Silk Research Articles

Electrochemical Exfoliation and Growth of Nickel–Cobalt Layered Double Hydroxides@Black Phosphorus Hetero‐Nanostructure Textiles for Robust Foldable Supercapacitors

AbstractAdvanced innovation of flexible electrode with adequate redox activity and stably mechanical endurance that promotes charges kinetic migration and faradaic storage is pivotal for textile‐based supercapacitors (T‐SCs). Herein, this study reports a high‐performance T‐SCs electrode based on nickel–cobalt layered double hydroxides@black phosphorus (NiCo‐LDHs@BP) on a conductive silk (c‐silk) textile (NiCo‐LDHs@BP/c‐silk). Under negative voltage‐induced electrochemical exfoliation, the Ni2+ and Co2+ are embedded into bulk BP framework to form exfoliated BP nanosheets, and the NiCo‐LDHs are in situ grown within the BP networks, generating 3D NiCo‐LDHs@BP hetero‐nanostructure. Significantly, the NiCo‐LDHs@BP exhibits a large space‐charge area, enhanced adsorption energy for OH− and accelerated charges transfer/storage as confirmed using density functional theory calculations. Additionally, the T‐SCs electrode is fabricated by loading the blended NiCo‐LDHs@BP, sericin, and carbon nanotubes on fibroin textile via a silk reconstruction strategy, producing large area production, superior mechanical flexibility, and impressive electrochemical performance. The resultant NiCo‐LDHs@BP/c‐silk electrode exhibits large specific capacitance of 1291.3 F g−1 and considerable rate capacity in 1 M KOH electrolyte. Furthermore, the flexible solid‐state asymmetric T‐SCs deliver high specific areal energy density of 279.6 µWh cm−2 and robust folding capability (85.6% capacitance retention after 5000 folding cycles), which successfully power wearable watch and heart rate meter devices.

Enhanced mechanical qualities of sericin‐removed silk by direct feeding of silkworms with cellulose nanofiber

AbstractRecently, the modification of silkworm silk fibers (SFs) by adding fillers has been investigated. Previously, we have reported that SFs obtained from silkworms fed diets supplemented with 5 wt.% cellulose nanofiber (CNF) and whose surface was covered with sericin exhibited excellent tensile properties. On the other hand, to use SF in silk products, the sericin must be removed, and it is necessary to ensure that CNF‐enriched silkworm SFs with the sericin removed (i.e., fibroin) exhibit high tensile properties. Therefore, this study evaluated the tensile properties of sericin‐removed SF obtained from silkworms fed a CNF diet. The results showed that the average CNF with SF—near 7.5 wt.% exhibited high mechanical properties. Adding CNF to the silkworm diet did not affect their growth and cocoon yield. The analysis of the SF microstructure confirmed that CNF is a fibrous material on the surface of fibroin. Kelly‐Tyson's equation suggested that almost all of the CNF in fibroin contributed to the increased tensile strength.

Modulating Polyalanine Motifs of Synthetic Spidroin for Controllable Preassembly and Strong Fiber Formation.

Spider dragline (major ampullate) silk is one of the toughest known fibers in nature and exhibits an excellent combination of high tensile strength and elasticity. Increasing evidence has indicated that preassembly plays a crucial role in facilitating the proper assembly of silk fibers by bridging the mesoscale gap between spidroin molecules and the final strong fibers. However, it remains challenging to control the preassembly of spidroins and investigate its influence on fiber structural and mechanical properties. In this study, we explored to bridge this gap by modulating the polyalanine (polyA) motifs in repetitive region of spidroins to tune their preassemblies in aqueous dope solutions. Three biomimetic silk proteins with varying numbers of alanine residues in polyA motif and comparable molecular weights were designed and biosynthesized, termed as N16C-5A, N15C-8A, and N13C-12A, respectively. It was found that all three proteins could form nanofibril assemblies in the concentrated aqueous dopes, but the size and structural stability of the fibrils were distinct from each other. The silk protein N15C-8A with 8 alanine residues in polyA motif allowed for the formation of stable nanofibril assemblies with a length of approximately 200 nm, which were not prone to disassemble or aggregate as that of N16C-5A and N13C-12A. More interestingly, the stable fibril assembly of N15C-8A enabled spinning of simultaneously strong (623.3 MPa) and tough (107.1 MJ m-3) synthetic fibers with fine molecular orientation and close interface packing of fibril bundles. This work highlights that modulation of polyA motifs is a feasible way to tune the morphology and stability of the spidroin preassemblies in dope solutions, thus controlling the structural and mechanical properties of the resulting fibers.

Synthesis, Characterization and Application of Reactive Dyes Based on 4,4'- Methylene Bis Orthonilic Acid on Silk, Wool and Cotton Fibres

Synthesis, Characterization and Application of Reactive Dyes Based on 4,4'- Methylene Bis Orthonilic Acid on Silk, Wool and Cotton Fibres

Fabrication and Physico-mechanical Characterization of Short Natural/Synthetic Fiber–Reinforced Hybrid Composites: Effects of Biodegradation and Chemical Aging

The main goal of this study was to develop eco-friendly and low-cost multiple short natural fiber-reinforced hybrid composites with the hybridization of comparatively high-strength glass fibers. The hybrid composites were fabricated via hand lay-up by using short jute, silk, water hyacinth, and glass fibers for the reinforcements and unsaturated polyester resin for the thermoset polymer matrix. The reinforcing fibers were randomly oriented, and five types of hybrid composites were fabricated with different types of fiber content (wt.%). The performance of the manufactured hybrid composites was assessed by tensile, flexural, and impact testing, as well as water uptake (%). It was revealed that composites with high glass fiber content (wt.%) exhibited optimum mechanical performance in most cases, while poor moisture resistance performance was exhibited for the hybrid composites containing higher natural fibers (wt.%). The hybrid composite samples were also aged in soil medium (biodegradation) for 25 days and different chemical solutions (alkaline, acidic, and salt) for 10 days. After biodegradation, the drop of tensile strength (TS) and tensile modulus (TM) was revealed to be approximately 38–61 and 58–72%, respectively. On the other hand, after chemical aging, the drop of TS and TM was exhibited to be approximately 49–76% and 51–65%, respectively, for alkali solution aging; 42–75% and 29–76%, respectively, for acid solution aging; and 43–59% and 51–65%, respectively, for salt solution aging.

Dragline silk fibers from golden orb‐web spider Trichonephila clavata ensure structural and mechanical robustness against ultraviolet radiation

AbstractA diurnal spider, Trichonephila clavata (T. clavata), is often called a golden orb‐weaver because its dragline or lifeline silk fibers exhibit a golden color. However, little is known about the biological roles of the golden pigment. Meanwhile, Araneus ventricosus, which is a nocturnal spider, spins colorless silk fibers. Here, we investigated the effect of ultraviolet (UV) irradiation on physical properties of silk fibers obtained from these diurnal and nocturnal spiders. After UV exposure, the dragline silk of the nocturnal spiders appeared abraded and became insoluble due to gelation, whereas the diurnal spider silk remained intact. A dynamic mechanical thermal analysis under different humidity conditions revealed that the storage modulus of the silk from the nocturnal spider dropped markedly at low humidity levels after UV irradiation. This indicated that the molecular weight of this silk degraded under UV exposure and that the number of terminal amino and carboxyl groups increased due to the breakage of the main protein chains. In contrast, the structural and mechanical properties of the diurnal spider silk were maintained regardless of the UV irradiation. Therefore, the golden pigments in the dragline silk of T. clavata most likely played a role in protecting the silk from UV damage.

Repercussion of natural silk fibers from spider and silkworms on the mechanical properties of composite materials

Costly synthetic fibers like kevlar, glass, and carbon lead to expensive production costs for products made from these materials, necessitating the development of alternate materials. As a more sustainable and affordable substitute for synthetic reinforcement materials like glass, carbon, and kevlar, natural fiber has gained popularity. Silk fiber obtained from spiders and silkworms is one type of natural fiber that has excellent mechanical properties such as tensile strength, tensile modulus, and breaking elongation. Its mechanical and biocompatibility characteristics are unmatched by those of other synthetic and natural fibers. This article discusses various silk fiber-related topics such as chemical composition, mechanical properties, and applications with respect to spiders and silkworms. Also, the requirement for silk fiber to be used as a reinforcement in composite materials is highlighted. Furthermore, the mechanical properties of silk fiber-reinforced composites (SFRCs) are also explored in this review. It is acceptable to draw the conclusion that the use of SFRCs in the creation of useful and possibly lucrative applications as novel materials in many industrial areas is inevitable.

Sustainable appraisal of lipstick tree seeds (Bixa orellana)-based bixin natural orange colorant for green mordanted silk fabrics and wool yarns.

This research aims to optimize the silk and wool dyeing process using natural dyes from Bixa orellana (annatto) through response surface methodology. Central composite design experiments highlight the significant enhancement of color outcomes achieved through microwave treatment. For silk, the optimal conditions (80 °C for 40 min) with annatto extract yield a color strength (K/S) of 17.8588, while wool achieves a K/S of 7.5329. Introducing eco-friendly bio-mordants, such as pomegranate peel and red sumac tannins, enhances color strength. Pre-dyeing treatments with 2% red sumac, 1.5% pomegranate peel, and weld flower extracts for silk produce high color strength, with K/S values of 16.4063, 16.3784, and 12.1658, respectively. Post-dyeing, the K/S values increase to 40.1178, 17.4779, and 21.6494. Wool yarn exhibits similar improvements, with pre-dyeing K/S values of 13.1353, 13.5060, and 16.3232, escalating to 10.5892, 15.3141, and 23.4850 post-dyeing. Furthermore, this research underscores improved colorfastness properties, including notable enhancements in light, wash, and rubbing fastness for both silk fabric and wool yarn. These findings underscore the efficacy of the proposed sustainable dyeing methods, offering valuable insights for eco-friendly textile production.

Book review: Amit Kumar, Precious Threads and Precarious Lives: Histories of Shawl and Silk Industries of Kashmir, 1846–1950

Amit Kumar, Precious Threads and Precarious Lives: Histories of Shawl and Silk Industries of Kashmir, 1846–1950 (Routledge, 2022), 163 pp.

Fabrication of the Ag/silk fibers for electrically conductive textiles

As a good substrate, silk fibers are widely employed in the field of intelligent textiles. In this work, the surface of silk fibers were firstly roughened by formic acid and sensitized by tannic acid, and then the silver ammonia solution was reduced by glucose to synthesize nano-silver in situ on the silk surface to obtain composite conductive silk fibers with resistivity as low as 0.24 mΩ·cm. It was proved by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) tests that a uniformly deposited nano-silver layer was fabricated on the silk surface. The prepared silk fibers had stable mechanical, thermal, electrical, and antibacterial properties and can be used for human sensing.

Design of fluorine-free superhydrophobic silk fabrics with mechanical durability and self-cleaning properties for oil-water separation

The separation of oil and water can be effectively addressed through the application of superhydrophobic coatings. This method, known for enhancing the self-cleaning, anti-corrosive, and friction-reducing properties of materials, typically employs fluorine reagents to ensure the durability of the coating nanostructure. However, the use of fluorine reagents raises concerns related to health and the environment. We present a straightforward and efficient approach to fabricate a robust, fluorine-free superhydrophobic composite coating. The coating solution, comprised of hydrophobic silica nanoparticles and polydimethylsiloxane (PDMS), is formed through sonication. The resulting superhydrophobic coating is effortlessly applied to silk fabric through immersion and subsequent drying/curing. micrograph confirms the creation of porous micro/nanostructures on the silk fabric's surface. Exceptional superhydrophobicity is demonstrated with a water contact angle (WCA) of 161 °±1.5 ° and a small sliding angle (SA) of 5 °±0.5 °. The coating's firmness, durability, and UV resistance are assessed through 20 cycles of sandpaper friction (load 200 g) and repeated tape peeling tests. Furthermore, the modified silk fabrics exhibit excellent capabilities in oil-water separation. This fluorine-free superhydrophobic coating, characterized by its robustness, environmental friendliness, and ease of manufacture, holds promising applications in the textile industry.

Modern ecofriendly approach for extraction of luteolin natural dye from weld for silk fabric and wool yarn dyeing

The increasing apprehension regarding the ecological effects of synthetic dyes has prompted a transition towards sustainable and environmentally friendly substitutes in the textile sector. This research examines the eco-friendly use of a natural pigment obtained from the weld flower for dyeing of silk fabric and wool yarn. The study investigates the use of microwave-assisted extraction to acquire the luteolin based pigment found in the weld flower. An assessment is conducted to evaluate the effectiveness of microwave radiation in improving the extraction process, emphasizing its capacity to accelerate and enhance the production of the natural colorant. Moreover, the process of optimizing dyeing conditions is carried out utilizing a response surface approach, with a specific focus on parameters including temperature, time, pH, and salt content. The study also investigates the influence of mordants, such as iron salt, and aluminum salt, on improving color fastness and attaining bright and enduring hues. The study expands its research to examine the impacts of plant-based extracts, such as madder root, and oak, as bio-mordants for producing a wide array of colors. The study additionally highlights the favorable influence on color fastness, exhibiting significant enhancements in light fastness, wash fastness, and rubbing fastness for both silk and wool. The measurable results validate the effectiveness of the suggested environmentally friendly dyeing techniques, provide numerical evidence of their suitability for sustainable textile manufacturing.

Chestnut shell dyes extracted by deep eutectic solvent in green dyeing of silk fibers for enhanced washable, antibacterial and UV protection properties

As an important biomass resource, chestnut shells are often discarded and wasted. In this study, we report an innovative, low-cost and environmentally friendly approach of dyeing silk fibers with natural pigments extracted from chestnut shells using deep eutectic solvent (DES) and imbuing them with antibacterial and ultraviolet protection properties. To improve the extraction ratio of chestnut shell pigment, DES of choline chloride and urea (ChCl/Urea) with high solubility performance was adopted to extract pigment from chestnut shells and then directly used for silk dyeing. The color spectral curve, washing durability, antibacterial and ultraviolet resistance of dyed silk were tested and compared with the silk dyed by metal salt mordant. The result showed that compared with ethanol extraction, DES extraction method had a higher extraction rate and better stability of the extraction solution. Owing to the swelling, surface modification and high permeability of ChCl/Urea DES to silk fibers, the affinity between the pigment solution and silk fibers was enhanced, and the pigment molecules entered the amorphous area inside the silk fibers, forming a tight bond with the fiber matrix during dyeing. Therefore, the dyed silk fabric has excellent washing durability and soft luster, and the color strength (K/S) remained unchanged after three washings. Meanwhile, the antibacterial activity and ultraviolet protection coefficient of silk dyed with chestnut shell pigment reached above 97% and 42.26, respectively, which exhibits excellent antibacterial and ultraviolet protection properties.

A new strategy for structural color fabrics: Transfer of photonic crystal coatings from slides to fabrics

The construction of three-dimensional photonic crystals on textile surfaces has emerged as a highly effective method to create fabrics with structural color, generating significant interest among researchers. However, the strict requirements of the substrate fabrics and the challenges associated with patterning coatings for bright structural colors have hindered the widespread application of photonic crystal materials in the textile industry. In this study, we present a strategy for obtaining patterned structural color coatings on fabrics made of different materials. Pre-crystallized poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) liquid photonic crystals (LPCs) are used as raw material for the rapid preparation of solid photonic crystals (SPCs). These SPCs with structural colors are used as templates and transferred to various fabrics through transfer printing techniques. Importantly, the SPCs maintain an ordered face-centered cubic structure both before and after transfer. Such a feature ensures that the processed structural color fabrics exhibit vibrant and iridescent structural colors. This result is achieved by modification of the substrate fabric with viscous polymer and the intact retention of SPCs. The sandwich structure formed by the adhesive polymer on the base fabric and the encapsulation of the film-forming material on the SPCs imparts good stability to the structural color fabric. It is worth noting that patterned photonic crystal coatings can be easily obtained on the fabrics made of different materials (cotton, linen, wool, and silk fabrics) by manipulating the shape of the viscous polymer. Additionally, a wide range of common materials, such as paper, wood, steel, and others, can be used as target substrates. This novel dyeing strategy not only offers new ideas for preparing patterned structural color fabrics but also further promotes the application of photonic crystal materials in textile printing or display.

Spectral Analysis of Pink Mealy Bug Damaged Mulberry Plants Using Hyperspectral Radiometry

Mulberry (Morus spp.) foliage forms a sole food to silkworms, Bombyx mori L. Its quality plays a pivotal role in superior silk fiber production. Like any other plants, mulberry is susceptible to detrimental diseases and infested by insect pests. Many sucking pests cause damage to mulberry among which, pink mealybug causes severe damage leading to significant loss in mulberry leaf yield (12-25 %). Conventional approaches to assess and manage damage caused by pink mealybugs demand substantial manpower and expertise, resulting in time-consuming and inefficient processes. However, leveraging modern tools and technologies like remote sensing has emerged as a remarkably effective strategy for crop protection and management.Specifically, hyperspectral remote sensing proves invaluable by furnishing insights into the biophysical and biochemical traits of crops. This is achieved through the recording of narrow wave bands that reflect specific plant characteristics. The main objectives were to understand the spectral reflectance characteristics of healthy and pink mealy bug damaged mulberry crops, to identify the optimal spectral bands and vegetative indices for detecting pink mealy bug damage in mulberry and to explore the feasibility of estimating pest damage levels based on the spectral properties of mulberry crops. Top of FormAt the mulberry garden of the Department of Sericulture, Tamil Nadu Agricultural University (TNAU), Coimbatore, studies were conducted on spectral analysis of pink mealy bug damaged mulberry plants using hyperspectral radiometry during 2018. In this trial, at 15-day intervals during the active damage stage, the percentage damage was observed in plots infested with pink mealy bugs and those that were healthy. Measurements of spectral reflectance across various wavelengths and vegetation indices (VIs) were taken using a hyperspectral radiometer. The analysis included evaluating the sensitivity of different spectral bands and VIs to pink mealybug damage, along with employing correlation and regression analyses between the extent of pest damage and the VIs. The findings revealed distinct differences in the spectral reflectance profiles of mulberry plants compared to their healthy counterparts. Typically, affected plants exhibited increased reflectance in the red (620–680 nm) and green (520–590 nm) bands and reduced near-infrared (NIR) reflectance (770–860 nm). The average values of the Normalized Difference Vegetation Index (NDVI), Green Red Vegetation Index (GRVI), and Ratio Vegetation Index (RVI) were significantly lower in the pink mealybug-damaged plants across all measurements. Notably, red reflectance demonstrated the greatest sensitivity to pink mealybug-induced damage. The study highlighted the Simple Ratio (SR) index as particularly effective for identifying pest damage. Damage estimation by pink mealybugs was refined using linear regression models based on spectral indices, specifically NDVI, RVI, and GRVI. The correlation intensity analysis pinpointed the green region at 516.73 nm as showing the most significant negative correlation (r = -0.02), whereas the highest positive correlation with pink mealybug damage was observed in the NIR region (r = 0.77), underscoring the precise wavelengths and indices most indicative of pest impact. Thus, using hyperspectral radiometry identification of damage caused by pink mealy bug possible, through analysis of spectral bands and indices.

Commercial Culture of Cordyceps militaris from Waste Products of Sericulture in India

Cordyceps militaris, an entomopathogenic fungi belonging to Ascomycota group are currently in the limelight for its synthesis of Cordycepin, – an anti-cancer component. The host range of Cordyceps is extremely broad, with predominance on the orders Lepidoptera, Coleoptera, and Hymenoptera. Although this fungus is extremely rare in nature, its artificial culture is becoming more and more popular on the global market. However, the commercial culture of this fungus has been hampered by the difficulty in getting seeding material and the complex developmental technique. For ages, the silkworm (Order: Lepidoptera) has played a significant economic role in the food and silk industries of Asian nations. The waste product of the silkworm rearing process is the dead silkworm pupae, which are generated in large quantities after stifling of the cocoons for the purpose of producing raw silk. Waste from Sericulture in India has the potential to be used as a promising culture media for the growth of the Cordyceps-related sector, helping the silk farmers in their quest for future financial gain and the social advancement of the tribal society.

Biomimetic Design of Hydration‐Responsive Silk Fibers and their Role in Actuators and Self‐Modulated Textiles

AbstractHydration‐induced shape‐morphing behavior has been discovered in many natural fiber‐based materials, yet this smart behavior in regenerated fibers from biopolymers lacks investigation. Here, hierarchically structured silk fibers are developed with anisotropic long‐range molecular organization and water‐responsive effects resembling natural spider silk. The regenerated silk fibers exhibit the water‐triggered shape‐memory effect and a water‐driven cyclic response. The reversible hydrogen bonds and transformation in the metastable secondary structure from α‐helices/random coils to β‐sheets are explored as the mechanisms responsible for the water‐responsiveness. The silk fibers obtained possess a tensile strength higher than 104 MPa at a fracture strain of ≈100%, showing noticeable toughness. The water‐responsive silk fibers exhibit a shape recovery rate of ∼83% and generate a maximum actuation stress of up to 18 MPa during the water‐driven cyclic contraction that outperforms most traditional natural textile fibers. The regenerated silk fibers show potential for use in water‐driven actuators, artificial muscle, and smart fabrics based on the integration of suitable mechanical properties and water responsiveness.

Customizable and scalable manufacture of aesthetic ionic conductive silk yarns for e-textile devices

Electronic textiles (e-textiles), which combine the comfort of textiles with the functionality of soft electronics, have attracted much attention in wearable applications. However, scale-up fabrication of stretchable textiles with concurrent high stability and aesthetic appeal features poses significant challenges. Here, we report a scalable and customizable dip-coating strategy for the preparation of multiple-colored and functionally stable ionic conductive silk yarns (i-SY) and demonstrate their effectiveness in exercise posture correction. The i-SY preserves the inherent properties of silk fibers and ionic liquids, exhibiting improved mechanical properties, weaving capabilities, flame retardancy, and electrical conductivity. The method leverages the exceptional transparency of ionic liquids, facilitating the large-scale production of colored i-SYs to meet aesthetic demands. Additionally, the i-SY sensor exhibits exemplary sensing sensitivity and stability, enabling the real-time monitoring of human joint movements and facilitating precise posture correction during fitness exercises. We envision that the proposed sensing textile holds promise for applications in wearable devices, healthcare monitoring, and human–machine interfaces.

Supramolecular coordination platinum metallacycle–based multilevel wound dressing for bacteria sensing and wound healing

The exploitation of novel wound healing methods with real-time infection sensing and high spatiotemporal precision is highly important for human health. Pt-based metal-organic cycles/cages (MOCs) have been employed as multifunctional antibacterial agents due to their superior Pt-related therapeutic efficiency, various functional subunits and specific geometries. However, how to rationally apply these nanoscale MOCs on the macroscale with controllable therapeutic output is still challenging. Here, a centimeter-scale Pt MOC film was constructed via multistage assembly and subsequently coated on a N,N'-dimethylated dipyridinium thiazolo[5,4-d]thiazole (MPT)-stained silk fabric to form a smart wound dressing for bacterial sensing and wound healing. The MPT on silk fabric could be used to monitor wound infection in real-time through the bacteria-mediated reduction of MPT to its radical form via a color change. The MPT radical also exhibited an excellent photothermal effect under 660 nm light irradiation, which could not only be applied for photothermal therapy but also induce the disassembly of the Pt MOC film suprastructure. The highly ordered Pt MOC film suprastructure exhibited high biosafety, while it also showed improved antibacterial efficiency after thermally induced disassembly. In vitro and in vivo studies revealed that the combination of the Pt MOC film and MPT-stained silk can provide real-time information on wound infection for timely treatment through noninvasive techniques. This study paves the way for bacterial sensing and wound healing with centimeter-scale metal-organic materials.

Preparation of polyphenol-structural colored silk fabrics with bright colors

Conventional textile dyeing relies on the use of dyes and pigments, which can cause severe environmental contamination and waste a large amount of water. Structural coloring is one of the effective ways to achieve environmentally friendly coloring of textiles. In this work, three plant polyphenols with the same o-benzenetriol structure (tannic acid (TA), gallic acid (GA), and tea polyphenol (TP)) were selected as raw materials. Three plant polyphenols can quickly form nanofilms at the gas-liquid interface through a Schiff base reaction with polyethyleneimine (PEI) under mildly alkaline conditions, which were deposited to the surface of silk fabric, allowing precise control over the thickness of film by adjusting the time, resulting in various structurally colored silk fabric. This method for creating structural colors is not substrate-specific and enables the quick production of structural colors on various textile substrates. Furthermore, the structural color silk fabric based on plant polyphenol has antibacterial performance. This textile coloring method is simple, cost-effective and environmentally friendly, providing a new approach to eco-friendly textile dyeing.