Fibers and Polymers最新文献

Combining phase change materials with textile materials is an important method to give textiles temperature regulation function. Herein, the microcapsulated phase change materials with ZnO@ZIF-8@SiO₂-doped polymethyl methacrylate (PMMA) as hybrid shell (ZZS/PMMA MPCMs) were prepared through Pickering emulsion polymerization with n-octadecane (C18) as core and ZnO@ZIF-8@SiO₂ grafted with polyacrylic acid (MZZS) particles possessing radiation cooling performance as stabilizers. The effect of MZZS content on the morphology of phase change microcapsule, radiation cooling and temperature regulation properties of coated cotton fabrics was studied. The results indicated that when the MZZS content increased to 3.0 wt%, the prepared phase change microcapsule’s encapsulation efficiency was 50.34%, showing excellent latent heat storage and release properties. Furthermore, compared with the uncoated cotton fabric, the rising and dropping rate of the temperature of ZZS/PMMA MPCMs coated cotton fabric was much slower in different seasons, indicating excellent radiation cooling and temperature regulation performance.

In this research, natural dyeing studies were conducted using indigo, and dyeability was compared using sodium hydroxide, calcium hydroxide, and calcium carbonate as bases. As a reducing agent, sodium hydrosulfite and glucose were compared. For a more environmentally friendly method, 3D-printed thermoplastic polyurethane (TPU) materials were dyed with natural indigo using glucose as the reducing agent and calcium hydroxide as the alkali. The dyeability of TPU materials was investigated under various conditions. The color fastness to light, rubbing, and washing of dyed 3D-printed TPU materials were investigated. At a 15 g/l glucose concentration and a 10 g/l calcium hydroxide concentration, the K/S value increased significantly, showing the color of the PB series. The K/S value tended to increase as dyeing temperature, dyeing time, and indigo dye concentration increased. However, the effect of indigo dye concentration was not significant, and there was no significant increase after the dyeing temperature was 90 °C and the dyeing time was 60 min. The color fastness to light was poor, but for washing and rubbing the fastness was good. Therefore, it was confirmed that more environmentally friendly 3D-printed TPU material dyeing is possible by indigo dyeing using glucose by replacing sodium hydrosulfite.

Due to the excellent energy-absorbing properties of the tubular structures, they are commonly used as energy-absorbing elements. In this paper, two types of hollow glass microspheres (HGMs) are mixed with epoxy resin to prepare composite foams. Three densities of composite foams were used as reinforcing materials for carbon fiber tubes (CFRTs). The CFRTs were reinforced with uniform and gradient structures (A, X, O). The axial compression tests were conducted under quasi-static loading to observe the mechanical properties, failure modes, and crashworthiness. The specific energy absorption (SEA) of the CFRTs reinforced with gradient structures to compare with metal energy-absorbing structures. The distribution and fragmentation of HGMs in the epoxy resin by were observed using a scanning electron microscope (SEM). The results show the C20/60 exhibits the highest peak force (PF) of 85.17 kN. Different types of composite foam and gradient designs have different effects on the structure’s failure modes, including tearing of the tube walls, shearing, and compression failure of the core. The SEM observed the HGMs of C20 are the most broken. The X-gradient composite foam-filled tube demonstrates superior crashworthiness compared to C20/60, except for the PF. The energy absorption (EA), SEA, meaning crushing force (MCF), and crushing force efficiency (CFE) have improved by 9.8%, 17.1%, 9.8%, and 25.9%, respectively. The SEA of X is higher than the aluminum round tube, the aluminum alloy secondary nested square tube, and the magnesium round tube, the value is 3.6, 2.7, and 1.3 times, respectively. Therefore, the composite foam-reinforced CFRTs are an ideal energy-absorbing configuration.

Flexible dielectrics and piezoelectric sensors have attracted a number of applications in advanced electronic systems. In this regard, poly(vinylidene fluoride) (PVDF) is considered as a promising option due to its flexibility and ferroelectric properties. In this study, a highly flexible non-woven fabric was developed from electrospun PVDF nanofibers containing cationic and anionic surfactants. Cetrimonium bromide (CTAB) was used as a cationic surfactant, while sodium lauryl sulfate (SLS) was used as an anionic surfactant. The presence of cationic and anionic surfactants played a pivotal role in the production of finer fibers. PVDF-SLS nano-fabric exhibited oriented fibers, while PVDF-CTAB nano-fabric displayed randomly arranged fibers. PVDF-SLS-based nano-fabric displayed the highest β-phase content of 98.2%, while PVDF-CTAB non-woven showed a β-phase content of 91.6%. A significant improvement in the dielectric properties of PVDF nano-fabric was observed upon the addition of cationic and anionic surfactants. Furthermore, PVDF-SLS nano-fabric demonstrated exceptional dielectric and piezoelectric properties, generating a piezoelectric voltage of ~ 19 V. In comparison, PVDF-CTAB nano-fabric exhibited a piezoelectric voltage of 12.5 V. The power density of PVDF improved significantly upon the addition of SLS surfactant. Such attributes position PVDF-SLS nanofabrics as valuable candidates for diverse applications, particularly in the field of piezoelectric sensors and energy storage devices. The research not only advances the understanding of optimizing PVDF nanofabrics, but also establishes a foundation for future exploration in the realm of flexible electronics.

Graphical Abstract

Centrifugal spinning has demonstrated to be one of the effective techniques for the preparation of micro-/nanofibers. It is utilizing centrifugal force to extrude polymer solution/melt out of the nozzle and form a serious of stretching jets. Then, the micro-/nanofibers were formed after the evaporation of the solvent or drop down of jet temperature during jets stretching process. In the process, the structure of spinneret and the flow field of gas outside of spinneret has a great influence on fiber formation and quality. Therefore, the motion mechanism of spinning fluid in spinnerets and nozzles with different structures is studied in this paper. Based on the experimental analysis of fiber spinnability, the motion equation and wave equation of polymer jet in space Cartesian coordinate system are derived, and the two-dimensional flow field of polymer solution is analyzed. Through the simulation of the motion mechanism of the solution in different nozzles and the gas flow field outside different spinnerets, the optimal structure of the spinnerets and nozzles is determined. In addition, the effects of solution properties, rotation speed and nozzle diameter on the fiber morphology are analyzed. Results showed that spinneret of nozzle-free expressed more uniform flow field and were suitable for the preparation of highly oriented micro-/nanofibers. The spinneret with nozzles presented a more turbulent flow field, while fibers with smaller diameters and more uniform distribution could be obtained. The structure of nozzle had a greatly influence on fiber diameters, distribution of fiber diameters, and fiber morphology.

Polyester is extensively used in the textile industry for fabricating fibers and fabrics. Dyeing for polyester fabrics has a huge demand. Given that dyeing is one of the least environmentally friendly industrial processes, decreasing the attempts for dyeing (a.k.a realizing “one-shot” successful dyeing) is of vital importance to the dyeing manufacturing for polyester fabrics. This can be achieved by accurately predicting the dye concentrations for a dyeing recipe with provided target color information on the polyester fabrics. In this paper, we report a data-driven approach for accurately predicting industrial dyeing recipes of polyester fabrics. We intensively discuss the data preprocessing skills for this purpose. We show that log-transform and using full reflectance spectra for the color as input are two effective preprocessing techniques to improve the model performance. An effective model based on gradient-boosting regression tree (GBRT) has been developed to quantitatively model the relationship between the colorimetric information and the dye concentrations of industrial dyeing data of polyester fabrics. The developed approach can predict dye concentrations for dyeing tasks for polyester fabrics with error at 10–20%.

In the current study, a novel wound dressing material for an effective wound healing was developed by loading Uridine (URD), an endogenous compound known for its regenerative properties, into polycaprolactone (PCL) nanofibers. Initially, PCL nanofibers without URD were fabricated from different PCL solutions (7, 8, 10 and 11% w/w) by electrospinning and optimum PCL concentration (10% w/w) for URD loading was determined. After loading URD at different concentrations (0.1, 0.5 and 1% w/w) into 10% PCL solution, PCL/URD nanofibers were electrospun. Structural characteristics, release kinetics as well as in vitro and in vivo effects of the PCL/URD nanofibers were studied and in vivo effects were compared with a conventional wound dressing material. Loading URD increased nanofiber diameters from 248 to 509 nm and decreased contact angles from 123.76° to 94.3° with increasing URD concentrations. URD showed a burst release in the first 60 min following a more gradual release up to the 5th day which best fitted with Korsmeyer–Peppas model. PCL/URD mats provided enhanced viability in vitro in MTT assay using mouse L929 fibroblast cell line. Furthermore, in vivo wound closure studies revealed an immediate and robust wound healing in rats treated with PCL/URD mats compared to PCL mats without URD as well as the conventional wound dressing material. These data suggest that URD-loaded PCL nanofiber mats are promising materials as wound dressing.

Graphical abstract

Currently, the dyeing processes between natural fibers and dyes heavily rely on inorganic electrolytes, posing significant challenges to ecological and sustainable development. In this work, zinc ion was used to modify the surface of Angora wool through high-voltage electrospray technology (HVET), aiming to enhance the binding capacity with natural dyes. The optimized zinc ion dosage and the treatment voltage have been explored and determined as 6% o.w.f and 25 kV. In addition, tannic acid, as a mordant, was implemented to achieve the complete coordination of metal ions while also imparting antibacterial properties to the fabric (above 90% of bacterial reduction). Thanks to the synergistic effect between zinc ions and tannic acid, the dyeing performances of modified Angora wool has been significantly improved. Density functional theory (DFT) calculations further support that the introduction of zinc ions enhances the reactivity of the modified fibers and lowers the energy barrier of dyeing reactions. The dyeing rate, the dyeing depth, and the dyeing fastness of the modified fabric/gardenia yellow dyes optimized can reach to 66.9%, 4.7, and grade 4–5, which is much better than untreated fibers.

Colorful nanofiber membranes applied to wearable textiles and products with the direct waterless dope dyeing method are gaining a lot of interest in the research area. However, the challenge remains to produce it with a less chemical and easier process. The study analyzed the mechanical strength and colorimetric properties of thermoplastic polyurethane (TPU) colorful nanofibers by varying the electrospinning machine parameters and variables. TPU and dye content were implemented within the specified range of 0.015–0.035 wt% and 0.0015–0.0045 wt% accordingly. The electrospinning parameters were varied at the distance of 5–20 cm, the fiber collection drum was fixed at 250 RPM, the feed rate was constant at 1–2 mL/h, and the applied voltage was not fixed; it was adjusted by understanding the solution viscosity, temperature, and humidity. The voltage range was 12–22 kV. The TPU 0.25 wt% sample showed smooth and less bead morphology and the colorfastness to wash, rub, perspiration, light, and laundry result showed excellence for most of the samples, and the mechanical strength was up to 9.8 MPa, which was acceptable for commercial decorative applications compared to pure TPU. Two printing techniques were utilized: pigment print, which is a flat-screen 1D print, and high-density pigment print, which is a kind of 3D printing. It will enhance the aesthetic appearance of the membrane. This printed membrane was stitched into t-shirts and fashion accessories. The first aim was to make colorful nanofiber using the dope dyeing method in an electrospinning machine; the second purpose was to apply 1D and 3D printing to the colorful nanofiber membrane; and the third objective was to sew the printed colorful nanofiber into commercial apparel and accessories for the common consumer. This work may open a new path for nanofiber colorful dyeing with low cost and energy resources, and it may promote waterless dyeing for wearable printed textiles, decorative products, and accessories.

Hydrogel fibers that can be raided possess considerable promise in the realm of flexible electronic gadgets, as they exhibit both exceptional durability and excellent conductivity. Using a continuous coaxial wet-spinning method, we have created a hydrogel long fiber with a core-sheath structure that is both strong, conductive, frost-resistant, and braidable. Hydroxymethylpropyl cellulose (HPMC) added lowconcentration polyvinyl alcohol (PVA) toform the core layer of the fiber he sheaths made of highconcentration PVA. Next, the fibers are submerged in a sodium chloride solution to create PVA@PVA-HPMC hydrogel fibers that exhibit remarkable tensile strength (6.7 MPa), extensive elongation (450%), excellent electrical conductivity (9.23 S/m), and exceptional resistance to freezing temperatures (below −20 °C). The hydrogel fibers are further encapsulated using PSPI copolymers to enhance their environmental stability. Finally, the PVA@PVA-HPMC fibers are applied as flexible sensors to detect human joint movements, and assembled into e-textiles to monitor the positional distribution of pressure.