Recent Research on Preparation and Application of Smart Joule Heating Fabrics

Multifunctional wearable heaters have attracted much attention for their effective applications in personal thermal management and medical therapy. Compared to passive heating, Joule heating offers significant advantages in terms of reusability, reliable temperature control, and versatile coupling. Joule-heated fabrics make wearable electronics smarter. This review critically discusses recent advances in Joule-heated smart fabrics, focusing on various fabrication strategies based on material-structure synergy. Specifically, various applicable conductive materials with Joule heating effect are first summarized. Subsequently, different preparation methods for Joule heating fabrics are compared, and then their various applications in smart clothing, healthcare, and visual indication are discussed. Finally, the challenges faced in developing these smart Joule heating fabrics and their possible solutions are discussed.

Improving ultraviolet protection properties of cotton textiles using Zinc oxide (ZnO) nanomaterials: an approach for controlling occupational and environmental exposures

Ultraviolet (UV) radiation exposure is one of the most important risk factor among workers. it may stimulate health outcomes such as multiple skin injuries and blinding eye diseases. So, UV protection is mainly important for people who expose to it. Modification of cotton textiles by nanomaterials is a new approach to overcome this problem. So, the aim of this study is to review studies conducted on using ZnO nanoparticles for improving ultraviolet protection of cotton textiles. The search strategy was provided by cochrane guideline. 45 studies were regarded as appropriate. The results show that UPF for textiles has improved by coated ZnO. However, UPF was depended on the physicochemical characteristics of ZnO and textiles such as yarn structure, effect of woven fabric construction, fabric porosity, and impurity of textiles and laundering conditions. Also, plasma technology has improved UPF, it is recommended that more studies be done to achieve better results.

Fabric-Enhanced Vascular Graft with Hierarchical Structure for Promoting the Regeneration of Vascular Tissue

Natural blood vessels have completed functions, including elasticity, compliance, and excellent antithrombotic properties because of their mature structure. To replace damaged blood vessels, vascular grafts should perform these functions by simulating the natural vascular structures. Although the structures of natural blood vessels are thoroughly explored, constructing a small-diameter vascular graft that matches the mechanical and biological properties of natural blood vessels remains a challenge. A hierarchical vascular graft is fabricated by Electrospinning, Braiding, and Thermally induced phase separation (EBT) processes, which could simulate the structure of natural blood vessels. The internal electrospun structure facilitates the adhesion of endothelial cells, thereby accelerating endothelialization. The intermediate PLGA fabric exhibits excellent mechanical properties, which allow it to maintain its shape during long-term transplantation and prevent graft expansion. The external macroporous structure is beneficial for cell growth and infiltration. Blood vessel remodeling aims to combine a structure that promotes tissue regeneration with anti-inflammatory materials. The results in vitro demonstrated that it EBT vascular graft (EBTVG) has matched the mechanical properties, reliable cytocompatibility, and the strongest endothelialization in situ. The results in vitro and replacement of the resected artery in vivo suggest that the EBTVG combines different structural advantages with biomechanical properties and reliable biocompatibility, significantly promoting the stabilization and regeneration of vascular endothelial cells and vascular smooth muscle cells, as well as stabilizing the blood microenvironment.

Tri-Layered Bicomponent Microfilament Composite Fabric for Highly Efficient Cold Protection

Functional thin fabric with highly efficient cold protection properties are attracting the great attention of long-term dressing in a cold environment. Herein, a tri-layered bicomponent microfilament composite fabric comprised of a hydrophobic layer of PET/PA@C6 F13 bicomponent microfilament webs, an adhesive layer of LPET/PET fibrous web, and a fluffy-soft layer of PET/Cellulous fibrous web is designed and also successfully been fabricated through a facile process of dipping, combined with thermal belt bonding. The prepared samples exhibit a large resistance to wetting of alcohol, a high hydrostatic pressure of 5530 Pa, and brilliant water slipping properties, owing to the presence of dense micropores ranging from 25.1 to 70.3 µm, as well as to the smooth surface with an arithmetic mean deviation of surface roughness (Sa) ranging from 5.112 to 4.369 µm. Besides, the prepared samples exhibited good water vapor permeability, and a tunable CLO value ranging from 0.569 to 0.920, in addition to the fact that it exhibited a very suitable working temperature range of -5 °C to 15 °C. Additionally, it also showed excellent clothing tailorability including high mechanical strength with a remarkably soft texture and lightweight foldability that suitable for cold outdoor clothing applications.

All-In-One Evaporators for Efficient Solar-Driven Simultaneous Collection of Water and Electricity

The shortage of fossil fuels and freshwater resources has become a serious global issue. Using solar energy to extract clean water with a photothermal conversion technology is a green and sustainable desalination method. Integrated electricity generation during the desalination process maximizes energy utilization efficiency. Herein, a solar-driven steam and electricity generation (SSEG) system based on an all-in-one evaporator is prepared via a scalable technology. Carbon black is selected as the absorber for solar energy harvesting as well as the functional substance for simultaneous electricity generation. Fabric substrate with flexible structure, porous channel, and capillary effect is vital for directional brine supply, multiple solar absorption, and thermal management. The high evaporation rate (1.87 kg m-2  h-1 ) and voltage output (324 mV) can be achieved with an all-in-one device. The stable electricity output can be maintained over 40000 s. The SSEG performance remains constant after 15 operation cycles or 20 wash cycles. The integrated device balances excellent effectiveness and practicality, providing a viable path for clean desalination and electricity generation.

Multisensory Texture Perception in Individuals with Williams Syndrome

The sensory profile of people with Williams syndrome (WS) is characterised by atypical visual and auditory perceptions that affect their daily lives and learning. However, no research has been carried out on the haptic perception, in particular in multisensory (visual and haptic) situations. The aim of this study was to evaluate the communication of texture information from one modality to the other in people with WS. Children and adults with WS were included, as well as typically developing (TD) participants matched on chronological age (TD-CA), and TD children matched on mental age (TD-MA). All participants (N = 69) completed three matching tasks in which they had to compare two fabrics (same or different): visual, haptic and visuo-haptic. When the textures were different, the haptic and visual performances of people with WS were similar to those of TD-MA participants. Moreover, their visuo-haptic performances were lower than those of the two TD groups. These results suggest a delay in the acquisition of multisensory transfer abilities in individuals with WS. A positive link between MA and visual and visuo-haptic abilities only in people with WS suggests that they could benefit from an early intervention to develop their abilities to process and transfer multisensory information.

Extraction of the Microstructure of Wool Fabrics Based on Structure Tensor

The trends of "fashionalization", "personalization" and "customization" of wool fabrics have prompted the textile industry to change the original processing design based on the experience of engineers and trial production. In order to adapt to the promotion of intelligent production, the microstructure of wool fabrics is introduced into the finishing process. This article presents an automated method to extract the microstructure from the micro-CT data of woven wool fabrics. Firstly, image processing was performed on the 3D micro-CT images of the fabric. The raw grayscale data were converted into eigenvectors of the structure tensor to segment the individual yarns. These data were then used to calculate the three parameters of diameter, spacing and the path of the center points of the yarn for the microstructure. The experimental results showed that the proposed method was quite accurate and robust on woven single-ply tweed fabrics.

Stent-Graft Fabrics Incorporating a Specific Corona Ready to Fenestrate

In situ fenestration of endovascular stent-grafts has become a mainstream bailout technique to treat complex emergent aneurysms while maintaining native anatomical visceral and aortic arch blood supplies. Fabric tearing from creating the in situ fenestration using balloon angioplasty may extend beyond the intended diameter over time. Further tearing may result from the physiologic pulsatile motion at the branching site. A resultant endoleak at the fenestrated sites in stent-grafts could ultimately lead to re-pressurization of the aortic sac and, eventually, rupture. In an attempt to address this challenge, plain woven fabrics were designed. They hold a specific corona surrounding a square-shaped cluster with a plain weave fabric structure, a 2/2 twill, or a honeycomb. The corona was designed to stop potential further tearing of the fabric caused by the initial balloon angioplasty and stent or later post-implantation motion. The cluster within the corona was designed with relatively loose fabric structures (plain weave, 2/2 twill weave, and honeycomb) to facilitate the laser fenestration. Two commercial devices, Anaconda (Vascutek, Terumo Aortic) and Zenith TX2 (Cook), were selected as controls for comparison against this new design. All the specimens were characterized by morphology, thickness, and water permeability. The results demonstrated that all specimens with a low thickness and water permeability satisfied the requirements for a stent graft material that would be low profile and resistant to endoleaks. The in situ fenestrations were performed on all fabrics utilizing an Excimer laser followed by balloon angioplasty. The fabrics were further observed by light microscopy and scanning electron microscopy. The dimension of the fenestrated apertures was smaller than the balloon's diameter. The tearing was effectively confined within the corona. The clinical acceptability of this concept deserves additional bench testing and animal experimentation.

Construction of Wash-Resistant Photonic Crystal-Coated Fabrics based on Hydrogen Bonds and a Dynamically Cross-Linking Double-Network Structure

Structural coloration as the most possible way to realize the ecofriendly dying process for textiles or fabrics has attracted significant attention in the past decades. However, photonic crystals (PCs) are a typical example of materials with structural color usually located on the surface of the fabrics or textiles, which make them not stable when rubbed, bent, or washed due to the weak interaction between the PC coatings and fabrics. Here, double networks were constructed between the PC coatings and the fabrics for the first time via a hydrogen bond by introducing tannic acid (TA) and dynamic cross-linking with 2-formylphenylboronic acid to increase the wash resistance of the structural colored fabrics. On modifying the monodispersed SiO₂ nanoparticles, poly(dimethylsiloxane), and the fabrics, the interaction between the PC coatings and the fabrics increased by the formation of double networks. The structural color, wash, and rub resistance of the PC-coated fabrics were systematically studied. The obtained fabrics with the TA content at 0.030% (SiDT30) showed the best wash and rub resistance. The construction of double networks not only improved the wash and rub resistance of PCs but also retained the bright structural color of the PC coatings, facilitating the practical application of structural coloration in the textile industry.

Designing better cloth masks: The effect of fabric and attachment-style on discomfort

Cloth masks are a tool for controlling community transmission during pandemics, as well as during other outbreak situations. However, cloth masks vary in their designs, and the consequences of this variability for their effectiveness as source control have received little attention, particularly in terms of user discomfort and problematic mask-wearing behaviors. In the present studies, common design parameters of cloth masks were systematically varied to ascertain their effect(s) on the subjective discomfort and frequency of problematic mask-wearing behaviors, which detract from the effectiveness of cloth masks as source control. The type of fabric comprising a mask (flannel or twill made of 100% cotton) and the attachment-style of a mask (i.e., ear loops or fabric ties) were varied in adults (18 to 65 years) and children (ages 6 to 11 years). For adults, ear loops were less comfortable than ties (p = .035) and were associated with greater face- (p = .005) and mask-touching (p = .001). Children, however, found flannel masks to be more breathable than twill masks (p = .007) but touched their masks more frequently when wearing a mask made of flannel than twill (p = .033). Common design parameters of cloth masks not only affect user discomfort and behavior but do so differently in adults and children. To improve the effectiveness of cloth masks as source control, the present studies highlight the importance of measuring the effect(s) of design decisions on user discomfort and behavior in different populations.

Biomedical and Textile Applications of Alternanthera sessilis Leaf Extract Mediated Synthesis of Colloidal Silver Nanoparticle

The aqueous extract of Alternanthera sessilis (As) acts as the precursors for the quick reduction of silver ions, which leads to the formation of silver nanoparticles. In the agar, well diffusion method of the Klebsiella pneumoniae shows the minimal inhibitory concentration of 12 mm against A. sessilis mediated silver nanoparticles (As-AgNPs) at 60 µg/mL concentration. Fabric treated with novel AS-AgNPs is tested against the K. pneumoniae and shows an inhibitory action of 12 mm with mixed cotton that determines the antimicrobial efficacy of the fabrics. Uv- visible spectrophotometer was performed, showing a surface plasmon resonance peak at 450 nm cm^-1. FTIR shows the vibration and the infrared radiation at a specific wavelength of 500-4000 cm^-1. The HR-TEM analysis showed the presence of black-white crystalline, spherical-shaped As-AgNPs embedded on the fabrics range of 15 nm-40 nm. In the scanning electron microscope, the presence of small ball-shaped As-AgNPs embedded on the fabrics at a voltage of 30 KV was found with a magnification of 578X. EDAX was performed in which the nanoparticles show a peak of 2.6-3.9 KeV, and it also reveals the presence of the composition, distribution, and elemental mapping of the nanoparticles. The cytotoxic activity of synthesized nanosilver was carried out against L929 cell lines, which show cell viability at a concentration of 2.5 µg mL^-1. Cell proliferation assay shows no cytotoxicity against L929 cell lines for 24 h. In this study, the green synthesis of silver nanoparticles from A. sessilis appears to be a cheap, eco-friendly, and alternative approach for curing infectious ulcers on the floor of the stratum corneum. Nanotechnology conjoined with herbal therapeutics provides a promising solution for wound management.

A Brief Review on Factors Affecting the Tribological Interaction between Human Skin and Different Textile Materials

The application of tribology is not just limited to mechanical components of engineering systems. As a matter of fact, the understanding of friction and wear can be applied to everyday life. One of the important fields is skin tribology, as human skin interacts with various surfaces of different materials. This paper focuses on the friction behavior of the skin when in contact with the fabric and other materials in relative motion. The excessive friction at the fabric-skin interface may lead to discomfort, blistering, chafing, and pressure ulcers especially in athletes who experience higher friction due to rapid movement for an extended period. Other than understanding the fabric properties, it is equally important to understand the structure and properties of the skin to evaluate its function and interaction with the different fabric materials. The identification of the contributing factors of skin friction can help to design suitable fabric materials. An overview of skin functions and the factors that affect the friction on the skin-textile material interface are presented in this review article.

Controlling the Spreading of Nanoliter-Scale Droplets on the Fibers of Fabrics for Enhancing Image Quality and Ink Utilization

Electronic and traditional textiles have been widely manufactured through inkjet printing. However, nanoliter-scale ink droplets tend to excessively spread along the fiber direction, which results in poor image quality and low ink utilization. Here, hydroxyethyl cellulose (HEC) and hydroxypropyl methyl cellulose (HPMC) were introduced to control the spreading of nanoliter-scale droplets on cotton fabrics. The results showed that both HEC and HPMC could reduce the spreading of nanoliter droplets along the fibers through increasing the hydrophobicity of the fabric. However, the effect of HPMC was much better than that of HEC due to its higher surface activity. The flow of nanoliter droplets along the fibers was well consistent with the Washburn function. After HPMC treatment, the depositing length of one droplet reduced from beyond 200 μm to about 50 μm. The imaging quality was greatly improved. In addition, the dye utilization increased by 33-78% due to the decrease in the diffusion of dye solution to the back of the fabric. This study is of great significance for improving the quality of inkjet printing and the utilization of depositing materials, particularly expensive materials.

Fabrics Attached with Highly Efficient Aggregation-Induced Emission Photosensitizer: Toward Self-Antiviral Personal Protective Equipment

Personal protective equipment (PPE) is vital for the prevention and control of SARS-CoV-2. However, conventional PPEs lack virucidal capabilities and arbitrarily discarding used PPEs may cause a high risk for cross-contamination and environmental pollution. Recently reported photothermal or photodynamic-mediated self-sterilizing masks show bactericidal-virucidal abilities but have some inherent disadvantages, such as generating unbearable heat during the photothermal process or requiring additional ultraviolet light irradiation to inactivate pathogens, which limit their practical applications. Here, we report the fabrication of a series of fabrics (derived from various PPEs) with real-time self-antiviral capabilities, on the basis of a highly efficient aggregation-induced emission photosensitizer (namely, ASCP-TPA). ASCP-TPA possesses facile synthesis, excellent biocompatibility, and extremely high reactive oxygen species generation capacity, which significantly outperforms the traditional photosensitizers. Meanwhile, the ASCP-TPA-attached fabrics (ATaFs) show tremendous photodynamic inactivation effects against MHV-A59, a surrogate coronavirus of SARS-CoV-2. Upon ultralow-power white light irradiation (3.0 mW cm^-2), >99.999% virions (5 log) on the ATaFs are eliminated within 10 min. Such ultralow-power requirement and rapid virus-killing ability enable ATaFs-based PPEs to provide real-time protection for the wearers under indoor light irradiation. ATaFs' virucidal abilities are retained after 100 washings or continuous exposure to office light for 2 weeks, which offers the benefits of reusability and long-term usability. Furthermore, ATaFs show no toxicity to normal skin, even upon continuous high-power light illumination. This self-antiviral ATaFs-based strategy may also be applied to fight against other airborne pathogens and holds huge potential to alleviate global PPE supply shortages.

Current Status of Cellulosic and Nanocellulosic Materials for Oil Spill Cleanup

Recent developments in the application of lignocellulosic materials for oil spill removal are discussed in this review article. The types of lignocellulosic substrate material and their different chemical and physical modification strategies and basic preparation techniques are presented. The morphological features and the related separation mechanisms of the materials are summarized. The material types were classified into 3D-materials such as hydrophobic and oleophobic sponges and aerogels, or 2D-materials such as membranes, fabrics, films, and meshes. It was found that, particularly for 3D-materials, there is a clear correlation between the material properties, mainly porosity and density, and their absorption performance. Furthermore, it was shown that nanocellulosic precursors are not exclusively suitable to achieve competitive porosity and therefore absorption performance, but also bulk cellulose materials. This finding could lead to developments in cost- and energy-efficient production processes of future lignocellulosic oil spillage removal materials.

Experimental Evidence for the Optimal Design of a High-Performing Cloth Mask

Cloth masks can be an alternative to medical masks during pandemics. Recent studies have examined the performance of fabrics under various conditions; however, the performance against violent respiratory events such as human sneezes is yet to be explored. Accordingly, we present a comprehensive experimental study using sneezes by a healthy adult and a tailored image-based flow measurement diagnostic system evaluating all dimensions of protection of commonly available fabrics and their layered combinations: the respiratory droplet blocking efficiency, water resistance, and breathing resistance. Our results reveal that a well-designed cloth mask can outperform a three-layered surgical mask for such violent respiratory events. Specifically, increasing the number of layers significantly increases the droplet blocking efficiency, on average by ∼20 times per additional fabric layer. A minimum of three layers is necessary to resemble the droplet blocking performance of surgical masks, and a combination of cotton/linen (hydrophilic inner layer)-blends (middle layer)-polyester/nylon (hydrophobic outer layer) exhibited the best performance among overall indicators tested. In an optimum three-layered design, the average thread count should be greater than 200, and the porosity should be less than 2%. Furthermore, machine washing at 60 °C did not significantly impact the performance of cloth masks. These findings inform the design of high-performing homemade cloth masks.

Detection of suspected carcinogen azo dyes in textiles using thermogravimetric analysis

Textiles that are in direct contact with human skin are problematic due to the possibility of transferring the dyes or their aromatic amine metabolites through direct contact. 18 samples of women underwear panties of different colors and fabrics materials were examined for their content of azo dyes using thermogravimetric-gas chromatography-mass spectrometry (TGA-GCMS) technique. The nature of fabrics (cotton, nylon, and polyesters) was identified based on their unique thermogravimetric analyses (TGA) pattern. Aromatic amines produced from thermal degradation of the samples were identified using NIST mass spectra data base. Aniline was found in all samples regardless of their color or fabric composition. Black cotton textiles were characterized by the presence of diaminobenzene, red cotton sample showed the presence of 4-amino-3-nitrobenzene-1-sulfonic acid, blue cotton sample showed the presence of chlorobenzenediamine and chloroaniline, and purple cotton textiles showed the presence of 4-nitroaniline. All four purple nylon samples contained nitroaniline and biphenylamine, the three red nylon samples contained nitroaniline and methyldihydro-thiadiazole, the two pink samples showed the presence of chloro-2-(trifluoromethyl) anilinechloro- benzenediamine, the purple polyethylene sample show the presence of diphenyldiazene, and the brown polyester sample showed the presence of 2-amino-1,4-phenylene) dimethanol.[Formula: see text].

Soft like velvet and shiny like satin: Perceptual material signatures of fabrics depicted in 17th century paintings

Dutch 17th century painters were masters in depicting materials and their properties in a convincing way. Here, we studied the perception of the material signatures and key image features of different depicted fabrics, like satin and velvet. We also tested whether the perception of fabrics depicted in paintings related to local or global cues, by cropping the stimuli. In Experiment 1, roughness, warmth, softness, heaviness, hairiness, and shininess were rated for the stimuli shown either full figure or cropped. In the full figure, all attributes except shininess were rated higher for velvet, whereas shininess was rated higher for satin. This distinction was less clear in the cropped condition, and some properties were perceived significantly different between the two conditions. In Experiment 2 we tested whether this difference was due to the choice of the cropped area. On the basis of the results of Experiment 1, shininess and softness were rated for multiple crops from each fabric. Most crops from the same fabric differed significantly in shininess, but not in softness perception. Perceived shininess correlated positively with the mean luminance of the crops and the highlights' coverage. Experiment 1 showed that painted velvet and satin triggered distinct perceptions, indicative of robust material signatures of the two fabrics. The results of Experiment 2 suggest that the presence of local image cues affects the perception of optical properties like shininess, but not mechanical properties such as softness.

Factors influencing the filtration performance of homemade face masks

The outbreak of the COVID-19 pandemic is causing a shortage of personal protective equipment (PPE) across the world. As a public health response to control the pandemic, wearing homemade face coverings has been proven as a resort to protect both the wearer and others from droplets and aerosols transmission. Although aerosols and droplets can be removed through these non-medical materials with a series of filtration mechanisms, their filtration performances have not been evaluated in detail. Moreover, many factors, such as the fabric properties and the method of usage, also affect filtration performance. In this study, the size-dependent filtration performances of non-medical materials as candidates for face coverings were evaluated comprehensively. The flow resistance across these filter materials, an indicator of breathability, was also examined. The effect of materials properties, washing and drying cycles, and triboelectric effect on particle filtration was also studied. Results showed that the filtration efficiency varied considerably from 5-50% among fabrics materials due to the material properties, such as density and microscopic structure of the materials. Microfiber cloth demonstrated the highest efficiency among the tested materials. In general, fabric materials with higher grams per square meter (GSM) show higher particle filtration efficiency. The results on washing and drying fabric materials indicated decent reusability for fabric materials. The triboelectric charge could increase the filtration performance of the tested fabric materials, but this effect diminishes soon due to the dissipation of charges, meaning that triboelectric charging may not be effective in manufacturing homemade face coverings.

Earthworm-Inspired Ultradurable Superhydrophobic Fabrics from Adaptive Wrinkled Skin

Wrapped by periodically wrinkled skin, soft earthworm shows excellent robustness against sticky soil. Mimicking this deformation adaptability, here, we report an ultradurable superhydrophobic fabric by exploiting the formation of adaptive, soft wrinkled poly(dimethylsiloxane) (PDMS) skins. Uniform wrinkles are created on woven fabric fibers due to the surface instability of PDMS coating with a cross-linking gradient induced by Ar plasma treatment. Both the surface topography of wrinkles and the viscoelasticity of the underlying compliant layer to release stress endow the treated superhydrophobic fabrics with extraordinary durability, withstanding 800 standard laundries or 1000 rubbing cycles under 44.8 kPa. Additionally, superhydrophobic fabrics are self-healable after heating or plasma treatment. This insight of engineering soft skins with periodic submicron surface topography and gradient modulus provides a pathway for the design of ultradurable, multifunctional wearables.

Innovative textile structures designed to prevent type III endoleaks in endovascular stent-grafts

The damage caused to the fabric of endovascular stent-grafts most often occurs at the contact zones between the fabrics where they are attached to the apices of Z-shaped stents as a result of normal physiologic pulsatile movement within angulated vessels in vivo. Although design improvements were made over the years, the risks were not fully eliminated even with the newer M-shaped stent reconfiguration. In this study, we proposed to create and manufacture a novel fabric for stent-grafts with specifically designed reinforced zones to enhance resistance to fabric abrasion. These reinforced zones are set at the vicinity of the apices of the Z-shaped stents and between two adjacent Z-shaped stents where folding and pleating are commonly observed to occur in angulated vessels. Three innovative weaving structures with two different types of yarns and two controls were designed and prepared. Two commonly used commercial devices supported, respectively, with ringed stents, and Z-shaped stents were selected as the references for comparison. Textile structures including thickness, water permeability, mechanical properties, (more specifically tensile and bursting stress, as well as fatigue simulation) were tested on all fabrics. Compared to commercially available plain weaves, the fabrics with locally reinforced zones showed improved mechanical characteristics and fatigue resistant properties. A fabric designed with specifically reinforced zones has now clearly been shown to effectively reduce the abrasion caused by the apices of Z-shaped stents. However, further optimization may still be possible.

Flame-Retardant Systems Based on Chitosan and Its Derivatives: State of the Art and Perspectives

During the last decade, the utilization of chitin, and in par0ticular its deacetylated form, i.e., chitosan, for flame retardant purposes, has represented quite a novel and interesting application, very far from the established uses of this bio-sourced material. In this context, chitosan is a carbon source that can be successfully exploited, often in combination with intumescent products, in order to provide different polymer systems (namely, bulky materials, fabrics and foams) with high flame retardant (FR) features. Besides, this specific use of chitosan in flame retardance is well suited to a green and sustainable approach. This review aims to summarize the recent advances concerning the utilization of chitosan as a key component in the design of efficient flame retardant systems for different polymeric materials.

Germ-Free Mice Under Two-Layer Textiles Are Fully Protected From Bacteria in Sprayed Microdroplets: A Functional in vivo Test Method of Facemask/Filtration Materials

Several studies have measured the effectiveness of masks at retaining particles of various sizes in vitro. To identify a functional in vivo model, herein we used germ-free (GF) mice to test the effectiveness of textiles as filtration material and droplet barriers to complement available in vitro-based knowledge. Herein, we report a study conducted in vivo with bacteria-carrying microdroplets to determine to what extent household textiles prevent contamination of GF mice in their environment. Using a recently validated spray-simulation method (mimicking a sneeze), herein we first determined that combed-cotton textiles used as two-layer-barriers covering the mouse cages prevented the contamination of all GF animals when sprayed 10-20 bacterial-droplet units/cm2. In additional to exposure trials, the model showed that GF mice were again protected by the combed-cotton textile after the acute exposure to 10 times more droplets (20 "spray-sneezes", ~200 bacterial-droplet units/cm2). Overall, two-layer combed-cotton protected 100% of the GF mice from bacteria-carrying droplets (n = 20 exposure-events), which was significantly superior compared to 100% mouse contamination without textile coverage or when 95% partly covered (n = 18, Fisher-exact, p < 0.0001). Of relevance is that two different densities of cotton were equally effective (100%) in preventing contamination regardless of density (120-vs. 200 g/m2; T-test, p = 0.0028), suggesting that similar density materials could prevent droplet contamination. As a practical message, we conducted a speech trial (counting numbers, 1-100) with/without the protection of the same cotton textile used as face cover. The trial illustrated that contamination of surfaces occurs at a rate of >2-6 bacteria-carrying saliva-droplets per word (2.6 droplets/cm2, 30 cm) when speaking at 60-70 decibels and that cotton face covers fully prevent bacterial surface contamination.

Synthesis of Active Graphene with Para-Ester on Cotton Fabrics for Antistatic Properties

The excellent electrical properties of graphene provide a new functional finishing idea for fabricating conductive cotton fabrics with antistatic properties. This work develops a novel method for synthesizing active graphene to make cotton fabrics conductive and to have antistatic properties. The graphite was oxidized to graphene oxide (GO) by the Hummers method, and was further acid chlorinated and reacted with the para-ester to form the active graphene (JZGO). JZGO was then applied to cotton fabrics and was bonded to the fiber surface under alkaline conditions. Characterizations were done using FT-IR, XRD and Raman spectroscopy, which indicated that the para-ester group was successfully introduced onto JZGO, which also effectively improved the water dispersibility and reactivity of the JZGO. Furthermore, this study found that the antistatic properties of the fabric were increased by more than 50% when JZGO was 3% by weight under low-humidity conditions. The washing durability of the fabrics was also evaluated.

How long can nosocomial pathogens survive on textiles? A systematic review

Aims: Healthcare-associated infections linked to contaminated textiles are rare but underline their potential role as a source for transmission. The aim of the review was to summarize the experimental evidence on the survival and persistence of the different types of nosocomial pathogens on textiles.

Methods: A literature search was performed on MedLine. Original data on the survival of bacteria, mycobacteria, and fungi and persistence of viruses on textiles were evaluated.

Results: The survival of bacteria at room temperature was the longest on polyester (up to 206 days), whereas it was up to 90 days for some species on cotton and mixed fibers. Only low inocula of 100 CFU were found on all types of textiles with a short survival time of ≤3 days. Most bacterial species survived better at elevated air humidity. The infectivity of viruses on textiles is lost much faster at room temperature, typically within 2–4 weeks.

Conclusions: Contaminated textiles or fabrics may be a source of transmission for weeks. The presence of pathogens on the coats of healthcare workers is associated with the presence of pathogens on their hands, demonstrating the relevance of textile contamination in patient care.

Unique Thermal Properties of Clothing Materials

Cloth wearing seems so natural that everyone is self-deemed knowledgeable and has some expert opinions about it. However, to clearly explain the physics involved, and hence to make predictions for clothing design or selection, it turns out to be quite challenging even for experts. Cloth is a multiphased, porous, and anisotropic material system and usually in multilayers. The human body acts as an internal heat source in a clothing situation, thus forming a temperature gradient between body and ambient. But unlike ordinary engineering heat transfer problems, the sign of this gradient often changes as the ambient temperature varies. The human body also perspires and the sweat evaporates, an effective body cooling process via phase change. To bring all the variables into analysis quickly escalates into a formidable task. This work attempts to unravel the problem from a physics perspective, focusing on a few rarely noticed yet critically important mechanisms involved so as to offer a clearer and more accurate depiction of the principles in clothing thermal comfort.

Multifunctional Directional Water Transport Fabrics with Moisture Sensing Capability

Previous fabrics with directional fluid transport capability typically have a single function to transport liquid. Multifunctional directional fluid fabrics are highly desirable for making "smart" textiles but remain a challenge to develop. In this study, we have for the first time prepared a multifunctional, directional water transport fabric. By using a two-step coating process, we applied polypyrrole (PPy), a conducting polymer, on one side of a hydrophilic fabric (cotton). We showed that the single-side PPy-coated fabrics had reasonable conductivity (surface resistance in the range of 43-54 kΩ/□) and a one-way water transport function. We further showed that by integrating metal-plated nylon wires on the two sides, the fabric can be used as a capacitive sensor to sense water content in the fabric. The conducting layer enables the sensor device to have a sufficient capacitance response. Reasonable integration of the metal electrodes allows the device to have a minimal effect on the directional water transport and breathability of the fabric. Such a novel multifunctional fabric may find applications in making "smart" clothing.

Autocatalytic Metallization of Fabrics Using Si Ink, for Biosensors, Batteries and Energy Harvesting

Commercially available metal inks are mainly designed for planar substrates (for example, polyethylene terephthalate foils or ceramics), and they contain hydrophobic polymer binders that fill the pores in fabrics when printed, thus resulting in hydrophobic electrodes. Here, a low-cost binder-free method for the metallization of woven and nonwoven fabrics is presented that preserves the 3D structure and hydrophilicity of the substrate. Metals such as Au, Ag, and Pt are grown autocatalytically, using metal salts, inside the fibrous network of fabrics at room temperature in a two-step process, with a water-based silicon particle ink acting as precursor. Using this method, (patterned) metallized fabrics are being enabled to be produced with low electrical resistance (less than 3.5 Ω sq-1). In addition to fabrics, the method is also compatible with other 3D hydrophilic substrates such as nitrocellulose membranes. The versatility of this method is demonstrated by producing coil antennas for wireless energy harvesting, Ag-Zn batteries for energy storage, electrochemical biosensors for the detection of DNA/proteins, and as a substrate for optical sensing by surface enhanced Raman spectroscopy. In the future, this method of metallization may pave the way for new classes of high-performance devices using low-cost fabrics.

Recent Progress in Magnetron Sputtering Technology Used on Fabrics

The applications of magnetron sputtering technology on the surface coating of fabrics have attracted more and more attention from researchers. Over the past 15 years, researches on magnetron sputtering coated fabrics have been mainly focused on electromagnetic shielding, bacterial resistance, hydrophilic and hydrophobic properties and structural color etc. In this review, recent progress of the technology is discussed in detail, and the common target materials, technologies and functions and characterization of coated fabrics are summarized and analyzed. Finally, the existing problems and future prospects of this developing field are briefly proposed and discussed.

Superhydrophobic/Superhydrophilic Janus Fabrics Reducing Blood Loss

Hemostatic fabrics are most commonly used in baseline emergency treatment; however, the unnecessary blood loss due to the excessive blood absorption by traditional superhydrophilic fabrics is overlooked. Herein, for the first time, superhydrophobic/superhydrophilic Janus fabrics (superhydrophobic on one side and superhydrophilic on the other) are proposed: the superhydrophilic part absorbs water in the blood to expedite the clotting while the superhydrophobic part prevents blood from further permeating. Compared with the common counterparts, effective bleeding control with reducing blood loss more than 50% can be achieved while the breathability largely remain by using Janus fabrics. The proposed prototypes can even prolong the survival time in the rat model with serious bleeding. This strategy for reducing blood loss via simply tuning wettability is promising for the practical applications.

Preparation of 2D Carbon Materials by Chemical Carbonization of Cellulosic Materials to Avoid Thermal Decomposition

Cellulosic materials, including regenerated cellulose, are promising precursors for a variety of carbon materials. However, thermal decomposition, typically accompanying carbonization at high temperatures, hinders cellulosic materials from being efficiently carbonized (i.e., very low carbon yields). Herein, this study presents a new and efficient method for the preparation of porous 2D carbon materials from sheet-like cellulosic materials, such as papers and fabrics, involving a catalyzed chemical reaction at high temperatures without thermal decomposition. Thus, cellulosic materials are treated with sulfonic acid solutions and significantly dehydrated at high temperatures via evaporation of water. As a result, black materials are obtained at a weight near the theoretical carbon content of cellulose and remain in the carbonized materials. The as-obtained porous 2D carbon materials are flexible and suitable for a wide range of applications such as in electrodes and gas absorbents.

Argon-Plasma Reinforced Superamphiphobic Fabrics

A novel method for preparing durable superamphiphobic fabrics is reported, which involves preapplying a solution consisting of perfluoroalkyl acrylate, epoxide-containing silane, and silica nanoparticles onto fabric and subsequent argon-plasma treatment. The coated fabrics show superphobic to both water and oil fluids (surface tension >21.5 mN m^-1 ). The coating is durable to withstand repeated laundries and multicycles of abrasion without apparently altering the superamphiphobicity. The coating is also very stable in boiling water, strong acid, and base, but has little effect on the fabric handle and air permeability. The argon-plasma-enhanced coating may offer a facile way to prepare durable superamphiphobic fabrics.

Evaluation of anti‐bacterial activity of silver nanoparticles synthesised by coprophilous fungus PM0651419

The study explored biological synthesis of metallic silver nanoparticles (AgNPs) from the less explored non‐pathogenic coprophilous fungus, sterile mycelium, PM0651419 and evaluates the antimicrobial efficacy of biosynthesised AgNPs when impregnated in wound fabrics and in combination with six antimicrobial agents. AgNPs alone proved to be potent antibacterial agents and in combination they enhanced the antibacterial activity and spectrum of antibacterials used in the study against a microbiologically diverse battery of Gram positive, Gram negative and multidrug‐resistant bacteria. AgNPs impregnated on the wound dressings established their antibacterial activity by significantly reducing the bacterial load of pathogenic bacteria like Staphylococcus aureus and Bacillus subtilis e stablishing potential as effective antimicrobial wound dressings for treatment of polymicrobial wound infections. This study presents the first report on the potential of biosynthesis of AgNPs from the under explored class of coprophilous fungi. Their promise to be used in wound dressings and as potent antibacterials alone and in combination is evaluated

From air to clothing: characterizing the accumulation of semi-volatile organic compounds to fabrics in indoor environments

Uptake kinetics of semi-volatile organic compounds (SVOCs) present indoors, namely phthalates and halogenated flame retardants (HFRs), were characterized for cellulose-based cotton and rayon fabrics. Cotton and rayon showed similar accumulation of gas- and particle-phase SVOCs, when normalized to planar surface area. Accumulation was 3-10 times greater by rayon than cotton, when normalized to Brunauer-Emmett-Teller (BET) specific surface area which suggests that cotton could have a longer linear uptake phase than rayon. Linear uptake rates of eight consistently detected HFRs over 56 days of 0.35-0.92 m³ /day.dm² planar surface area and mass transfer coefficients of 1.5-3.8 m/h were statistically similar for cotton and rayon and similar to those for uptake to passive air sampling media. These results suggest air-side controlled uptake and that, on average, 2 m² of clothing typically worn by a person would sequester the equivalent of the chemical content in 100 m³ of air per day. Distribution coefficients between fabric and air (K') ranged from 6.5 to 7.7 (log K') and were within the range of partition coefficients measured for selected phthalates as reported in the literature. The distribution coefficients were similar for low molecular weight HFRs, and up to two orders of magnitude lower than the equilibrium partition coefficients estimated using the COSMO-RS model. Based on the COSMO-RS model, time to reach 95% of equilibrium for PBDEs between fabric and gas-phase compounds ranged from 0.1 to >10 years for low to high molecular weight HFRs.

Hesperetin-loaded lipid-core nanocapsules in polyamide: a new textile formulation for topical drug delivery

Chronic venous insufficiency is characterized by chronic reflux disorder of blood from the peripheral to the central vein, with subsequent venous hypertension and resulting changes in the skin. Traditionally, nonsurgical treatments relied on the use of compression therapy, and more recently a variety of flavonoids have been shown to have positive effects. There have also been developments of more effective drug delivery systems using various textiles and nanotechnology to provide new therapeutic options. Our objective was to use nanotechnology to develop a new formulation containing hesperetin (Hst), a substance not previously used in the treatment of chronic venous insufficiency, impregnated into textile fibers as a possible alternative treatment of venous diseases. We prepared the nanocapsules using the interfacial deposition of preformed polymer method with an Hst concentration of 0.5 mg/mL and then characterized the size and distribution of particles. To quantify the Hst in the samples, we developed an analytical method using high-performance liquid chromatography. Studies of encapsulation efficiency (98.81%±0.28%), microscopy, drug release (free-Hst: 104.96%±12.83%; lipid-core nanocapsule-Hst: 69.90%±1.33%), penetration/permeation, drug content (0.46±0.01 mg/mL) and the effect of washing the textile after drug impregnation were performed as part of the study. The results showed that nanoparticles of a suitable size and distribution with controlled release of the drug and penetration/permeation into the skin layers were achieved. Furthermore, it was established that polyamide was able to hold more of the drug, with a 2.54 times higher content than the cotton fiber; after one wash and after five washes, this relation was 2.80 times higher. In conclusion, this is a promising therapeutic alternative to be further studied in clinical trials.

Nature-Inspired Strategy toward Superhydrophobic Fabrics for Versatile Oil/Water Separation

Phytic acid, which is a naturally occurring component that is widely found in many plants, can strongly bond toxic mineral elements in the human body, because of its six phosphate groups. Some of the metal ions present the property of bonding with phytic acid to form insoluble coordination complexes aggregations, even at room temperature. Herein, a superhydrophobic cotton fabric was prepared using a novel and facile nature-inspired strategy that introduced phytic acid metal complex aggregations to generate rough hierarchical structures on a fabric surface, followed by PDMS modification. This superhydrophobic surface can be constructed not only on cotton fabric, but also on filter paper, polyethylene terephthalate (PET) fabric, and sponge. Ag^I, Fe^III, Ce^III, Zr^IV, and Sn^IV are very commendatory ions in our study. Taking phytic acid-Fe^III-based superhydrophobic fabric as an example, it showed excellent resistance to ultraviolet (UV) irradiation, high temperature, and organic solvent immersion, and it has good resistance to mechanical wear and abrasion. The superhydrophobic/superoleophilic fabric was successfully used to separate oil/water mixtures with separation efficiencies as high as 99.5%. We envision that these superantiwetting fabrics, modified with phytic acid-metal complexes and PDMS, are environmentally friendly, low cost, sustainable, and easy to scale up, and thereby exhibit great potentials in practical applications.

Directional Fluid Transport in Thin Porous Materials and its Functional Applications

Directional fluid motion driven by the surface property of solid substrate is highly desirable for manipulating microfluidic liquid and collecting water from humid air. Studies on such liquid motion have been confined to dense material surfaces such as flat panels and single filaments. Recently, directional fluid transport through the thickness of thin porous materials has been reported by several research groups. Their studies not only attract fundamental, experimental and theoretical interest but also open novel application opportunities. This review article summarizes research progress in directional fluid transport across thin porous materials. It focuses on the materials preparation, basic properties associated with directional fluid transport in thin porous media, and their application development. The porous substrates, type of transporting fluids, structure-property attributes, and possible directional fluid transport mechanism are discussed. A perspective for future development in this field is proposed.

Flame Retardant Polyamide Fibres: The Challenge of Minimising Flame Retardant Additive Contents with Added Nanoclays

This work shows that halogen-free, flame retarded polyamide 6 (PA6), fabrics may be produced in which component fibres still have acceptable tensile properties and low levels (preferably ≤10 wt %) of additives by incorporating a nanoclay along with two types of flame retardant formulations. The latter include (i) aluminium diethyl phosphinate (AlPi) at 10 wt %, known to work principally in the vapour phase and (ii) ammonium sulphamate (AS)/dipentaerythritol (DP) system present at 2.5 and 1 wt % respectively, believed to be condense phase active. The nanoclay chosen is an organically modified montmorillonite clay, Cloisite 25A. The effect of each additive system is analysed in terms of its ability to maximise both filament tensile properties relative to 100% PA6 and flame retardant behaviour of knitted fabrics in a vertical orientation. None of the AlPi-containing formulations achieved self-extinguishability, although the presence of nanoclay promoted lower burning and melt dripping rates. The AS/DP-containing formulations with total flame retardant levels of 5.5 wt % or less showed far superior properties and with nanoclay, showed fabric extinction times ≤ 39 s and reduced melt dripping. The tensile and flammability results, supported by thermogravimetric analysis, have been interpreted in terms of the mechanism of action of each flame retardant/nanoclay type.

Detection of azo dyes and aromatic amines in women undergarment

Women are exposed to several chemical additives including azo dyes that exist in textile materials, which are a potential health hazard for consumers. Our objective was to analyze suspected carcinogenic azo dyes and their degradation aromatic amines in women underwear panties using a fast and simple method for quantification. Here, we evaluated 120 different samples of women underwear for their potential release of aromatic amines to the skin. Seventy-four samples yielded low level mixtures of aromatic amines; however eighteen samples were found to produce greater than 200 mg/kg (ppm) of aromatic amines. Azo dyes in these 18 samples were extracted from the fabrics and analyzed by reverse phase thin layer chromatography in tandem with atmospheric pressure chemical ionization mass spectrometry. Eleven azo dyes were identified based on their mass spectral data and the chemical structure of the aromatic amine produced from these samples. We demonstrate that planar chromatography and mass spectrometry can be really helpful in confirming the identity of the azo dyes, offering highly relevant molecular information of the responsible compounds in the fabrics. With the growing concern about the consumer goods, analysis of aromatic amines in garments has become a highly important issue.

Nanotechnology in Textiles

Increasing customer demand for durable and functional apparel manufactured in a sustainable manner has created an opportunity for nanomaterials to be integrated into textile substrates. Nanomoieties can induce stain repellence, wrinkle-freeness, static elimination, and electrical conductivity to fibers without compromising their comfort and flexibility. Nanomaterials also offer a wider application potential to create connected garments that can sense and respond to external stimuli via electrical, color, or physiological signals. This review discusses electronic and photonic nanotechnologies that are integrated with textiles and shows their applications in displays, sensing, and drug release within the context of performance, durability, and connectivity. Risk factors including nanotoxicity, nanomaterial release during washing, and environmental impact of nanotextiles based on life cycle assessments have been evaluated. This review also provides an analysis of nanotechnology consolidation in the textiles market to evaluate global trends and patent coverage, supplemented by case studies of commercial products. Perceived limitations of nanotechnology in the textile industry and future directions are identified.

Bacterial Exchange in Household Washing Machines

Household washing machines (WMs) launder soiled clothes and textiles, but do not sterilize them. We investigated the microbial exchange occurring in five household WMs. Samples from a new cotton T-shirt were laundered together with a normal laundry load. Analyses were performed on the influent water and the ingoing cotton samples, as well as the greywater and the washed cotton samples. The number of living bacteria was generally not lower in the WM effluent water as compared to the influent water. The laundering process caused a microbial exchange of influent water bacteria, skin-, and clothes-related bacteria and biofilm-related bacteria in the WM. A variety of biofilm-producing bacteria were enriched in the effluent after laundering, although their presence in the cotton sample was low. Nearly all bacterial genera detected on the initial cotton sample were still present in the washed cotton samples. A selection for typical skin- and clothes-related microbial species occurred in the cotton samples after laundering. Accordingly, malodour-causing microbial species might be further distributed to other clothes. The bacteria on the ingoing textiles contributed for a large part to the microbiome found in the textiles after laundering.

Robust Polypropylene Fabrics Super-Repelling Various Liquids: A Simple, Rapid and Scalable Fabrication Method by Solvent Swelling

A simple, rapid (10 s) and scalable method to fabricate superhydrophobic polypropylene (PP) fabrics is developed by swelling the fabrics in cyclohexane/heptane mixture at 80 °C. The recrystallization of the swollen macromolecules on the fiber surface contributes to the formation of submicron protuberances, which increase the surface roughness dramatically and result in superhydrophobic behavior. The superhydrophobic PP fabrics possess excellent repellency to blood, urine, milk, coffee, and other common liquids, and show good durability and robustness, such as remarkable resistances to water penetration, abrasion, acidic/alkaline solution, and boiling water. The excellent comprehensive performance of the superhydrophobic PP fabrics indicates their potential applications as oil/water separation materials, protective garments, diaper pads, or other medical and health supplies. This simple, fast and low cost method operating at a relatively low temperature is superior to other reported techniques for fabricating superhydrophobic PP materials as far as large scale manufacturing is considered. Moreover, the proposed method is applicable for preparing superhydrophobic PP films and sheets as well.

One-step modification of fabrics with bioinspired polydopamine@octadecylamine nanocapsules for robust and healable self-cleaning performance

An in-situ polymerization to coat fabrics with polydopamine-encapsulated octadecylamine endows the fabrics with self-cleaning and self-healing abilities. The treated fabric exhibits self-healing after losing its hydrophobicity. It is durable against washing and mechanical abrasion without changing the hydrophobicity. Thanks to the versatile adhesive property of polydopamine, the approach is compatibile with a variety of substrates, such as fabrics, glass, sponge, paper, and polymeric materials.