High Color Fastness Research Articles

Multi-color photochromic waterborne polyurethane with high color fastness from hydroxyl-functionalized trichromatic spiropyrans

With advancements in smart materials, photochromic polyurethane (PU) shows considerable promise for applications in anti-counterfeiting, optical storage, and colorimetric sensing. However, significant challenges remain, such as reliance on solvent-based PU, poor color fastness due to blending methods, and limited color options, hampering its broader application. In response, this study selected trichromatic spiropyrans (SPs, SP-R, SP-Y, and SP-B) from preparing 14 hydroxyl-containing SPs. Under UV irradiation, SP-R, SP-Y, and SP-B can colorless transform to red, yellow, and blue, respectively. The photochromic waterborne polyurethanes (WPUs) were synthesized by incorporating trichromatic SPs as end-capping agents into WPU chains (denoted as CWPU-R/Y/B), exhibiting excellent photochromic performance. Unlike simple blending, the CWPU-R/Y/B process superior photochromic fatigue resistance (50 cycles), emulsion stability (6-month storage), solvent resistance, and color fastness (achieving the highest grade of 5), due to the covalent bonding effect. Furthermore, CWPU films with various colors were achieved through simple color mixing, providing a broader spectrum to meet diverse application needs. The potential application of CWPU in the anti-counterfeiting field was preliminarily explored, showing the gratifying results. This study presents a novel material applicable to the next generation of smart packaging, electronic information, and coatings.

Dyeing of Mixed Cotton and Polyester Fabrics with New Dyes—Complexes of Collagen with Transition Metal Ions

Uniform, stable, one-step dyeing of textile fabrics made from a mixture of natural and synthetic fibers using traditional methods remains problematic to this day. As an alternative to traditional methods, a one-step method for dyeing mixed cotton and polyester fabrics with a new natural dye—a complex of collagen and [Formula: see text] and [Formula: see text] ions—was proposed for the first time. Dyeing of pre-prepared cotton, polyester, and cotton–polyester fabrics is carried out by dipping in an aqueous dye solution, squeezing, drying, and heat setting. The influence of the mass ratio of dye components, fixation temperature, and pH of the solution on the degree of dye fixation was determined. A degree of sorption of dyes (14–25%) from the solution onto the surface of fabrics was established, which after heat fixation decreases slightly (1–3%). During washing processes, the copper complex is almost completely washed out from polyester and blended fabrics and remains in small quantities (2.4–3.8%) on the surface of cotton fabrics. After water washing, the degree of fixation of the collagen–chrome complex in fabrics is as follows: in cotton—8–10%, in polyester—10–12%, and in cotton–polyester—8–9%. The color coordinates of cotton and cotton–polyester fabrics hardly change before and after washing, but for polyester fabric, the changes are significant. The mechanism of interaction of the complex dye with the fibers was studied using the Fourier transform infrared method, and the morphology and distribution of the dye on the surface of the samples using the SEM-EDS method. The dye binds to cellulose through ionic and coordination bonds, and to polyester through joint melting. Therefore, unlike pure polyester fabric, cotton and cotton–polyester fabrics demonstrated high color fastness to washing and light fastness. The use of production waste, the exclusion of synthetic dyes and harmful chemicals, and single-stage dyeing of the material reduce the environmental burden.

Robust mechanical strength and high colorfastness of amorphous photonic crystals on fabrics with durable antibacterial and anti-static properties

The technique of utilizing structural color dyeing presents a sustainable and energy-conserving approach to textile dyeing. However, the coating with structural coloration always exhibited cracks and inadequate colorfastness attributed to the presence of capillary tension. In this study, we employed a hydrophilic silane called 3-aminopropyltriethoxysilane (KH550) to chemically modify the fabric. This method endowed the fabric with reactive amino groups, thereby augmenting the interfacial bonding strength between polydopamine (PDA)@SiO2@Ag+/Ag NPs and the fabric substrate through metal coordination and covalent bonds. Additionally, by utilizing catechol complexation, we successfully loaded Ag ions onto the PDA coating of composite microspheres. These Ag ions acted as linkers during self-assembly of microspheres. The active amino groups on the surface of chemically modified cotton fabric reacted with PDA at a specific temperature, resulting in the formation of robust covalent bonds simultaneously. The resulting fabric demonstrated excellent water resistance as well as efficient antibacterial and anti-static properties, which were confirmed through various mechanical tests such as washing, folding, and rubbing experiments. This research presents an innovative approach for creating durable structural colored fabrics with multifunctional properties based on metal coordination and covalent bonds that can be effectively applied in textile printing and dyeing.

Preparation of high color fastness structural colored cotton fabric via SiO2@PDA photonic crystal

Structural color is an important way to achieve the ecological coloring of textiles. SiO2 microspheres with sizes in the range of 200–337 nm were synthesized by the Stober method and then covered with highly light-absorbing melanin PDA to form SiO2@PDA photonic crystals. The SiO2@PDA photonic crystals were assembled onto the surface of white cotton fabrics by gravity deposition to achieve structural color. The addition of polyvinylpyrrolidone (PVP) enhances interfacial bonding by forming multiple hydrogen bonds between its lactam group and the phenolic hydroxyl group of PDA, resulting in a structured color cotton fabric with high color fastness. Scanning electron microscopy (SEM) was used to study the structure and morphology of SiO2@PDA microspheres. The chemical compositions of PDA and PVP were surveyed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The surface structural color of cotton fabrics was investigated by UV–Vis reflectance spectroscopy.

Manufacturing of isocyanate-based oligomeric dyes with high coloring capabilities: synthesis and application in the dyeing of organic chrome-free leather

Leather dyeing is a critical step in leather manufacturing, as it is responsible for providing leather products with an eye-catching visual aspect and adequate quality properties to meet customers' expectations. This step is becoming more and more challenging as the leather industry advances hand in hand with new environmentally friendly policies and regulations to achieve a safer and healthier planet by replacing the highly polluting Cr-based leather tanning technology with greener alternatives. As a result, achieving high-performance dyeing of organic chrome-free leather is one of the bottlenecks for the sustainable development of the leather industry. Herein, we propose a novel strategy to fabricate an isocyanate-based oligomeric dye (IBD) with high coloring capabilities (component content higher than 62.8%) based on toluene 2,4-diisocyanate and reactive red dye 180. This material has been tested for the dyeing of biomass-derived aldehyde (BDA)-tanned leather with excellent outcomes. The experimental results showed that the crust leather dyed with our novel IBD dyeing agent had higher color fastness and better fullness than the leather dyed with conventional anionic (CAD) or reactive red 180 (RRD-180) dyes. These excellent and promising results open new avenues in manufacturing high-performance organic Cr-free leather products and help to ensure the sustainable transition of the leather industry from Cr-based leather tanning to more sustainable alternatives, maintaining the final quality of the leather products.Graphical abstract

Divinyl polysiloxane modified polyacrylate for promoting the directional migration of disperse dyes in digital jet dyeing of polyester fabric without washing

Future developments in the printing and dyeing industry will involve greenisation and personalisation. Less/no water digital technology has drawn much attention over traditional printing and dyeing for reducing carbon and emissions. Based on the solubility parameter difference between disperse dyes and monomers, divinyl polysiloxane modified polyacrylate (PSMA) with the directional migration effect for disperse dyes was prepared herein via mini-emulsion polymerisation. PSMA was used as wash-free polymer additive in the digital jet dyeing of polyester fabrics with disperse dyes, which yielded wash-free dyed fabrics with high color yield and color fastness. The results showed that PSMA achieved the optimum overall performance at a molar ratio of octamethylcyclotetrasiloxane to 1,3-divinyltetramethyldisiloxane 44:1 and divinyl polysiloxane dosage of 4 wt%. PSMA had the best tensile properties, good flexibility, certain hydrophobicity and high directional migration of disperse dyes. When the PSMA dosage was 9 wt% in the wash-free ink, the front and back color yield of the wash-free dyed fabric were 18.23 and 13.56, respectively. Compared with the fabric dyed with pure liquid disperse red, the front color yield of the wash-free dyed fabric increased by about 35.2 % and the back color yield had a little change. Its color fastness to dry/wet rubbing were improved from grade 3 to 4 and from grade 2–3 to 3, respectively. The handle of the wash-free dyed fabric basically maintained the level of original fabric.

Acrylic yarns pre-treated with different mordants and their dyeing potential with annatto dye

The study aimed to identify the best conditions for dyeing acrylic fiber with natural annatto dye, considering the presence of metallic mordants such as alum and ferrous sulfate, and evaluating the influence of soy milk or the absence of a mordant. Exhaust dyeing tests were conducted with the extract at different pH ranges to understand the behavior of the carotenoids bixin and norbixin in annatto seeds. Color intensity was measured by spectrophotometry, while colorfastness tests were performed to assess color transfer. The alum mordant showed less colorfastness than dyeing without a mordant, suggesting interference in dye fixation despite high color intensity values. On the other hand, the ferrous sulfate mordant exhibited limited leveling but high colorfastness. The natural pH range of the extract with soy milk mordant demonstrated good colorfastness and moderate intensity, resulting in a light-yellow shade. These findings underscore the complexity of interactions between natural dyes, synthetic fibers, and different mordants, emphasizing the importance of considering various factors to optimize desired outcomes in acrylic fiber dyeing.

Chameleon-inspired structural coloration of textiles with non-close-packed photonic crystals for high color saturation and color fastness

Photonic crystals (PCs) as eco-friendly structural coloring materials have great application potential in the textile coloration. However, the difficulties in scale production of structurally colored fabrics with PCs, as well as in achieving the balance between the structural stability and optical properties of PCs, limit the widespread use of such textiles. Herein, inspired by chameleon skin, the structural coloration of textiles with non-close-packed PCs was designed and prepared. The soft-shell and hard-core PS@P(MMA-BA) nanospheres were designed and prepared via stepwise emulsion polymerization for constructing soft non-close-packed PCs. The liquid photonic crystals (LPCs) were controllably prepared using a rotary evaporation/surfactant method. Therewith, the designed step by step self-assembly method enabled one to realize the controllable assembly of the nanospheres on the fabric surface, whereby the non-close-packed PCs with the cross-linked hard core as the skeleton and the fused soft shell as the filling medium were obtained. On the basis of step by step self-assembly, large-scale structurally colored fabric with non-close-packed PCs was prepared by continuous pilot equipment. The prepared structurally colored textiles possess high structural stability and color saturation, as well as the mechanochromic properties, and has the potential as a smart textile.

Progress in Stability Adjustment of Photonic Crystal Coatings on Fabrics or Fiber: A Review

Photonic crystals with bright colors have shown great potential application in bio-sensing, anti-counterfeiting, and smart wear. Different methods are used to construct photonic crystals on fabrics using different raw materials. However, building photonic crystals on fibers or fabrics with vibrant colors and good stability is still challenging. Various strategies have been used to increase the stability (e.g. wash, bend, friction stability, and so on) of the photonic crystal coatings on the fabrics or fibers. Therefore, this paper reviews great efforts to construct photonic crystal-coated materials, the methods to increase the stability of photonic crystal coatings on the fabrics, and their possible applications. The summarization of this review may lay the foundation for the construction of photonic crystals on fabrics with high color fastness and application in fabric coloring.

Effect of tannic/gallic acid-iron dyeing treatment on surface color and light fastness of bamboo veneer

Currently, the quest for bamboo materials with high color fastness, rich colors and environmental friendliness is rapidly rising due to its potential applications in construction, furniture and decoration. However, finding an easy-to-operate and environmentally friendly dye for bamboo is a necessary task because of the difficulty in treating the dyeing waste liquid of acid dyes and the complexity of the production process of reactive dyes.Five formulations involving metal polyphenol complexes were employed to straightforwardly produce eco-friendly dyed bamboo and the impact of various formulations on the light aging resistance of the dyed veneers was examined. The results indicated that the light resistance of bamboo veneer dyed with the solution containing only FeSO4·7H2O and tannic acid reached level 4, surpassing the undyed bamboo veneer by three levels. The mechanism of enhanced lightfastness of dyed bamboo veneer was elucidated by XPS analysis. The polyphenol iron complex serves a dual purpose: it absorbs ultraviolet rays and scavenges free radicals within the system. Additionally, it reduced the oxidation of phenolics in the substrate, transforming them into dark-colored quinone structures. This process enhanced the light-aging resistance of the finishing materials. Therefore, this work provides a simple and environmentally friendly method for changing the color of bamboo and provides a new idea for the selection of dyes for bamboo dyeing in actual production.

Low temperature reactive dyeing of silk: An investigation into dyeing conditions, and strength loss and friction damage of fabric

The low temperature dyeing of textiles has obvious energy-saving effect. Silk fabric suffers from friction damage in the rope dyeing process, and additionally silk is complained about unsatisfactory color fastness. To address the aforementioned issues, the reactive dyeing of silk fabric at low temperatures was studied in terms of dyeing conditions, dye selection, alkali resistance of silk, and strength loss and friction damageoffabric. Reactive dyes exhibited higher fixation to silk in alkaline bath than acidic and neutral baths. The breaking strength and whiteness of silk fabric was less affected by sodium bicarbonate, but greatly affected by sodium carbonate. Silk fabric treated with sodium carbonate at 50–60 ℃ had acceptable loss of breaking strength (<10 %). Silk fabric dyed at 60–80 ℃ using sodium bicarbonate exhibited higher color depth than that dyed at 50–60 ℃ using sodium carbonate. The high temperature dyeing in alkaline bath caused the friction damage and fuzz appearance of silk fabric, which did not occur in low temperature and alkaline conditions. The reactive dyes selected from commercial products could be applied at 50 ℃ and met requirements for high fixation, high color fastness and a variety of colors.

Initial research results on the possibility of using metacarbonate formations in Tan Lap - Cho Don - Bac Kan province as decorative stone

Based on the study of the characteristics of materials, structure, textures and physical properties of metacarbonate rocks at Tan Lap area, Cho Don district, Bac Kan province, it is possible to provide the initial possibility of using these rocks as decoration stones. Methods applied in the study include field investigations and sampling; sample analysis for thin-section microscopes, for the chemistry of sicilate and physical properties. The results indicate that metacarbonate rocks consist mainly of marbles which are allocated within the 3rd unit of the upper part of Mia Le formation (D1ml2). The rocks are thick layered structure, granoblastic texture, fine- to medium-grained marbles. Cao is the predominate chemical composition while heavy metals and radioactive elements are of very low contents. The rocks are pure white, exhibiting high color fastness and gloss. The outcomes of this study could serve as a scientific basis for guiding in exploration, exploitation, and utilization of mineral resources (marble) in the Tan Lap area particularly as well as in Vietnam's territory.

Excellent fixation and color fastness of nylon fibers dyed with low-water-soluble reactive dyes based on the reactivity and stability of vinyl sulfone

Reactive dyes in nylon dyeing have been associated with utilization inefficiencies despite their high color fastness. A potential solution to this issue involves combining the benefits of reactive dyes and milling acid dyes to obtain low-water-soluble reactive dyes (LWSRDs), which can stain and fix to nylon fibers under neutral conditions. To identify a suitable functional group for LWSRDs, six model dyes comprising one vinyl sulfone and five monochloro- s-triazines were prepared and reacted with glycine or hydrolyzed to simulate the fixation progress on nylon fibers. The results show that vinyl sulfone exhibited sufficient reactivity with glycine, and ∼3% hydrolysis over 90 min. Consequently, vinyl sulfone was considered a superior functional group for LWSRDs. Based on these results, four LWSRDs with monofunctional groups were synthesized and used for dyeing nylon 6 microfibers. Notably, these dyes exhibited fixation of &gt;91% and demonstrated exceptional color fastness against washing and rubbing, exceeding grade 4. These results underscore the potential of LWSRDs as highly efficient and effective dyes for nylon, offering a solution to the limitations associated with conventional dyeing techniques.

Environment-friendly and high-performance azo dye substitutes for enhanced optical characteristics and color fastness: Design and screening, risk assessment and mechanism analysis

Azo Dyes (ADs) are one of the most widely used dyes as they are characterized by high molar extinction coefficient and color fastness. However, it is difficult to remove them from the environment because of their stable structure. One of the bottlenecks in this field is to design environment-friendly and high-performance AD substitutes. Disperse Blue 79, which is commonly used in the dye industry, has been used as a target molecule for designing AD substitutes. A total of 27 substitutes with higher comprehensive effect value of molar extinction coefficient and color fastness (amplification > 20 %) were designed. After the assessment of environmental characteristics, stability and human health risk using the 3D-QSAR, molecular docking, density functional theory (DFT), and toxicokinetic techniques, the Derivative-47 was screened out. The synthetic possibility and characteristic enhancement mechanism of Derivative-47 were calculated using DFT and time-dependent density functional theory (TDDFT). Results showed the designed substitutes could be potentially synthesized in real environment (Gibbs free energy = −122.37 a.u < 0). The change in MO pairs, orbital transition and the electron transfer characteristics between the ground and excited states were the main reasons for the enhancement of molar extinction coefficient. Moreover, the increased color fastness could be primarily related to the reaction intensity of nucleophilic reaction site and the ability of molecules to lose electrons. This study aims to establish a system that integrates design, selection, and evaluation processes, provides new insights for the design of environment-friendly AD substitutes with higher molar extinction coefficient and color fastness.

Plasma-assisted in-situ preparation of silver nanoparticles and polypyrrole toward superhydrophobic, antimicrobial and electrically conductive nonwoven fabrics from recycled polyester waste

The preparation of multifunctional polyester fabric has been recently attractive research. Herein, a composite film of silver nanoparticles (AgNPs) and polypyrrole (Ppyr) were prepared and incorporated in situ into plasma-pretreated polyesters using the pad-dry-cure procedure of silver nitrate and pyrrole into polyester to provide a multifunctional textile. Recycled polyester waste was shredded and melt-spun to provide nonwoven fabric. Polypyrrole was generated in situ via REDOX polymerization process of pyrrole. This polymerization process was accompanied with reduction of Ag+ to Ag0 NPs, leading to permanent insoluble property within the structure of the polyester fibers. Thus, high colorfastness was monitored without varying the comfort features of the finished polyesters. The produced polypyrrole acted an electrically conductive agent, whereas silver nitrate functioned as an antmicrobial agent. By curing with hexadecyltrimethoxysilane (HDTMS), the superhydrophobic properties were imparted to polyester fabrics. The morphological studies were explored by energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM). The bend length and air-permeability of the finished polyesters were investigated to assess their comfort characteristics. The antibacterial behavior to S. aureus and E. coli were examined. Additionally, the finished fabrics showed ultraviolet shielding and electrical conductivity.

A Review of Environmental Impact of Azo Dyes

Green plants are one of nature’s factories, fixing inorganic chemicals into organic compounds through photosynthesis and other reactions. Microbes are one of the nature’s most effective tools, converting organic materials—dead plants and animals—into inorganic forms through decomposition and mineralization. Together, green plants and microbes are responsible for maintaining a balance between the organic and inorganic worlds, but pollutants, such as synthetic dyes, can upset this balance. Compared with synthetic dyes, natural dyes are safer and more environmentally friendly, but they are also costlier and more difficult to apply, so they are not viable in most commercial applications. Azo dyes are low cost and have high intensity and color fastness, so they are the most frequently used class of synthetic dyes. The main threats related to the dumping of untreated azo dyes into the environment come from their primary byproducts––aromatic amines––which result from the cleavage of the central azo bonds, and which have been classified as significant carcinogenic compounds, representing a great risk to humans as well as the environment. To address this threat, the degradation of synthetic azo dyes is showing promise as an approach to treating azo-dye wastewater. In this review, the classification of azo dyes and their color mechanism is presented first, and then an overview of the research on their environmental impacts is provided, including their effects on biochemical and chemical oxygen demand, water ecosystems, plants, and crops. Finally, the legislation and guidelines on azo dyes and their byproducts are discussed. Keywords: azo dyes; climate change; biochemical oxygen demand; chemical oxygen demand; aromatic amines

Microwave-assisted sustainable coloration of wool fabric using Rheum emodi-based natural dye

The use of natural colorants in modern dye factories is a potential green chemistry idea that should be widely promoted to minimize the dependency of wool dyeing on some hazardous and non-biodegradable synthetic colors. In this study, an effort was undertaken to see if Rheum emodi (rhubarb) extract might be used as a natural dye for wool dyeing for the replacement of synthetic dyes. The dyeing of wool fabric was carried out using microwave (MW) ray treatment. By combining several mordants, a stunning color palette of shades of varying hues and tones was created. Comparative evaluation of the effects of various chemical mordants (aluminum salt, iron salt, tannic acid and cream of tartar) and bio-mordants (pomegranate extract and pine nut hull extract) on the characteristics of dyed wool samples was carried out to choose the best mordant for each application. It was found that MW-treated wool fabric using a bio-mordant showed a higher colorfastness value of 4/5 to 5 and a color strength value of approximately 10–20 than using metallic mordant. Scanning electron microscopy photographs and Fourier transform infrared spectroscopy analyses revealed the difference between irradiated and unirradiated wool fabrics. The employment of MW rays and bio-mordants in the natural coloring of wool fabric is encouraged due to their biocompatibility and non-toxicity when combined with MW treatment of wool fabric, as well as their high colorfastness and color strength performance. As a result, naturally extracted dyes from rhubarb can be a replacement for synthetic dyes for the coloration of wool fabric in the textile industry due to their environmental friendliness.

Preparation of structural colors on cotton fabrics with hydrophobicity and high color fastness through chemical bonds between polyphenolic hydroxyl groups and polysiloxanes

Preparation of structural colors on cotton fabrics with hydrophobicity and high color fastness through chemical bonds between polyphenolic hydroxyl groups and polysiloxanes

Investigation of the uptake and compatibility behaviors of special disperse dyes developed for sustainable color matching in supercritical carbon dioxide

The uptake and compatibility behaviors of nine developed special disperse dyes belonging to different temperature groups were investigated for the first time on polyester fabric to achieve appropriate dyes for sustainable color matching in supercritical fluid of carbon dioxide (SCF-CO2). Different temperature-rising dyeing rate curves for the special dyes were established and employed to explore their uptake behaviors, compatibilities and other performances in SCF-CO2. Furthermore, the dye uptake behaviors and coloration compatibilities were also investigated at different system temperatures, pressures and dyeing durations. Then, a practical color matching was further carried out by utilizing low-temperature group dyes as a model in SCF-CO2. The obtained results show that an overall satisfactory uptake and compatibility behaviors of the developed dyes were achieved as for sustainable color matching, which were assigned to different temperature types in SCF-CO2. The temperature-rising dyeing rate curves for high-, moderate- and low-temperature type dyes show that very similar uptake behaviors and enhancement tendencies were obtained with the increase of system temperature and duration, accompanied with good coloration performances at uptake ratio ranging from 70 % to 90 % in a large supercritical dyebath. Moreover, significant and similar effects on the uptake behaviors of an individual group dyes from the parameters were achieved, which further indicate that good color matching compatibilities and uptake behaviors for each group dyes were available at different conditions. The practical color matching as well as the monochrome coloration in SCF-CO2 shows that different target shades in gray or various neutral colors, etc., were successfully achieved with low-temperature group dyes, by exhibiting perfect leveling property, high color fastness, which fully met industrial requirements in quality and environmentally friendly characteristics with water free.

Agricultural crop of Scrophularia striata as a new dye for eco-friendly dyeing and bioactive finishing of handwoven piles

Today, great efforts were carried out to introduce sustainable colorants with low cost and high efficiency to protect the environment as much as possible. In this study, an agricultural crop (Scrophularia striata) was introduced as a new source of natural colorant for the dyeing wool yarns. The response surface method was used to deduce optimum dyeing conditions and to investigate the interactive effects of main dyeing parameters. Obtained results show that the total flavonoid and polyphenolic contents of the hydroalcoholic extract of S. striata were estimated to be equal to 44.37 mg quercetin equivalent/g of extract and 98.47 mg gallic acid equivalent/g of extract, respectively, thereby suggesting S. striata to be an ecological and low-cost novel dye for woolen coloration process. A statistically predictive model of the dyeing procedure was developed to correlate the operating variables and the dependent factors. The results also reveal that the dyed samples at the optimized dyeing condition show relatively high colorfastness and noticeable antibacterial properties against Gram-positive and negative bacteria. This means that the extract of S. striata could be considered a natural dye for the wool dyeing process with remarkable antibacterial performance and low energy consumption and environmental impact. Hence, the introduced colorant in the present work seems to be of potential use for a value-adding green waste management.