Search Results (48)

Cotton is a vital economic crop, and cotton fiber serves as the primary raw material for the textile industry. Lignin in cotton fiber is closely associated with fiber quality. Lignin is synthesized through the phenylpropanoid metabolic pathway, where the cinnamyl alcohol dehydrogenase gene CAD6 plays a significant role. In this study, we obtained successfully transformed overexpression plants by constructing an overexpression vector and performing genetic transformation and tissue culture. To verify the function of the GhCAD6 gene in upland cotton, we analyzed the agronomic traits, fiber quality, cell wall structure, and lignin content of GhCAD6-overexpressing plants. Our results indicate that the GhCAD6 gene is predominantly expressed during the stages of fiber elongation and secondary wall synthesis. Overexpression of the GhCAD6 gene resulted in increased plant lignin content and fiber upper half mean length, boll number per plant, fiber uniformity index, strength, and lint were improved. The fiber surface was smoother, and the fiber cell wall was more compact. These findings demonstrate that the GhCAD6 gene positively regulates lignin synthesis and fiber quality formation, contributing to the enhancement of cotton fiber quality. Full article

The fast fashion industry has significantly increased global textile demand, driving a surge in fiber production. However, only a minimal portion of this fiber comes from recycled sources. In the United States alone, a vast amount of textile waste is generated annually, with over half ending up in landfills, contributing to environmental degradation and global warming. These developments underscore the urgent need for scalable and efficient textile recycling solutions to address both economic and ecological challenges in the fashion industry. Among recycling methods, mechanical recycling stands out for its low cost and simplicity, making it suitable for processing various types of textile waste. This article reviews current knowledge, identifies key research gaps, and provides direction for future studies in mechanical textile recycling. Despite progress, significant challenges remain in improving the quality and efficiency of recycled fiber. This study shows the importance of advancing pretreatment methods and sorting technologies, and highlights understanding regarding shredding, opening processes, and fabric structural properties. Full article

The aim of this study is to identify the textile materials used to make Bulgarian folk costumes and to support the process of conservation and restoration of ethnographic objects. In the 18th and 19th centuries, folk costumes were made almost exclusively of natural materials, while in the first half and middle of the 20th century, they included contemporary synthetic and regenerated cellulose materials, as well as blends of these materials with natural fibers. A series of historical textiles and contemporary industrial fabrics were studied using a variety of analytical approaches, including micro-chemical staining and solubility tests, optical microscopy, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), and infrared (IR) spectroscopy. IR measurements were carried out in attenuated total reflectance (ATR) and external reflectance (ER) modes using a portable IR spectrometer, which enabled non-invasive analysis. The analysis revealed that the composition of the industrial fabrics and historical textiles encompassed synthetic fibers, such as polyester and polyamide, while others were made of regenerated cellulose fibers like viscose. Additionally, some textiles had a mixed composition of cotton and polyester or silk and viscose. The combined analytical approach provided reliable identification of both the synthetic and natural textile materials. Full article

Treating silk with metal salts was a common practice starting in the second half of the 19th century until the early 20th century. It aimed to increase the weight and thickness of the fibres. However, the presence of metal salts is believed to accelerate and aggravate the deterioration of historical silk textiles, and weighted silks are nowadays considered one of the most pressing issues in textile conservation. This paper explores the history of the practice of metal salt weighting of silk: the materials and methods used, the reasons behind weighting, and how this practice developed as the product of a specific historical and economic context. A total of 147 primary textual sources (patents, dyers’ manuals, and books) were investigated and from these 136 weighting methods were collected and reviewed. The results highlighted tin salts as the most commonly mentioned metal salts for weighting silks of any colour. Iron compounds combined with tannins were the method of choice for dark silks, although also in combination with tin in half of the cases. The knowledge gained from this research will help further the study of the degradation pathways of historical silk fabrics, as representative reproductions of weighted silks will be produced based on the findings. Full article

This systematic review explores recent advancements in antenna and rectifier systems for radio frequency (RF) energy harvesting within the gigahertz frequency range, aiming to support the development of sustainable and efficient low-power electronic applications. Conducted under the PRISMA methodology, our review filtered 2465 initial records down to 80 relevant studies, addressing three research questions focused on antenna design, operating frequency bands, and rectifier configurations. Key variables such as antenna type, resonant frequency, gain, efficiency, bandwidth, and physical dimensions were examined. Antenna designs including fractal, spiral, bow-tie, slot, and rectangular structures were analyzed, with fractal antennas showing the highest efficiency, while array antennas exhibited lower performance despite their compact dimensions. Frequency band analysis indicated a predominance of 2.4 GHz and 5.8 GHz applications. Evaluation of substrate materials such as FR4, Rogers, RT Duroid, textiles, and unconventional composites highlighted their impact on performance optimization. Rectifier systems including Schottky, full-wave, half-wave, microwave, multi-step, and single-step designs were assessed, with Schottky rectifiers demonstrating the highest energy conversion efficiency. Additionally, correlation analyses using boxplots explored the relationships among antenna area, efficiency, operating frequency, and gain across design variables. The findings identify current trends and design considerations crucial for enhancing RF energy harvesting technologies. Full article

Dyed wool samples and lake pigments prepared from the same dyestuffs were exposed to light over the course of 14 months. Brazilwood or sappanwood, cochineal, madder, and weld were used for both wools and pigments, with the addition of dyer’s broom, indigo, and tannin-containing black dyes for the wools and eosin for the pigments. The wools were dyed within the MODHT European project on historic tapestries (2002–2005), using recipes derived from fifteenth- to seventeenth-century sources. The pigments were prepared according to European recipes of the same period, or using late nineteenth-century French or English recipes. Colour measurements made throughout the experiment allowed for overall colour difference (ΔE₀₀) to be tracked and half-lives to be calculated for some of the colour changes. Alterations in the samples’ hue and chroma were also monitored, and spectral information was collected. The results showed that, for both textiles and pigments, madder is the most stable red dye, followed by cochineal, and then brazilwood. Eosin was the most fugitive sample examined. Comparisons of textile and lake samples derived from the same dyestuff, whether red or yellow, indicate that the colourants are more stable when used as textile dyes than in analogous lake pigments. Full article

The textile industry is among the world’s largest, producing an estimated 124 million tonnes of fibres in 2023, with more than half of these being made from virgin polyester. Less than 0.1% of polyester fibres are recycled into new textiles at the end of their lives. Mechanical, thermo-mechanical, and chemical textile-to-textile polyester recycling are all technically possible, but thermo-mechanical recycling is reported to provide the most promising compromise between cost and quality. Myriad chemicals are used in polyester production, and this paper is the first to review the related academic literature to better understand their impact on recyclability. It has been demonstrated that chemicals used during the production and processing of polyester textiles can either provide resistance to, or catalyse, the degradation of polyester during thermo-mechanical recycling processes. However, the effect of combinations of these chemicals on recycling is largely unknown. Limiting, standardising, and transparently reporting the chemicals used during textile production would simplify research and could lead to better quality products after recycling. Full article

Textile recycling approaches require input material streams of defined purity. Establishing sorting facilities and defining viable sorting fractions for efficient subsequent recycling necessitates knowledge on the composition and material content of the textiles to be processed. Subsequently, this information is crucial for the implementation of a sustainable circular economy for textiles. This study presents the results of a comprehensive waste textile sampling and characterisation along with data on the quantities and composition of waste textiles in Vienna in 2022. The data reveals that only 28% of the 19,975 t of waste textiles generated end up in separate collection, of which a significant amount goes to the international market. However, the results regarding the fibre composition show that textiles from mixed municipal solid waste and separate collection are very similar. Cotton fibres accounted for approx. half of the fibre mass from non-complex textiles, with 9328 t overall (6776 t in the mixed municipal solid waste and 2522 t in separate collection). A further analysis regarding fibre blends found that a total of 6275 t of single-fibre materials and 5132 t of two-fibre materials were present. This reveals great potential for using this waste stream in fibre-to-fibre recycling processes. Collecting accurate data on this waste stream enables sorters and recyclers to tailor their processes to the expected input material. By increasing the amount of recycled materials, the share of incinerated or landfilled textiles will decrease, which in turn will have a positive impact on the environment. However, further research in textile identification and material separation as well as regulations to keep these materials in a sustainable closed loop are required. Full article

The dyes used to produce two Palestinian garments from the British Museum’s collection attributed to the late 19th–early 20th century were investigated by high pressure liquid chromatography coupled with diode array detector and tandem mass spectrometry (HPLC-DAD-MS/MS). Palestinian embroidery is a symbol of national identity and the topic of scholarly research. However, little attention has been given to the dyes and how these changed with the introduction of new synthetic formulations in the second half of the 19th century. The results revealed the use of natural indigoid blue and red madder (Rubia tinctorum), in combination with tannins. Yellow from buckthorn (probably Rhamnus saxatilis) and red from cochineal (probably Dactylopius coccus) were found mixed with synthetic dyes in green and dark red embroidery threads, respectively. Early synthetic dyes were identified in all the other colours. These include Rhodamine B (C.I. 45170), Orange II (C.I. 15510), Orange IV (C.I. 13080), Metanil Yellow (C.I. 13065), Chrysoidine R (C.I. 11320), Methyl Violet (C.I. 42535), Malachite Green (C.I. 42000), Fuchsin (C.I. 42510), Auramine O (C.I. 41000) and Methyl Blue (C.I. 42780). As the date of the first synthesis of these dyes is known, the production date of the garments was refined, suggesting that these were likely to be produced towards the end of the 1880s/beginning of the 1890s. The continuous use of historical local sources of natural dyes, alongside new synthetic dyes, is of particular interest, adding rightful nuances to the development of textile-making practices in this region. Full article

Industrial and construction wastes make up about half of all world wastes. In order to reduce their negative impact on the environment, it is possible to use part of them for concrete production. Using experimental–statistical modeling techniques, the combined effect of brick powder, recycling sand, and alkaline activator on fresh and hardened properties of self-compacting concrete for the production of textile-reinforced concrete was investigated. Experimental data on flowability, passing ability, spreading speed, segregation resistance, air content, and density of fresh mixtures were obtained. The standard passing ability tests were modified using a textile mesh to maximize the approximation to the real conditions of textile concrete production. To determine the dynamics of concrete strength development, compression and flexural tests at the ages of 1, 3, 7, and 28 days and splitting tensile strength tests of 28 days were conducted. The preparation technology of the investigated modified mixtures depending on the composition is presented. The resulting mathematical models allow for the optimization of concrete compositions for partial replacement of slag cement with brick powder (up to 30%), and natural sand with recycled sand (up to 100%) with the addition of an alkaline activator in the range of 0.5–1% of the cement content. This allows us to obtain sustainable, alkali-activated high-strength self-compacting recycling concrete, which significantly reduces the negative impact on the environment and promotes the development of a circular economy in the construction industry. Full article

Pollution in ecosystems has increased, especially in water, due to the pollutant agents that alter their chemical, physical and biological characteristics. This requires actions to resolve or at least reduce the harmful effects generated on the environment and people’s health. Many of the contaminants present in water come from the industrial sector, with the textile industry being one of the most impactful as it uses mostly synthetic dyes, which are characterized as being recalcitrant and toxic, so they cannot be degraded by conventional water treatment methods. Advanced oxidation processes have a great potential for application, especially those that use heterogeneous photocatalysis. The present research evaluates the efficiency in the adsorption and degradation of the triazoic Direct Blue 71 dye in aqueous mediums at concentrations of 600 ppm by the heterogeneous photocatalysis method. The photocatalysts used are layered double hydroxides (LDHs) with a Mg/Al = 3 ratio and are thermally activated and doped with Fe at 1, 3 and 5% w/w. The most efficient materials achieved removal percentages greater than 80% by means of a second-order kinetic model with a DB71 half-life decolorization of less than one hour; as shown by an HPLC study, the absence of intermediate products would confirm the mineralization of the dye. Full article

Thermochromic textiles possess the capability to indicate ambient temperature through color changes, enabling real-time temperature monitoring and providing temperature warnings for body heat management. In this study, three thermochromic dyes—blue, red, and yellow—were synthesized using crystalline violet lactone (CVL), 6′-(diethylamino)-1′,3′-dimethyl-fluoran (DDF), and 3′,6′-dimethoxyfluoran (DOF) as leuco dyes, respectively, with biomass tea polyphenol serving as the color developer and tetradecanol as the phase change material. The chemical structures of these dyes were characterized using UV spectroscopy, infrared spectroscopy, Raman spectroscopy and ¹H NMR. The thermochromic mechanisms were investigated, revealing that the binding bonds between the leuco dyes and the color developer broke and reorganized with temperature changes, imparting reversible thermochromic property. Polyester fabrics were dyed using an impregnation method to produce three reversible thermochromic fabrics in blue, red, and yellow. The structure and properties of these fabrics were analyzed, showing a significant increase in the UPF value from 26.3 to approximately 100, indicating enhanced UV resistance. Water contact angle measurements revealed that the contact angle of undyed polyester fabrics was 139°, while that of dyed polyester fabrics decreased by about 40°, indicating improved hydrophilicity. Additionally, the fabric inductive static tester showed that the static voltage half-life of dyed polyester fabric was less than 1 s, demonstrating a significant antistatic effect. Infrared thermal imaging results indicated that during the warming and cooling process, the thermochromic polyester fabric exhibited specific energy storage and insulation effects at 38 °C, close to the human body temperature. This study presented a novel approach to developing smart color-changing textiles using biomass-derived thermochromic dyes, offering diverse materials for personal thermal management, and intelligent insulation applications. Full article

This paper investigates the effects of pre-gelation on cellulose dissolved in LiCl/DMAc solutions to enhance the properties of regenerated cellulose materials. This study focuses on characterizing the crystallinity, molecular orientation, and mechanical performance of cellulose fibers and hydrogels prepared with and without pre-gelation treatment. X-ray diffraction (XRD) analysis reveals that crystallinity improvement from 55% in untreated fibers to 59% in fibers pre-gelled for 3 and 7 days, indicating a more ordered arrangement of cellulose chains post-regeneration. Additionally, XRD patterns show improved chain alignment in pre-gelled fibers, as indicated by reduced full width at half the maximum of Azimuthal scans. Mechanical testing demonstrates a 30% increase in tensile strength and a doubling of the compression modulus for pre-gelled fibers compared to untreated fibers. These findings underscore the role of pre-gelation in optimizing cellulose material properties for applications ranging from advanced textiles to biomaterials and sustainable packaging. Future research directions include further exploration of the structural and functional benefits of pre-gelation in cellulose processing and its broader implications in material science and engineering. Full article

A textile bandwidth-enhanced half-mode substrate-integrated cavity (HMSIC) antenna based on embroidered shorting vias is designed. Based on the simulated results of the basic HMSIC antenna, two embroidered hollow posts with square cross-sections are added as shorting vias at the intersections of the zero-E traces of the ${\mathrm{T}\mathrm{M}}_{210}^{\mathrm{H}\mathrm{M}}$ and ${\mathrm{T}\mathrm{M}}_{020}^{\mathrm{H}\mathrm{M}}$ modes to shift the ${\mathrm{T}\mathrm{M}}_{010}^{\mathrm{H}\mathrm{M}}$-mode band to merge with the bands of the higher-order modes for bandwidth enhancement. A prototype is practically fabricated based on computerized embroidery techniques. Measurement results show that the prototype is of an expanded −10 dB impedance band of 4.87~6.17 GHz (23.5% fractional bandwidth), which fully covers the 5 GHz wireless local area network (WLAN) band. The simulated radiation efficiency and maximum gain of the proposed antenna are above 97% and 7.6 dBi, respectively. Furthermore, simulations and measurements prove its robust frequency response characteristic in the proximity of the human tissues or in bending conditions, and the simulations of the specific absorption rate (SAR) prove its electromagnetic safety on the human body. Full article

Cotton textiles improved with metal oxide nanoparticles acquire additional features that may enhance their action against antimicrobial-resistant pathogens due to the unique properties and characteristics of the nanoparticles. The main objective of this work is to evaluate the antimicrobial features of two-sided-coated cotton textiles with ZnO nanoparticles. Nanoparticles were deposited using green chemistry technology with low-temperature oxygen plasma. ZnO particles formed stable structures on textile fibers. The optimal deposition parameters (150 W plasma power, 120 min immersion time) achieved the best effects against Gram-negative and Gram-positive bacteria and microscopic fungi. Two-sided-coated cotton with ZnO nanoparticles showed high antibacterial action on Gram-negative and Gram-positive bacteria. Modification with zinc oxide inhibited the growth of Candida albicans by more than half. Full article