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.
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•Microwave-irradiated fabrics have better dye-exhaustion, dye-uptake and tint than their un-irradiated counterparts.•Post-mordanting was discovered to be the best mordanting technique.•Π–Π, extra H–bond and conjugates interaction imparted the desired colorfastness onto the herbal-mordanted dyed fabric.
The revival of natural dyes in different walks of life is due to stringent environmental standards imposed by many associations. For current studies, flowers of haar singhar (
Nyctanthes arbor-tritis
...) has been chosen for bio-dyeing of cotton fabric using microwave irradiation techniques. For this purpose, liquid extracts and fabrics were exposed to microwave for 5 min at various conditions. These treated and un-treated dye extracts obtained in respective media were employed to dye the radiated and non-radiated cotton fabrics. The characterization of extract and untreated and undyed irradiated fabrics samples was done through FTIR. Different dyeing variables were optimized under CCD response surface methodology as a statistical tool. With the introduction of new shades and improvement of colorfastness properties, different concentrations of sustainable chemical and bio-mordant were employed. All dyed cotton fabrics were exposed to CIE-color space system for estimation of color coordinates and color strength by using spectra flash SF600 and to rate colorfastness properties using ISO standard methods for light, dry and wet rubbing, washing fastness. Cotton fabric was dyed with haar singhar flower extract of 7 pH from 4 g of powder, using 1.5 g/100 mL salt solution at 60 °C for 30 min. To get acceptable shades, aqueous extract after microwave treatment for 4 min provided excellent color strength. Pistachio (
K/S
= 3.6342) is a bio-mordant with great results, and aluminum (
K/S
= 4.8205) is a chemical mordant with outstanding results. It is found that green methods for isolation of colorant and green mordants for getting new shades should be employed.
Melissa officinalis L. plant has been used in European and Iranian traditional medicine since ancient times. This plant possesses various phytochemicals such as volatile compounds, triterpenoids, ...phenolic acids, and flavonoids. The presence of substantial amounts of flavonoids in M. officinalis L. necessitates further examination of its usage as a source of natural colorants for developing natural and beautiful shades on wool yarns in addition to its pharmaceutical, cosmetic, and food preservative applications. This will definitely add new direction to the use of M. officinalis L. as an effective natural dye source. Therefore, simple adsorption of aqueous dye extract on wool surface was done followed by the evaluation of build-up properties using different metal mordants and their binary combinations. The dyeing was carried out on pre-mordanted wool by exhaust dyeing method and dyed samples were analyzed via reflectance spectroscopy under D65 illuminant and 10° standard observer in terms of color strength, CIEL*a*b*, and CIEL*C*h
o
values. The results showed that overall 22 eco-friendly shades of very good to excellent washing, rubbing and light fastness properties were produced by facile use of different metallic salts and their combinations on wool fibers.
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
p
H 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.
Graphical abstract
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 fabric at 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.).
Graphical abstract
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 and wool fabrics have been US treated for 15–60 min. 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 60 min 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 to excellent fastness rating.
Graphical Abstract
The application of natural dye in the textile industry is gaining popularity because of the increasing awareness of environmental effects, the ecological effects, and the pollution caused by ...synthetic dyes. Rose flowers, which are one of the best sources of natural dye, have been selected for fabric dyeing due to the presence of anthocyanin pigment. Dyeing of wool is done at optimal conditions such as pH, temperature, time, and salt. It is found that at different percentages (1%, 3%, 5%, 7%, and 9%) chemical and bio mordants mediums gave a variety of shades of good color and better fastness properties onto natural fabrics. By using different chemical and bio mordants and their combinations to analyze the color strength and fastness properties could be enhanced. Bio-mordants gave shades with good color strength and acceptable for the universe. The plant extract has therapeutic values like antioxidant, anti-inflammatory, and antibacterial activity against some gram-positive and gram-negative pathogenic bacteria.
This research focuses on flavonoid-based natural dyes for the coloration and antibacterial finishing of wool fabrics. In the present study, we accessed the suitability of biocolorants from Gingko ...biloba L. waste/fallen leaves extract to develop colored antibacterial wool fabrics to reduce the environmental pollution and dependency of the textile industry on the synthetic antibacterial agents. Specifically, we present a novel method to counteract the growing antibiotic resistance using G. biloba L. leaves extract as a potent antibacterial agent in conjunction with ampicillin. Natural colorants were extracted in 50% aqueous ethanol at 70 °C for 60 min under acid conditions of pH 3. Before dyeing procedures, the extracted dye powder was assessed for thermal stability by TGA analysis. Structural characterization of the extracted dye was done by UV–visible and FT-IR spectral analysis. Optimal dyeing results were achieved at 90 °C for 70 min with a dye concentration of 50% (o.w.f.). Additionally, dye adsorption (Isotherm constants) and dye performances were effectively reported during this study. Pseudo-second order and sips isotherm model provided the best fitting of experimental data with high regression coefficient (R2 = 0.99). Valuated indicators (color strength (K/S), color characteristics, and fastness properties) of dyed wool fabric were effectively reported in response to washing pretreated with different metallic and natural mordants. The antibacterial potential of extracted natural dye was enhanced in combination with ampicillin (synergism) which can be correlated with the significant reduction in the corresponding MIC values. Fe2+ and Sn2+ salts demonstrated negative effects on the antibacterial performance of the dyed wool fabric, whereas most of the biomordants showed enhanced antibacterial performances. The effective use of the extracted yellow dye from G. biloba L. fallen/waste leaves in textile dyeing and finishing will enhance the industrial applications of the green waste over its normal applications.
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•Waste leaves of G. biloba L. have been used for natural dye production.•Natural dye was extracted in 50% aqueous ethanol solution under acidic conditions.•Adsorption kinetic showed pseudo-second-order fitting.•MIC of dye extract was enhanced in conjunction with ampicillin.•Biomordants were more effective in enhancing antibacterial properties.
Sustainable products particular plant pigments as colorants have gained a worldwide fame due to their ayurvedic and eco-friendly nature. In this research, improvement in colorfastness of Coral ...Jasmine (Nyctanthes Arbortristis) based yellow natural pigment has been investigated using eco-friendly shade developers (mordants) after being separated from crude mixture in aqueous medium and applied before and after dyeing of wool at given conditions in microwave radiation (MW). It has been found that 35 mL of yellow water extract (6 pH) of Coral Jasmine after irradiation upto 4 min, has given high colour yield onto MW-irradiated wool when used to dye wool at 85 °C for 35 min in presence of 2 g/100 mL of salt. Before dyeing 0.5% of tannic acid and 0.5 % of orange peel, 2 % of acacia and 1.5 % of pomegranate extract has developed colourfast shades of high strength. Similarly after dyeing, 2.5 % of tannic acid, 2 % of orange peel, 2.5 % of acacia and 1.5 % of pomegranate extract has developed colourfast shades of high strength also. It is inferred that eco-friendly mordants has played promising role in improving bio-colouring behaviour of wool with Nyctanthes Arbortristis but also addition of MW-rays to get high yield has made process more sustainable and valuable.
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•The microwave-assisted extraction of Nyctanthes dye was investigated.•Bio-mordanting were used as a replace of metal mordant.•Bio-dyeing of wool shown excellent fastness properties.•Nyctanthes Arbortristis based yellow natural dye can be an alternative of synthetic dyes.
Little information regarding the utilization of algal-based pigments in textile industry is available despite their abundance in aquatic ecosystems, varying color nature, and relatively fast-growing ...habit than other photosynthetic organisms. The aim of the current study is to optimize the conditions in order to harness the colorants from selected marine algal species and evaluating their dye yielding potential for fabric dyeing. Cotton fabrics were dyed with aqueous, alkaline, acidic or organic extracts of four algal species, the brown algae
Iyengaria stellata
,
Sargassum muticum
,
Colpomenia sinuosa
, and the red alga
Laurencia obtusa
under varying conditions of temperature, pH, and exhausting agent concentration. Results showed that 4% KOH and 80% acetone extraction produced maximum color strength of dyed cotton fabric. Among the four species of algae used in the study,
L. obtusa
showed the highest yield of colorant. However, all four species extract behaved differently to dyeing conditions. Mordanting experiments results revealed that iron sulphate and tannic acid were excellent pre- and post-mordanting agents for producing darker color shades of cotton fabrics dyed with all the four algal species used in the study. FTIR analysis indicated that the dominant coloring agents in all four algal species were phenolics in nature. The fabric dyed with extract of
I. stellata
,
C. sinuosa
, and
L. obtusa
showed creamy white shade, while
S. muticum-
treated fabric produced light brown shade. Pre- and post-mordanting of algal powder dyed fabric with chemical mordants, particularly the tannic acid produced other shades, such as light and dark brown.
