Search Results (98)

As part of an implementation in the Peruvian textile industry, the use of different sources to obtain blue hues in alpaca fiber has taken on a prominent role. The present study investigated the optimization of the dyeing process of alpaca fibers using indigo carmine as dye. The methodology was based on a central composite design (CCD) and response surface methodology (RSM) with color strength (K/S) as response variable. The results demonstrate that the independent variables significantly affected the color strength (K/S). In this context, an increase in both mordant concentration (3.9887 g/L) and dyeing temperature (95 °C), coupled with lower exhaust time (30.0019 min), enhanced levels of superficial dye adsorption. Additionally, color fastness properties provided tolerable values according to the gray scale. In conclusion, the optimization of the dyeing process of alpaca fibers using indigo carmine enabled the achievement of a blue shade with satisfactory fastness properties in the fiber yarns. Full article

Bamboo’s single color and susceptibility to mold substantially limit its wide application. Therefore, dyeing and mold prevention have become pivotal technologies for the high-value-added utilization of bamboo. This study selected the extracts of three plants (Caesalpinia sappan L. (Cs), Rubia cordifolia L. (Rc), and Carthamus tinctorius L. (Ct)) for dyeing and mold prevention experiments. The results showed that the three extracts had good dyeing effects on bamboo, with total color differences (ΔE*) of 31.69, 21.61, and 32.29 compared to untreated bamboo, respectively. Additionally, these had a moderate inhibitory effect on mold. The introduction of metal mordants effectively enhances the dyeing effect of plant dyes and the effectiveness of mold inhibition. Through the joint modification of Cs and Cu, the color fixation rate increased from 3.12% to 9.20% compared with the Cs extract. A Cu 1 g:300 mL Cs extract impregnation of bamboo can completely inhibit the growth of Aspergillus niger, and a 1 g:1100 mL ratio can completely inhibit the growth of Trichoderma viride. This study provides a new concept for applying plant dyes in the dyeing and mold prevention treatment of bamboo. The dual-effect treatment of dyeing and mold prevention enhances the visual characteristics of bamboo while imparting it with good mold prevention performance. Full article

Increasing awareness of protecting the environment from chemically aided naive ecosystem degradation has encouraged the use of eco-friendly (biomass) materials in industrial production globally. This study investigated the application of a natural wine-colored extract from Brazilian plume (BP) leaf, obtained through a microwave-assisted modern aqueous extraction technique, for toxic-free dyeing of mordant-functionalized cotton fabric. Dyeing of mordanted cotton fabric was optimized by varying dyeing parameters, such as dyeing contact time (10 to 90 min), pH (1 to 11), liquor ratio (1:5 to 1:30), and temperature (30 to 90 °C). UV-visible and Fourier transform infrared spectroscopic analyses confirmed that the chemical constituents of the extract were not altered by microwave radiation. The desired color strength ($K/S$) and dye-uptake (Q) were obtained at a dyeing time of 50 min, a pH of 7, a liquor ratio of 1:20, and a dyeing temperature of 60 °C. Varieties of elegant shades with desired colorfastness were developed through the involvement of less-toxic electrolyte and herbal mordants as functionalizing agents. BP extract is established as a potential sustainable and ecological colorant for textile industrial application. Full article

As people attempt to elude the environmental issues associated with synthetic dyes, interest in natural dyes has recently increased significantly. Oolong tea stems act as a common agricultural waste yet offer advantages like high production, low cost, and a stable supply. The objectives of this research are to investigate the potential utilization of oolong tea waste, specifically tea stems, as a natural dye source for the development of organic cotton fabrics with added health benefits. In this study, using the Kubelka–Munk (K/S) value as an indicator, the dyeing process was refined through response surface methodology (RSM) by investigating the pH of the dye solution, temperature, and duration. Accordingly, it was demonstrated that the optimal effect was achieved at a pH value of 7.9, a duration of 80 min, and a temperature of 90 °C. Furthermore, under these conditions, the color fastness and functional performance of dyed organic cotton were compared with and without chitosan as a mordant. The results showed that the organic cotton dyed with oolong tea stem extract not only had a good color fastness grade but also presented excellent antibacterial properties, ultraviolet protection properties, and oxidation resistance. Especially with the assistance of chitosan, the dyed fabric achieved excellent performance above grade 4 in all color fastness test items; moreover, its antibacterial activity against Staphylococcus aureus reached more than 90%, the ultraviolet protection coefficient reached 25.3, and the antioxidant activity exceeded 90%. Consequently, considering environmental concerns, natural dyes extracted from discarded oolong tea stems are promising substitutes for synthetic dyes in the textile sector. Full article

The industrial and artisanal textile industries necessitate the adoption of sustainable dyeing practices. Although the natural dye derived from Dactylopius coccus presents a viable option, its traditional application requires metallic mordants that pose environmental and health risks. This study investigates the utilization of atmospheric-pressure plasma jet (APPJ) technology for dyeing wool with Dactylopius coccus dye, with the objective of optimizing the process and minimizing its environmental impact. The APPJ technique was employed for wool dyed with Dactylopius coccus dye, and the textile properties, medullation, and colorimetry were evaluated using an optical fiber diameter analyzer (OFDA) and a spectrometer with an integrating sphere. The results demonstrated that the APPJ enhanced the color intensity and uniformity, facilitating improved dye penetration into the fibers. Plasma treatment darkened the fiber, generated reddish and yellowish tones, and increased the color saturation and intensity. The wool samples treated with plasma exhibited an increase in DMF and SF but a decrease in IC and greater size variability. The APPJ reduces total medullation in wool dyed with cochineal dye. In conclusion, the APPJ was demonstrated to be a promising method for dyeing wool with Dactylopius coccus dye, offering an effective and sustainable alternative to traditional methods, with enhanced color vibrancy and uniformity and reduced resource utilization. Full article

The objective of this research was to evaluate the effect of dye obtained from Buddleja coriacea and metallic mordants on the chromatic properties, textile characteristics, spectral profiles, and color stability in alpaca fibers. The dye extraction technique involved boiling in an aqueous solution, followed by filtration. Subsequently, alpaca yarns were dyed using the resulting extract following a standard protocol. The applied mordants included sodium sulfate (Na₂SO₄), aluminum sulfate and potassium dodecahydrate (KAl(SO₄)₂·12H₂O), and oxalic acid (C₂H₂O₄). Spectroscopy UV-Vis and FTIR spectrophotometry methods were used for the characterization of the dyed samples and analysis of the dye during the dyeing process. The findings revealed the formation of four distinct color tones. Additionally, it was determined that the mordants influenced the chromatic properties of the fibers dyed with Buddleja coriacea extract without modifying their textile characteristics. The identified spectral bands corresponded to keratin, the structural protein of the fibers. Changes in the intensity of these spectral bands were observed in the dyed samples, attributable to the presence of different mordants. Wet rub fastness was found to be inferior to dry rub fastness, which has implications for textile maintenance. In conclusion, Buddleja coriacea flowers provide an effective yellow dye, and when combined with various mordants, they allow for a variety of shades and hues in alpaca fiber yarns. Full article

Background/Objectives: The use of natural colourants is gaining attention due to their biocompatibility and functional benefits. This study introduces a different approach using turmeric (Curcuma longa L.) dye extract combined with chitosan to significantly enhance the antibacterial and UV-shielding properties of silk. Methods: The turmeric dye’s chemical composition was analyzed using liquid chromatography mass spectrometry (LC-MS), UV–visible spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). The dyed silk’s colourfastness was tested through rubbing, washing, and light exposure. Results: The chitosan-mordanted silk showed strong antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as well as antifungal activity against Aspergillus niger (A. niger). It also demonstrated a high ultraviolet protection factor (UPF). For comparison, alum-mordant was used, and chitosan proved more effective. Beyond its use as a dye, turmeric is renowned for its medicinal properties. Its antioxidant, anticancer, and anti-inflammatory properties have been extensively researched, which are primarily linked to its curcuminoid compounds. Turmeric is used in traditional medication to treat digestive issues, arthritis, and skin diseases. Conclusions: This work underscores the innovative use of plant-based dye extracts and natural mordants like chitosan as a sustainable alternative to conventional metallic mordants, paving the way for the evolution of bioactive silk with improved functional properties. Full article

Recently there has been growing interest in dyeing biomaterials using natural sustainable plant extracts classified as eco-friendly. The microwave-assisted method provides fast heating and energy efficiency, more homogenous heat distribution in dyeing baths, less use of chemicals, and less heat loss, resulting in this method being greener—more sustainable and ecological. Artificial neural networks (ANNs) are used to predict the dyeing properties of fibers, which are often complex and dependent on multiple variables. This saves time and reduces costs compared to trial-and-error methods. This study presents the green dyeing of merino wool fiber with natural dye extracted from Aesculus hippocastanum (horse chestnut) shells using the microwave-assisted method. Before dyeing, the merino wool fiber underwent a pre-mordanted process with aluminum potassium sulfate with different concentrations using the microwave-assisted method. Spectrophotometric analysis of the light, washing, and rubbing fastness of the dyed merino wool fibers was performed. The color strength, light, washing, and rubbing fastness of the dyed merino wool fiber were developed using the pre-mordanting process. After the pre-mordanting process, the light fastness of the samples improved from 1–2 to 3, the color change increased from 2 to 3–4, and the rubbing fastness developed from 2–3 to 4 according to mordant concentration, mordanting time, and dyeing time quantities. The spectrophotometric analysis results indicate that color coordinates vary based on mordant concentration, mordanting, and dyeing duration. Furthermore, the results proved that microwave energy significantly shortened the mordanting and dyeing duration, resulting in an eco-friendly dyeing process. In this investigation, a feed-forward neural network (FFNN) model with sigmoid hidden neurons and a linear output neuron was used to predict the color strength dyeing property of merino wool fiber. Experimental results showed that the proposed model achieved a regression value of 0.9 for the color strength dyeing property. As demonstrated, the proposed FFNN model is effective and can be utilized to forecast the color strength dyeing properties of merino wool fiber. Full article

Smart colorimetric packaging has been an important method to protect human health from external hazardous agents. However, the currently available colorimetric detectors use synthetic dye probes, which are costly, toxic, difficult to prepare, and non-biodegradable. Herein, an environmentally friendly cellulose nanocrystal (CNC)-supported polyvinyl alcohol (PVA) nanofibrous membrane was developed for the colorimetric monitoring of food spoilage. Anthocyanidin (ACY) is a naturally occurring spectroscopic probe that was isolated from pomegranate (Punica granatum L.). By encapsulating the anthocyanin probe in electrospun polyvinyl alcohol fibers in the presence of a mordant (M), M/ACY nanoparticles were generated. After exposure to rotten shrimp, an investigation on the colorimetric changes from purple to green for the smart nanofibrous fabric was conducted using the coloration parameters and absorbance spectra. In response to increasing the length of exposure to rotten shrimp, the absorption spectra of the anthocyanin-encapsulated nanofibrous membrane showed a wavelength blueshift from 580 nm to 412 nm. CNC displayed a diameter of 12–17 nm. The nanoparticle diameter of M/ACY was monitored in the range of 8–13 nm, and the nanofiber diameter was shown in the range of 70–135 nm. Slight changes in comfort properties were monitored after encapsulating M/ACY in the nanofibrous fabric. Full article

In recent decades, fabric-dyeing processes involved greener processes because, since ancient times, dyers used mordants based on metals to make the color better adhere to the textile fibers, but this is the reason for their increased pollution. To develop new strategies, attention was focused on finding the best condition for a dyeing method for natural fibers of vegetable and animal origin (cotton and wool) using an ancient natural dye known as folium. Folium was used mostly in miniature painting in an attempt to avoid the use of classical mordants and solvents. To this purpose, plasma treatment and chitosan coating were employed. Firstly, the textile fibers were analyzed through infrared spectroscopies to verify surface modifications; subsequently, the post-treatment morphological variations were observed via scanning electron microscopy. Both techniques highlighted a significant variation of the surface functional groups due to plasma treatments with He-O₂ mixtures, which allowed a greater adhesion of chitosan on the fiber’s surface. Finally, the color strength of samples dyed with folium was tested through fiber optic reflectance spectroscopy, and the folium absorbance peaks were still detected after fabric washing. It is thus shown how an ancient, traditional raw matter has become relevant for developing new modern technologies. Full article

The increasing demand for sustainable practices in the textile industry has led to the exploration of natural dyes and eco-friendly dyeing processes. This study focuses on the potential of used coffee grounds (UCG) as an eco-friendly natural dye for Nylon 6.6 woven fabrics. Five dyeing processes were evaluated, varying in the use of mordants and acids, to assess their impact on the color saturation, colorfastness to laundering, and crocking resistance of Nylon 6.6. fabric. The processes included a control with no mordant or acid and others that incorporated tannic acid, acetic acid, and ferrous sulfate heptahydrate. The results demonstrated that process 4, which combined tannic acid pre-mordanting with acetic acid in the dye bath, provided the best balance between color saturation and colorfastness. Process 2, utilizing only tannic acid, offered some durability in laundering and crocking tests. Process 5, being the least eco-friendly process, demonstrated high color saturation, but it performed poorly in colorfastness to crocking, which means that it released the UCG-based dye after rubbing the dyed Nylon 6.6. fabric. The findings confirm that UCG can be an effective and sustainable natural dye for Nylon 6.6, with pre-mordanting and acid treatment significantly enhancing dye uptake and retention. However, further research is needed to optimize color intensity and expand the application of UCG in textile dyeing. Full article

In this current research, various amino acids (lysine, betaine, and cysteine) and peptides (oxidised or reduced glutathione) were considered as potential environmentally friendly alternatives to wool bleaching. A greener methodology was also applied to dyeing. Different agro-wastes (red cabbage, peppercorns, and red and yellow onion peels) served as raw pigment materials. The process’s efficiency was characterised by the whiteness degree, colour strength, and fastness to accelerated washing and perspiration. A higher whiteness index value was observed in the cysteine-based formulations. The onion peel exhibited significant tinctorial properties due to the presence of some natural mordants. All the proposed treatments were designed with a primary focus on environmental sustainability. These treatments offer a sustainable and environmentally friendly alternative to traditional bleaching and dyeing methods for wool. They reduce costs and energy consumption while creating added value by valorising waste. Full article

The current study proceeded to reduce the environmental hazards spreading worldwide due to synthetic dyes. To overcome these problems, eco-friendly natural dyes are introduced as alternative sources of synthetic dyes. The present study was focused on exploring the bio-colorant of the aqueous and acidic extract of the bark of Melia azedarach L. for the dyeing of both silk and cotton samples. The results of the extraction medium specified that the aqueous extract gave maximum colorant solubility and upon fabric dyeing produced higher color strength in contrast to the acidic medium. The optimization experimentation data showed that excellent color strength of silk fabric was found at 45 min dyeing time duration, in 35:1 mL dye extract, and using 2% salt (NaCl) as an exhausting agent, whereas cotton fabric showed the maximum K/S value at 60 min dyeing time, in a 45:1 mL liquor ratio, and with the use of 2% salt. Bio-mordants produce different shades on both fabrics. Bio-mordanting experiments on silk revealed that pre-mordanting with 2% turmeric and 3% pomegranate, and post-mordanting using 3% turmeric and 2% pomegranate produced a darker shade. In the case of cotton, the pre-mordanted samples with 2% turmeric and 3% pomegranate and the post-mordanted samples with 4% turmeric and 4% pomegranate gave the highest color strengths. All the mordanted samples gave excellent fastness ratings. Overall, it has been found that Bakain bark proved to be an excellent source of tannin. The result of this study showed that it could be a cost-effective and eco-friendly dye source for textile progress. Full article

Recently, the natural dyeing process has achieved great importance in the textile wet processing industry due to its clean dyeing, eco-friendliness, and nontoxicity in nature. In the above research project, a unique natural dye extracted from dragon fruit was applied to wool fabric using various mordanting agents to encourage the use of natural dyes and lessen the negative environmental effects caused by synthetic dyeing. The color characteristics (K/S), fastness properties, Fourier transform infrared spectroscopy (FTIR), absorption spectra, and thermal and ultraviolet (UV) resistance of the extracted dye and dyed wool samples were tested and characterized. The K/S values of the dyed wool fabrics were between 5.75 and 13.29. The color fastness ratings obtained from the dyed wool fabric were found to be between good and excellent. Hence, the overall results proved that the novel natural dye obtained from dragon fruit can be utilized for dyeing wool material for the production of eco-friendly and sustainable antimicrobial textiles. Full article

Early modern materials are not well represented in dye and mordant analyses despite extensive documentary evidence suggesting the enormous demand for coloured fabrics, even among those below the elite. Non-wovens likewise receive less attention than woven textiles despite their ubiquity in the early modern historical record. Knitted garments, in particular, have rarely been subjected to dye analysis. One garment is noteworthy for its colourfulness, despite not being visible in formal wear. Men throughout society wore knitted undergarments known as waistcoats from the late sixteenth century. The waistcoats under investigation here are from the collections at the London Museum and the Grimsthorpe and Drummond Castle Trust, Scotland. They are made of silk and are now a pale blue-green colour. Small samples were taken from each and subjected to a series of analytical techniques: micro-Raman spectroscopy, UV-Vis microspectrofluorimetry, and high-performance liquid chromatography (HPLC) coupled with a mass spectrometer. Using this protocol, it was possible to characterise the dyes in the waistcoats by ensuring that maximum information was gleaned from a sample before it was exhausted. Full article