Fibers and Polymers最新文献

Electrospun nanofibrous mats have shown great potential for dressing skin wounds. In this study, a nanofibrous mat composed of polycaprolactone (PCL), Gelatin (GLT), and Lucilia sericata larva extract (LSLE) was fabricated by the electrospinning method. The morphology of the fabricated nanofibrous mat and its morphological properties (fibers distribution frequency, fiber diameter, pore area, number of pores, and intersection density) were evaluated by scanning electron microscopy (SEM) and ImageJ software. The PCL/GLT/LSLE nanofibrous mat had well-branched and porous structure with a mean diameter of 500.2 ± 20.46. The presence of functional groups of PCL and GLT polymers in the structure of the PCL/GLT/LSLE mat was confirmed by Fourier-transform infrared spectroscopy (FTIR). Contact angle measurement and swelling behavior assessment showed that the PCL/GLT/LSLE mat had better surface wettability (75.67 ± 2.71) and hydrophilicity (241.8 ± 27.01) properties in comparison with the PCL and PCL/GLT mats. Findings from the MTT assay indicated the biocompatibility of the PCL/GLT/LSLE mat for human dermal fibroblasts (HDFs). In addition, the anchorage and proliferation of HDFs on the PCL/GLT/LSLE mat was confirmed by SEM. Macroscopic and histopathological evaluations were performed at the end of the 3, 7, and 14 days after the conduction of experimental burn wound injury in rats. The results indicated that grafting the skin wounds with the PCL/GLT/LSLE nanofibrous mat accelerated the wound closure and improved histopathological score compared to the other animal groups dressed with the PCL and PCL/GLT mats. In conclusion, the PCL/GLT/LSLE nanofibrous mat has promising potential for dressing skin wounds.

Graphical Abstract

With the global prevalence of infectious diseases, the development of antimicrobial textiles has become imperative. In this study, a synergistic antibacterial powder of IZnO–SCSB was obtained by modifying zinc oxide (ZnO) nanoparticles with 3-isocyanatopropyltriethoxysilane (IPTS) and chitosan cinnamaldehyde Schiff base (SCSB). The powder was then mixed with a PET solution and a PET/IZnO–SCSB composite antibacterial fiber membrane was prepared using electrospinning. This composite fiber membrane demonstrates excellent mechanical properties, breathability, hydrophobicity, and antibacterial effects. The tensile strength and elongation at break were 2.4 MPa and 240.9%, respectively. When the membrane was loaded with 3 wt% of IZnO–SCSB, the antimicrobial rates against Gram-positive (S. aureus) and Gram-negative (E. coli) reached 99.80% and 97.08%, respectively. Therefore, this composite antibacterial fiber membrane has broad application prospects in antibacterial textiles such as masks and medical gauze.

Energy harvesting through piezoelectric materials is considered an alternative to conventional power sources. Polyvinylidene fluoride (PVDF) is a piezoelectric material that has garnered significant attention from researchers. Blending PVDF with thermoplastic polyurethane can enhance its elastic properties. Numerous studies have successfully generated electric currents from piezoelectric materials by applying pressure and impact. This study, however, explores the generation of an electric current in piezoelectric materials by applying cyclic tensile loading. For this purpose, a tensile loading device was designed and built at the laboratory scale. Subsequently, a PVDF/PU polymer alloy layer (in a 25:75 ratio) was fabricated using the electrospinning method and installed in the loading device for testing. The results demonstrated that the electrical resistance decreased upon applying tension to the layer. Employing cyclic loading on the alloy layer resulted in an output voltage ranging between 3 and 9 mV, which confirmed the feasibility of energy harvesting from the polyblend layer. In a novel approach undertaken in this study, an electric current was generated by applying cyclic tensile loading, resulting in subsequent buckling. The potential energy harvesting mechanism from cyclic tensile loading and buckling is also elaborated upon. In addition, the study assessed and reported the effect of increasing the cyclic loading frequency on energy harvesting.

This study conducted a comprehensive assessment of the reliability of automobile glass-braid-reinforced polymer (GBRP) composite coil springs fabricated using a braiding technique. The evaluations encompassed durability, plastic deformation, and resistance to chipping, adhering to the industrial standards established for steel springs within the automobile industry. In addition, a method to evaluate the void distribution and impregnation rate is proposed to quantitatively evaluate the quality of the composite fabrication. A method for testing part of manufactured springs was developed using finite element analysis, and the validity of this testing method was confirmed through empirical testing. Upon completing the durability and plastic deformation examinations, the changes in the free height of the GBRP composite coil springs exceeded those of their steel counterparts by 47% and 162.5%, respectively. Notably, these tests revealed no discernible surface failures or fractures on the composite springs. To elucidate the changes in free height observed post-testing, scanning electron microscopy was employed to assess the incurred damage. Furthermore, results from the chipping resistance tests substantiated that the GBRP composite's safety attributes were not compromised by any surface damage.

Reactive dyes are widely used in the textile industry due to their versatility of shades, high wash fastness properties, and the ease of application. Dyeing properties such as exhaustion, substantivity, fixation, time to half dyeing, migration index and effect of metal salts were studied for a novel reactive dye (named RR_Na) synthesized with one vinylsulfone as reactive group. The aim of this study is to figure out the influence of the ultrafiltration process this dye went through on its aforementioned properties. It was found that the ultrafiltrated reactive dye shows higher exhaustion, substantivity, dye uptake than the original dye, which is attributed to the purification performed by the ultrafiltration process. The migration index is slightly lower for the ultrafiltrated dye which indicates that its mobility is lower, due to the possible formation of more covalent bonds between the dye and the substrate. The effect of metals (Fe, Co, Cu) was also studied and the color strength of the dyeings in the presence of sulfate salts was compared with the control sample. It was found that Co²⁺ and Cu²⁺ have a detrimental effect on the shade obtained, whereas Fe³⁺ reduces color strength to a lower extent.

Multifunctional cotton fabrics with antibacterial property and hydrophobicity were prepared using surface modification. Cotton fabrics were treated with the coating solution containing N-halamine compound poly[5,5-dimethyl-3-(3’-triethoxysilylpropyl) hydantoin] (PSPH) and TiO₂ nanoparticles, followed by treated with polydimethylsiloxane (PDMS) to reduce the surface energy of cotton fabrics. The prepared cotton fabrics were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS), and X-ray diffractometry (XRD). After chlorination, the prepared cotton fabrics exhibited excellent hydrophobicity with contact angle of 143°. The antibacterial results demonstrated that the prepared cotton fabrics had excellent antibacterial activity and could completely inactivate 4.54 cfu/sample of S.aureus and 4.92 cfu/sample of E. coli O157:H7 within 30 min of contact. The treated cotton fabrics also possessed robust stability under washing, UV light irradiation, and abrasion. Moreover, the breaking strength and air permeability of cotton fabric could maintain to the required values for practical application after treatment.

Edge effect is a common phenomenon in liquid composite molding (LCM), which has a significant impact on the performance of composite components. Plain-weave fabric is widely used in LCM process. Nevertheless, the yarns of plain-weave fabric in edge area are easy to shed which will cause the edge effect. Meanwhile, the current LCM process is non-isothermal, which the infiltration effect and curing efficiency are improved by heating the resin and the mold. Few systemic researches can be found in the edge effect of LCM process caused by shedding yarns under non-isothermal conditions. This article applied a method to calculate the permeability which considered the yarn shedding of plain-weave fabric. A non-isothermal rheological model of resin is established through resin viscosity and differential scanning calorimetry (DSC) experiments. A simulation model of the edge effect due to yarns shedding under non-isothermal conditions is proposed. This model divides the flow region into the central area, edge area and gap area. Simulation of edge effect is realized by setting three different permeability areas and combining them with the non-isothermal rheological model. Simulation results of edge effect are verified by the non-isothermal flow experiments.

Bioactive ceramics have gained increasing interest in biomedical applications. Strontium (Sr)-based ceramics show unique bioactivity in stimulating cell proliferation and migration and promoting angiogenesis. Incorporation of bioactive ceramics into nanofibers represents a facile approach to alter the material properties of electrospun nanofiber membranes. Herein, we prepared SrO-incorporated nanofiber membranes by electrospinning and investigated the effects of SrO particles on the physicochemical properties and cytocompatibility of these membranes. Our results indicate that simple one-stream electrospinning could smoothly introduce SrO particles into poly(L-lactic acid) (PLA)/gelatin nanofibers. SrO-incorporated membranes showed significantly improved wettability but became brittle compared with PLA/gelatin nanofiber membranes. Cells differentially responded to SrO-incorporated membranes: endothelial cells showed greater cell area and coverage on SrO-incorporated membranes; in contrast, fibroblasts were inhibited on these membranes. These findings suggest that SrO-incorporated membranes might find opportunities in specific biomedical applications in which pro-angiogenesis and antiadhesion are simultaneously demanded.

The spinnability of semi-dilute poly(p-phenylene-benzimidazole-terephthamide) (PBIA) spinning solution was regulated by a small amount of polyethylene glycol (PEG) to make it suitable for dry-jet wet spinning. The effects of different molecular weights and contents of PEG on the rheological properties and spinnability of PBIA spinning solution were investigated. Results show that the PBIA spinning solution with PEG 50,000 has the highest viscosity and the best spinnability, which can be smoothly spun by dry-jet wet spinning. The dynamic viscoelasticity study shows that the energy storage modulus and loss modulus of the PBIA spinning solution keeps increasing with PEG 50,000 and achieves the maximum value of 0.5% wt. The maximum draw ratio between the first roll and the spinneret (D_m) also reached a maximum value of 3.0 when the addition of PEG 50,000 reached 0.5% wt. Moreover, primary PBIA fibers prepared by dry-jet wet spinning and a higher draw ratio have a smoother surface appearance and better mechanical properties.

3D printing technology has been developing rapidly in recent years. This technology is extensively used for producing prototypes of products and their designs with a wide range of materials in the manufacturing industry. The Fused Deposition Modelling (FDM) process uses the extrusion of molten thermoplastic materials through heated printing nozzle to create design objects layer by layer. The current research was to develop 3D printing technology on textile fabrics to create surface design based on FDM process using the Ultimake 3D printer. Printing parameters play an important role for printing on fabrics specially to achieve strong adhesion between the printed patterns and the surface of the fabrics. This research developed a method for assessing the attachment strength in the interface between the printed objects and the surface of fabrics. The effect of the initial setting distance between the printing nozzle and the printing platform on the performance of 3D printed fabrics was investigated. The research work demonstrated the ability to create different design patterns in 3D on the fabrics with excellent durability to washing, which shows potential for the commercial application in fashion industry.