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Self-cleaning surfaces are functional structures with application in smart textiles. In this study, self-cleaning cotton fabrics were fabricated by coating photocatalytic zinc oxide nanoparticles (ZnO NPs) on cotton surfaces, using a traditional dip-pad-dry-cure coating process. The coatings and ZnO content-dependent self-cleaning properties of the coated fabrics were investigated to evaluate their potential in practical application. The ZnO NP-coated cotton fabrics were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscopy, and thermogravimetric analysis. Methylene blue was used as a test contaminant to qualitatively assess the self-cleaning properties of the fabrics. The removal efficiency was determined for fabrics with different ZnO contents, under different solar irradiation times. Consecutive photocatalytic degradations were carried out to investigate the self-cleaning durability of the fabrics. This involved repeatedly contaminating the same fabric position and subsequent cleaning by photocatalytic degradation. The self-cleaning properties of the fabrics depended on their ZnO NP content. A higher wt% of ZnO NPs in the coated fabric resulted in more pronounced photocatalytic degradation than fabrics with a lower wt%. The self-cleaning performance of the higher wt% ZnO NP fabric decreased slightly after the third consecutive photocatalytic degradation. Results of wash fastness showed color removal after 10 times washing under light irradiation. Moreover, the ZnO NP-coated fabrics exhibited excellent ultraviolet blocking properties. These findings provide a potential model for the practical application of self-cleaning textiles.

Some textiles and apparel cannot be laundered, such as astronauts’ clothes on the space station, smart textiles that contain optical fiber electronic devices. Thus, self-cleaning technology can be considered as a potential technique that can be used to remove sebum, which is secreted by the human body, from such textiles and apparel. In this study, the photocatalytic self-cleaning properties of cotton fabrics coated with TiO2 nanoparticles were evaluated for their efficacy in removing the sebum that is transferred from human skin to the fabric. Cotton fabric was treated with four different weight ratios of the TiO2 photocatalyst, and the surface morphology, elemental composition, and thermogravimetric analysis were determined and evaluated. For the self-cleaning properties, the color changes of the photographic images and the differences in the colors were recorded and obtained using oleic acid as the pollutant and Oil Red O as the coloring agent before and after simulated sunlight irradiation. The results showed that, compared to 0 wt% coated fabric, the 20 wt% coated fabric decolorized in the shortest time, and it showed a higher initial speed in color difference. For the lower weight ratios, such as 1 wt%, much more time was required to obtain the same color difference as the 20 wt% coated fabric. It meant that increasing the weight ratio and irradiation time provided enhanced self-cleaning properties. In addition, Fourier Transform Infrared Spectroscopy (FTIR) spectra were evaluated in order to obtain a quantitative evaluation of the pollutants. Examination of the peaks of oleic acid clarified that the self-cleaning properties increased as the weight ratio and irradiation time increased. Moreover, results of the high performance liquid chromatography (HPLC) showed that besides 0 wt% coated fabric, it cannot detect the contaminant on the other samples after irradiation, which were found to concide with the results showed by FTIR. Based on this study, we found that the color changes from photographs and the colorimeter can be used as references, but they do not provide decisive evidence of degradation, especially for colorless pollutants. The FTIR spectra and liquid chromatography can be used to make decisive judgements concerning the self-cleaning properties of photocatalysis. The findings in this study identified a potential application for textiles and apparel that cannot be washed in liquid media, such as astronauts’ suits on the station, smart textiles for actuators and sensors.Graphic abstract

A fibrous flexible sensor, with its small size, minimally burdens the human body, ranking among the most user‐friendly flexible sensors. However, its application is often limited by damage caused by electrode movement, as flexible sensors are typically attached to joints, which can be greatly alleviated by placing the two electrodes on the same side. Inspired by the hydrogen bonds in the double‐helical structure of DNA, the double‐helical electrode design is commonly found and applied in fiber‐based batteries and supercapacitors into fibrous flexible sensors through coaxial wet‐spinning and further treatment. The double helical sensor exhibits high strength and maintains stable operation and is prepared under over 300% strain with gauge factors (GF) of 0.9, 39.5, and 349, respectively, in its working ranges. This unique single‐sided electrode structure also enabled applications such as water flow sensing. The sensor into a smart glove capable of real‐time is further integrated, five‐channel finger motion detection, and used a convolutional neural network (CNN)‐based machine learning algorithm to achieve 98.8% accuracy in recognizing six common gestures. This study provides a novel approach to optimize the electrode distribution in fiber‐based flexible sensors through an internally encapsulated double‐helical structure, making a significant contribution to the field of flexible sensing. By precisely tuning a coaxial wet‐spinning process, the delicate, fluffy core–shell fibers have been crafted. When two of these fibers are twisted together and subjected to controlled heat treatment, their surfaces seamlessly bond without damage, yielding a perfectly merged double‐helical fiber with an almost circular cross‐section. This innovative structure forms the single‐sided and dual‐electrode fiber‐based flexible sensors, offering unique applications.

This study focused on the m-Aramid/p-Aramid blend ratio of the fabrics, clarified the quantitative relationship between UV exposure and strength retention, and developed a mathematical model to calculate tensile strength from an arbitrary amount of UV exposure energy. The results of tensile strength tests before and after UV exposure showed that the decrease in tensile strength due to UV degradation depended on the combination of p-Aramid and m-Aramid blend percentages. Tensile strength for all blend ratios decreased exponentially with UV exposure energy and was within the range of results for fabrics with p-Aramid 100% and m-Aramid 100%. The retention fraction of tensile strength, which represents the tensile strength after UV exposure relative to the initial tensile strength, decreased exponentially with increasing the fraction of UV exposure energy for all fabrics used in this study. Fitting the retention fraction of tensile strength to the fraction of UV exposure energy, two groups of fabrics were classified based on m-Aramid blends of 40% or more and 60% or less. This model can predict the tensile strength of firefighter clothing fabrics that retain high mechanical strength when exposed to UV light and design the strength of firefighter clothing with consideration of degradation over time.

The interface between the active electronic and its osculatory target dominates the sensing response of high-sensitivity sensors. However, the interface properties are difficult to be adjusted and preserved owing to the limited strategies for surface engineering. In this work, inspired by nature frond leaf, a spatial multi-level nanofibrous membrane with grid-like microstructure of uniform distribution was fabricated, in which carboxylated carbon nanotubes (CCNTs)/poly(3,4-ethylenedioxythiophene) (PEDOT) was modified onto the surface of grid-like polyurethane (PU) nanofiber via the combination of metal mesh template, in situ polymerization and ultrasonic treatment. Nanofibrous membrane enables a pressure sensor with high sensitivities (5.13 kPa −1 ), fast response/recovery time (80 ms and 120 ms), and ultralow detection limit of 1 Pa. In addition, as a scalable and integrable platform, we also demonstrate its multifunctional applications for electro-thermal conversion and energy harvesting. All these results indicate the proposed nanofibrous membrane may potentially be applied to next-generation wearable devices.

In this study, a kind of honeycomb-structured woven fabric was investigated and the effect of yarn size and fabric layer on the compression property of the fabric-reinforced polyurethane elastomer composites was discussed. The honeycomb-structured fabric was analyzed from the cross-sectional view of combined regular hexagonal cells. The three-layer fabric and four-layer fabric were designed and fabricated using three different finenesses of weft yarns. After that, polyurethane elastomer was used as matrix resin and the 3D honeycomb-structured fabrics were composited. In-plane compression test was conducted to investigate the cushioning property. For samples with doubled weft yarns, such as 3L-2W, the stress value when compressed to 65% of its initial thickness (CV65%), energy absorption (EA), and specific energy absorption (SEA) showed higher values than 3L-1W and 3L-1.5W. It was concluded that the weft yarn fineness had an important effect on the compression property of fabric composites. The thicker yarn size, the stronger cell wall, and the lightweight honeycomb-structure composite was difficult to be compressed. As to the fabric layers, three-layer composites showed a higher compression property than four-layer ones. The reason for this was considered to be the fiber volume content, which was the key parameter affecting composite mechanical properties. As the real fiber volume content in a three-layer fabric composite was higher than that of a four-layer fabric composite, it was resulted in a higher allowable safe stress and energy absorption ability. It can be concluded that the yarn fineness and fabric layers had an influence on the compression property, which can be seemed as the design parameters of honeycomb-structured fabrics for cushion applications.

Hyperbranched polymer HSDA was synthesized from methyl acrylate, tetraethylenepentamine, and dodecanoic acid by melt polycondensation. ZnO nanoparticle colloidal solution was prepared in one step by mixing Zn(NO 3 ) 2 and HSDA aqueous solution under hydrothermal condition. The results of transmission electron microscopy and ultraviolet–visible (UV–Vis) spectroscopy indicated that ZnO nanoparticles were formed in colloidal solution. Bamboo pulp fabric was treated with ZnO nanoparticle colloidal solution by an impregnation method to provide the bamboo pulp fabric with antibacterial and UV protective properties. The whiteness, antibacterial activity, UV protective property, and washing durability of the ZnO nanoparticle-treated fabrics were determined. The results indicated that the bamboo pulp fabric treated with ZnO nanoparticles showed good UV protective properties and its ultraviolet protection factor (UPF) can reach 90.38. The UPF value of treated fabric drops to 70.42 after washing for 20 times, but it retains good UV protective properties. The ZnO nanoparticle-treated fabric showed 99.91 % bacterial reduction of Staphylococcus aureus and 99.97 % bacterial reduction of Escherichia coli . The fabric retained over 98.93 % reduction level even after being exposed to 20 consecutive home-laundering conditions. In addition, the results of scanning electron microscopy and X-ray spectroscopy confirmed that ZnO nanoparticles were fixed and well dispersed on bamboo pulp fabric.

High-performance yarns are widely used to produce protective fabrics, including stab-resistant materials. The most common approach to studying the mechanism of puncture prevention is to use simulation to assist analysis. However, the anisotropy of the yarn is often overlooked during simulation owing to various factors. In fact, there is a marked difference between the axial and radial properties of a yarn. This may lead to large errors in research. In the present study, a composite material with a grid structure for puncture analysis was designed to investigate the influence of yarn anisotropy on the accuracy of simulation results. The present study combined an actual experiment with a simulation. In the actual experiment, Kevlar yarn/epoxy resin was used to prepare a mesh composite with a spacing of 1 mm. In the simulation, a 1:1 simulation model of composite material was established using finite element software. A simulated puncture experiment was conducted based on the actual experimental conditions and material parameters. After considering yarn anisotropy, the simulation results were closer to the actual experimental results. The simulation revealed that the main failure modes of the mesh material were the fracture of the resin and the bending deformation of the yarns at the junctions, while the surrounding areas were almost unaffected.

Polyester is a popular class of material used in material engineering. With its 0.4% moisture regain, polyethylene terephthalate (PET) is classified as highly hydrophobic, which originates from its lack of polar groups on its backbone. This study used a parallel-plate nonthermal plasma dielectric barrier discharge system operating at medium pressure in dry air and nitrogen (N ) to alter the surface properties of PET fabrics to increase their hydrophilic capabilities. Water contact angle, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) were utilized to analyze any effect from the plasma treatment. The wettability analysis revealed a reduction in the contact angle of more than 80% within 5 min for both discharges. Scanning electron microscopy analysis showed no microscopic damage to the fiber structure, guaranteeing that the fabrics’ structural integrity was preserved after treatment. AFM analysis showed an increase in the nanometer roughness, which was considered beneficial because it increased the total surface area, further increasing the hydrophilic capacity. XPS analysis revealed a sharp increase in the presence of polar functional groups, indicating that the induced surface changes are mostly chemical in nature. Comparing that of untreated fabrics to treated fabrics, a Increase in water absorption capacity was observed for air-treated and N -treated fabrics, when these fabrics were used immediately after plasma exposure.

Wastewater has long been a highly important insurmountable problem in the textile industry. Since the rapid development of antimicrobial silver nanoparticle (AgNP)-coated textiles in the recent several decades, AgNP-containing wastewater produced in the finishing process has gradually posed a greater threat to the ecological environment than that by traditional organic dyes because of the former’s strong antimicrobial ability. Herein, we designed an environmentally friendly, energy-efficient, bottom-up nanocoating strategy for cotton fibers through the cooperative self-assembly of heterogeneous AgNPs functionalized by amino-terminated hyperbranched poly(amidoamine) (HBPAA) and hydroxyl-terminated hyperbranched poly(amine-ester) (HBPAE), respectively. The HBPAA-functionalized AgNPs possessed a positive surface charge of +40.8 mV and dense amino end groups, whereas the HBPAE-functionalized AgNPs had a slightly negative surface charge (−15.8 mV) and abundant OH end groups. Therefore, given the intermolecular recognition and interactions between HBPAA and HBPAE, the heterostructured AgNPs selectively co-precipitated on the natural fiber surfaces. Our scanning electron microscopy (SEM), field emission SEM, and X-ray photoelectron spectroscopy studies confirmed that the heterostructured AgNPs were uniformly anchored on the surface of the cotton fibers, indicative of their excellent physical and prolonged chemical stability. The coated cotton fibers showed excellent antibacterial activity. At the extremely low Ag content of 3 mg/g, the coated cotton fibers showed satisfactory antibacterial effects with over 99% antimicrobial rates. The developed cooperative self-assembly strategy demonstrated a nearly complete AgNP uptake by natural fibers and the ability to precisely control silver content. As such, the cooperative self-assembly method promises a high potential for practical production.