Wastewater recovery is one of the most pressing contaminant-related subjects in the textile industry. Many cleaning and recovery techniques have been applied in recent decades, from physical separation to chemical separation. This work reviews textile wastewater recovery by focusing on natural or synthetic nanoclays in order to compare their capabilities. Presently, a wide variety of nanoclays are available that can adsorb substances dissolved in water. This review summarizes and describes nanoclay modifications for different structures (laminar, tubular, etc.) to compare adsorption performance under the best conditions. This adsorbent capacity can be used in contaminant industries to recover water that can be used and be recontaminated during a second use to close the production circle. It explores and proposes future perspectives for the nanoclay hybrid compounds generated after certain cleaning steps. This is a critical review of works that have studied adsorption or desorption procedures for different nanoclay structures. Finally, it makes a future application proposal by taking into account the summarized pros and cons of each nanoclay. This work addresses contaminant reuse, where part of the employed dyes can be reused in printing or even dyeing processes, depending on the fixing capacity of the dye in the nanoclay, which is herein discussed.

Electrochemical polymerization is known to be a suitable route to obtain conducting polymer-carbon composites uniformly covering the carbon support. In this work, we report the application of a filter-press electrochemical cell to polymerize polyaniline (PAni) on the surface of large-sized activated carbon cloth (ACC) by simple galvanostatic electropolymerization of an aniline-containing H₂SO₄ electrolyte. Flexible composites with different PAni loadings were synthesized by controlling the treatment time and characterized by means of Scanning Electron microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS), physical adsorption of gases, thermogravimetric analysis (TGA), cyclic voltammetry and direct current (DC) conductivity measurements. PAni grows first as a thin film mostly deposited inside ACC micro- and mesoporosity. At prolonged electropolymerization time, the amount of deposited PAni rises sharply to form a brittle and porous, thick coating of nanofibrous or nanowire-shaped structures. Composites with low-loading PAni thin films show enhanced specific capacitance, lower sheet resistance and faster adsorption kinetics of Acid Red 27. Instead, thick nanofibrous coatings have a deleterious effect, which is attributed to a dramatic decrease in the specific surface area caused by strong pore blockage and to the occurrence of contact electrical resistance. Our results demonstrate that mass-production restrictions often claimed for electropolymerization can be easily overcome.

Microcapsules can be added to fabric in industrial processes; however, they have not been widely spread among industrial companies. In this study, we suggest the possibility of reloading microcapsules onto a fabric while clothes are washed. The effectiveness of different resins when microcapsules are applied in washing machine during domestic laundry process has been studied. Microcapsules containing lavender fragrance and melamine formaldehyde shell were adhered to the fabric by means of one acrylic acid as a resin (RES) or some cross-linking agents, such as butanetetracarboxylic acid or succinic acid (SUC). In order to evaluate their behaviour, some laundering or ironing tests were conducted according to international standards (ISO). Every sample from the laboratory was studied with scanning electron microscopy and with a particle size counter. As a result, we could observe which was the most suitable auxiliary used to bind microcapsules to fabric, and conclude that the conditions in which we obtained the application with SUC as binder and cured at 150 °C for 2 min show the optimal results. It was demonstrated that domestic laundry is a suitable process to incorporate microcapsules to garments.

Three-dimensional printing technology is being increasingly applied in a multitude of sectors. However, this technology is not generally applied in the same way as in other sectors, possibly due to the difficulty of adhesion between the polymer and the textile substrate. A textile garment is subjected to wear and tear during its lifetime, and a low tensile strength or rubbing resistance hinders a garment in most of the applications of this type of research. This study examined the influence of the characteristics of the cotton textile substrate, such as the weave structure and the yarn thickness, on the tensile strength of a 3D-printed element with conductive filament. Starting from the fabric with the highest tensile strength, different prints were made using this technology to incorporate conductive and heating properties into the fabric. The results validate the possibility of providing new properties to the textile by means of this technology; however, the correct selection of the textile used as a base substrate is important.

Natural dyes, obtained from plants, insects/animals, and minerals, are renewable and sustainable bioresource products with minimum environmental impact. However, there are still many issues to solve related to natural dyes; consequently, synthetic dyes are still wildly used. Natural dyes have a low affinity towards the substrate cotton, so a solution had to be found: mordants. Mordants can also be harmful to the environment, which is why bio-mordants are used. The mordant used in this paper is chitosan. Cotton is pre-mordanted using the pad dyeing method. By using the exhaustion method, the fabric was coloured with red Camellia sinensis (tea) extracts. The colour, absorption of polyphenols and tannins, and ultraviolet protection (UPF) were tested. A comparison study was carried out between the cotton fabric and the cotton padded with chitosan at two different concentrations. The results are impressive. Cotton pre-mordanted with chitosan can absorb more polyphenols and tannins than cotton itself, and the colour fastness and UPF, once the fabric is laundered, demonstrate there is some kind of bonding between the fibre, quitosan, and active compounds from tea. The UPF was also doubled by using chitosan and the reddish colour obtained by Camellia sinensis extracts were darker on the cotton fabric. The increase in UPF protection on mordanted fabrics is higher than the gap obtained by colour difference, which means there are active compounds that do not confer colour, but enhance UPF protection.

The work is framed within Printed Electronics, an emerging technology for the manufacture of electronic products. Among the different printing methods, the roll-to-roll flexography technique is used because it allows continuous manufacturing and high productivity at low cost. Nevertheless, the incorporation of the flexography printing technique in the textile field is still very recent due to technical barriers such as the porosity of the surface, the durability and the ability to withstand washing. By using the flexography printing technique and conductive inks, different printings were performed onto woven fabrics. Specifically, the study is focused on investigating the influence of the structure of the woven fabric with different weave construction, interlacing coefficient, yarn number and fabric density on the conductivity of the printing. In the same way, the influence of the weft composition was studied by a comparison of different materials (cotton, polyester, and wool). Optical, SEM, color fastness to wash, color measurement using reflection spectrophotometer and multi-meter analyses concluded that woven fabrics have a lower conductivity due to the ink expansion through the inner part of the textile. Regarding weft composition, cotton performs worse due to the moisture absorption capacity of cellulosic fiber. A solution for improving conductivity on printed electronic textiles would be pre-treatment of the surface substrates by applying different chemical compounds that increase the adhesion of the ink, avoiding its absorption.