The worldwide resurgence of natural dyes in all fields is due to the carcinogenic effects of effluent loads shed by synthetic industries. Coconut coir (
Cocos nucifera
) containing tannin as a source ...of natural colorants has been selected for coloration of bio-mordanted silk under the influence of ultrasonic radiations at various dyeing conditions. For extraction of tannin dye from cocos powder, different media were employed, and dyeing variables such as dyeing time, dye bath pH, dyeing bath temperature, and the effect of salts on dyeing were optimized. For achieving new shades with excellent color characteristics, bio-mordants in comparison with chemical mordants were employed. It has been found that acid-solubilized extract after ultrasonic treatment for 45 min has yielded high color strength, when coconut coir extract of 4 pH from 6g of cocos powder, containing 5g/100mL salt solution as exhaust agent, was used to dye silk at 75°C for 65 min. Among bio-mordants turmeric (
K
/
S
=13.828) and among chemical mordants iron has shown excellent results (
K
/
S
=2.0856). Physiochemical analysis of fabric before and after US treatment shows that there is no change in the chemical structure of the fabric. It is found that ultrasonic waves have excellent potential to isolate the colorant followed by dyeing and environmental friendly mordanting at optimal conditions, but also the usage of herbal-based plant anchors, i.e., bio-mordants, has made the natural dyeing process more sustainable and clean.
The revival of cultural heritage in a form of natural colorants for textile dyeing is gaining popularity due to their soothing nature and bright shades. The present study was conducted to explore the ...coloring potential of harmala (
Peganum harmala
) seeds and to improve color strength of dye using microwave radiations followed by a mordanting process. The results showed that harmala plant seeds could be an excellent source of natural dyes for cotton dyeing if the irradiated acidified methanolic extract (RE, 4 min) is used to dye un-irradiated fabric (NRC) at 85 °C for 45 min using a dye bath of pH 9.0 having salt concentration of 7 g/100 mL. Alum (1%) as pre-mordants and iron (7%) as post-mordants have improved the color strength in chemical mordanting more than other mordants employed. The bio-mordants employed reveal that 10% of acacia as pre-bio-mordants and 7% of acacia as post-bio-mordants are effective amounts to obtain high color strength. Suggested ISO standards for colorfastness illustrate that bio-mordanting has given more excellent rating as compared to chemical mordants. It is concluded that harmala seeds have a great potential to act as a source of natural colorant for cotton dyeing under the influence of microwave radiation.
Ecofriendly exploration of Arjun bark (
Terminalia arjuna
) is a herbal natural colorant for cotton dyeing. This is because the demand for natural dyes has been increased worldwide due to their ...therapeutic usage and other food, textiles, agriculture, engineering, and medical applications. Therefore, this study has been carried out due to the isolation of colorant from Arjun bark in an acidified methanolic medium after exposure to ultrasonic rays up to 60 min. Additionally, using bio-mordants, it has been found that the application of 10% of Zeera (
Cuminum cyminum
) extract as meta-bio-mordant, 3% of Ilaichi (
Elettaria cardamomum
) extract as meta-bio-mordant, and10 % of Harmal (
Peganum harmala
) and Neem (
Azadirachta indica
) extract as meta-bio-mordants has given excellent color strength. These bio-mordants have not only made the coloration process more eco-friendly, viable, and greener, but also improved color strength with various tonal effects from red to reddish brown shades. Thus, it has been found that ultrasonic treatment as an environment-friendly tool has not only enhanced the color strength of natural colorant isolated from Arjun bark onto the cotton fabric under mild conditions.
Graphical abstract
Revival of natural colorants in textile dyeing is one of the important strategies to reduce synthetic chemical-based environmental pollution. The study has been conducted to explore the coloring ...potential of durum (
Triticum durum
Desf
.
) and bread (
Triticum astivum
L.) wheat husk for fabric dyeing. The results showed that both wheat species husk could be an excellent source of natural dye, if extracted in alkaline medium. It has been observed that durum wheat husk based dye worked best at 70°C with a pH 11.0 and salt concentration of 8.0 g/100 ml of solution. Similarly, alkaline extract of bread wheat husk worked better at 80°C with dyeing solution pH 9.0 and salt concentration of 8.0 g/100 ml. Bio-mordanting experiments results revealed pomegranate rind (7%) as most effective bio-mordant to obtain high color strength of wheat husk treated fabric. In chemical-mordanting, tannic acid (5%) as pre-mordant and chrome (5%) as post-mordant have improved the color strength more than all other quantities of employed mordants. FTIR analysis indicated the presence of flavonoids as major colorant compounds in wheat husk–based natural dye. Suggested ISO standards for colorfastness illustrated good color strength ratings of husk-based dyed fabric when treated with bio-mordants as compared to chemical counterparts. Hence, husk of both bread and durum wheat species has great potential to be used as source of eco-friendly natural colorant for cotton dyeing.
Present study is concerned with the dyeing behavior of gamma irradiated cotton using direct dyes. The fabric and dye powder was exposed to absorbed doses of Cs-137 gamma irradiator between 14 and ...26 kGy. It was found that 18 kGy is the optimal absorbed dose for tuning the surface of fabric to get colour strength using Direct Yellow 12, whereas good colour strength was obtained by dyeing irradiated fabric at 70 °C for 70 min by keeping M:L of 1:30 using dyeing bath of pH 10 in the presence of 2 g/L of table salt. While 14 kGy is the most effective absorbed dose for Direct Yellow 27 where good colour strength was obtained at 80 °C for 60 min keeping M:L of 1:70 in presence of 10 g/L of salt using neutral dyeing bath. At these conditions not only leveled dyeing was achieved but the colourfastness was also improved.
The recent pandemic scenario has caused demand for green products that have medicinal aspects, as well as greener approaches for global health. Natural dye from plants, particularly from harmal ...seeds, is an excellent alternative to carcinogenic yellow synthetic dyes. The current study has been conducted to isolate natural colorants from harmal seeds in methanolic medium through Gamma-Assisted Extraction (GAE). The dyeing variables that are necessary for shade development before and after mordanting were selected. It has been found that 6 kGy is the optimal absorbed dose for extraction of colorant from 6 g of powder to isolate the colorant in the methanolic medium through the Gamma-irradiated extraction mode (GAE). To get excellent results, 30 mL of methanolic extract containing 6 g/100 mL of Glauber salt was sued for dyeing of irradiated wool at 45 °C for 65 min. For improving the color strength and acceptable rating of fastness, 9% of henna, 3% of acacia, 10% of turmeric, and 7% of pomegranate extracts as pre-bio-mordants as well as 7% of acacia, 3% of pomegranate, 9% of henna, and 10% of turmeric extracts as post-mordants have given high results compared to when chemical mordants have been used. It was concluded that Gamma-ray treatment has excellent color strength in the dyeing of bio-mordanted wool using harmal seed extracts under mild conditions, and has good fastness ratings after using chemical and bio-mordanting methods as well.
Sustainability in all applied fields particularly in textiles is to protect our globe, environment, and community, where green dyed products are playing their role. For the current study, Esfand (
...Peganum harmala
) has been explored using a green isolation tool, i.e., ultrasonic (U.S.) rays, and applied onto fabric. Different dyeing parameters have been explored statistically through response surface methodology by employing temperature (50–80°C), time (25–65 min), extract volume (15–55 mL), salt (1–5 g/100 mL), and dye bath pH (4–7) through series of experiments. For developing new shades, green mordants such as elaichi, neem, turmeric, and zeera have been utilized. It has been found that exposure of 35 mL extract of 7 pH containing 3 g/100 mL of salt as exhausting agent to U.S. rays for 30 min for the dyeing of silk at 70°C for 45 min has given maximum color strength with reddish-yellow shades. Color characteristics obtained in the CIE Lab system reveal that 5% of turmeric as meta bio-mordant has given good quality reddish-yellow shades. It is found that U.S. rays have not only good potential to isolate colorant followed by dyeing of silk under reduced condition but also the application of bio-mordants have made the process more greener, sustainable, and cleaner.
Graphical abstract
Natural products with therapeutic nature are nowadays warmly welcomed in textiles. Current study is concerned with isolation of tannin from neem bark (Azadirachta indica) and its application onto ...silk fabric. For improvement in shades, chemical & bio-mordants have been employed at optimal dyeing conditions. It is found that methanolic extract of pH 5 obtained 8 g dye powder after US Treatment for 30 min has given high color strength if used to dye irradiated silk for 65 min at 75 °C. Bio-mordanting using herbal plants has improved the color characteristics as compared to chemical mordants used. ISO standards for color fastness reveal that herbal based bio-mordants have improved the rating from good to excellent as compared to chemical mordants used. It is concluded that US treatment has not only isolate the colorant for neem bark under mild condition but also given excellent characteristic using bio mordants onto silk fabrics.
Natural products particularly natural colorants have attained worldwide importance and being eco-friendly can be considered an alternative to toxic dyes in order to reduce environmental pollution. ...The current study is based on the exploration of natural coloring behavior of bitter gourd leaves extract for cotton dyeing. Colorant was extracted using different extraction media like aqueous, alkali, organic, and acidic at different conditions. It has been found that on application of 50 ml of acidic extract having 6 g/100 ml of table salt for 55 min at 60 C°, maximum color yield has been obtained onto cotton. Upon using chemical and bio-mordants, new shade with good color fastness rating was obtained. FTIR analysis of extract showed the presence of flavonoids. It is concluded that under mild condition, bitter gourd leaves extract can be considered potential source of natural colorant for cotton dyeing and the presence of bio-mordant has made the process more soothing and sustainable in nature.
In the era of the industrial revolution with the increased demand for sustainable products, the use of natural products particularly herbal‐based bio‐colorants in every walk of life is increasing. In ...the current study, cinnamon as a source of natural dye for wool has been explored under the influence of microwave radiations and the application of sustainable bio‐mordants has been done under mild conditions. Microwave radiations for 1–6 min have been used to increase the extraction yield and 1–10 g/100 ml of sustainable chemical and bio‐mordants have been employed to get excellent color characteristics. The utilization of reduced amounts of herbal nature‐based bio‐mordants in comparison with chemical anchors after microwave irradiation of extract and the woolen fabric has not only produced new shades but also improved the color characteristics from good to excellent. It is concluded that the use of microwave treatment as the sustainable tool has excellent potential to isolate the colorant from cinnamon bark under mild conditions; whereas the addition of bio‐mordants has valorized the coloring process greener and more valuable.
