in their diameter and crystallinity.

Sustainability has gained attention due to its role in addressing environmental issues in recent years. Natural fibers, especially jute, have enough potential to become an essential reinforcing element in fiber-reinforced latex composites. To achieve a high puncture resistance in jute composites, woven structures are considered as load-bearing preforms with varying dimensions. Various woven structures, including two-dimensional (2D), 2.5-dimensional (2.5D), and three-dimensional (3D), are considered to study the effect of dimension and to optimize other structural parameters of woven-jute/latex (WJL) composites. Compression molding was performed after a hand layup procedure to prepare WJL composites. Scanning electron microscopy (SEM) analysis was employed to validate the penetration of latex inside the 2D, 2.5D, and 3D woven structures. The reinforcing efficiencies of the 2D, 2.5D, and 3D woven fabrics were compared, and it was found that the fiber arrangement inside the woven structure largely influenced shore hardness and puncture resistance. The puncture resistance of jute-latex composites was 300.2 N with 2D jute-based preforms and enhanced to 839N with 3D orthogonal jute-based preforms, and the shore hardness value was improved from 65 in 2D to 84.5 with 3D orthogonal preforms. The performance of the 2.5D jute-based preform fell between that of 2D and 3D jute-based preforms. This research will provide a solid foundation for introducing different woven structures in WJL composites for various composite products. With a higher correlation coefficient, the statistical model's suitability and correctness were validated. Indicating that the experimental results align with the statistical model, stronger correlation coefficients (R²) were found for both puncture (0.977) and hardness (0.877).

This study presents an eco-friendly approach to developing multifunctional textiles by incorporating microencapsulated lemongrass essential oil (LEO) onto cotton–polyester blended fabrics. The treated fabrics were designed to exhibit mosquito repellent, antibacterial, and aromatic properties, offering a natural alternative to conventional synthetic finishes. LEO microcapsules were synthesized using the complex coacervation method and applied to the fabric via the pad-dry-cure method. The morphology of the microcapsules was analyzed using optical microscope, while the treated fabric was examined with scanning electron microscope (SEM). The functional performance of the treated fabric was evaluated through the arm-in-cage test, antibacterial assays, and sensory evaluation. Results showed that fabrics treated with 15% LEO microcapsules achieved 88% mosquito repellence efficacy protection before washing and 59% after 30 washing cycles, demonstrating durable functionality. The treated fabrics also maintained effective antibacterial activity and pleasant aroma retention. This study highlights a sustainable and eco-friendly finishing strategy for producing bio-functional textiles with potential applications in healthcare, outdoor wear, and wellness-related clothing.

Graphical Abstract

Poly(ε-caprolactone) (PCL) is a biodegradable polyester widely used in biomedical applications due to its biocompatibility and tunable mechanical properties. However, its lack of inherent antimicrobial activity limits its utility in infection-prone settings. This study reports the covalent modification of PCL with 6-aminocoumarin (6-AMC) to create functional composites (PCL/6-AMC) with enhanced crystallinity, fluorescence, and antimicrobial properties. The composites were synthesized via solvent casting and characterized using XRD, FTIR, NMR, UV–Vis spectroscopy, and SEM. XRD analysis revealed that 6-AMC incorporation increased PCL crystallinity by up to 40%, while FTIR and NMR confirmed covalent bonding via aminolysis of PCL ester groups. UV–Vis spectra demonstrated successful 6-AMC integration, with a characteristic absorption peak at 400 nm. Antimicrobial assays against Staphylococcus aureus, Escherichia coli, Candida albicans, and Aspergillus niger showed dose-dependent activity, with PCL/6-AMC (6 wt.%) achieving 100% growth inhibition of S. aureus and E. coli. Cytotoxicity assays on human fetal lung fibroblasts (Wi38) confirmed biocompatibility for PCL and its PCL/6-AMC (IC₅₀ ranged from 721.78, 1020.83, and 1143 µg/mL for PCL, PCL3/6-AMC, and PCL6/6-AMC, respectively). The composites combine PCL’s biodegradability with 6-AMC’s antimicrobial and fluorescent properties, offering potential for applications in drug delivery, tissue engineering, and antimicrobial coatings.