Search

Abstract The use of natural bioresources in textile dyeing has attracted significant research interest due to their environmentally friendly and low-toxic nature. This study investigated the utilization of waste oyster shell (WOS) as a bio-mordant combined with sappan wood extract to dye silk fabrics using pre-, meta-, and post-mordanting method. The crystal structure of CaCO3 derived from WOS and their impact on color properties, color strength and color fastness were analyzed. The dyed fabrics displayed a range of shades from light pink to deep red and brown. FTIR analysis confirmed chemical interactions among dye, silk, and WOS mordants. Notably, silk treated with WOS at 800 °C as a pre-mordant showed color strength approximately 2.6 times higher than that of un-mordanted samples. Additionally, bio-mordanted samples exhibited improved color fastness compared to untreated ones (rating 2), with pre-mordanting offering the highest resistance to washing (rating 4–5). These findings shed light on the potential of waste oyster shell as an effective, sustainable alternative to conventional metal mordants in textile dyeing. This study not only support the utilization of waste but also enhances environmental and resource efficiency of the dyeing process.

Abstract The utilization of waste plant residues in useful work particularly as the source of green dyes in textiles is now a days welcoming by global community. In this study, brown bollygum chips (Litsea glutinosa) called tallow laurel has been explored for silk dyeing using ecofriendly approaches. Extraction has been done in suitable medium and utilized onto fabric before and after microwave (MW) treatment up to 10 min. Response surface methodology was employed to observe the significant of selected dyeing parameters at which shade development with improved colorfastness was observed. It was found that 2 min radiation to both acidic extract of tallow laureal and silk fabric is the useful condition to get colorfast shade when employed before and after mordanting with iron salt and tannic acid solution as eco‐chemical agent, whereas with walnut bark and pine nut hulls extract as eco bio agents. The highest color strength value of 4.58 was observed using tannic acid as postchemical mordant for silk dyeing. The standard methods for fastness as per ISO to light, washing, and rubbing reveal that using selected shades made under ecofriendly cost time and energy effective conditions, stable colorfast hues were rated good with the value of 4/5. Therefore, it is recommended that MW treatment in addition with statistical approach i.e., central composite design used for exploring new dye yielding plant, then using eco‐mordanting technique will help in getting promising colorfast shades.

The investigation of novel strategies to combat harmful bacteria is warranted given the serious threat that antimicrobial resistance poses to world health. Out of all of these, treating textile materials with antimicrobial compounds has attracted a lot of attention due to its potential to stop the spread of infectious diseases. The goal of this study was to evaluate how silk and lyocell materials' inherent antibacterial qualities might be improved by giloy dyeing and lemon mordanting. The goal of mordanting was to improve dye adhesion by using only natural ingredients such as citrus lemon extract. Using dye from Azadirachta indica, which was made by aqueous boiling, Lyocell and Silk materials were dyed under various circumstances. Following Giloy dyeing and Lemon mordanting, the antibacterial efficiency significantly improved, notably against common infections like Klebsiella pneumoniae and Staphylococcus aureus, according to the results. Furthermore, the study assessed washing and perspiration fastness capabilities, which yielded positive results and confirmed the method's feasibility. This method has the potential to considerably improve infection control measures in textiles, particularly in fields focused on public health and cleanliness. Given the serious issue of antimicrobial resistance, adopting new textile treatments like this can help to build effective and sustainable solutions. Future studies can investigate further uses and adjustments, assuring its adaptability and wider adoption across many environments.

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. [ABSTRACT FROM AUTHOR]

The utilization of waste plant residues in useful work particularly as the source of green dyes in textiles is now a days welcoming by global community. In this study, brown bollygum chips (Litsea glutinosa) called tallow laurel has been explored for silk dyeing using ecofriendly approaches. Extraction has been done in suitable medium and utilized onto fabric before and after microwave (MW) treatment up to 10 min. Response surface methodology was employed to observe the significant of selected dyeing parameters at which shade development with improved colorfastness was observed. It was found that 2 min radiation to both acidic extract of tallow laureal and silk fabric is the useful condition to get colorfast shade when employed before and after mordanting with iron salt and tannic acid solution as eco‐chemical agent, whereas with walnut bark and pine nut hulls extract as eco bio agents. The highest color strength value of 4.58 was observed using tannic acid as postchemical mordant for silk dyeing. The standard methods for fastness as per ISO to light, washing, and rubbing reveal that using selected shades made under ecofriendly cost time and energy effective conditions, stable colorfast hues were rated good with the value of 4/5. Therefore, it is recommended that MW treatment in addition with statistical approach i.e., central composite design used for exploring new dye yielding plant, then using eco‐mordanting technique will help in getting promising colorfast shades. [ABSTRACT FROM AUTHOR]

For minimizing the pollution associated with synthetic colorants, the world again is going to realize the benefits of natural colorants in applied fields such as textiles, food flavors, etc. As part of the ongoing research project, hematein is being investigated as a potential natural colorant derived from logwood chips, and its implementation on silk fabric is being investigated under the effect of microwave radiations. A number of dyeing variables, including pH, dyeing duration, temperature of the dye bath, volume of extraction, and salt concentration, have been investigated, and the effect of isolation medium has also been evaluated. For new shades with improved fastness ratings, extracts of various sustainable bio-mordants and chemical mordant such as salts of aluminum and copper, and tannic acid were also used. An experiment revealed that treating un-irradiated silk with 40 mL of methanolic extract with a pH of 2, irradiated for 6 min, produced outstanding outcomes when dyed at 90 °C for 60 min. The dyeing process included the addition of 9 g of salt per 100 mL of solution as an exhausting agent. In these circumstances, the utilization of sustainable mordants has not only enhanced the ratings of color fastness but has also rendered the procedure more environmentally friendly and less polluting. Therefore, microwave radiation has great potential for extracting colorants from plants and effectively applying them to natural materials under decreased conditions.

The study explores the application of tea leaf-extracted tannin as a bio-mordant and thyme extract as a natural dye on cationized silk-cotton blend fabric to enhance colour fastness and absorption. The colour strength and depth (shown as DL, Da, and Db values) on silk-cotton blend fabric were investigated in the CIE lab test. The results showed that temperature, shade percentage, and mordanting had a substantial impact on the dyeing process efficacy at DL = 30.61, Da = 11.49 and Db = 12.77. When the temperature was raised to 90 °C and the dye content was increased to 120%, the dyed sample's colour fastness (as measured by wash, rubbing, and perspiration) significantly improved, acquiring a grade of 4 to 5, which indicates good to excellent. There was a slight change in wet rubbing fastness from grade 3 to grade 4, indicating good to fair. The K/S values of the silk and cotton fibres, which ranged from 8.89 to 7.94 on average, respectively, demonstrated that the processes of bio-mordanting and cationization enhanced the absorption of dye. Tensile strength and extension increased in the weft direction to 22.19 N force and 5.21% extension at break, while the warp direction showed a fall to 6.63 N force and a rise in extension of 0.72%. FTIR spectroscopy confirmed the presence of Amino (N-H) bonds, Carbohydrate bonds (CH), Tannins, and Terpenoid phytochemicals of thyme in the dyed sample. The study highlights the potential of thyme extract as a natural dye and its benefits in improving the dyeing properties of silk-cotton blend fabric.

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.

The Anatolian acorn (Quercus ithaburensis Decne) is a promising resource for a variety of industries in Turkey and the world. It has the potential to serve as a bio-mordant, natural dye for textiles and leather, providing an eco-friendly alternative to synthetic dyes and reducing dependence on chemicals and petrochemicals. The commercial viability of the acorn and its export potential make it a valuable resource for supporting regional trade and boosting the local economy, with the potential to create new job opportunities. In addition, the acorn has a unique colour range, fastness, and antimicrobial properties, making it a desirable choice for manufacturers looking for a sustainable alternative. Overall, the Anatolian acorn holds great potential as a natural dye and a valuable resource for supporting regional trade and sustainability goals. The development and commercializatio

Today, reducing industrial pollution and using agricultural waste has become very important in preserving the environment and increasing productivity. The textile industry has a high level of pollution caused by wastewater containing dyes, and the use of natural dyes can overcome this weakness. To increase color strength, it is customary to use a mordant. The use of natural mordant can help to complete the sustainable cycle of the dyeing process. In This study extracts of madder and Oleaster or Russian Olive were utilized as natural dye and mordant, respectively. The phenolic content of Oleaster and its components (peel, seed, and flesh) were investigated and the results illustrated that the components of Oleaster, especially the peel and seeds, can be used as natural mordant as agricultural waste. The Fourier transform infrared spectral behavior of mordanted yarns were similar, which indicates the similar performance of different components of Oleaster. The color strength was studied in the presence of different mordants, and the results showed that the use of different components of the Oleaster can improve the color strength. Moreover, the dyed yarns were subjected to stability evaluations using standard methods. Washing, rubbing and light fastness of dyed yarns using mordant were good, good and moderate, respectively. [ABSTRACT FROM AUTHOR]

The textile industry stands as a prominent contributor to global environmental pollution, primarily attributable to its extensive reliance on synthetic dyes, hazardous components, and solvents throughout the textile dyeing and treatment processes. Consequently, the pursuit of sustainable textile solutions becomes imperative, aimed at replacing these environmentally unfriendly constituents with biobased and bioactive pigments, antibacterial agents, and, notably, natural solvents. Achieving this goal is a formidable yet indispensable challenge. In this study, the dyeing ability of the crude gel prodigiosin, produced by non-pathogenic bacteria Serratia plymuthica, was investigated on various multifiber fabrics at different conditions (temperature and pH) and by using salts and alternative mordants (the conventional Ferrous Sulphate (FeSO4) and a new bio-mordant, L-Cysteine (L-Cys)). Additionally, a novel gel-based Choline chloride (ChCl)/Lactic acid (LA) (1:2) deep eutectic solvent (DES) dyeing medium was studied to replace the organic solvents. Nylon fabrics dyed with 3.0% over the weight of the fiber (owf) L-Cys at pH = 8.3 had improved color fastness to washing, while the gel-based ChCl/LA (1:2) DES dyebath provided a better color fastness to light. Moreover, nylon fabrics under these conditions exhibited remarkable antimicrobial activity against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). In conclusion, the utilization of the crude gel-based prodigiosin pigment demonstrates a distinct advantage in dyeing textile materials, aligning with the growing consumer demand for more eco-friendly and sustainable products. Additionally, the application of the natural reducing agent L-Cys, previously untested as a bio-mordant, in conjunction with the use of gel-based DES as a dyeing medium, has showcased improved colorimetric and antibacterial properties when applied to nylon that is dyed with the crude gel prodigiosin pigment. [ABSTRACT FROM AUTHOR]

In the present study, cotton fabric has been dyed with aqueous extract of babul bark (Acacia nilotica) using gallnut (Quercus infectoria) as bio-mordant containing hydrolyzable tannins like gallic acid, elagic acid and polyphenolic gallotannins to produce light yellow color. On the other hand when gallnut bio-mordanted cotton is subsequently dyed with babul bark extract as a natural dye containing similar but non-hydrolyzable tannin-rich color component including small amount of catechin and epi-gallo-catechin, it produces a medium to deep brown color through formation of giant insoluble colored complex of cotton-gallotannins (gallnut)-catechin/epigallocatechin and other color components present in babul bark extract. The process variables for extraction, pre-mordanting and dyeing have been optimized to standardize this dyeing technique. Scattered CDI values for dye-bath pH and dye concentration identified them as the most important dyeing parameters that need to be controlled for obtaining uniform dyeing. High UPF value of upto 35 rendered by application of both gallnut and babul bark through preferential absorption of UV light by the gallotannins in both gallnut and babul bark indicates good UV protection properties of dyed cotton fabrics.

The main topic of this study is Green and environmentally wool dyeing. For this purpose, yellow and black myrobalan extract as green mordants and madder and resedaluteola as natural dyes were used. The FTIR-ATR spectra of the washed wool yarns, mordanted wool yarns and dyed wool yarns confirmed bonding of wool yarns with the green mordant and dyes through comparing chemical structures. The effective linkage between yarn, mordant and dye molecules removes the C-N peaks in FTIR-ATR spectra. After dyeing process, fastness and dyeing properties of dyed wool yarns were investigated. The K/S values of dyed wool yarns with extracted madder and resedaluteola were quantified values; and fastness properties including light, wash, and rubbing fastness were defined as per ISO standard methods. The research pointed out that the myrobalan extraction as a potential route for the development of eco-friendly dyeing in green production of dyed yarns.

Environmental issues are rising day by day in the global community due to the cumulative effects of hazardous effluent load and due to the introduction of biological active natural products into all aspects of life. In this study, the waste tea-leaves-based tannin natural dye has been extracted under the influence of microwave treatment and employed onto bio-mordanted wool fabric. For extraction of dye, microwave (MW) irradiation up to 6 min has been employed and for improvement in color strength, bio-mordants in comparison with chemicals mordants. It has been found that acidic extract of tea leaves after MW treatment for 6 min has given excellent color depth (K/S) on MW treated wool at 80°C. Using bio-mordants, it has been found that 4% of acacia extract, 1% of pomegranate extract and 5% of turmeric extract as pre bio-mordant, whereas 5% of acacia and 2% of pomegranate and turmeric as post bio-mordants have given excellent color strength, whereas in comparison, ferrous sulfate (2%) has given excellent results. It has been concluded that microwave treatment as an environmentally sustainable tool has not only improved the color strength of tannins dye onto wool fabric but also with the addition of bio-mordants has made the process more sustainable.

Environmental issues are rising day by day in the global community due to the cumulative effects of hazardous effluent load and due to the introduction of biological active natural products into all aspects of life. In this study, the waste tea-leaves-based tannin natural dye has been extracted under the influence of microwave treatment and employed onto bio-mordanted wool fabric. For extraction of dye, microwave (MW) irradiation up to 6 min has been employed and for improvement in color strength, bio-mordants in comparison with chemicals mordants. It has been found that acidic extract of tea leaves after MW treatment for 6 min has given excellent color depth (K/ S) on MW treated wool at 80°C. Using bio-mordants, it has been found that 4% of acacia extract, 1% of pomegranate extract and 5% of turmeric extract as pre bio-mordant, whereas 5% of acacia and 2% of pomegranate and turmeric as post bio-mordants have given excellent color strength, whereas in comparison, ferrous sulfate (2%) has given excellent results. It has been concluded that microwave treatment as an environmentally sustainable tool has not only improved the color strength of tannins dye onto wool fabric but also with the addition of bio-mordants has made the process more sustainable. [ABSTRACT FROM AUTHOR]

The textile industry stands as a prominent contributor to global environmental pollution, primarily attributable to its extensive reliance on synthetic dyes, hazardous components, and solvents throughout the textile dyeing and treatment processes. Consequently, the pursuit of sustainable textile solutions becomes imperative, aimed at replacing these environmentally unfriendly constituents with biobased and bioactive pigments, antibacterial agents, and, notably, natural solvents. Achieving this goal is a formidable yet indispensable challenge. In this study, the dyeing ability of the crude gel prodigiosin, produced by non-pathogenic bacteria Serratia plymuthica, was investigated on various multifiber fabrics at different conditions (temperature and pH) and by using salts and alternative mordants (the conventional Ferrous Sulphate (FeSO4) and a new bio-mordant, L-Cysteine (L-Cys)). Additionally, a novel gel-based Choline chloride (ChCl)/Lactic acid (LA) (1:2) deep eutectic solvent (DES) dyeing medium was studied to replace the organic solvents. Nylon fabrics dyed with 3.0% over the weight of the fiber (owf) L-Cys at pH = 8.3 had improved color fastness to washing, while the gel-based ChCl/LA (1:2) DES dyebath provided a better color fastness to light. Moreover, nylon fabrics under these conditions exhibited remarkable antimicrobial activity against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). In conclusion, the utilization of the crude gel-based prodigiosin pigment demonstrates a distinct advantage in dyeing textile materials, aligning with the growing consumer demand for more eco-friendly and sustainable products. Additionally, the application of the natural reducing agent L-Cys, previously untested as a bio-mordant, in conjunction with the use of gel-based DES as a dyeing medium, has showcased improved colorimetric and antibacterial properties when applied to nylon that is dyed with the crude gel prodigiosin pigment.

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. [ABSTRACT FROM AUTHOR]

Sustainable extraction of functional colorant from dye-yielding plant through microwave radiations is gaining popularity due to its cost, time and effective nature. Current study is concerned with the microwave-assisted exploration of Arjun bark natural colorant for dyeing of mordanted wool fabric. Extracts obtained in various media were irradiated up to 6 min and were used to dye wool. It is found that acid methanol-solubilized extract (3 pH) from 4 g powder upon irradiation for 4 min has given darker shades onto irradiated wool at dyeing for 75 min. FTIR analysis shows that there is no change in chemical nature of functional site of wool, whereas SEM analysis shows that there are some morphological changes occurring at the surface. At optimal conditions, acceptable fastness characteristics are obtained, when 9% of turmeric extracts as pre- and post-bio-mordant and 5% of Fe as pre- and 3% of Fe as post-mordant is employed. It is concluded that microwave has not only improved the functional behavior of natural colorant from Arjun bark for wool dyeing but also the addition of green mordants has made dyeing process more esthetic.

Food products as a source of natural colorants are gaining widespread popularity around the globe due to their ayurvedic and eco-friendly nature. Current study is aimed with the utilization of food products (Saffron and madder) as a source of dye for woolen yarn. It is found that, for Saffron, irradiation of yarn for 6 min gives high color strength by dyeing for 45 min in the presence of 2% of salts using un-irradiated dye bath of 1 pH, whereas for madder, 4 min is optimal irradiation time for extract to dye irradiated yarn for 25 min in the presence of 6% of salts using the irradiated dye bath of pH 1. The mordanting carried out at optimal conditions show that using both extracts, woolen yarn dyed at optimal conditions has given good color characteristics. It is concluded that microwave radiation has not only improved natural dyeing process but also make the process more eco-friendly and sustainable as well.

Due to an increase in awareness of harmful aspects of synthetic dyes among the global community, the demand of natural dyes in textile sector has been dramatically increased. The current study has been conducted to explore new eco-friendly source of natural brown colorant from arjun bark for textile. Both bark powder and silk fabrics were microwave irradiated for 1–6 min. Dyeing was performed at different variables onto irradiated and un-irradiated silk using extracts obtained from irradiated and un-irradiated powder. To make the dyeing process more sustainable, two chemical and bio-mordants were employed at optimal conditions. The results show that acidified methanolic extract from irradiated powder (RP, 8g) has given high color strength if irradiated silk (RSi) is dyed for 65 min. at 65°C using dye bath of 1 pH in presence of 7% of Na2SO4 as exhausting agent. Good shades and improved fastness characteristics have been obtained by employing 1% of Fe (iron sulfate) and Al (aluminum sulfate) as Chemical and 1% of turmeric and pomegranate extracts as bio-mordants. Hence, microwave radiation has not only explored the coloring efficacy of arjun bark as potential source of natural brown dye but also made its applicability under sustainable conditions.

The current study is aimed to utilize the microwave for isolation of colorant from neem bark and its application onto chemical & bio-mordanted cotton fabric. For the purpose, aqueous, acid and organic media have been employed to isolate the colorant and to make its application onto surface modified and bio-mordanted cotton fabric followed by microwave treatment up to 6min. It is found that using optimum extraction and dyeing conditions, acceptable fastness properties have been rated when 9% of Al & Fe, 7% of tannic acid as pre chemical, 7% of acacia, 9% of henna, 7% of pomegranate & 5% of turmeric extract as pre bio mordants. Similarly, 5% of Al, 9% of T.A, 7% of pomegranate, and turmeric extract as post-mordants have been employed. It is recommended that isolation of colorant & dyeing under MW treatment has not only improved the natural dyeing process but also the addition of herbal-based bio-mordants have made the dyeing process more sustainable & ayurvedic. So it is concluded that microwave treatment has not only explored the coloring potential of neem bark but also made possible use of bio-mordants for making process more green with excellent color characteristics under reduced optimal conditions.

The resurgence of natural colorant in textile dyeing is gaining popularity due to their ecofriendly benefits. The current study has been concerned with dyeing of silk fabric using extract obtained from safflower (Carthamus tinctorius L.) which was microwave irradiated for 1–5 min. To make dyeing process more ecofriendly, bio-mordants and chemical mordants have been employed at optimal conditions. It is found that microwave treatment to the extract for 3 min is suitable to get darker shades with acceptable color characteristics using un-irradiated silk. It has been found that dyeing of un-irradiated silk fabric for 60 min using acidic extract of Safflower (pH 2) has given high color strength. Rating of colorfastness reveals that 7% of curcumin and lawsone as bio-mordant has not only given high color depth but also rated excellent fastness properties as compared to chemical mordants used. It is found that microwave treatment has not only improved the dyeing behavior of carthamin but also enhanced the color characteristics.

The revival of natural dyes in textiles is gaining popularity due to their sustainable nature. The current study has been undertaken to improve the dyeing behaviors of cochineal-based natural dye (carminic acid) for wool dyeing under the influence of microwave treatment. For the purpose, wool fabric and extract obtained from cochineal insects (Dactylopius coccus costa) were irradiated for 1–6 min. The nature of dye bath (pH) and dyeing temperature were optimized using optimal irradiation conditions. To make dyeing process more sustainable and eco-friendly, bio-mordants and chemical mordants have been employed at optimal conditions. It is found that microwave treatment of extraction for 5 min is suitable to get darker shades with acceptable color characteristics using unirradiated wool fabric. K/S was found using acidic dye bath of cochineal insect of pH 1 for dyeing unirradiated fabric at 70°C using acidic extract of Cochineal bugs. Suggested ISO standards for color fastness revealed that 5% of henna and 3% pomegranate as bio-mordant have not only given high color depth but also rated excellent fastness properties as compared to chemical mordants used. It is found that MW treatment has not only improved the dyeing behavior of carminic acid but also enhanced the color characteristics.

The coloring behavior of laccaic acid, a natural red dye derived from lac insects, has been investigated in this work for the dyeing of silk and viscose fabrics while being heated in MW radiation. The extract was made in an aqueous and acidic media and then used to color fabrics under microwave treatment for up to 10 min. For developing new shades, eco-friendly green bio-mordants and, in comparison, chemical mordants were employed at given conditions. The obtained results revealed that the aqueous extract after 4 min of radiation exposure produced a high color strength (K/S  =  17.132) onto silk and the aqueous extract after 6 min of radiation exposure produced better color strength (K/S  =  6.542) onto viscose at selected conditions. The fastness ratings evaluation as per ISO standards demonstrates that bio-anchors have provided good ratings under selected irradiation and dyeing conditions. It is concluded that this environmentally friendly technique has improved the natural coloration process of fabrics as well as addition of green mordants has furnished colorfast shades using lac-derived natural anthraquinone dye., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

In this study, an alternative cleaner process over traditional metallic mordanting process for wool dyeing with madder, Rubia tinctorum L., root natural dye was presented. Wool surface was modified with novel eco-friendly and biocompatible cationizing agent having numerous free amine groups, namely chitosan-polypropylene imine dendrimer hybrid (CS-PPI). Modified wool demonstrated remarkable increase in dye uptake as compared to raw wool. Optimal dyeing results were obtained when CS-PPI 7 %, madder dye 20 % and dyeing pH 7 were employed. Dyeing results such as percent dye exhaustion and color depth emphasized auxiliary agents, i.e., metallic mordant and acid could be eliminated from wool dyeing process with madder dye. Saturation point shifted to lower dye concentrations in the treated wool suggested the same color depth could be obtained using lower amount of crude dye material. Wool modification with CS-PPI demonstrated no adverse impact on other properties such as colorfastness and color shade characteristics. In addition, treated wool exhibited excellent antimicrobial activity (nearly 100 % microbial reduction) against two common pathogenic microorganisms, Escherichia coli and Staphylococcus aureus which were almost durable after dyeing and subsequent repeated washes. In general, the results of this investigation showed that CS-PPI can be employed as an alternative eco-friendly 'bio-mordant' as well as effective antimicrobial finishing material in wool dyeing with madder dye. [ABSTRACT FROM AUTHOR]

Natural dye's poor affinity for cotton and poor fastness properties still hinder its applications in the textile industry. In this study, a doubled-layered chitosan coating was cured on cotton fabric to serve as bio-mordant and form a protective layer on it. Under the optimal treatment conditions, the maximum q e (adsorption amount) of the natural dye sodium copper chlorophyllin (SCC) calculated from the Langmuir isothermal model was raised from 4.5 g/kg to 19.8 g/kg. The dye uptake of the treated fabric was improved from 22.7% to 96.4% at 1% o.w.f. dye concentration. By a second chitosan layer cured on the dyed fabric via the cross-linking method, the wash fastness of the cotton fabric dyed with SCC can be improved from 3 to 5 (ISO 105 C-06). The natural source of the biopolymer material, chitosan, and its ability to biodegrade at end of life met with the initial objective of green manufacturing in applying natural dyes and natural materials to the textile industry.