Metallic Mordants Research Articles

Sustainable wool fibers dyeing using henna extract in non-aqueous medium

Dyeing processes usually consume a large amount of water and toxic chemicals, thus inducing environmental pollution. Therefore, we have designed here an eco-friendly process of dyeing wool fibers using natural dyes extracted from henna leaves in decamethyl cyclopentasiloxane. In this process, traditional hazardous metallic mordants and heavy metal salts were substituted by safe chitosan to pretreat wool fibers. Decamethyl cyclopentasiloxane was used to reduce the consumption of the high amount of water needed in traditional dyeing. Chitosan-treated and untreated samples were dyed with different henna extract/decamethyl cyclopentasiloxane suspensions at 40 °C, 60 °C, 80 °C and 90 °C. Results showed that dye uptake, fixation rate and apparent color depth of the samples dyed in henna extract/decamethyl cyclopentasiloxane suspensions were higher than water-based dyed samples. The dye uptake of samples dyed using our system reached 80–98%, as compared with 70–75% for water-based dyed samples; accordingly, the color strength and fixation rate were increased.

Natural dyeing of merino wool fibers with Cinnamomum camphora leaves extract with mordants of biological origin: a greener approach of textile coloration

In this research work, an attempt has been made to investigate the possibility of wool dyeing with natural dye extracted from the Cinnamomum camphora middle aged/mature leaves. Visually, a range of ecofriendly shades with quite different color gamut of varying hue and tone were produced via the application of different natural mordants. The effect of various natural mordants (gallnut, pomegranate peel, arjun bark, chlorophyll extract, and citric acid) and some commonly used metal mordants (ferrous sulfate, copper sulfate, stannous chloride, and sodium dichromate) on color and fastness properties of dyed wool samples was comparatively evaluated in conjunction with 50% (o.w.f.) of C. camphora natural dye. Dyeing experiments were performed with and without mordants employing pre-mordanting technique. The color of dyed wool fibers were investigated in terms of CIELab (L*, a*, and b*) and color strength values (K/S); and fastness properties were determined as per ISO standard test methods. In general, pre-biomordanted wool fibers with P. granatum (3, 4 and 5% o.w.f.), citric acid (5% o.w.f.) and chlorophyll extract (10–50% o.w.f.) showed comparable color and fastness results compared to those of metal treated samples. Durability of color was also checked to assess the effect of washing of dyed wool fibers. This research work on the use of ecofriendly biomordants will provide a valuable reference in future for ecological and environmentally safe dyeing.

Improving the efficiency of Nesogordonia papaeverifera (Danta) as a natural dye in textile making industry

An attempt was made to extract natural colourant from the bark of N. papaeverifera. The optimisation of the extraction procedure was evaluated using various solvents. The optimal colourant extraction was observed with acetone as solvent at constant temperature of 70 °C for 1 h. The main extracted colourant compound was isolated using column chromatography and characterised by ultraviolet-visible spectrophotometer, mass spectrometry, proton and 13C nuclear magnetic resonance spectrometry and Fourier transform infrared spectroscopy. The dyeing and durability of the colourant extract were evaluated. This low-cost biomass was obtained from a timber industry and its extract used to dye cotton and nylon 6,6 fabrics with only small amounts (6% and 4%) of metallic mordants, namely, copper(II) sulfate and stannous chloride. Dyed cotton and nylon were analysed for their K/S, CIE L*, a*, b*, c*, h* values and the colour fastness properties to light, crocking (rubbing) and washing. The UV-visible spectral result suggest the presence of such chromophores as C=O and –C=C–. The broad FTIR result at 3596 cm-1 is indicating a carbonyl group, the 13C NMR spectrum showed absorption at 206 ppm while the proton NMR gave absorption at 4.37 to 5.24 ppm suggesting –OH protons. Colour shades of brown were obtained. Significant differences in colour depth were observed depending on the mordant type. Copper(II) sulfate was found to produce the most significant colour changes, the deepest brownish colour, and the best light fastness and wash fastness values. The colourant extract itself (without mordant) had a light fastness of 3 (fair) on cotton fabric and 3/4(good) on nylon 6,6 fabric. In general, colour fastness to light was good (grade 5 for cotton and grade 4/5 to 5 for nylon) colour fastness to washing was very good (grade 4 to 4/5 for cotton and grade 3/4 to 4 for nylon) and colour fastness to rubbing was very good (grade 3/4 to 5). KEY WORDS: Natural colourant, Optimised extraction, Mordanting, Percentage of dye absorbed, Fastness Bull. Chem. Soc. Ethiop. 2019, 33(3), 415-424. DOI: https://dx.doi.org/10.4314/bcse.v33i3.3

Functionalization of wool fabric using lignin biomolecules extracted from groundnut shells

Food and agro-processing industries generate a huge quantity of solid waste which is rich in bio-macromolecules like lignin. The extraction of lignin biomolecules can help in the efficient management of such waste along with the generation of wealth from the waste. The groundnut shells are one of the lignin-rich wastes which could be utilized for the extraction of lignin biomolecules. The present work investigates an innovative approach involving the application of extracted lignin biomolecules for the value-addition to wool fabrics. Metallic mordants were utilized to get a wash-fast attachment of lignin with wool. The change in the appearance of wool fabrics was analyzed using reflectance spectroscopy. The finished fabrics were further evaluated for the functional properties like antioxidant activity, antibacterial activity and UV protection. The functionalized wool fabrics displayed a variety of shades with different combinations of groundnut shell lignin (GSL) and mordant. Thermal stability of treated wool fabrics was analyzed by thermogravimetric analysis. The functionalized wool fabrics showed significant antioxidant activity (69.5–84.5%), antibacterial activity (79.7–86.3%) and UV protection (UPF ratings of 50+).

Biomordants and new alternatives to the sustainable natural fiber dyeings

The textile industry is considered a major polluter of the environment using chemical substances such as color fixatives and the production of toxic waste. There is a growing demand in the fashion market for products that are less aggressive to the environment and use of environmentally friendly processes. Considering the use of natural dyes as an alternative to synthetic dyes, and the use of natural mordants as alternatives to metal mordants, this study investigated the use of Acacia mearnsii sawdust as a biomordant for color fixation. Dyeing and color fixing tests were carried out on banana fiber, and the natural dyes of Hibiscus sabdariffa, Allium cepa and Curcuma longa. The results show the efficacy of Acacia as a biomordant for the tested dyes, presenting intense color and fiber softness. Thus, it is intended to contribute with new alternatives to natural dyeing through materials and sustainable processing procedures applied to natural fibers.

Natural dyeing of wool with henna and yarrow enhanced by plasma treatment and optimized with response surface methodology

In this study, response surface methodology was employed for optimization of natural dyeing of wool with henna leaves and yarrow flowers. As natural dyes have generally low affinity towards textile fibers and need considerable amounts of metal mordants to be absorbed satisfactorily, plasma treatment was used as an environmentally friendly pretreatment to enhance the dyeability and lower the amount of mordant needed. The results showed that the color value of the samples increased by increasing the plasma treatment power, dyebath temperature, and alum mordant concentration. However, the color value was higher at lower pH values. ATR-FTIR, SEM, and AFM investigations confirmed the significant surface chemical and topographical changes of the fibers. Plasma treatment can be considered as an alternative of wet chemical treatments for surface modification of wool to improve its dyeability and reduce the need for potentially toxic metallic mordants.

An overview of faba bean: utilisation of husks in natural dyeing

PurposeThe purpose of this paper is to reveal the potential use of faba bean husk as natural dye, to create a color gamut and to observe the effect of different mordants. Dyeing properties of polyamide/elastane fabric using faba been husk were investigated. The effect of alum [KAl(SO4)2], iron II sulfate Fe(SO4)7H2O, tin II chloride (SnCI22H2O), copper II sulfate (CuSO4), citric acid (C6H8O7), tartaric acid (C4H6O6), oxalic acid (H2C2O4), ammonium sulfate [(NH4)2SO4], sodium acetate (C2H3NaO2), combination of alum-iron, iron-tin and alum-tin were evaluated in terms of color yield, color coordinates and wash fastness.Design/methodology/approachMainly, dyeings were conducted in accordance with a simultaneous mordanting method. However, pre-mordanted dyeings were also implemented with selected concentration (0.8 g/L) of metallic mordants to enrich color gamut. Control sample (without mordant) was used as a reference for examining the effect of different mordants. Dyed samples were compared mutually in the light of visual evaluation and color measurements and alternatives to metallic mordants were also assessed.FindingsSignificant differences occurred in color coordinates of dyed samples. The biggest color difference and completely different color shades were achieved with tin II chloride. The type of acid did not create visible color differences. As alternatives to metallic mordants; all of them may be used instead of alum (0.8 g/L). Tartaric acid and oxalic acid, instead of iron II sulfate (0.2 g/L), and ammonium sulfate (0.2 g/L) and sodium acetate (0.8 g/L), instead of alum (0.8 g/L), can be used. Sodium acetate cannot be replaced with iron. A combination of alum-iron and iron-tin can be the alternative to 0.2 and 0.8 g/L copper, respectively. All the samples provided good wash fastness (4/5) values.Originality/valueValorization of industrial, agricultural and domestic wastes as novel natural dye sources is an ecological and sustainable approach. Moreover, the use of man-made fibers in natural dyeing is an issue that needs to be developed and expanded. Few literatures have been found concerning the use of husks of faba bean as a natural colorant. In this initial study, husks of faba been as a vegetable waste were utilized in natural dyeing of polyamide/elastane fabric. It is suggested that this waste can be turned into an economic value through its valorization in natural dyeing.

Exploring the Potential of Tannin Based Colorants Towards Functional Value Addition of Wool Textiles

Nature has been a first inspiration for the evolution of mankind. Natural colorants of plants origin highly influenced the textile industry and target a wide range of textile functionalities. Tannins from Terminalia chebula fruits have been explored to develop colored, UV protective and antioxidant functional wool textiles. Metallic mordants (Alum, ferrous sulfate, and stannous chloride) under ecological permissible limits are utilized to establish the correlation with the functional properties achieved on textiles. Shades of various colors on wool are characterized in terms of CIEL*a*b* and color strength (K/S) values on Hunter-Lab spectrophotometer. Ultra-violet (UV) protection ability was measured in terms of UV transmittance and UPF (UV protection factor) values. UV transmittance is consistently below 5 % in all dyed wool fabrics, while it was upto more than 30 % in undyed wool. Antioxidant results of both mordanted and unmordanted (control) dyed wool fabrics are found highly appreciable up to 99 % of activity. Multifunctional colored wool textiles are developed with ecofriendly and economically viable process and resources.

Extraction of natural dyes from the stem of Caulis spatholobi and their application on wool

Researchers are continuously exploring new candidates in the field of natural dyeing to lighten the burden of synthetic dyestuff on living organisms. In this research, novel natural dye was explored using the Caulis spatholobi plant. The extraction was carried out through the conventional extraction method in the aqueous medium. Various parameters of the natural dye extraction process, such as the material-to-liquor ratio, pH, time and temperature, were optimized to 1:40, 12, 120 min and 100℃, respectively. The extract was filtered twice and used for the characterization and dyeing of wool fabric. The extract was characterized using Fourier transform infrared spectroscopy for the determination of dominant functional groups. Natural dyeing of wool was carried out with and without metal mordants, such as aluminum sulfate, ferrous sulfate, copper sulfate and zinc sulfate. Pre-mordanting, meta-mordanting and post-mordanting techniques were employed. The performances of dyed fabrics were evaluated in terms of color strength K/ S values. The fastness properties of dyed fabrics were also measured. The dyed fabric showed various color shades based on the type of mordant used. Furthermore, enhancement in the colorfastness was observed with mordanting.

Dyeing of Mulberry Silk Using Binary Combination of Henna Leaves and Monkey Jack Bark

ABSTRACT The present work deals with the dyeing of mulberry silk yarns with a mixture of two colorants extracted from Lawsonia inermis and Artocarpus lacucha. The dyes were extracted with acid, alkaline and neutral medium. Different proportions of the dye and metallic mordants were made and the dyeing was performed at 80°C with pre, post and meta mordanting techniques. The extent of dyeing was studied on the basis of K/S values. It was found that, the highest dye intensity was obtained when a mild alkaline medium was used for dye extraction. The highest color value was obseved for the combination of monkey jack dye mordanted with copper sulfate by the meta mordanting method. The color fastness properties were also found to be good. The phytochemical analysis of the selected dyes showed the presence of active components like saponins, glycosides, terpenoids and tannins, which was further confirmed by Fourier Transform Infrared Spectroscopy.

Functional Dyeing of Cellulose-based (Linen) Fabric Using Bombax Ceiba (Kapok) Flower Extract

Linen fiber, which is claimed to be more comfortable than cotton, is an important textile fiber obtained from Linum usitatissimum (Flax) plant. However, the lack of functional properties of linen limits its application in functional textile products. Nowadays, use of natural colorant for textile dyeing has become an attractive option for sustainable textile coloration. Kapok flower is an unexplored source of natural dyestuff which can also be utilized for functionalization of cellulose-based textiles. In the current work, kapok flower extract (KFC) was utilized as a functional dye for dyeing of linen fabric in the presence of metallic mordants. The dyed fabrics were evaluated for coloration properties (color values, color coordinates, and fastness properties) as well as functional properties viz. antibacterial activity, UV protection, and antioxidant activity. The satisfactory level of dyeing with acceptable fastness ratings was achieved on linen fabrics. The dyed fabrics displayed an excellent antibacterial activity against gram-positive and gram-negative bacteria. The efficient level of UV protection and radical scavenging (antioxidant activity) was also obtained. The mechanism of functional modification of linen using KFC was discussed.

Extraction of Carotenoid Colorants from Tagetes erecta (Marigold) Flowers and Application on Textile Substrate for Coloration

Background: Dyeing of textiles and textile substrates has been known since ancient times. Now the increased awareness about natural products, use of eco-friendly products has been increased worldwide. Natural colorants from wastes may be the eco-friendly alternate towards this approach of finding new sources of colorants with simultaneous lowering of environmental pollution. Marigold is one of the wastes discarded, particularly in India after using for religious purposes or garlands. This study is a step towards waste utilization for industrial application. Methods: Extraction of natural colorants (carotenoids) from marigold flowers was carried out and characterized via UV/Visible and FT-IR spectroscopy. Mordanting of wool by three mordants; alum, iron and tin is followed by dyeing of wool fibers by marigold dye. Dyed wool fiber samples were tested for colorimetric and fastness properties. Results: Spectroscopic techniques (UV/Visible and FT-IR) established the final structure of carotenoids, the coloring compounds in Marigold. Marigold dye imparted yellow colored shades on wool. Colorimetric results are excellent in terms of exclusivity of the shades by application of various mordants. Fastness results in terms of washing, light exposure and rubbing were found in practically acceptable range. Conclusion: Dyeing potential of marigold was evaluated. Production of large range of shades with good colorimetric and fastness results on the application of mordants and their combinations successfully evaluated. Mordant combinations used in this study have not been found with satisfactory results relatively but developed exclusive shades. T. erecta natural dye can provide bright hues with good color fastness properties with metallic mordants. Keywords: Carotenoids, mordant, natural dye, Tagetes erecta, wool, coloration.

Dyeing Parameters, Fastness and Ultraviolet Protection Properties of Nylon Dyed with Mangrove Bark Extract

Abstract Investigation of dyeing parameters (temperature, time and pH), color fastness assessments and ultraviolet protection factor (UPF) of mangrove bark extract on nylon fabric were conducted. The optimum dyeing conditions were obtained at 90°C, 60 min and pH 5, respectively. Dyeing with different metal mordants (aluminium potassium sulfate, ferrous sulfate, copper sulfate, and stannous chloride) was also investigated. The ratings of color fastness testing showed that most of color fastness properties of dyed fabrics were generally acceptable except color fastness to washing due to considerable change in color of samples after subjected to washing test. Dyed nylon fabrics showed the improvement in UV-protection property.

Statistical study of the effect of metallic mordants on tensile strength of wool

Despite the vast variety of studies in the field of effect of different mordants on dyeing and fastness properties of wool with natural dyes, there is no thorough investigation on the effect of metal mordants on tensile properties of wool. In this study, five different metallic salts namely aluminum potassium sulfate, tin chloride, potassium dichromate, copper sulfate, and ferrous sulfate were applied on wool with concentrations ranging from 1 %owf to 20 %owf. The tenacity of the samples was measured and SPSS software was employed to investigate the effect of different concentrations of various mordants on tensile strength of woolen yarn compared with raw sample. The results showed that aluminum potassium sulfate and ferrous sulfate had no statistically significant effect on the tenacity of the yarns while tin chloride showed the highest inverse effect and lowered the yarn strength significantly. Aluminum potassium sulfate and ferrous sulfate reduced the tenacity for maximum of 4.2 %owf and 4.4 %owf respectively while the tin chloride treated sample was completely destroyed when applying higher than 5 %owf of the mordant.

Surface activation of textile fibers by plasma DBD for dyeing with teak leaf

The use of natural dyes is a field of great interest to solve the problems related to environment pollution and health risks. The objective of this research was to study the plasma discharge of double dielectric barrier (DDB) to modify the fabrics surfaces of polyamide 6.6 (PA66), silk (SK) and cotton (CO) dyed with leaf extract of teak (Tectona grandis). It was also aimed the improvement in the penetration and fixation properties to the natural dyes even without using metal mordants, which are toxic and usually used in this type of dyeing. The dye extract obtained from the teak leaves was chemically characterized by using UHPLC/QTOF-MS. The color parameters were calculated by means of spectroscopy to evaluate the color intensity (K/S) and its fastness was evaluated for washing, friction and perspiration.

Metal-free Dyeing of Cotton Fabric Using Mangrove Bark Polyphenols via Azoic Dyeing

This study proposed a novel azoic dyeing method, in which mangrove bark extract was used as the colorant. This approach eliminates the use of toxic metallic mordants. Polyphenols from mangrove bark were selected as the natural coupling component. These were applied to cotton fabric using an exhaust method, then reacted with diazonium salt prepared from a powerful primary aromatic amine (p-nitroaniline). Four concentrations of p-nitroaniline were tested from 0.5-7 % owf, produced a range of shades from pale to dark. The study confirmed that fabric was effectively and efficiently dyed with a high degree of color yield. Azoic dyeing produced a uniform bright yellow shade, with homogeneous penetration of the dye molecules. An extended range of plant materials were then investigated, and a significant correlation was found between the total phenolic content of the plant materials and the K/S of the dyed cotton. This confirmed that the proposed method can be used to fix natural dye to a cotton substrate, as long as the plant extract contained polyphenol. The colorimetric properties (L* a* b*, and K/S) of the dyed fabric were compared with those produced by traditional mordants (AlK(SO4)2 and FeSO4). The formation of azo linkages on the fabric was confirmed by ATR FTIR. Color fastness to washing and dry crock fastness were found to be acceptable, though the wet crock fastness and light fastness were low, due to the formation of surface dye on the fibers.

Valorization of natural dye extracted from date palm pits (Phoenix dactylifera) for dyeing of cotton fabric. Part 2: Optimization of dyeing process and improvement of colorfastness with biological mordants

This paper investigates the feasibility of dyeing cotton fibers with solution extracted from date pits which are abundant vegetal material. The extraction step and its optimization were conducted in the first part of this paper. This second part studies the influence of the main dyeing conditions on the color yield K/S and the CIELab coordinates. The studied parameters are pH of the dye bath, temperature and duration of dyeing. Experiments were carried out using Box-Behnken experimental design to be able to analyze the main effects of each parameter, to detect interactions between these parameters and to deduce optimum conditions for dyeing process. The fastness properties of dyed samples were also evaluated. Obtained results indicate interesting sweat, washing and rubbing fastness in the range of 4–5. Three metallic mordants (Alun, ZnSO4 and CuSO4) and three biological mordants (gall nuts, chlorophyll (a) and green almond shell) were used to improve the degree of absorption as well as the color fastness of cotton fabrics dyed with aqueous extract from date pits. The obtained results showed high improvement of fastness (sweat, friction, washing and light fastness) for biological mordants than the metallic ones.

Polyphenol-Assisted Natural Coloration on Various Synthetic Textile Materials

With the increasing awareness of sustainability development and public health in the modern society, environmentally-friendly coloration process draws tremendous attention in the textile industry. Toxic heavy metal mordants are forbidden to be used in the application of natural colorants in the coloration process. In this study, an environmentallyfriendly coloration process with natural colorants on various synthetic textile materials was developed in the presence of dopamine, whose in-situ self-polymerization could produce rich polyphenolic coloration anchors. Using the proposed method, various synthetic textile materials could be easily coloured with natural colorants in a simple process, which is especially suitable to those materials which are difficult to be colored. Compared with the control process, synthetic textile materials were endowed with better exhaustions of natural colorants, as verified by their deeper colour appearance and higher K/S values. The colored materials were also characterized by colorimetric analysis as well as scanning electron microscopy and optical microscopic analysis, which also confirmed the successful application of the proposed coloration process. Moreover, the proposed strategy could also be applied on a wide variety of materials. It is an innovative green coloration process in the textile material fields.

Economically viable UV-protective and antioxidant finishing of wool fabric dyed with Tagetes erecta flower extract: Valorization of marigold

Technological advancements and upgraded human choices have opened scientific ways to utilize ecofriendly and never ending natural resources. Natural dyeing compounds extracted from plants, well known for various biological activities, are playing significant role for the growing demands of textile industrial and healthcare sectors. Marigold (Tagetes erecta), a multipurpose plant, is utilized for wool functionalization; coloration, UV protection and antioxidant finishing. Carotenoid compounds of marigold aqueous extract produced natural yellow shades on wool fabric of good color and fastness properties. Obtained color palettes were broadened with the application of metallic salt mordants. UV protection ability of dyed wool fabric was assessed in terms of UPF (UV protection factor) and UV transmittance values in ultra-violet region (UV-A and UV-B). More adsorbed dye compounds on wool accordingly increased the activity from 6.85 to 50+ in terms of UPF values and much lowered UV transmittance (less than 5%). Application of mordants enhanced dye adsorption via increased active sites through coordination bonding and improved activity simultaneously. UV radiations hazardous effect is also associated with oxidative stress by free radicals production. Carotenoids abstract peroxy free radicals, and extended conjugation in their chemical structure makes a stable entity (carbon centered free radical) via resonance stabilization. Dye concentration and metallic mordants positively affected antioxidant activity owing to more compounds adsorption.

First-time application of biomordants in conjunction with the Alkanna tinctoria root extract for eco-friendly wool dyeing

ABSTRACTAssociated environmental hazards with the use of synthetic dyes and toxic metal mordants in the textile industry lead to concerns for alternatives. Natural dyes and biomordants are the new eco-friendly and biocompatible resources for textile coloration obtained from never-ending natural flora. The coloration potential of naphthoquinone-based colorants from Alkanna tinctoria roots on wool was investigated in this study with the application of both metallic mordants as well as biomordants. Color characteristics were evaluated on a spectrophotometer under the D65 illuminant, 10° standard observer, and fastness properties by using standard methods. A wide range of shades was obtained with good color characteristics and fastness results. Iron among metallic mordants, pomegranate peel extract (PPE) and babool among biomordants increased the color yield of dyed wool. Scanning electron microscopy (SEM) confirmed the undamaged physical structure and surface morphology of dyed wool.