The presented review summarizes recent studies in the field of electro conductive textiles as an essential part of lightweight and flexible textile-based electronics (so called e-textiles), with the ...main focus on a relatively simple and low-cost dip-coating technique that can easily be integrated into an existing textile finishing plant. Herein, numerous electro conductive compounds are discussed, including intrinsically conductive polymers, carbon-based materials, metal, and metal-based nanomaterials, as well as their combinations, with their advantages and drawbacks in contributing to the sectors of healthcare, military, security, fitness, entertainment, environmental, and fashion, for applications such as energy harvesting, energy storage, real-time health and human motion monitoring, personal thermal management, Electromagnetic Interference (EMI) shielding, wireless communication, light emitting, tracking, etc. The greatest challenge is related to the wash and wear durability of the conductive compounds and their unreduced performance during the textiles’ lifetimes, which includes the action of water, high temperature, detergents, mechanical forces, repeated bending, rubbing, sweat, etc. Besides electrical conductivity, the applied compounds also influence the physical-mechanical, optical, morphological, and comfort properties of textiles, depending on the type and concentration of the compound, the number of applied layers, the process parameters, as well as additional protective coatings. Finally, the sustainability and end-of-life of e-textiles are critically discussed in terms of the circular economy and eco-design, since these aspects are mainly neglected, although e-textile’ waste could become a huge problem in the future when their mass production starts.
In the present study, cotton (Co) and polyester (PES) fabrics were screen-printed with a conductive poly3,4-ethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS) printing paste along with a ...commercially-available screen-printing binder (SFXC) or waterborne polyurethane resin (WPU), in order to enhance wash and wear durability, and to improve some functional properties, without essentially influencing the physical–mechanical properties of the base material, as well as the introduced fabrics’ conductivity. The application of a conductive polymer coating reduced transmittance in the whole UV region drastically, indicating good UV-shielding ability in the treated fabrics. Moreover, the employed binders improved the fabrics’ protection against harmful solar UV radiation significantly, depending on the type of fibre and binder. Furthermore, the SFXC binder intensified the hydrophobicity of Co as compared to the WPU binder, and, on the other hand, WPU reduced the hydrophobicity of PES. Finally, the screen-printed fabrics were washed up to 20 cycles and rubbed up to 20,000 cycles, and characterised by means of mass loss determination and electrical resistivity measurement. Both binders enlarged polymer stability against the effect of washing and rubbing, depending on the number of cycles, the type and amount of employed binder, the type of fibres, and the thickness and uniformity of coatings.
The presented study assesses the efficiency of selected adsorbents, zeolite 4A in two particle sizes and pelletized activated carbon (AC), for the potential removal of color, chemical oxygen demand ...(COD), total organic carbon (TOC) and metals from wastewaters after natural wool dyeing. Firstly, the natural coloring compounds were extracted from dried common walnut (
) leaves and used further for exhaustion dyeing of wool fibers, together with three different metallic salts in two concentrations (meta-mordanting). Effluents with higher mordant concentration were additionally treated according to a shake-flask adsorption experiment. The obtained results revealed efficient removal of exceeded metallic ions by zeolite (up to 94.7%), on account of their superior ion exchange capability as compared to AC. The zeolites also reduced turbidity and electrical conductivity significantly. On the other hand, AC was more efficient for the reduction in organic pollution, COD up to 96% and TOC up to 95%, due to its higher specific surface area and total pore volume, and, thus, higher potential for adsorption of different compounds in comparison to 4A. All three proposed adsorbents lowered wastewaters' coloration remarkably, up to 78% (AC) and up to 71% (4A), depending on the type of effluent/mordant and inspected wavelength; although, the spectral absorbance coefficient (SAC) values remained highly above the limit values for discharge of wastewaters into watercourses.
The rapid growth in wearable technology has recently stimulated the development of conductive textiles for broad application purposes, i.e., wearable electronics, heat generators, sensors, ...electromagnetic interference (EMI) shielding, optoelectronic and photonics. Textile material, which was always considered just as the interface between the wearer and the environment, now plays a more active role in different sectors, such as sport, healthcare, security, entertainment, military, and technical sectors, etc. This expansion in applied development of e-textiles is governed by a vast amount of research work conducted by increasingly interdisciplinary teams and presented systematic review highlights and assesses, in a comprehensive manner, recent research in the field of conductive textiles and their potential application for wearable electronics (so called e-textiles), as well as development of advanced application techniques to obtain conductivity, with emphasis on metal-containing coatings. Furthermore, an overview of protective compounds was provided, which are suitable for the protection of metallized textile surfaces against corrosion, mechanical forces, abrasion, and other external factors, influencing negatively on the adhesion and durability of the conductive layers during textiles’ lifetime (wear and care). The challenges, drawbacks and further opportunities in these fields are also discussed critically.
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•Zeolites included in the nanofibers increased the adsorption capacity of model VOC.•Silicalite type of zeolite adsorbed 60 % higher amount of model VOC.•Up-scaling of the process ...with a 150 fold increase of formed CA/UHSZ nanofibers.•Diffusion of ammonia vapours is not influenced by the structure of the material.
The optimized preparation of novel electrospun nanofibrous composites from cellulose acetate (CA) and ultra-high silica zeolites (UHSZ) are reported as a promising material for the adsorption of Volatile Organic Compound (VOCs). Two types of UHSZs, i.e. silicalite and USY were prepared by hydrothermal crystallization while the fabrication of composites was performed using single needle and needle-less electrospinning systems, demonstrating the scalability of the composite fibres’ manufactured. Herein, factors such as properties of spinning solutions and electrospinning process parameters were studied, as well as interactions between the CA and UHSZs. In addition, Quartz Crystal Microbalance - Dissipation technique (QCM-D) was employed with an aim to study the adsorption behaviour of newly developed composites using ammonia as a model pollutant. The QCM-D data revealed that the presence of UHSZs in the CA materials increased adsorption capacity, designating CA/UHSZ composites as potential materials suitable for a large-scale removal of VOCs from polluted air.
The aim of the presented study was to evaluate the release of the enzymatically initiated production of hexanal from double emulsion electrospun bio-active membranes at a temperature of fruit ...storage. Among different formulations of water-in-oil (W1/O) primary emulsions, the emulsion composed of 12% w/v Tween20 and 0.1 M NaCl in water (W1) and 6% of poly(glycerol) poly(ricinoleate) dissolved in sunflower oil (O) using W1/O ratio of 80/20 (w/w) (Tween20-NaCl/6% PGPR) was selected, for further incorporation of enzymes, based on the lowest average droplet size (391.0 ± 15.6 nm), low polydispersity index (0.255 ± 0.07), and good gravitational stability also after 14 days. Both enzymes, lipase and lipoxygenase are needed to produce hexanal (up to 58 mg/L). Additionally, double emulsions were prepared with sufficient conductivity and viscosity using different W1/O to W2 ratios for electrospinning. From the selected electrospun membrane, up to 4.5 mg/L of hexanal was released even after 92 days.
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•Stable primary emulsion was prepared from Tween20/NaCl in water (W1) and 6% PGPR in edible oil (O).•Enzymes were incorporated into W1/O emulsion from which double emulsions were prepared.•Electrospun bio-active membranes were fabricated using needle-less semi-industrial device.•Hexanal was produced from edible oil by enzyme catalysis at a temperature of fruit storage.•4.6 mg/L of hexanal was released from the electrospun membrane even after 92 days.
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•CNF/LS/CaCl2 composite membranes are formed by a dispersion casting procedure.•The addition of CaCl2 reduces the ζ potential and promotes the aggregation of CNF.•The addition of ...CaCl2 promotes LS deposition on CNFs already in dispersion phase.•Composite membranes provide excellent passive flame retardancy.•LS component contribute for up to 100 % UVA/UVB shielding capacity.
The use of biomass to produce value-adding materials is a core objective of the circular economy, which has attracted great research interest in recent decades. In this context, we present here a simple dispersion-casting process for consolidation of cellulose nanofibrils (CNF), lignosulphonate (LS)-rich bio-waste and CaCl2 in composite membranes. The addition of CaCl2 to CNF and LS dispersions reduces the ζ potential, due to an electrostatic screening, which promotes the aggregation of CNF, increases its moisture content and promotes LS deposition on CNFs already in the dispersion phase. Addition of both the LS and CaCl2 to CNF dispersion has an adverse effect on the mechanical properties of the final membranes. The effectiveness of the new composite membranes has been described in terms of their passive (charring) flame retardancy and 100 % UVA/UVB shielding capacity, both identified for membranes with the highest LS content, as well as high electronic resistance.
Three industrially-prepared (via the sulphate synthesis process) and commercially-available nanoTiO2 colloidal suspensions were coated on polyester fabric using the conventional pad-dry-cure ...procedure, in order to enhance fabric functionalities by imparting self-cleaning and UV-protection ability. Various characterization techniques, i.e. transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and UV/Vis spectroscopy of the suspensions revealed the presence of anatase TiO2 spherical-shaped nanoparticles of different crystallite sizes, as well as its prominent absorption capacity within the UV region. Scanning electron microscopy (SEM) was adopted to analyse the morphological structure of nanoTiO2-modified PES fabrics. Furthermore, the photocatalytic activity was investigated through the discolourations of red wine and red beet stains under two types of light sources, i.e. direct day light and artificial UV light, by means of a spectrophotometry. The UV-protective properties were also evaluated by calculating the ultraviolet protective factors of individual coated fabric. The obtained results show acceptable blocking properties against UV-rays, as well as the adequate self-cleaning abilities of TiO2-modified PES fabrics as governed by the types and concentrations of applied TiO2 suspension.
•Functional modification of PES fabric was carried-out by pad-dry-cure procedure.•Industrially prepared nano-sized TiO2 in the form of colloidal suspensions were used.•Only diffraction peaks of anatase phase were observed from XRD in used suspensions.•Spherical TiO2 nanoparticles with different crystallite size were detected by TEM.•Polycrystalline TiO2 displayed superior photocatalytic and UV shielding ability.
Novel multifunctional bio-based nanofibrous mats were prepared which contain the commonly used pain reducing local anesthetic benzocaine (BZC) and the in situ pH-detecting dye bromocresol green ...(BCG). These can serve as a dual nano-carrier system for wound healing applications, especially in the treatment of infected wounds. BZC and BCG were introduced into cellulose acetate (CA) based nanofibers using a single-step needleless electrospinning process. The resulting CA nanofibers show a homogenous fiber diameter distribution around 600 nm, hydrophobicity with a water contact angle of 134°, and simultaneous porosities on the nano-micro- scale. In spite of their hydrophobic character, the nanofibrous mats showed a huge water absorption capacity (1657%), as well as good stability at physiological pH (negligible degradation). All the mentioned properties remain unchanged upon the inclusion of either BZC or BCG. Results from the in vitro drug release studies showed a pH dependent (i.e. controllable) release of BZC, and confirmed the expected maximum drug release rate at pH 9.0, which would correspond clinically to the pH of an infected wound. The accompanying color change of the nanofibrous mats, provided through the encapsulated BCG (from yellow to blue), is noticeable within a few seconds after the pH changes from acidic to alkaline. This rapid response of NSAID, together with the visible absorption of included dye, show the capacity of the proposed nanofibrous mats as an in situ pH-detecting system. Finally, the biocompatibility of the proposed nanofibrous mats was proven using human skin fibroblast cells, confirming their potential to be used in wound treatment.
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The main objective of the presented research was to study the possibility of using natural colourants obtained through the aqueous extraction of fresh leaves from the Junglans regia (J. regia), or ...common walnut tree, for the dyeing of wool yarn. A unique principle was explored by combining the phases of extraction and mordanting into one with the aim of shortening the dyeing procedure, while at the same time extracting more colouring components. Spectrophotometric studies revealed the signifi cant impact of both mordant addition and dye-bath pH on the absorbance curve and thus on the colour and K/S values of the dyed samples. A meta-ordanting technique using ferrous sulphate produced a greater depth of shade at a wavelength of 400 nm, with respect to the concentration of mordant and the liquid ratio of the extraction. Finally, wool yarn dyed with pure leaf extracts exhibited a potent inhibiting activity against Candida albicans (C. albicans) with a moderate reduction rate of 59%, and an inhibited response against Staphylococcus aureus (S. aureus) with a low reduction rate of 38.6%.
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