Natural dyes have been the focus of textile industry for their environmental protection properties. However, some limitations such as poor photostability has limited their wide application, and the ...researches of the discoloration mechanism of fabric with natural dye are relatively limited. As one of the most important natural dye, madder has been widely used in textile field. Herein, as the main pigment of madder, alizarin was selected as the model natural dye to explore the photo-fading progress of alizarin-dyed fabrics. The photodegradation progress of alizarin was explored by UV, HPLC, HPLC-MS and Datacolor (computer color matching system). When exposed to light, alizarin could be oxidized into colorless small molecules through ·OH radical-mediated route, and finally resulting in the fading of alizarin. In addition, the influence of pre-mordant and the liquid rate has also been studied. These results provide us a good insight into the photo-fading progress of natural dyes, and our work could help to open the way to further studies aiming at improving the photostability of natural dyes or developing new photo-stable dyes.
The study was focused on the usability of olive tree leaves fallen during olive harvesting in dyeing and antibacterial finishing of cotton fabrics for cleaner production. Valorizing these waste ...(olive tree leaves) obtained during harvesting and using them in textile treatment processes would ensure a cleaner and more sustainable production. For this aim, olive tree leaves were subjected to an extraction process before their use in dyeing as well as directly use without any previous extraction. Six mordanting agents were also tested. Dyeing was done at two different temperatures (80°C and 100°C), and the liquor ratio was 1:60. First, the treated samples were tested for fastness and color variety. It was observed that sufficient fastness and color variety can be produced by using olive tree leaves with or without mordanting agents. Antibacterial tests were also conducted for samples dyed without mordanting agents. The antibacterial effects of mordants were also tested. The samples were tested against Escherichia coli and Staphylococcus aureus. It was found that mordanting agents provide significant antibacterial efficiency against both tested bacteria and minimum of 90% bacterial reduction was observed. Using olive tree leaves without any mordants also demonstrated antibacterial efficiency and better bacterial reductions were observed for both bacterial species in dyeings at 80°C. The reason of antibacterial efficiency caused by the olive tree leaves were investigated by ICP-MS analysis. Addition to the oleuropein content of the extract, the elements detected by ICP-MS assumed as responsible for the bacterial reduction.
•Waste “olive tree leaves” come out during harvesting can be used as a source of natural dyeing.•The combination olive tree leaves with metal salts (mordant) in dyeing of cotton can serve for alteration of the colors.•Dyeing of cotton with the extract from olive tree leaves at low temperature can serve for antibacterial activity.•The processing with mordants can ensure antibacterial activity in the cotton fabrics.
Morus nigra L. is a biologically important plant. In addition to the biological importance of the extracts obtained from its various parts, it is used as a material in various fields. In this work, ...dyeing properties of the cotton fabrics and the wool yarns with Morus nigra L. leaf extracts were investigated. In dyeing studies using Morus nigra L. leaf extracts, yellow tones were obtained in dyeing cotton fabrics, and green and yellow tones were obtained in dyeing wool yarns. Washing, rubbing and light fastness of dyed textile products were examined. According to the results, cotton fabrics showed better dyeing potential than wool yarns. As a result, Morus nigra L. leaf can be used as a natural dyeing agent in the dyeing of textile products.
Traditional cotton fiber dyeing requires an abundance of salt, which leads to environmental pollution. Consequently, decreasing or eliminating the use of salt has become the primary focus of current ...research. In this study, Crocein Orange G was used to dye carboxymethyl cotton. Carboxymethyl cotton has better color shades than raw cotton and it is used along with a mordant in a simultaneous-mordant dyeing process, at a pH of 7, Al
2
(SO
4
)
3
·18H
2
O as the mordant. In addition, it was found that the adsorption kinetics of carboxymethyl cotton followed a pseudo-second-order kinetic model. The equilibrium adsorption capacity increased as the temperature increased from 30 to 50 °C, and the maximum equilibrium adsorption was 8.21 mg g
−1
at 50 °C. Furthermore, the adsorption isotherm data exhibited good agreement with the Freundlich isotherm. These results will help achieve salt-free dyeing of cotton fabric in the textile industry.
Wood staining is a crucial technique for enhancing the decorative effect of wood. Different mordants and mordant processes can influence the staining effect of wood. In this study, three types of ...mordants and mordant methods were selected to improve the color difference and colorfastness to the washing of poplar veneer, using green peanut pigment as the dye. An orthogonal test was conducted to investigate the effects of mordant temperature, mordant time, and mordant concentration on color difference and colorfastness to washing. Range and variance analysis were employed to determine these properties’ main factors. A fuzzy comprehensive evaluation method was used to evaluate and optimize the color difference value and colorfastness of washing. The results revealed that all three factors had significant impacts on both color difference and colorfastness to washing during the process of mordant staining. The optimal process conditions (temperature, concentration, time) for achieving desirable staining effects on poplar veneer were determined as 50 °C, 0.8%, and 2 h, respectively. Furthermore, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses demonstrated that the dye formed complexes with poplar wood, enabling it to adhere to wood grain apertures and tube walls effectively. Mordant treatment increased the crystallinity of stained wood significantly while improving its overall staining performance considerably. This study provides substantial data support for future optimization processes involving natural pigment coal staining in wood.
Color is a major attraction component of any fabric regardless of how admirable its constitution. Industrial production and utilization of synthetic dyestuffs for textile dyeing have consequently ...become a gigantic industry today. Synthetic dyestuffs have introduced a broad range of colorfastness and bright hues. Nonetheless, their toxic character has become a reason of serious concern to the environment. Usage of synthetic dyestuffs has adverse impacts on all forms of life. Existence of naphthol, vat dyestuffs, nitrates, acetic acid, soaping chemicals, enzymatic substrates, chromium-based materials, and heavy metals as well as other dyeing auxiliaries, makes the textile dyeing water effluent extremely toxic. Other hazardous chemicals include formaldehyde-based color fixing auxiliaries, chlorine-based stain removers, hydrocarbon-based softeners, and other non-biodegradable dyeing auxiliaries. The colloidal material existing alongside commercial colorants and oily froth raises the turbidity resulting in bad appearance and unpleasant odor of water. Furthermore, such turbidity will block the diffusion of sunlight required for the process of photosynthesis which in turn is interfering with marine life. This effluent may also result in clogging the pores of the soil leading to loss of soil productivity. Therefore, it has been critical for innovations, environmentally friendly remediation technologies, and alternative eco-systems to be explored for textile dyeing industry. Different eco-systems have been explored such as biocolors, natural mordants, and supercritical carbon-dioxide assisted waterless dyeing. Herein, we explore the different types of dyeing processes, water consumption, pollution, treatment, and exploration of eco-systems in textile dyeing industry.
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.
Bridelia ferruginea
B dye was extracted from the bark of the tree using aqueous extraction method. Extracted dye was used to dye cellulosic (cotton) fabric in presence of 5% calcium chloride (CaCl
2
...) or 5% alum (KAl(SO
4
)
2
·12H
2
O) of weight of fabric (o.w.f) as mordant. Fabric dyed without mordant was lighter in hue than metal ion mordanted dyed fabrics. The fabrics dyed in presence of calcium chloride as mordant are of deeper hue than those dyed with alum as mordant. Hence, their dye-uptake and color strength (K/S) are in the same order. K/S value of fabric dyed with alum is 43.71% higher than that without mordant and fabric dyed with calcium chloride has K/S value 51.09% higher than dyed with alum as mordant. CIEL*a*b* coordinate indicator and color space quadrant showed that those dyed fabrics without mordant and with alum as mordant are closer to yellow than red color. Those cellulosic fabrics dyed with calcium chloride as mordant are closer to red than yellow color as confirmed in colour space quadrant. Pre-mordanted dyed fabrics are of deeper color than post-mordanted dyed fabrics than meta-mordanted dyed fabrics than unmordant dyed fabric. Fastness properties of
B
.
ferruginea
B dyed cellulosic fabrics ranged from good (3) to excellent (5).
Natural dyes, obtained from plants, insects/animals, and minerals, are renewable and sustainable bioresource products with minimum environmental impact. However, there are still many issues to solve ...related to natural dyes; consequently, synthetic dyes are still wildly used. Natural dyes have a low affinity towards the substrate cotton, so a solution had to be found: mordants. Mordants can also be harmful to the environment, which is why bio-mordants are used. The mordant used in this paper is chitosan. Cotton is pre-mordanted using the pad dyeing method. By using the exhaustion method, the fabric was coloured with red Camellia sinensis (tea) extracts. The colour, absorption of polyphenols and tannins, and ultraviolet protection (UPF) were tested. A comparison study was carried out between the cotton fabric and the cotton padded with chitosan at two different concentrations. The results are impressive. Cotton pre-mordanted with chitosan can absorb more polyphenols and tannins than cotton itself, and the colour fastness and UPF, once the fabric is laundered, demonstrate there is some kind of bonding between the fibre, quitosan, and active compounds from tea. The UPF was also doubled by using chitosan and the reddish colour obtained by Camellia sinensis extracts were darker on the cotton fabric. The increase in UPF protection on mordanted fabrics is higher than the gap obtained by colour difference, which means there are active compounds that do not confer colour, but enhance UPF protection.
The current study is the first report of using biomordants with prina extract as a possible substitute for environmentally unfavourable metallic mordants. As a part of sustainable and cleaner ...production approach, eco-friendly natural dyeing conditions were presented in terms of cost and consumption efficiencies. A novel and renewable natural dye source prina is an essential by-product of olive oil production. This biomass was valorized in wool dyeing in conjunction with biomordants namely powder of iris germanica (I. Versicolor), valex (acorn of Quercus ithaburensis ssp.macrolepis), pomegranate (Punica granatum L.) rind, rosemary (Rosmarinus officinalis), and thuja (thuja orientalis). Their color coordinates and fastness properties were compared and assessed versus metallic mordants. Prina extract itself without mordant has a fair light fastness of 3 and an excellent washing fastness of 4-5 both for color change and bleeding. Valex, pomegranate rind, iris, rosemary, and thuja leaves were proposed as promising alternatives to alum, iron II sulfate, copper II sulfate, stannous chloride, and potassium dichromate. Biomordants generated significant color yield increment and exhibited equivalent fastness properties to metallic mordants. Water, energy, dye, chemical cost, and consumption of natural and synthetic dyeings on the basis of mill conditions were also calculated and compared mutually. Total recipe cost and chemicals/auxiliary consumption of natural dyeing are on average significantly less than with synthetic dyeing. Considerable savings are possible with natural dyeing, especially one-bath, in terms of cost, time, and consumption.
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