Chemical Mordants Research Articles

Cashew (Anacardium occidentale L) bark extract for eco-safe dyeing of mordanted cotton fabric: Colorimetric and biomedical functional properties

Large volume of wastewater containing toxic chemicals often discharged into the environment by textile industry is adversely damaging the quality of the ecosystem. This study aimed to circumvent this unfortunate practice through replacement of toxic chemical-mordants with eco-safe herbal-mordants in the cashew bark (CB) naturally dyed cotton fabric. The high dye yield obtained within short period of time vindicated microwave (MW) radiator as a cost, time and labor efficient modern heating tool in dye extraction from natural source. The MW-assisted CB dye extract was chosen for dyeing cotton fabric based on its desired properties (like high yield, low moisture content and bulk density). It was discovered that dye exhaustion, dye-uptake and tint strength of cotton fabric were enhanced after 4 min MW treatment. Utilization of calcium (II) chloride (CaCl2) and iron (II) sulfate (FeSO4) as chemical mordants, Vernonia amygdalina and Sorghum bicolor leaf extracts as bio-mordants has given a set of attractive shades (yellow to chocolate). The mordanted CB dyed cotton fabrics have desired dye exhaustion, dye-uptake and tint strength. The good colorfastness and biomedical functional properties of MW induced CB dyed cotton fabric were enhanced to excellent after post-mordanted with the herbal-anchors. Overall, MW treatment and exploitation of herbal-anchors have showcased the cotton natural dyeing process as the potential industrial cleaner, ecological-friendly and sustainable practice.

Enhancing silk dyeing with eco-friendly colorant extracted from Cassia fistula brown pods using green mordants

This research project focuses on the extraction of the natural brown colorant, anthraquinone, from Cassia fistula pods using microwave radiation as a method for dyeing silk fabric. The colorant was isolated in aqueous and acidic mediums before and after microwave radiation for up to 6 min, and subsequently used for dyeing purposes. To achieve new and diverse hues, environmentally friendly chemical mordants (iron salt, aluminum salt, and tartaric acid) and biological mordants (red sumac, pomegranate, and hulela zard) were applied in varying quantities (ranging from 0.5g to 2.5g per 100 mL). Colorfast shades were developed by employing these mordants before and after the dyeing process on silk fabric. The dyeing variables essential for shade development before and after mordant application were determined through the utilization of central composite design for statistical analysis. The results indicated that the optimal conditions for irradiating both silk and extract were 6 min, while dyeing the irradiated silk fabric should be conducted at 75 °C for 45 min using 30 mL of extract irradiated at a pH of 3, with a salt concentration of 1.5g/100 mL. The optimized dyeing conditions also showed maximum level of colorfastness properties of 5 for light, 5 for wash, 5 for dry rubbing and 4/5 for wet rubbing. As a result, the extraction of anthraquinone from Cassia fistula pods using microwave radiation has the potential to be effective and ecologically benign, allowing for the creation of bright and colorfast hues on silk fabric. The results support the development of novel and sustainable dyeing techniques in the textile sector.

Microwave-assisted cleaner extraction of tannin from Terminalia chebula: A promising green method for sustainable leather dyeing

Natural dyes have gained significant attention in recent years due to their environmentally friendly characteristics. This research paper focuses on the dyeing of leather using a natural dye extracted from hulela zard (Terminalia chebula). The objective of this study was to evaluate the efficiency of microwave-assisted extraction in isolating tannin from hulela zard and its subsequent application in leather dyeing. The research involved optimizing various dyeing parameters, such as temperature, time, pH, salt concentration, and extract volume, using a central composite design and response surface methodology. The results showed that microwave treatment significantly improved the extraction yield of tannin from hulela zard, while also enhancing the sorption behavior of leather. Scanning electron microscope (SEM) analysis confirmed the surface modification of leather without affecting its chemical structure. Fourier transform infrared spectroscopy (FTIR) revealed no significant changes in the functional groups of dyed and undyed leather samples, indicating the preservation of the leather's chemical integrity. The colorfastness properties of the dyed leather were evaluated, and it was found that the combination of specific chemical mordants and bio mordants resulted in desirable colorfastness ratings. Overall, this research demonstrates the effectiveness of microwave-assisted extraction for obtaining tannin from hulela zard and its successful application in leather dyeing, offering a sustainable and environmentally friendly alternative to synthetic dyes.

Environmental friendly utilization of plant wastes in combination as a source of natural colorants for binary mordanted silk dyeing.

This study investigates the absorption behavior of natural dyes on silk fabric: madder roots (red dye) and amaltas (brown dye). The dyes were extracted under optimized conditions in an acidic medium. Binary mixtures of these dyes in different proportions were employed to develop various shades. This research work has explored the impact of single as well as binary mixture of chemical mordants on the dyeing behavior of natural dyes on silk. Al (Alum), iron (Fe), and tannic acid (T.A.)were used as pre- and post-mordants. Different concentrations of the dye mixtures were used to achieve different shades. The absorption behavior of the binary mixture of natural dyes was assessed using a spectra photometer Colori-spectra SF600. The study found that the highest color strength was achieved when an acidic extract with a table salt concentration of 2 g/100 mL was applied to silk fabricat 65 °C for 55 min and subjected to microwave treatment for 6 min. The study revealed excellent results for the selected binary mixtures of chemical mordants, such as (Al + Fe), (Al + T.A.), and (Fe + T.A.), in comparison by employing single mordants such as (Al, Fe, and T.A.).

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.

Sustainable Microwave-Assisted Extraction of Santalin from Red Sandal Wood Powder (Ptrecarpus santalinus) for Bio-Coloration of Mordanted Silk Fabric

The coloring behavior of santalin, a natural reddish-brown dye derived from sandalwood, has been investigated in this work for the dyeing of silk fabrics while being heated in MW radiation. Microwave (MW) radiation up to 5 min has been employed to isolate colorant (Santalin) from red sandalwood (Ptrecarpus santalinus) in selected medium, and bio-mordants in competing with salts as chemical-mordants have been included. Statistical analysis was made and dyeing variables were selected for getting dark shades though mordants. MW treatment for 3 min. to both extract and fabric was selected and mild dyeing conditions were optimized statistically to get dark shades. On applying chemical mordants, selected amount of salts of Al+3, Fe+2 and T.A. before and after dyeing, has given good results. Comparatively, selected extracts of plant based sources have shown colorfast shades of high strength. The MW radiation has excellent potential to extract dye form plants using optimum medium through less time and energy, and the application of plant extracts along with sustainable salts have developed colorfast shades.

Sustainable and Environmental Dyeing with MAUT Method Comparative Selection of the Dyeing Recipe

The textile industry is one of the most complex sectors, in terms of the materials and chemical processes used from petroleum and the environmental degradation during its production and disposal. It is therefore a sector looking for new possibilities and for more sustainable materials and applications. One option is to use natural dyes, as they are considered biodegradable, do not pollute the environment, and have potential use for many sectors, including the fashion industry. In this study, Alanya silk was dyed by a natural dyeing method with crocus sativus, Helichrysum arenarium, and Glycyrrhiza glabra L., plants that grow in and around the Alanya region. Quercus aegilops L. grown in the region was preferred as mordant, a natural binder, and is one of the plants with the highest tannin content, and it was used with a more environmentally friendly and sustainable approach to increase the binding in natural dyeing instead of chemical mordants. The aim is to provide an environmental and scientific contribution to the dyeing producers in this region. According to the MAUT (Multi-Attribute Utility Theory) method, the best dyes in terms of fastness and color efficiency were determined as the dyes made with the Glycyrrhiza glabra L. plant.

Microwave-assisted sustainable exploration of cocklebur leaves (Xanthium strumarium L.) as a novel source of distinct yellow natural colorant for dyeing cotton fabric.

During current times, the use of bio-colorants attained public acceptance as a sustainable alternative to synthetic ones which in turn reduced the environmental contamination. The present study focused on the green, safe, and clean technology for the resurgence of natural colorant from cocklebur (Xanthium strumarium L.) leaves and their application to cotton fabric. Natural colorants were extracted by employing an eco-friendly microwave-assisted extraction process using an aqueous and alkaline medium. Dyeing of cotton fabric was carried out using irradiated and unirradiated cotton fabric with irradiated and unirradiated natural dyes of cocklebur leaves. The results of extraction experiments revealed that 4min microwave-assisted alkaline extract exhibited significantly outstanding color strength onto microwave-treated cotton fabric compared to aqueous one. Further to investigate the optimum dyeing conditions for cotton fabric, various dyeing variables such as dyeing time, dyeing temperature, dye concentration, and exhausting agent were monitored and found a superior result using a dye concentration of 45ml, for dyeing cotton fabric at 75°C for 50min in the presence of 4g/100ml of table salt. For improvement in color strength and color fastness properties, the effects of various bio-mordants, such as eucalyptus bark, acacia bark, turmeric rhizome, and onion shells, and chemical mordants (aluminum and copper) on dyed cotton fabric were also evaluated. It was also observed that cotton fabric dyed with alkaline extract of cocklebur leaves using bio-mordants as pre-mordants (4% acacia, 4% eucalyptus, 2% onion) and post-mordants (3% onion, 3% eucalyptus, 4% acacia) exhibited the highest color strength and various hues with acceptable colorfastness properties against light, washing, and rubbing in comparison to chemical mordants. The ISO standard for fastness also revealed that bio-mordanting has enhanced the rating from good to excellent in comparison to chemical mordants. The results provide ample scope for the extraction of yellow natural dye from the cocklebur leaves for eco-friendly coloration of fabrics using bio-mordants.

Sustainable Isolation and Application of Plant Extract-Based Natural Dye for Bio-Dyeing of Silk Fabric

Green products such as plant pigments are gaining fame globally due to their excellent ayurvedic and biological characteristics. In this study, microwave (M.W.) has been employed to isolate colourant from black pepper (Piper nigrum L.), and bio-mordants have been included to obtain colourfast shades. Central Composite design (CCD) was formulated under response surface methodology (RSM) to optimize dyeing variables statistically. The results obtained after a series of experiments show that using 35 mL of irradiated acidic extract (RE = 6 min) of (pH4) in the presence of 1 g/100 mL of table salt as an exhausting agent at 65 °C for 55 min has demonstrated excellent colour depth (K/S) onto microwave-treated silk fabric (RS = 6 min). By applying bio-mordants, it has been found that walnut extract (1.5%), pinenut hull extract (1%), and orange peel extract (1.5%) are there before dyeing. In contrast, walnut extract (1.5%), pinenut hull extract (1.5%), and orange peel extracts (1.5%) after dyeing have shown colourfast shades of high strength. Comparatively, salts of Al+3 (1.5%), salts of Fe+2 (1.5%), and T.A. (tannic acid = 1.5%) before dyeing, while salts of Al+3 (0.5%) and salts of Fe+2 (2%) and T.A. (Tannic acid = 1%) after dyeing, have given good results. It has been observed that the use of M.W. radiation has not only improved the yield of dyes extracted from leaves when applied to silk fabric but also the inclusion of the optimum amount of bio and chemical mordants have resulted in moderate to good and excellent colour fastness ratings.

Lantana camara flowers as a natural dye source for cotton fabrics

ABSTRACT Environmental concerns about synthetic dyes and their carcinogenic properties renewed interest in eco-friendly natural dyes. Natural dyes produce a wide range of tints and shades with the same dye material. In this study, natural colorants from Lantana camara flowers, a Verbenaceae plant, have been applied to bleached cotton fabrics following pre-mordanting, simultaneous mordanting, and post-mordanting with different chemical mordants (copper sulfate, ferrous sulfate, nickel sulfate, potassium aluminum sulfate, potassium dichromate, stannous chloride). Dyed samples were tested for wash-fastness, light-fastness, and rubbing-fastness, as per Standard IS methods. The colors of dyed pieces were evaluated with color matching software using CIELAB (ΔL*, Δa*, Δb*) coordinates and K/S values for dye absorption on cotton. Pre-mordanting produced good dye uptake. The extracted natural dye was analyzed using Ultraviolet-Visible Spectroscopy, Fourier-Transform Infrared Spectroscopy, and Inductively Coupled Plasma Mass Spectrometry. This study demonstrated that the flowers of Lantana camara are an excellent source of eco-friendly natural dye, and the dye extract is free from heavy metals such as antimony, arsenic, cadmium, and lead. Cotton and natural fiber textiles can be commercially dyed with the dye extracted from the Lantana camara flowers using a variety of chemical mordants to achieve different color shades.

Investigation of Mordant Application in Reactive Dyeing of Nylon Fabrics

Nylon fibers were the first synthetic fibers to be produced on an industrial scale, and they are one of the most consumed synthetic fibers due to their visual and usage properties. Reactive dyes have been commercially produced since the mid-20th century, and they are mostly preferred in dyeing cellulosic fibers. The most important property of reactive dyes is their ability to make covalent bonds within the fiber. Mordants are used mainly in the application of natural dyes to hold and retain the dye molecules in the fiber. In this paper, nylon fabrics were dyed with three reactive dyes having different reactive groups (monochlorotiazine, trifluoropyrimidine and monochlorotriazine/vinylsulfone) in the presence of three chemical mordants (iron (II) sulfate, potassium aluminum sulfate and tannic acid) to obtain better exhaustion and coloration properties. Pre-mordanting, meta-mordanting, and post-mordanting processes were used for dyeing. The dyeings were performed at two dyeing concentrations (0.5% and 2% owf), and at three pH levels (pH 2, 4, and 6). The percentage of dyebath exhaustion (%E), the percentage fixation of the dye which exhausted (%F) and the overall percentage fixation (%T) were calculated after pyridine extraction. Wash and light fastness tests were applied on the dyed samples. The results were discussed via % E, % T and CIELAB color differences (Δ Eab*). The results revealed that mordant usage improved the coloration properties of reactive dyes on nylon fabrics. The % E and % T results changed according to the independent variations of pH level, mordant chemical and mordanting method. The correct pH level and mordanting method gave the best dyeing and fastness results for the dyes under test.

Alkanna tinctoria-based sustainable alkanin natural colorant for eco-dyeing of wool.

The awareness of sustainability and widespread utilization of green technologies in textile dye houses are revolutionizing not only textile industries but related fields. The current study is concerned with ultrasonic (US)-assisted utilization of extracts of Alkanna tinctoria (a source of natural alkanin dye) for wool dyeing. The extracts are obtained in various media, and both extracts andwool fabrics have been US treated for 15-60min. Dyeing is performed by applying variable parameters and utilizing herbal-based extracts as a source of bio-mordant, hence improving the fastness rating and enhancing color strength. Good color strength and fastness ratings are obtained using irradiated extract at 4 pH when the US-treated wool fabric is dyed at 65°C for 60min before and after chemical and bio-mordanting. For comparative studies, chemical mordants are also employed. In contrast to chemical mordants, the bio-mordants have made the dyeing process more sustainable with good toexcellent fastnessrating.

Environmental friendly bio-dyeing of silk using Alkanna tinctoria based Alkannin natural dye

Application of bio-dyes, especially plant-based, is becoming increasingly popular in many industries such as textiles, food and pharmaceuticals. This trend could be explained by the ecological and durable nature of these compounds. The current paper aimed to investigate the microwave-assisted isolation of Alkannin dye from Alkanna tinctoria followed by the dyeing of bio-mordanted silk. For the purpose, acid solubilized, water solubilized, and acid-methanol solubilized extracts were obtained. Both respective extracts and silk fabrics were microwave irradiated for 2, 4 and 6 min. To ensure a green and clean dyeing process, bio-mordants were used. It is observed that acid solubilized extract applied at 55 °C for 55 min having 7 g/100 mL of NaCl salt as the exhausting agent has given extraordinary higher color strength (K/S) onto Microwave treatment (MW) treated silk fabric. Colorfastness tests using ISO-recommended requirements found that bio-mordants outperformed chemical mordants in terms of color depth and fastness. According to this study, it was proven that MW improved the dyeing performance of Alkannin in an acid-solubilized medium, where as in addition to the application of bio-mordants in comparison with sustainable chemical mordants have improved color characteristics of silk fabric dyed with Alkanna tinctoria extract.

Sustainable Extraction of Colourant from Harmal Seeds (Peganum harmala) for Dyeing of Bio-Mordanted Wool Fabric

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.

Microwave-Assisted Exploration of Yellow Natural Dyes for Nylon Fabric

Today, the global community is appreciating green technologies in the application of green products in textiles. The aim of the current study is to use a sustainable heating technique for the isolation of colorant from plant sources and to use eco-friendly anchors to improve the fastness of dyed fabrics with new shades. The current study used microwave radiation to isolate natural colorants from saffron (Crocus sativus) and safflower (Carthamus tinctorius L.) petals for polyamide (nylon) fabric dyeing. For this purpose, acidic extract and fabric were exposed to MW treatment for up to 6 min and employed at various conditions. To make the dyeing process sustainable, bio-mordants have been employed and compared with synthetic mordants. It has been found that 6 min is the optimal radiation time for the isolation of colorant to get good results onto irradiated polyamide (nylon) fabric when employed at 65 °C for 45 min containing 1 g/100 mL of table salt for saffron and 3 g/100 mL of table salt for safflower dyeing. For improving color strength and giving an acceptable rating of fastness, 7% of turmeric as a pre-bio mordant and 7% pomegranate as a post-mordant has given high results using saffron extract. Similarly, with safflower extract, 5% of turmeric as a pre-mordant and 5% of turmeric extracts as a post-mordant have given high results as compared to chemical mordants used. It is concluded that microwave treatment has a high potential for investigating the coloring efficacy of crocin-containing saffron petals and safflower petals as carthamin as a yellow natural dye for bio-mordanted polyamide fabrics. It is recommended that such tools for the isolation of colorant from new dye-producing plants should be used, whereas green mordants should be used to develop new colorfast shades to make process more green and sustainable.

Sustainable isolation of licorice (Glycyrrhiza glabra L.)-based yellow natural colorant for dyeing of bio-mordanted cotton.

Sustainability in the utilization of products in all fields particularly food textiles, solar cells, etc. is of prime concern to the global community. In this study, licorice (Glycyrrhiza glabra L.) as a source of herbal-based coloring agent for cotton dyeing has been explored under the influence of ultrasonic (US) waves. Methanolic extract of licorice bark after US treatment for 20min has shown excellent color depth (K/S) onto ultrasonically treated cotton fabric at 65°Cfor 45min. Applying bio-mordants, it has been found that acacia extract (1%), henna (5%), and pomegranate and turmeric extracts (7%) as pre-bio-mordant, whereas acacia, turmeric, and henna extracts (7%) and pomegranate extract (5%) as post-bio-mordants, exhibited superb color strength. Salts of Al (7%) and salts of Fe (3%) as pre chemical mordants, while salts of Al (3%) and salts of Fe (5%) as post chemical mordants, have given good results. Overall, it has been found that salt of Fe (3%) as pre-chemical mordant and extract of turmeric (7%) as post bio-mordant have shown superb color strength. It can be concluded that US treatment being an environmentally safe means has only improved the color strength of colorant onto cotton fabric and the adding of bio-mordants has contrived the method more sustainable.

Microwave Assisted Green Isolation of Laccaic Acid from Lac Insect (Kerria lacca) for Wool Dyeing

The utilization of sustainable products in the applied field is the recent demand of the global community. In this work the colouring behavior of laccaic acid as a source of natural red dye obtained from lac insect has been studied for the dyeing of wool fabric under microwave treatment. The extract was prepared in acidic medium and stimulated through MW treatment up to 7 min and used to dye fabrics. For developing new shades, eco-friendly green mordants such as extracts of acacia and turmeric were employed along with chemical mordants for comparative studies. The obtained results reveal that extract made in acidic medium after exposure for 5 minutes. has given high colour strength onto un-irradiated fabric when employed for 65 minutes at 75 °C. The rating of fastness properties shows that bio-anchors have given good ratings under optimal conditions. It is inferred that this eco-friendly tool has not only increased the coloring yield of natural anthraquinone dye from lac but also the inclusion of bio-mordants has made the natural coloration process more sustainable.

Sustainable application of Cassia obovata-based chrysophanic acid as potential source of yellow natural colorant for textile dyeing.

In the current pandemic scenario, sustainable green products particularly antiviral, antioxidant, and antibacterial in nature are gaining worldwide fame in almost every walk of life. Cassia obovata (C. obovata) has been valorized as a source of yellow natural dye for nylon dyeing. For the isolation of dye extracts and for surface tuning, nylon fabrics were treated with microwave rays up to 10 min. For getting new shades with good to excellent fastness characteristics, sustainable bio-mordants in comparison with chemical mordants have been used at 60 °C, 70 °C, and 80°C. It has been found that for getting effective colorant yield, acidic extract should be exposed to MW ray treatment up to 6 min, and for getting improved fastness rating, bio-mordants have given excellent color characteristics. Statistical optimization of dyeing variable shows that application of 40 mL of C. obovata acidic extract of RE of 6 pH containing 3 g/100 mL of salt when employed at 55 °C for 45 min has given excellent results onto irradiated nylon fabric (RNF). It is inferred that Cassia obovata has an excellent potential for coloration of surface-modified fabrics, where the application of low amount of bio-mordants under statistical optimized conditions has made process more ecological, economical, and sustainable.

Ecofriendly application of coconut coir (Cocos nucifera) extract for silk dyeing.

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.

Extraction of natural dye from Mammea suriga and its application on silk and cotton fabrics

In this study, raw silk and cotton fabrics have been dyed using the aqueous extract from Mammea suriga bark in the presence of chemical mordants. The variations in the colour are seen in the silk and cotton fabrics by using different mordants. The preliminary phytochemical tests reveal the presence of tannins in the bark extract of the plant, which is responsible for imparting brown colour shades to the silk and cotton fabrics. The results are found promising with good fastness property in all the three mordanting methods, i.e. pre-mordanting, simultaneous mordanting and post-mordanting. The SEM study shows no physical damage to the fibre dyed with M . suriga dye extract. Thus, this bark can be used as a cheaper source of raw material for the extraction of natural dye by dyers in dyeing industries.