Fibers and Polymers最新文献

This paper investigates the crashworthiness performance of circular advanced polylactic acid (PLA+) lightweight protective structures inspired by the natural morphology of the horsetail. The specimens were created using 3D-printing technology and tested under quasi-static axial compression. Three design parameters were employed, each with four levels, in order to calculate the crashworthiness behaviors and deformation histories of the intended tubes. The design parameters are the inner diameter (d) and the outer diameter (D) (d/D = 0.5/4, 1/4, 2/4, and 3/4), the number of ribs (N = 2, 4, 6, and 8), and the internal shape (S = circular, square, hexagonal, and octagonal). Furthermore, the designed tubes were compared with the hollow tube. Later on, various crashworthiness indicators, i.e., the initial peak load ({(F}_{text{ip}})), total absorbed energy (U), average crash load (({F}_{text{m}})), crash force efficiency (CFE), and specific absorbed energy (SEA), of the proposed tubes were evaluated. Based on the obtained results, the studied parameters have a noteworthy influence on the crashworthiness performance and the deformation history. In addition, the findings revealed that increasing the d/D and N led to enhanced energy absorption capacity. Furthermore, the circular inner shape documents the best inner structure. The maximum, ({F}_{text{ip}}), ({F}_{text{m}}), U, CFE, and SEA were recorded for the CN8R (1/4) specimen with an enhancement percentage of 120.09, 321.44, 320.86, 93.17, and 101.31% compared to the hollow tube, respectively.

In this research, N-hydroxymethylacrylamide (N-MA) was first treated on cotton fabric by pad-dry processes following with argon plasma treatment to induce the graft copolymerization of N-MA on the fabric, and then the fabric was chlorinated with sodium hypochlorite to impart its antimicrobial property. The presence of N-MA on the cotton fabric surface was confirmed with Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS) spectra, and scanning electron microscopy (SEM). The breaking strength, weight change, crystallinity, and antimicrobial property of the modified fabric were also characterized. The results showed that the fabric completely inactivated S. aureus and E. coli O157:H7 within 10 min of contact time and the antimicrobial property was rechargeable.

Biobased films have attracted much attention of researchers due to the advantages of biodegradability and biocompatibility. Chitosan–dopamine–montmorillonite composite films were prepared using genipin as a cross-linking agent, based on a biomimetic strategy through the “brick–mortar”structure design. Lignin nanoparticles (LNP) were used to construct efficient surface structures to enhance the water contact angles, as revealed by the AFM images. SEM images showed that the chitosan, montmorillonite and dopamine formed a homogeneous film. XRD curves indicated that the addition of genipin caused the rearrangement of chitosan and montmorillonite molecules. The water resistance of the obtained composite films added with genipin cross-linked dopamine was significantly enhanced. The resultant film could maintain intact shape in the acidic and alkaline solutions (pH = 2, 4.5, 9 and 11), and the addition of 1.11% LNP obviously enhanced the water contact angle values, which could be above 100° in 60 s. The appropriate dosage of LNP improved the strength performance, while the dosage of LNP on the transmittance and thermal stability of chitosan composite film was not significant. These findings indicated that this simple method was greatly helpful for enhancing the hydrophobic application performance of chitosan-based composite film.

The use of modern technologies in the world in various sciences has increased significantly and is expanding day by day. Relying on its unique properties, nanoscience has penetrated most sciences and has gained a special place. The textile industry, as one of the oldest and long-standing industries, has not benefited from this science and has benefited from it in various fields. Due to the large surface to volume ratio of nanofibers and the use of various polymers and raw materials as well as the variety of production processes, nanofibrous structures are one of the best materials in the application of nanotechnology. In this article, different methods of producing nanofibrous yarns in two types of yarns, continuous and non-continuous, and the parameters affecting the production are briefly introduced.

This research study was conducted to examine the effects of quenched biosilica on the composite material composed of cotton microfibers and vinyl ester. Examining the performance of quenched biosilica reinforced in a vinyl ester composite with cotton microfiber is the primary focus of this research. After the biosilica was quenched after being generated from hardly husk, a hand layup process was employed to create the composites. Adding quenched biosilica in silane-treated form significantly increases the load bearing characteristics, according to the comprehensive analysis of many composite materials. Results from the fatigue tests show that VCB3 has remarkable resilience to fatigue, with a maximum stress of 74 MPa maintained after 104 cycles and a subsequent decline to 16 MPa at 106 cycles. In the dynamic mechanical investigation, VCB3 showed the least amount of energy dissipation and highest stiffness with a peak loss factor of 0.38. This finding is supported by the creep test, which shows that VCB3 exhibits the best structural stability under continuous load, with creep strain values ranging from 0.0059 at 5000 s to 0.0084 at 15,000 s. When quenched silane-treated biosilica is included into the composite matrix, its resistance to deformation, propagation of fractures and energy loss is enhanced. These findings demonstrate the importance of quenched silane-treated biosilica in improving the mechanical performance of composite materials, making them suitable for demanding applications including drones, automobiles, homes, and sports that demand high levels of thermal stability and exceptional durability.

Flax fibers contain naturally colored substances, which need to be removed by bleaching to produce excellent flax-based textiles in the subsequent process. However, the traditional bleaching process has the disadvantages of high temperature, large water consumption and high chemical oxygen demand (COD) value. Therefore, an appealing alternative to make flax fiber more sustainable is to design an environmentally friendly bleaching process, which has the advantages of low water usage, easy operation at ambient temperature and without addition of chemicals. In this paper, the influence of ozone bleaching on the optical property of flax fibers at different parameter conditions (reaction phase, ozone concentration, bleaching time, water pickup value, initial pH value) was investigated. The physicochemical properties of fiber samples after ozone bleaching were analyzed and compared with those of traditional bleached fibers. Results showed that the lightness and whiteness index of SFT-O₃-Gas-70% increased to 80.85 and 53.33, yellowness index decreased to 10.14 (ozone concentration 20%, 20 min, WPV 70%, pH 2.0), which was comparable with the SFT-TMB (80.75, 51.87 and 11.33). SEM analysis showed that the non-cellulosic components (hemicelluloses and lignin) on the fiber surface were removed after bleaching treatment. The crystallinity and thermal stability of samples after bleaching treatment increased due to the removal of non-cellulosic components. Compared with the SFT-TMB (16.07 cN/tex and 1166), the tenacity and degree of polymerization (DP) of SFT-O₃-Gas-70% decreased to 11.40 cN/tex and 779, respectively. The whole ozone bleaching process is under gas phase, normal temperature and pressure conditions, which greatly reduces water consumption and COD values of bleach wastewater. This study provides some guidance on the use of ozone for bleaching lignocellulosic fibers and the selection of cellulose protectants.

The substance principal used to synthesize these materials is fibroin, obtained from the silkworm’s cocoon (Bombyx mori) in the form of a filament, but can be converted into nanometric particles. After the synthesis, the obtained samples were characterized by size and Zeta potential (via nanosizer), X-Ray diffraction (XRD), specific area determination by the BET method, Infrared Spectroscopy with Fourier Transform with attenuated diffuse reflectance (FTIR), transmission electron microscopy (TEM). The silk fibroin nanoparticles (SFNp) were immobilized on polylactic acid (PLA)-knitted fabric and functionalized with chitosan for FTIR and XRD analyses, in addition to cytotoxicity analysis with colorimetric test (MTT) and cell adhesion. The DLS, FTIR and MET results confirm the formation of spherical silk fibroin nanoparticles with average sizes between 48 and 156nm, and zeta potential of − 19.95mV which characterizes a good dispersibility. Cell-viability assessment showed that SFNp is a non-cytotoxic material at low concentrations up to 48h, confirming that the nanoparticle synthesis method using the ternary system is an effective and low-cost alternative. This technique has great potential for use in the development of biomaterials, due to the production of knitted tissues with PLA functionalized with chitosan and immobilized with SFNp, exhibiting mechanical strength and biocompatibility.

The objective of this study is to develop cotton fabrics that are capable of reversible color change in response to temperature changes and of providing an opportunity for thermal management. To achieve this objective, chitosan/sodium alginate natural polymer-walled microcapsules with a thermochromic phase change system core, produced by the complex coacervation method were applied to cotton fabrics by impregnation and exhaustion processes. The thermochromic system contains crystal violet lactone (dye), phenolphthalein (developer), and 1-tetradecanol (solvent) and offers a temperature regulation function thanks to 1-tetradecanol which act as a phase change material. The second objective of this study is to examine the performance characteristics of the microcapsules when applied to cotton fabric via the impregnation and exhaustion method. The visual photographs and colorimetric measurement results indicated that the fabrics treated with microcapsules exhibited thermochromic properties with both application methods. The performance of fabric (Fabric 2) treated with microcapsules by the exhaustion method was superior in terms of color change compared to fabric (Fabric 1) treated by the impregnation method. However, the T-history results demonstrated that the thermoregulation effect of Fabric 1 and Fabric 2 was comparable. The results of the air and water permeability tests on the fabrics indicated that both microcapsule application methods resulted in the pores of the fabrics being filled, thereby significantly reducing the permeability values. In addition, the bending rigidity of the fabrics increased with the addition of microcapsules to the fabrics, while the tear strength decreased. As a result, microcapsules can be effectively applied to cotton fabric by both methods. Moreover, the exhaustion method provided superior performance in relation to the affinity effect of the polymers forming the capsule wall structure against cotton cellulose molecules.

Antibacterial composite membranes were fabricated in this study through the utilization of the electrospinning technique, with the intention of employing it as a skin mask. The membranes, comprising polycaprolactone and gelatin, were used to provide mechanical support with bioactivity for the membranes. Salicylic acid was used in combination with algae and zinc oxide nanoparticles as ingredients for these membranes. The physical and chemical characteristics of the membranes were assessed and it was revealed that the membranes exhibited nanofibrous structure. Zinc oxide nanoparticles, salicylic acid and the microalgae Phaeodactylum tricornutum were integrated into a nanofibrous structure for the first time. In addition, the biodegradation quantity, salicylic acid release and zinc ion release profiles of the membranes showed their potential as antibacterial membranes. Moreover, there was no observed growth of E. coli and S. aureus on the membranes’ surface during the antibacterial studies. Overall, the findings from the study demonstrated that these electrospun membranes possess potential as skin masks due to their antibacterial properties.

This study evaluates the effect of different compression angles on the compression performance of carbon fiber-reinforced plastic (CFRP) thin-walled tubes. It explores the potential improvement of performance by aluminum foam filling. CFRP tubes with different wall thicknesses (1 mm, 1.5 mm, and 2 mm) were used in the experiments. Quasi-static compression tests were conducted at 0°, 15°, 30°, and 45° compression angles to investigate the effects of compression angle changes on the mechanical response and energy absorption characteristics of CFRP tubes. The experimental results showed that the compression angle significantly affected the damage mode, energy absorption (EA), specific energy absorption (SEA), peak crushing force (PCF), and collision force efficiency (CFE) of CFRP tubes. Under axial compression (0°), CFRP tubes display their highest energy absorption capacity and stability. However, as the compression angle increases, particularly up to 45°, there is a notable decline in the EA, SEA, PCF, and CFE. This decrease correlates with a rise in buckling and shear damage modes, which are characteristics of oblique compression. In addition, aluminum foam filling significantly improved CFRP tubes’ energy absorption efficiency and crashworthiness. Aluminum-filled CFRP tubes exhibited higher EA and CFE than unfilled tubes at all tested compression angles, especially at 0° compression angle, where aluminum-filled CFRP tubes with a wall thickness of 1.5 mm achieved 81.6% CFE. This result highlights the significant role of aluminum-filled foams in improving the performance of CFRP tubes.