Various Classes Of Dyes Research Articles

Multi-Analytical Techniques for the Study of Burial Clothes of Polish King Sigismund III Vasa (1566-1633) and His Wife Constance Habsburg (1588-1631).

The subjects of this research are the burial clothes of Polish King Sigismund III Vasa and his wife Constance, which were woven and embroidered with silk and metal threads. Fragments of the textiles underwent spectroscopic, spectrometric, and thermogravimetric analyses. The hydrofluoric acid extraction method was improved to isolate various classes of dyes from the textile samples that had direct contact with human remains. High-performance liquid chromatography, coupled with diode array and tandem mass spectrometry detectors with electrospray ionization (HPLC-DAD-ESI-MS/MS) facilitated the detection and identification of colorants present in the textiles. Cochineal, indigo-, madder-, orchil-, and tannin-producing plants were identified as the sources of dyes used. Scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDS) was employed to identify and characterize the silk fibers and mordants and the metal threads. The presence of iron, aluminum, sodium, and calcium in the silk threads suggests their potential use as mordants. The analysis of the metal threads revealed that most of them were made from flattened gilded silver wire, with only a few being cut from a sheet of metal. Typical degradation mechanisms of metal threads were shown, resulting from both burial environment and earlier manufacturing process, and the use of the textiles in clothing, i.e., a significant loss of the gold layer was observed in most of silver gilt threads, caused by abrasion and delamination. The results of the thermal analysis confirmed the presence of silk and silver threads in the examined textiles.

Eco-friendly dyeing of cellulosic fabric using Direct Red 28 and Direct Blue 15 dyes

<p>Sustainability in textiles is now a day’s key demand of consumers and traders, where the process with zero effluent emission or less emission has been considered for aim to utilize the ecofriendly process in direct dyeing of cotton to minimize effluent load. For this purpose, variable amount of Table salt and Glauber salt has been used to achieve maximum exhaustion during direct cotton dyeing. Different dyeing variables have been employed, shade made at the optimum conditions were assessed according to ISO standards. It has been found that 3g/100mL of table salt for Direct dyeing of cotton using 40mL of DR 28 (8pH) at 65oC for 45 min, whereas using 40mL of DB 15 (8pH) for dyeing of cotton at 65 °C for 45min containing 3g/100mL of Glauber slat has given acceptable color characteristics. The reduction in dyeing variable using low salt amount has proved that this method is cost, time and energy efficient process, which can be utilized for dyeing of natural fabrics using various classes of dyes to obtain sustainable textile products.</p>

Arachis hypogaea derived activated carbon/Pt catalyst: Reduction of organic dyes

Activated carbon from agro waste groundnut (Arachis hypogaea) shell was prepared by chemical activation and used as support for dispersion of 5% platinum nanoparticles. The Pt nanoparticles were obtained by the reduction in hydrogen gas medium. The synthesized groundnut activated carbon/platinum catalyst was characterized by various techniques such as X-ray powder diffraction, electron microscopies and X-ray photoelectron spectroscopy. The catalytic behaviour of the synthesized catalyst was investigated by exploring it as catalyst for the reduction of various classes of dyes; namely, triphenylmethane dyes such as malachite green, phenol red and bromophenol blue, xanthene dyes: rose bengal, rhodamine 6 G, rhodamine B, thiazine dye: methyelene blue, azo dye: congo red and 4-nitrophenol by sodium borohydride in aqueous medium. Under suitable reaction conditions, for all tested dyes, cationic dyes were reduced at a faster rate than anionic dyes. The rate of reduction on the structure of dye and nature of catalyst was employed.

Microwave Assisted Modulation of Vat Dyeing of Cellulosic Fiber: Improvement in Color Characteristics

ABSTRACTThe role of radiations in textile processing is gaining attention due to its low cost, energy effectiveness and eco-friendly process. This study is concerned with the improvement in modulation of microwave assisted vat dyeing of cellulosic fiber. It was found that radiation treatment of both cotton fabric and dye solution for 1 min gives good color strength, while for redox reaction, 2.5 g of NaHSO3, 2 mL of CH3COOH, and 1.5 mL of H2O2 are the optimized conditions which show it is a cost-effective tool. Good color strength was obtained at 65 °C for 1 h dyeing using 50 mL of optimal solution in dye bath at pH 9. Finally, ISO standards for color fastness to light, washing, rubbing and perspiration were applied at 0.5–2.5% of shade at optimal conditions which showed that microwave treatment has enhanced the color characteristics. Hence, the technique can successfully and easily be employed for surface modification of fabric for good quality dyeing with various classes of dyes.

Fficient Aerobic Degradation of Various Azo Dyes by a Sphingomonas sp Isolated from Petroleum Sludge

The extensive discharge of textile dyes in industrial wastewater and the recalcitrant nature of azo dyes have fueled a strong interest in exploring efficient and environmentally friendly approaches for wastewater remediation. In this present study, we report on the isolation and characterization of a Sphingomonas sp. strain from petroleum sludge that was capable of efficiently degrading various classes of dyes. A subsequent detailed analysis using a panel of 12 azo dyes showed that this strain was capable of efficient aerobic degradation of at least 7 diverse azo dyes. Furthermore, these dyes could also be degraded (more than 70% in 24 hours) under static (anaerobic) culture conditions by this Sphingomonas sp. Lastly, HPLC analysis of the metabolites of three different azo dyes showed that depending on the availability of oxygen during the culturing and dye degradation process, and different sets of metabolites could be produced from these dyes. The current study establishes the usefulness of screening petroleum sludge for the isolation of novel bacterial strains for efficient bioremediation and highlights the different degradative pathways that are taken during aerobic and anaerobic bacterial dye degradation processes

Study of processes of dyeing polyurethane fibres by various classes of dyes

Processes of dyeing polyurethane fibres with various classes of dyes, e.g., disperse and cationic, procinyl and acid, etc., were studied. Relationships of dyeability with dyeing temperatures were derived and kinetic and diffusion parameters of dyeability were investigated. Parallel studies of polyester, polyamide, and polyacrylonitrile fibres, and of wool were made for a comparison. The influence of dyeing conditions on the physicomechanical strength of polyurethane fibre was examined. The stability of the obtained colors on polyurethane fibre against external service impacts is evaluated.

Redox-mediated decolorization of recalcitrant textile dyes by Trichoderma harzianum WL1 laccase

The efficiency of crude and partially purified Trichoderma harzianum WL1 laccase for the decolorization of synthetic dyes (Rhodamine 6G, Erioglaucine and Trypan blue) with complex aromatic structures were evaluated. Selection of dyes was based on their extensive usage in local dyeing and textile industries around the study area. Studies on the role of redox potential of laccases on dye decolorization are rarely discussed and hence, for the first time we have shown the redox mediated dye decolorizing efficiency of T. harzianum WL1 laccase with the commonly employed redox mediator 1-hydroxybenzotriazole (HBT). The process parameters such as initial dye concentration, enzyme load and HBT concentration were studied and found that they had a great influence on dye removal process. When the dyes were treated with increased concentration of enzyme, it showed a greater percentage of decolorization. Compared to the crude laccase, partially purified laccase accounts for maximum decolorization of all the dyes studied. In addition, the rate of dye decolorization was considerably enhanced in presence of 4 mM HBT. Maximum and minimum decolorization were recorded for Rhodamine 6G and Trypan blue, respectively. The results of this study further confirmed that, T. harzianum laccase was found to be suitable with HBT and this laccase-mediator system (LMS) could be applied for the decolorization of various classes of dyes.

Fundamental principles and application of heterogeneous photocatalytic degradation of dyes in solution

Synthetic dyes are a major part of our life as they are found in the various products ranging from clothes to leather accessories to furniture. An unfortunate side effect of their widespread use is the fact that up to 12% of these dyes are wasted during the dyeing process, and that approximately 20% of this wastage enters the environment (mostly in water supply). Not surprisingly, various approaches have been developed to remove and degrade these carcinogenic dyes from the natural environment. Advanced oxidation processes (AOPs) are the most widely used approach that is employed for dye degradation studies. Over the past few years, there has been an enormous amount of work that has been done with AOPs and as a result various kinds of AOPs have been developed. The aim of this review is to address the fundamentals of one kind of AOP, namely, photocatalytic, and how it is used for dye degradations in aqueous suspensions using TiO 2 as a catalyst. Since AOPs rely on the generation and subsequent reaction of highly reactive oxygen radicals with dyes, there are many factors that can affect the efficiency of this process. Hence, this review will attempt to summarize and highlight the effect of a variety of conditions on TiO 2-photocatalysed decoloration of dyes, such as amount of catalyst, reaction pH, light intensity, concentration of organic dye, and the presence of additives such as ions. This review also summarizes the degradation pathways that azo dyes undergo, with some of the intermediates that are generated during their degradation. Finally, a survey is presented of the various classes of dyes and their relative ease of degradation by AOPs.

The Use of Coreactant Curing Agents with a Diepoxide to Impart Wrinkle Resistance to Cotton Fabrics

Wrinkle resistance can be imparted to cotton fabrics with a diepoxide when certain coreactant curing agents are used. Such materials coreact to become a part of the finished product and introduce linkages and chemical groups which differ from those obtained when a true catalyst is used. Several coreactants including, for example. phthalic anhydride, citric acid, 1-aminoethyl-2-methyl-imidazoline, triethanolamine, and potassium thiocyanate, were used with 1,3-diglycidylglycerol as the diepoxide. In some cases mere deposition seemed to occur while in other cases cross-linkage was accom plished. Some indications of the types of reaction were obtained from infrared data and from the responses of the treated fabrics to various classes of dyes. In some cases coreaction between the diepoxide and the curing agent appeared to take place at rela tively low temperatures, producing improved wrinkle resistance. Phthalic anhydride was used to investigate this aspect in more detail. For comparison with the coreactant materials, several acid salts were used as catalysts, and the results are reported. Among the more suitable acid catalysts are magnesium perchlorate, aluminum sulfate, and zinc fluoborate. The inorganic acid catalysts produced fabrics with excellent durability and wrinkle resistance. Tearing strength losses, however, were greater with epoxide-treated cotton than those observed, at equivalent crease recovery angle, when a typical methylolamide finishing agent with catalyst was used. The durability to alkaline solutions of some of the epoxide finishes applied with coreactant curing agents was not as good as that of fabrics prepared with the inorganic acid catalysts. Tearing strength and wrinkle re sistance of epoxide-treated cotton can be improved by inclusion of additives such as polvethylene, acrylic polymer, or silicone, in the finishing bath.

The Dyeing of Acrilan Acrylic Fibre

The methods of dyeing Acrilan are outlined, and the limitations of various classes of dyes stated. Data are presented to show how the concentration of sulphuric acid affects the handle of the fibre and the fastness properties of acid, chrome, and 2: 1 metal‐complex dyes. Generally, disperse dyes are the most satisfactory for the dyeing of Acrilan, although for specialised purposes azoic, acid, basic, chrome, metal‐complex, and reactive dyes are suggested.

Milestones in the Production of Synthetic Dyes for Cellulosic Fibres

The introduction of the various classes of dyes for cellulosic fibres is dealt with in Historical sequence from Mauve in to the latest phthalocyanine compound. Some of the prominent members of each class are briefly mentioned, giving the year of their introduction. The effect of their introduction on the dyeing industry as seen by the author is briefly outlined.