One‐bath union dyeing of a modified wool/acrylic blend with acid and reactive dyes

Pretreated wool/acrylic fibre was obtained by a facile amidoximation process. Fibre characterisation (nitrogen content, tensile strength, shrinkage, infrared spectra and X‐ray diffraction) proved the success of the pretreatment. Union dyeing of wool/acrylic fabrics with acid and reactive dyes, namely CI Acid Red 40, CI Acid Blue 25, CI Reactive Red 194 and CI Reactive Blue 25, was obtained using a one‐bath dyeing process. Different factors that may affect the dyeability of the blend fibre, such as dyebath pH, liquor ratio, temperature, time and dye concentration, were evaluated with respect to the dye exhaustion, fixation, colour strength, levelling and fastness properties. Excellent to good fastness was obtained for all samples, irrespective of the dye used. The result of the investigation offers a new viable method for union dyeing of wool/acrylic fibres in a one‐dyebath process.     

Synthesis of acid dyes containing polyetheramine moieties and their low‐temperature dyeing properties on wool fiber

To realize the low‐temperature dyeing of wool fibers, the use of auxiliaries and wool modification are common methods. Low‐temperature auxiliaries may cause water‐pollution problems, and wool modification is a costly and uncontrollable process. In this study, new acid dyes, named D1–D3, containing polyetheramine groups were synthesized and applied to wool fiber by conventional and low‐temperature exhaust dyeing procedures. The results indicate that the new acid dyes could interact with wool‐fiber‐like auxiliaries and render a high exhaustion rate to the wool fiber at a dyeing temperature of 80 °C. In comparison with Acid Blue 25, the D1–D3 dyes showed an increased dyeing rate, especially under a dyeing temperature of 80 °C. Despite the bigger relative molecular masses of D1–D3, the exhaustion rates of D1–D3 were still higher, and the times of half‐dyeing were shorter than that of Acid Blue 25. The color differences between the wool fabrics dyed with the four dyes at 80 and 98 °C, respectively, were compared. We found that the color differences of D1–D3 between 80 and 98 °C were smaller than that of Acid Blue 25. The interactions between the dyes and wool fiber were analyzed and manifested by the measurement of the ζ potential of the dyes and wool fiber. The leveling and transfer properties of the D1–D3 dyes were also investigated, and the color differences of the wool fabrics dyed with Acid Blue 25, D1, and D2 were very low at all measured pH values and temperatures. The fastnesses of D1–D3 on wool fabric were almost the same as that of Acid Blue 25. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45793.     

Reductive decolourization and total organic carbon reduction of the diazo dye CI Acid Black 24 by zero‐valent iron powder

In this study, wastewater contaminated by colour and total organic carbon from the diazo dye CI Acid Black 24 was successfully removed by reductive decolourization with zero‐valent iron powder. The effects on decolourization of experimental variables such as iron dosage, initial dye concentration, pH and dissolved oxygen level were evaluated. The best removal efficiencies for decolourization of 99.7% and total organic carbon of 57.4% were obtained with an initial dye concentration of 25.0 mg L^?1 and iron dosage of 200.0 g L^?1. Moreover, the decolourization rates followed pseudo‐first‐order kinetic equations with respect to dye concentration. The colour removal efficiency was simultaneously dependent on iron dosage and various initial dye concentrations, although the colour and total organic carbon removal efficiencies linearly increased with increased iron dosage, reaching a maximum at 100.0 g L^?1. A contour plot was developed to illustrate the 3D relation of removal efficiencies with initial dye concentration and iron dosage. For wastewater with a concentration range from 25 to 100 mg L^?1 CI Acid Black 24 the suggested ideal operation conditions are 100.0 g L^?1 iron dosage, pH 2‐4, normal oxygen concentration of 5‐7 mg L^?1 and reaction time of 30‐60 min. Copyright © 2006 Society of Chemical Industry     

Synthesis and application of a novel,triphendioxazine‐based,phosphorus‐containing acid dye for wool

A novel phosphorus‐containing acid dye based on triphendioxazine was designed and synthesised from diphenylamine through a series of reactions. The dye has a navy‐blue colour, high molar extinction coefficient of 5.32 × 10⁴ l/mol·cm, and high substantivity for dyeing wool in a salt‐free, aqueous dyebath. A high exhaustion value of 98.2% on wool fabrics was recorded at 3% omf and a liquor ratio of 1:20. The wash fastness values of the acid dye, including colour change and staining on cotton and wool, were grades 5, 4 and 4–5, respectively. The dry and wet fastness are grades 4–5 and 4, respectively. In addition, light fastness reaches grades 6–7 at 3% omf dye concentration. These dye properties are better than those of commercial triphendioxazine dyes, for example, CI Direct Blue 106 and CI Reactive Blue 198, under analogous dyeing conditions.     

Biotransformation of CI Acid Blue 113 and other dyes by Shewanella sp. P6

The isolate P₆, an indigenous Shewanella sp., was able to decolorise 90% of CI Acid Blue 113 in just 30 min of incubation under anoxic conditions. The decolorisation potential of cells was not significantly affected even in the presence of 2% (w/v) sodium chloride and 8% (w/v) sodium sulphate. Mass spectrometric analysis detected the formation of aniline sodium salt, 1,4‐diaminonaphthalene, 5‐amino‐8‐(phenylamino)‐naphthalene‐1‐sulphonic acid sodium salt and 8‐(phenylamino)‐naphthalene‐1‐sulphonic acid sodium salt. Further, cells of P₆ decolorised the raw effluent collected from the equalisation tank of a textile industry wastewater treatment plant. The water‐soluble dyes/intermediates present in the sludge, generated after chemical flocculation of raw effluent, were transformed by P₆ cells within 24 h of incubation under anoxic conditions. Thus, isolate P₆ has a potential application in the biological treatment of liquid and solid waste of textile processing plants because of its efficient decolorisation and transformation properties.     

Dyeing of leather with microencapsulated acid dye

CI Acid Black 210 was microencapsulated into liposomic systems, and the effects of the microencapsulation on dyebath exhaustion, depth of shade, colour fastness properties and through‐dyeing of chrome‐tanned leather were studied. In comparison with the original dyestuff form, the microencapsulated dye showed a deeper shade and a greater depth of through‐dyeing. Exhaustion and colour fastness values were the same.     

Study of the cytotoxicity of reactive dyeing effluent treated by Fenton oxidation

Fenton oxidative wastewater treatment of CI Reactive Black 5 and CI Reactive Blue 19 effluent was performed after a simulated laboratory‐scale dyeing process, and the cytotoxicity of the treated effluent was evaluated using human skin cell lines. Among the components for Fenton oxidation, the human skin cell results showed that iron(II)sulfate at 150 mm did not show any significant cytotoxic effect, while other components, such as Glauber's salt solution (20 g l^?1; 14%), CI Reactive Black 5 (30 mg l^?1; 24%), caustic soda (5 g l^?1; 30%), CI Reactive Blue 19 (30 mg l^?1; 32%), hydrogen peroxide (0.01 m ) and soda ash (5 g l^?1) showed cytotoxic potential; the reagent sodium sulfite (30 mm ; 48%) exhibited the strongest cytotoxicity level. Fast decolorisation (>95%) was achieved within 10 min for CI Reactive Black 5, while for CI Reactive Blue 19 it took longer (1.5 h) to achieve the same decolorisation. Studies showed that decolorisation for both dyes followed second‐order kinetics. In spite of the remarkable efficacy of the Fenton oxidation process in removing colour within a short period of time, the resulting treated wastewater (within a reaction time of 1.5 h) also showed cytotoxicity towards the human HaCaT skin keratinocyte cell line. This observation can be explained by the strong oxidant and intermediate species produced during the advanced oxidation process, and a treatment step using sodium sulfite and a prolonged residence time can help to reduce the cytotoxicity.     

Improvement of catalytic efficiency of chloroperoxidase by its covalent immobilization on SBA-15 for azo dye oxidation

Chloroperoxidase from the fungus Caldariomyces fumago was covalently immobilized on SBA-15 mesoporous material and assayed for the enzymatic oxidation of four azo dyes. All dyes were oxidized by the free and the immobilized enzyme to different extent. Acid Blue 120 and Direct Blue 85 dyes were decolorized almost completely. The catalytic efficiency, k _cat/K _M, of the immobilized enzyme was 27, 2.9, 137 and 28 times higher than the free enzyme for Basic Blue 41, Disperse Blue 85, Acid Blue 120 and Direct Black 22 oxidation, respectively. The immobilized enzyme displayed improved thermostability and a similar pH profile compared to the free enzyme. The immobilized chloroperoxidase showed excellent storage stability and maintained 100 % catalytic activity after 90 days at both 4 and 25 °C.     

Photocatalytic degradation of CI Acid Green 25 and CI Acid Red 88 in aqueous suspensions of titanium dioxide

The photocatalytic degradation of CI Acid Green 25 and CI Acid Red 88 in aqueous suspensions of titanium dioxide has been investigated by monitoring the depletion of the total organic carbon content as a function of irradiation time under a variety of conditions. The degradation rates were found to be strongly influenced by pH, catalyst concentration, substrate concentration and different titanium dioxide powders. The degradation of CI Acid Red 88 was found to occur faster than that of CI Acid Green 25. The degradation products were analysed by gas chromatography-mass spectrometry and probable pathways for the formation of products are proposed.     

Synthesis of branched azo dyes based on benzene sulphonamide intermediates and their spectral properties

Benzene sulphonamide intermediates and two series of branched azo dyes (one series with H‐Acid as the coupling component, and the other, with a pyrazolone derivative as the coupling component) derived from them were synthesised. The molecular structures, spectroscopic properties and dyeing properties of the dyes obtained have been investigated. The results indicated that these dyes showed one dominant hue, despite each separate branch of chromophore, and, in the first series, four chromophoric groups led to only a threefold increase in the extinction coefficient, while the same comparison in the second series produced a fully additive effect, i.e. a fourfold increase. Compared with the mono‐branch dye of each series, the dyeing properties of the H‐Acid series were improved, whereas the pyrazolone series that were run diversely for the two series were synthesised from different coupling components. In addition, the crystallographic structure of the tri‐branch intermediate showed a non‐coplanar structure, which indicated that the derived dye would perform as the sum of three similar chromophoric units.     

Electrocoagulation of azo dye production wastewater with iron electrodes: process evaluation by multi‐response central composite design

Central composite design was used to optimise electrocoagulation of CI Acid Blue 193 production wastewater. By applying a response surface quadratic model, the main process manipulators (effluent chemical oxygen demand, initial pH, electrical current density and treatment time) were optimised to achieve maximum colour, chemical oxygen demand and total organic compound removals. Analysis of variance indicated that the established polynomial regression models were significant and fitted the experimental data satisfactorily.     

Compatibility of a disperse dye mixture in supercritical carbon dioxide dyeing

The compatibility of three disperse dyes, CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, which are commonly used as a trichromatic combination for conventional dyeing, was studied in supercritical carbon dioxide dyeing. Both the dyeing rate and the build‐up of the selected dyes were measured. Experimental results showed that they were quite compatible. The dyeings of a binary combination (CI Disperse Orange 30 and CI Disperse Blue 79, mass ratio 1:1) and a ternary combination (CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, mass ratio 1:1:1) at different dye concentrations showed an on‐tone uptake and presented the same metric hue angles. This proved that the selected dyes could form a useful trichromatic combination in supercritical carbon dioxide dyeing. Furthermore, the uptake and exhaustion of the single dyes in supercritical carbon dioxide dyeing were similar to those in aqueous dyeing, implying that the dyeing media play only a minor role in the dyeing of polyester fibres with disperse dyes.     

Effect of inorganic salts on ferric oxalate-induced decomposition of CI Acid Black 234 under different weather conditions

In this study, sodium chloride and sodium sulphate were used for investigating their effects on photocatalytic decomposition of a triazo acid dye, CI Acid Black 234, used widely for the coloration of leather and wool products by the Fe ⁱⁱⁱ -oxalate complexes/hydrogen peroxide system under different weather conditions, respectively. Moreover, the photocatalytic degradation and mineralisation of CI Acid Black 234 was also examined by ultraviolet–visible spectrum and total organic carbon measurements. The results indicated that photocatalytic decoloration of CI Acid Black 234 was significantly limited in the presence of inorganic salt. Increasing the concentration of inorganic salt led to a lower decoloration percentage and kinetic reaction constant. The effect of inorganic salt on dye decomposition varied with solar light intensity. Sodium chloride exhibits a much stronger reduction effect on photocatalytic decoloration, degradation and mineralisation than sodium sulphate at similar reaction conditions, especially on a cloudy day.     

酸性媒介黑T生产工艺的改进

利用在生产过程的经验以及在实验室不断对工艺进行小试,比较了酸性媒介黑T合成的新老工艺不同点,如合成配比、一次调碱时间、偶合时间、染料酸化、漂洗等步骤。通过改进生产工艺,使酸性媒介黑T的色光、强度、溶解度有了很大的改善,从而使收率增加。     

Application of genetic algorithm to color recipe formulation using reactive and direct dyestuffs mixtures

Color reproduction is a science in constant development. In this article, a new model to solve the color recipe prediction problem using a genetic algorithm is proposed. The objective is to optimize the color recipe prediction stage by determining the dyes to use in a mixture and their respective proportions to reproduce the target color. Two ranges of dyes were used for dyeing 100% cotton woven fabrics: three reactive dyes (CI Reactive Red 238, CI Reactive Yellow 145, and CI Reactive Blue 235) and four direct dyes (CI Direct Orange 34, CI Direct Red 227, CI Direct Blue 85, and CI Direct Black 22). The criterion of optimization, in reproducing the desired shades, is to minimize the CMC color difference between the desired reference color and the color resulting of the predicted recipe. The proposed algorithm revealed good results with small CMC color differences between target and reproduced colors. The effectiveness of the algorithm was also evaluated and proven by calculating errors between the predicted concentrations in the proposed recipes and the actual concentrations.     

Reactive dyeing of silk using commercial acid dyes based on a three‐component Mannich‐type reaction

Acid dyes are employed for commercially dyeing silk, which results in ionic bonds between the silk fibroin and the dye. This generally leads to low wet fastness properties for dyed silk fabrics. In this work, three commercial acid dyes with aromatic primary amine structures were selected to dye silk using a Mannich‐type reaction, resulting in improved wet fastness of dyed silk by forming covalent bonds between silk fibroin and dye. The Mannich‐type reactive dyeing was applied to silk fabrics at both 30 and 90°C in trials. Dyeing at 90°C can shorten the dyeing time compared with dyeing at 30°C, even although dye exhaustion and relative fixation at 90°C were a little lower. The dyeing process was optimised when the dyeing temperature was 90°C, dyebath pH 4, dye‐to‐formaldehyde ratio 1:30 and holding dyeing time 60 minutes. The results showed that the dye exhaustion on silk fabrics for the three aromatic primary amine‐containing acid dyes exceeded 94% and their relative fixation was over 80%. Their washing and rubbing fastness reached grade 4 or higher. Hence, the colour fastness properties of dyed silk fabrics using the Mannich‐type reactive dyeing method is superior to the conventional acid dyeing method using the same aromatic primary amine‐containing acid dyes. The Mannich‐type reactive dyeing for silk fabrics at 90°C can be developed into a novel and rapid reactive dyeing method, promising an effective dyeing process with excellent colour fastness.     

Influence of wool bleaching with hydrogen peroxide on dyeing with CI Acid Blue 80

This study investigates the influence of wool bleaching with hydrogen peroxide on the kinetics of wool dyeing, using a milling dye CI Acid Blue 80. The dyeing kinetics were studied at different temperatures on both unbleached and bleached wool [15 and 30 ml hydrogen peroxide (35% w/w)] and the following parameters determined: kinetics of adsorption, diffusion coefficient and apparent activation energies of the dyeing system for each type of wool. The results show that the values of these parameters are greater for the unbleached wools than for the bleached ones and that the values decrease as the bleaching intensity increases.     

Colour recipe prediction using ant colony algorithm: principle of resolution and analysis of performances

This paper presents a new method for colour recipe prediction using ant colony optimisation. Three reactive dyes, namely CI Reactive Yellow 145, CI Reactive Red 238 and CI Reactive Blue 235, were used for colour formulation. Samples of 100% cotton fabrics were used for dyeing. The objective was to assure, control and optimise the colour formulation step by determining the dyes to be applied and their respective concentrations to reproduce the desired shades. The criterion of optimisation is to minimise the colour differences [Colour Measurement Committee (2:1)] between the target colour and the colour obtained by the proposed recipe. Errors between the proposed recipe and actual concentrations are also evaluated. The developed algorithm showed good performances with small colour differences between the target and reproduced colours (all lower than 0.7).     

Ozone,Hydrogen Peroxide/Ozone And UV/Ozone Treatment Of Chromium- And Copper-Complex Dyes: Decolorization And Metal Release

Metal-complex azo dyes constitute a significant fraction of the dyes used in the textile industry and exhibit properties such as superior light- and wash-fastness. While effluent color is not always regulated, the textile finishing industry often decolorizes wastewater using processes including chemical oxidation. In this study, the use of ozone, hydrogen peroxide/ozone and UV/ozone oxidant systems was examined for treatment of two common metal-complex (premetalized) dyes, Acid Black 52 (chromium) and Direct Blue 80 (copper). Oxidant dosages required for decolorization of these dyes were determined. The effect of bicarbonate alkalinity on the ozonation and the hydrogen peroxide/ozone processes also was examined.     

Extraction of reactive dyes from aqueous solutions by halogen‐free ionic liquids

Dyes are commonly used in various industries and unfortunately many of them are discharged into water bodies, causing environmental problems. In the current study, three hydrophobic, halogen‐free ionic liquids were synthesised and their capability as extracting agents was evaluated using four reactive dyes (CI Reactive Blue 4, CI Reactive Black 5, CI Reactive Orange 16 and CI Reactive Red 2). The ionic liquids, immiscible with the aqueous phase, could extract the reactive dyes from aqueous solutions, withdrawing the same amount of weight. The effects of pH and temperature on the extraction process were also studied. Trioctylmethyl ammonium ethylenediaminetetraacetate displayed a high extraction efficiency (99%), where only 33 mg of ionic liquids extracted 50 mg of CI Reactive Blue 4. Fourier Transform–infrared spectroscopy was used to screen the interaction between the ionic liquid and CI Reactive Blue 4 during the extraction stage.