The effect of mordant salts on antibacterial activity of wool fabric dyed with pomegranate and walnut shell extracts

Natural dyes have attracted increasing worldwide attention because of the carcinogenicity and environmental effects of synthetic dyes. In this study, wool fabric was treated with tannin‐rich extracts of Punica granatum peel and walnut shell in combination with some mordants. The effect of various mordants on the colorimetric and antibacterial properties of wool fabrics was investigated. The results showed that pretreatment with metallic mordants substantially improved the dyeing and fastness properties of wool fabrics. The extracts of Punica granatum peel and walnut shell showed a significant antibacterial activity at 5% concentration. In addition, antibacterial activity was dramatically enhanced using metallic salts. The antibacterial activity of samples dyed with natural dyes and without any mordant was not good, while the mordanted samples with copper, aluminum and tin salts obtained considerable antimicrobial properties following lightening and washing fastness. The extracts of Punica granatum peel and walnut shell can be considered as viable alternatives instead of artificial antibacterial agents for hospital textiles as well as an effective anti‐odour agent for sports and household textiles.     

Extraction of natural dyes from Alpinia blepharocalyx K. Schum. for dyeing of silk fabric

Natural dyes were extracted from the leaves and stems of Alpinia blepharocalyx K. Schum. Analysis of the designed experiment revealed that extraction at a plant/water ratio of 1:20 could reach an optimal production of natural dyes when extraction was performed at 80 °C, for 4 h, under 20 min ultrasound, in the presence of 10 g/l sodium hydroxide, and with two extractions. The extracted natural dyes were applied to the dyeing of silk fabrics using different methods, including or excluding a mordant. It was found that mordants had a significant effect on the colour of dyed silk fabrics. The silk fabric dyed with the pre‐mordant method using potassium aluminium sulphate as a mordant showed a bright yellow with a higher colour strength. The optimal dyeing conditions were reached when the extracted natural dyes were pre‐mordanted with 10 g/l potassium aluminium sulphate at pH 6, and for a 20 min dyeing time.     

Pomegranate fallen leaves as a source of natural dye for mordant-free dyeing of wool

The application of metal mordants is usually necessary in dyeing of wool with natural dyes to improve the dye exhaustion and fastness properties. The majority of metal salts generally used as mordants are considered as toxic and it is important to find replacements for them. Plant sources with high content of tannins are good candidates as bio-mordant or colourant to overcome this drawback. In this study, the waste fallen leaves of pomegranate tree were used as a source of natural dye for the eco-friendly dyeing of wool fabric without the use of metal mordants. The dyeing process variables including dye concentration, dyebath pH, and temperature were optimised using response surface methodology to obtain the highest colour strength. The colour strength was increased by increasing the natural dye powder up to 100%owf while the optimum pH and dyebath temperature were 4 and 100°C, respectively. The sample dyed under the optimal condition exhibited good fastness properties against washing and light. This study approved the potential of Punica granatum fallen leaves for the dyeing of wool without any mordant, while high fastness properties were obtained.     

Dyeing properties of textiles by Turkish hazelnut (Corylus colurna): leaves,coat, shell and dice

Turkey has a great number of hazelnut trees that possess nutritious components. However, only the inside part of the hazelnut is used as a nutrient, while the rest of it is waste. This study suggests that the waste parts of the Turkish hazelnut could be used as a natural dye for dyeing textile fabrics. The dyeing properties of the leaves, coat, shell and dice of the hazelnut were studied on wool, cotton and viscose fabric by using three different mordants: copper sulphate, iron sulphate and aluminium sulphate. The selected dyed fibre sample surfaces were observed using a scanning electron microscope. The colour strength (K/S), light, washing, rubbing, and perspiration fastness levels of the dyed fabrics were investigated. The experimental natural dyeing results indicate that waste hazelnut‐based products can be used as a natural dye for textile coloration.     

An alternative natural dye,almond shell waste: effects of plasma and mordants on dyeing properties

In this study, the effect of the plasma process and the possibility of replacing metallic mordants with plasma treatment were investigated in natural dyeing with almond shell waste as a novel natural colorant. The use of a smaller amount of metallic mordants and plant than most of the current natural dye applications is a major advantage of dyeing with almond shell extract. Plasma‐treated and untreated wool fabrics were dyed without mordant and using a smaller amount (0.2 g/l) of alum, iron(ii ) sulfate and copper(ii ) sulfate. Three mordanting methods, namely premordanting, simultaneous mordanting and post‐mordanting, were applied. Colour measurements and light and wash fastness values were compared. Significant colour differences were observed among the mordanting methods. Simultaneous mordanting resulted in the lightest colours with all the mordants. Generally, post‐mordanting produced duller colours and lower a* and b* values than premordanting. The plasma process generated significant colour value differences and colour yield increases, giving more homogeneous dyeing visually, and also ensured a greater impact of mordanting. However, compared with metallic mordants, plasma itself did not create completely different colour shades and fastness improvement. It was necessary to use mordants in order to achieve increased fastness properties (especially light fastness) and a different colour gamut.     

Mordant dye application on cotton: optimisation and combination with natural dyes

It is well known that cotton fibres can be dyed through the formation of coordinate bonds involving cellulose chains, mordants such as alum, and natural dyes such as alizarin. Similarly, synthetic dyes known as mordant acid dyes can be used to dye wool fibres. Unlike mordant dyes on wool, the fastnesses of natural dyes on cotton are often low. Although concerns surrounding textile sustainability have sparked renewed interest in the use of natural dyes, extensive replacement of synthetic dyes with natural dyes is neither practical nor fundamentally possible. However, similarities in dyeing methods using mordant and natural dyes raise the possibility of using mordant dyes as alternatives to natural dyes in the dyeing of cotton. Further, the potential for combining suitable dyes from these two classes to expand the colour gamut currently available from natural dyes on cotton seem worthy of exploration. The results of this study indicate that shades comparable with those produced by natural dyes can be obtained on cotton using select mordant dyes following Fe²⁺ and Al³⁺ pretreatments. The best results were obtained using a two‐step/two‐bath process and dyes such as CI Mordant Blue 13 and CI Mordant Orange 6. In evaluations of mordant and natural dye combinations using the two mordant dyes logwood and Osage orange as prototypes, interesting fabric shades were obtained. However, the fastness properties of these dyes must be improved in order to produce commercially viable dyeings.     

A method for dyeing cotton fabric with anthocyanin dyes extracted from mulberry (Morus rubra) fruits

For the first time, the natural anthocyanin dyes (mainly consisting of cyanidine 3‐glycoside) extracted from mulberry (Morus rubra) fruits has been successfully used to dye cotton fabric, with a dyeing property performance good enough for potential commercial applications. In this study, succinic acid was firstly incorporated into cotton fabrics by esterification to the hydroxyl groups of cellulose, forming an anionic site for the dyes. The performance of the modified material was characterised by Fourier transform infrared spectroscopy and tensile strength. Results showed that the tensile strength of cotton fabrics was mostly retained after modification. The anthocyanin extracts from mulberry fruits were used to study the dyeability of the control and modified cotton fabrics. Red and deep purple (aubergine) are two main shades of cotton fabrics dyed with mulberry fruit extracts. Most importantly, aubergine shade is rare in cotton fabrics dyed with natural dyes. Modification with succinic acid clearly increased the colour strength of the dyed cotton fabric. The colour strength of dyed cotton fabric was improved from 2.7 to 5.3 in the case of dyeing without mordants, and from 3.2 to 6.9 in the case of dyeing with tin mordanting. Meanwhile, the colour fastness was improved by 0.5–2 grades with increasing succinic acid concentration in the finish solution. The colour fastness to perspiration, crocking, light, and washing of fabric dyed with simultaneous tin mordanting and modified with 30 g l^?1 of succinic acid was found to be acceptable, with a grey scale grade of at least 3. As for home laundering, neutral soapy solution was more acceptable than alkaline soapy solution.     

合成纤维及其混纺纤维用染料的研究 Ⅰ.用于锦纶染色的含β-羟乙基砜硫酸酯基活性分散染料

本文综合了应用于锦纶染色的弱酸性染料酸性浴上色的高竭染率,活性染料与纤维的共价键结合,分散染料在纤维上迁移、匀染、盖染性好等优点,提出一类含β-羟乙基砜硫酸酯基的活性分散染料。用分子较小的分散染料结构,以含β-羟乙基砜硫酸酯为活性基;在弱酸性浴中染色,再在弱碱性浴中与聚酰胺纤维反应成共价键结合。 合成了一系列偶氮型和蒽醌型染料。进行了合成工艺、对锦纶的染色性能以及染色锦纶的牢度等试验。并讨论了染料与聚酰胺纤维的结合 这类染料可用于锦纶66和锦纶6丝纺、弹力锦纶丝和针织品,还可用于桑丝、柞丝及其与人造丝的提花织物。这类染料在锦纶上色泽鲜艳,竭染率较高,益染性优良,耐晒、耐湿处理等牢度较好,适于各种锦纶织物的染色。这类活性分散染料,具有酸性染料、活性染料和分散染料染锦纶的主要特点。     

Extraction of juglone from Pterocarya fraxinifolia leaves for dyeing,anti‐fungal finishing,and solar UV protection of wool

In many countries, the search for new sources of natural colourants has recently been intense. This paper deals with the extraction procedure, dyeing behaviour, antifungal activity, and ultraviolet protection of Pterocarya fraxinifolia as a new natural source of dyes. Juglone was found as the main extracted compound after characterisation by ultraviolet‐visible spectrophotometry and Fourier transform infrared spectroscopy. Mordanting and subsequent dyeing of wool with extracted juglone were then performed to study the dyeability and antifungal activities. Three metal salts, aluminium sulfate, copper sulfate, and iron sulfate, were used as chelating materials. The colorimetric properties of samples were evaluated using a reflectance spectrophotometer. Furthermore, the washing and light fastness properties were tested according to ISO 105‐CO3:1989 and ISO 105‐B01:2014. Interestingly, we found P. fraxinifolia to be a source of strong antifungal compounds against microorganisms. Extracted juglone also exhibited strong protection activity against solar ultraviolet rays.     

Developments in Coloration for the Carpet Industry

Meeting of the Bradford Junior Section, held in Bradford Technical College, on 13 October 1969, Mr R. S. Stringer in the chair The improvement in wet fastness of anionic dyes, e.g. C.I. Acid Blue 25, on nylon fibres by aftertreatment with natural tannins is attributable mainly to modification of the substrate by the tannin, which lowers the rates of diffusion of the dye (a) out of the dyed fibre and (b) into undyed adjacent nylon. Ultraviolet spectroscopy of solutions of tannic acid (a polygalloylated glucose) has given indications of the alkaline oxidative degradation of the tannin believed to be responsible for the discoloration of backtanned dyeings. Tartar emetic increases the effectiveness of backtanning by formation of a less soluble complex with tannic acid which is more resistant to alkaline oxidation. Formic acid increases the rate of diffusion and the equilibrium uptake of tannic acid on nylon. The adsorption and diffusion behaviour of several related anthraquinone acid and disperse dyes on nylon is discussed and possible explanations are advanced of the low effectiveness of backtanning in preventing loss of dye by dyed nylon 6 and staining of undyed wool. No conclusive evidence has been obtained of interaction between C.I. Acid Blue 25 and tannic acid or tartar emetic in aqueous solution.     

Ecofriendly ultrasonic natural dyeing of cotton fabric with enzyme pretreatments

Ecofriendly ultrasonic textile dyeing with natural dyes such as Acacia catechu and Tectona grandis show better and faster dye uptake after enzyme pretreatment on cotton fabric, and results of dyeing are better than metal mordanted fabric. It is observed that there is marked improvement in wash-fastness and light-fastness. The role of enzyme pretreatment is primarily for better absorbency, adherence and dyeability of these dyes on cotton fabric, thereby completely replacing metal mordants with enzyme for adherence of natural dyes on cotton. Scanning electron microscopy show surface characteristics at different stages of dyeing. The effect of sonication on the dyeing is compared with conventional heating. The study also shows enhancement in CIELab values.     

A route from olive oil production to natural dyeing: valorisation of prina (crude olive cake) as a novel dye source

An attempt has been made to valorise an agroindustrial solid waste in natural textile dyeing as a novel dye source. The dyeing and fastness properties of prina (crude olive cake/pomace) extract were evaluated to fill the gap in this field. This very cheap biomass was utilised (80 g/l) by applying chemical solvent‐free aqueous extraction to dye wool fabric with only small amounts (0.2, 0.4, 0.8, and 1.6 g/l) of metallic mordants, namely alum, iron(II) sulfate, copper(II) sulfate, stannous chloride, and potassium dichromate, and avoiding the use of alkali, acid, chemicals, and auxiliaries in dyeing and washing processes. Colour shades of beige, cream, sandy, apricot, straw, cumin, mustard, olive, and khaki were obtained. Significant differences in colour strength and CIELab coordinates were observed, depending on mordant type and mordanting method. Copper(II) sulfate and iron(II) sulfate ensured the most significant colour changes and nuances, the darkest colours, and the best light fastness values. Prina extract itself (without mordant) has a light fastness of 3 (fair) and excellent wash fastness of 4–5, both for colour change and bleeding. Irrespective of the concentration and mordanting method, alum, stannous chloride, and potassium dichromate did not generate a light fastness improvement compared with the control sample. Although good light and wash fastness values have been achieved without mordants, it is necessary to use them to widen the colour gamut and to obtain increased colour strength.     

Colorimetric and fastness studies and analysis by reversed‐phase high‐performance liquid chromatography with diode‐array detection of the dyeing of silk fabric with natural dye Helichrysum arenarium

In this study, silk fabric samples were dyed by various procedures using Helichrysum arenarium extracts. Alum, ferrous sulfate, stanium chloride, calcium nitrate, and potassium bitartrate were used as mordants. Reversed‐phase high‐performance liquid chromatography with diode‐array detection was utilised for identification of the dyes present in the dyed silk fabrics and the plant extracts. The extraction of dyes was carried out with a hydrochloric acid/methanol/water (2:1:1 v/v/v) mixture. The colour coordinates and K/S values, as well as wash, light, and rub fastness, were determined.     

Colour and fastness of natural dyes: revival of traditional dyeing techniques

Cotton and wool fabrics were dyed with nine natural dyes obtained by aqueous extraction of the original plants/insect in an attempt to reconstruct traditional textile dyeing recipes, to optimise the methodology at all stages, i.e. extraction, mordanting and dyeing, and to standardise it. Cochineal, madder, alkanna, henna, brazilwood, red sandalwood, safflower, indigo and logwood were used for the dyeings, which were carried out directly and after mordanting of the textile material. A variety of mordants, namely, aluminium potassium sulphate, potassium dichromate, copper sulphate, zinc chloride, iron(iii ) chloride, iron(ii ) sulphate and tin chloride, is anticipated to meet both early and recent requirements and options. The dyeings were evaluated through colour measurements and standard wash, light and rub fastness tests. Generally, the mordanting process known for many centuries and connected with the textile dyeing resulted in an improvement in dye absorption and fastness properties mainly for the cotton samples, as is concluded from the tests and measurement assessments.     

Improving the dyeability of polyimide by pretreatment with alkali

Polyimide fabric, as a high‐performance fabric, possesses advantageous properties, such as outstanding thermal stability and chemical resistance, but has poor dyeability. In this paper, polyimide fabric was dyed successfully with disperse dyes by high‐temperature and high‐pressure dyeing in the presence of a swelling agent and auxiliaries. Under optimal dyeing conditions, it is pretreated with NaOH 6 g l^?1 and dyed with disperse dyes 5% o.w.f., NaCl 1 m , benzyl alcohol 60 ml l^?1 at 135 °C for 45 min to obtain a satisfactory colour yield with good washing fastness and dry rubbing fastness with 93.3% strength retention. The experimental results demonstrate that the Nernst adsorption isotherm is a favourable model for polyimide fabric dyeing with disperse dyes.     

Improvement of the dyeing and fastness properties of a naphthalimide fluorescent dye using poly(amidoamine) dendrimer

In this study, 4‐amino‐9‐methoxypropylnaphthalimide fluorescent dye (dye 1 ) was reacted with poly(amidoamine) dendrimer G = ?0.5 to prepare a naphthalimide–dendrimer hybrid dye (dye 2 ). The chemical structures of the synthesised dyes were confirmed by elemental analysis, Fourier transform infrared spectroscopy, ¹H nuclear magnetic resonance spectroscopy, and ultraviolet‐visible spectroscopy. The solvatochromism of the dyes was evaluated in various solvents with respect to visible absorption properties, and positive solvatochromism was observed by solvent polarity change from chloroform to ethanol. The dyeing ability of the synthesised dyes was investigated by their application onto nylon fabric, and nylon substrates dyed with dye 2 exhibited marked enhancement both in terms of colour strength and general fastness properties. The results of this study clearly demonstrated the high potential and performance of dye 2 as a novel promising fluorescent dye as compared with dye 1 . Overall, it was inferred that the modification of the naphthalimide fluorescent dye with poly(amidoamine) denderimer could markedly improve the dyeing and fastness properties of the naphthalimide fluorescent dye on nylon fabrics.     

A new approach to improve dyeability of nylon 6 fibre using a subtilisin enzyme

This study confirms the structural changes of nylon 6 fibres using protease by measuring the dyeability, hydrophilicity, chemical changes and fastness properties. For this purpose, nylon 6 fabrics were first treated with different concentrations of protease enzyme in aqueous solutions. The dyeing process was then carried out on the treated fabrics with disperse and acid dyes. Acid and disperse dyes showed higher exhaustion on the enzyme‐treated samples. The results of colour measurement in the CIELAB system showed that the darkness of the samples increased with an increase in the enzyme percentage in the solution. The results of moisture regain showed that treatment of nylon fabrics with a proteolytic enzyme caused an increase in moisture absorbency. The wash and light fastness properties of samples were measured according to ISO 105‐C05 and daylight ISO 105‐B01 and are discussed.     

Synthesis of temporarily solubilised azo disperse dyes containing a β‐sulphatoethylsulphonyl group and dispersant‐free dyeing of polyethylene terephthalate fabric

Disperse dyes containing a β‐sulphatoethylsulphonyl group have temporary solubility and can be applied for dispersant‐free dyeing of hydrophobic fibre. Six novel temporarily solubilised azo disperse dyes having a β‐sulphatoethylsulphonyl group in their structures were synthesised, and their dyeing properties on polyester were investigated. As a dye intermediate, a diazo component having dibromo groups was prepared, and 4‐diethylamino‐4′‐(2‐sulphatoethylsulphonyl‐4,6‐dibromo)azobenzene dyes were prepared by a diazo‐coupling reaction. Then, the dyes containing dicyano groups were prepared by cyanation of corresponding dyes with dibromo groups. The absorption maxima of the dyes were affected by the substituents in the diazo and coupling component rings and varied from 434 to 616 nm in dimethylformamide. Polyethylene terephthalate woven fabric could be dyed with the synthesised temporarily solubilised dyes without using any dispersants. Dyebath pH affected the K/S value at maximum absorption as well as percentage exhaustion on polyethylene terephthalate fabric, and the optimum pH was 5. The dyes gave brownish orange, red, purple, and greenish blue hues on polyethylene terephthalate fabrics, and colour build‐up was good. Wash fastness was good to excellent, rubbing fastness was moderate to excellent, and light fastness was poor to moderate.     

Direct coloration of textiles with photochromic dyes. Part 1: Application of spiroindolinonaphthoxazines as disperse dyes to polyester,nylon and acrylic fabrics†

1,3,3‐Trimethylspiroindoline‐2,3′‐3H‐naphth[2,1‐b][1,4]oxazine ( 1a ) and 6′‐piperidino‐1,3,3‐trimethylspiroindoline‐2,3′‐3H‐naphth[2,1‐b][1,4]oxazine ( 1b ) were applied as disperse dyes to polyester, nylon and acrylic fabrics. Under optimised dyeing conditions, photochromic fabrics were produced which, on irradiation with ultraviolet or exposure to sunlight, turned blue ( 1a) or blueish‐purple ( 1b ). Dye 1a showed enhanced photochromic colour change performance compared with dye 1b . The photochromic colour build was highest on nylon and lowest on acrylic fabric. The colour change properties and the technical performance (wash fastness and photostability) of the photochromic fabrics were evaluated using specifically adapted colour measurement methods. The data were analysed in terms of variation of lightness, a*, b*, chroma, hue angle and ΔE, colour difference before and after exposure, and K/S curves as a function of irradiation time. The fabrics generally showed good wash fastness. Although the colour build‐up decreased with exposure to the Xenotest fadeometer, some residual photochromism remained after prolonged exposure.     

酸性金属络合染料上染锦氨织物的色牢度探讨

采用酸性金属络合染料对锦氨织物进行染色,从染料、染色工艺、助剂三个角度探讨了对染色牢度的影响。结果表明:酸性金属络合染料对锦氨织物染浅、中及中深色的牢度较好;染深色时,需通过工艺调整及助剂辅助。其优化的工艺条件为:染色温度93℃,保温时间30 min,染浴p H值在3~4,配合1.0 g/L氨纶防沾色剂,2%(omf)酸性固色剂DM-2539G及2.0 g/L增进剂CIBAFIX ECO后处理,各项牢度指标能提升到3-4级及以上。