Faqeer Mohammad

Eco-dyeing of wool using aqueous extract of the roots of Indian madder (Rubia cordifolia) as natural dye

The aqueous extract obtained from the powdered roots of Indian madder (Rubia cordifolia) was used for dyeing of woolen yarns. The effect of pH, dye concentration, and mordants on the colorimetric and fastness properties has been studied. Brilliant shades of bright red to scarlet were obtained with significant variation in hue and tone of shades depending on mordants and dye concentrations used. The color coordinates of the dyed samples were found to be in the red-yellow quadrant of the CIELab color space. It was found in all cases that mordanting with alum as well as ferrous sulfate has caused decrease in lightness (L*) values and increase in K/S values. All the dyed samples exhibited commercially acceptable fastness to light, washing, and rubbing. Scanning Electron Microscopy (SEM) morphological studies have also been performed on different woolen yarns.

Antimicrobial and fluorescence finishing of woolen yarn with Terminalia arjuna natural dye as an ecofriendly substitute to synthetic antibacterial agents

The current study deals with the use of Terminalia arjuna natural dye as an ecofriendly finishing agent for producing highly functional antimicrobial and fluorescent woolen yarn along with the evaluation of kinetic and thermodynamic adsorption characteristics. The effect of pH on the adsorption was investigated, showing an increase in adsorption capacity with decreasing pH over the range of 2–9, with maximum adsorption at pH 3.5. Two kinetic equations pseudo-first order and pseudo-second order were employed for determining adsorption rates. The pseudo-second order equation provided the best fit to experimental data with an activation energy of 105.58 kJ mol−1, indicating chemisorption. The equilibrium adsorption data was fitted to Langmuir, Freundlich and Redlich–Peterson adsorption isotherms. The adsorption behavior accorded with the Redlich–Peterson isotherm with exceptionally high regression coefficients for dyeing temperatures of 50, 70 and 90 °C with dye concentration varying from 0.5–10% (o.w.f). Comparative results of the colorimetric properties (CIEL*a*b* and K/S) using a spectrophotometer under D65 illuminant (10° standard observer) and color fastness (light, wash, and rub) of dyed woolen yarns were studied to quantify the effect of metal mordants. The antimicrobial potential of Terminalia arjuna solution and dyed woolen yarn were assessed in terms of percentage inhibition of bacterial growth against a wide variety of bacterial strains, showing more than 85% inhibition. Reduction in antimicrobial activity of dyed woolen yarn was observed with mordanted samples, however they were found to retain more antimicrobial activity as compared to unmordanted samples as a function of successive washing cycles. The chemical nature of different mordants and wool–mordant–dye complex forming ability were found to have significant impact on the colorimetric and fluorescence characteristics of dyed woolen yarn.

Silver nanomaterials as future colorants and potential antimicrobial agents for natural and synthetic textile materials

Over the past few years, antimicrobial textiles have gained considerable interest for use in different application fields. Because of these reasons, a wide range of antimicrobial agents with diverse chemical structures such as quaternary ammonium compounds, N-halamine siloxanes, heterocyclic compounds with anionic groups, polybiguanides, triclosan, metal salts, and synthetic colorants have been used to impart antimicrobial properties to different textile materials. However, most of these antimicrobial agents suffer from many disadvantages such as action on non-target microorganisms, toxicity to the environment and low durability of antimicrobial finish. To overcome these problems, silver nanoparticles with strong cytotoxicity towards a broad range of microorganisms, low toxicity to human cells, high selectivity, long term durability, increased dyeability and biocompatibility are drawing a tremendous level of attention from both academic research and industry. Silver nanomaterials, due to their unique properties are particularly attractive for production of textiles surfaces with novel properties such UV protection, water resistant, self cleaning and antimicrobial activity. The present review is intended to describe recent advances about the use of silver nanomaterials as novel colorants and antimicrobial agents for different textiles materials. Finally it also highlights the current challenges and provides scope for future studies.

Natural Colorants: Historical, Processing and Sustainable Prospects

With the public’s mature demand in recent times pressurized the textile industry for use of natural colorants, without any harmful effects on environment and aquatic ecosystem, and with more developed functionalities simultaneously. Advanced developments for the natural bio-resources and their sustainable use for multifunctional clothing are gaining pace now. Present review highlights historical overview of natural colorants, classification and predominantly processing of colorants from sources, application on textiles surfaces with the functionalities provided by them. Chemistry of natural colorants on textiles also discussed with relevance to adsorption isotherms and kinetic models for dyeing of textiles.Graphical Abstract

Phytochemistry, biological activities and potential of annatto in natural colorant production for industrial applications – A review

Bixa orellana commonly known as annatto is one of the oldest known natural dye yielding plants native to Central and South America. Various parts of annatto have been widely used in the traditional medical system for prevention and treatment of a wide number of health disorders. The plethora of traditional uses has encouraged researchers to identify and isolate phytochemicals from all parts of this plant. Carotenoids, apocarotenoids, terpenes, terpenoids, sterols, and aliphatic compounds are main compounds found in all parts of this plant and are reported to exhibit a wide range of pharmacological activities. In recent years annatto has received tremendous scientific interest mainly due to the isolation of yellow-orange natural dye from its seeds which exhibits high biodegradability, low toxicity, and compatibility with the environment. Considerable research work has already been done and is currently underway for its applications in food, textile, leather, cosmetic, solar cells, and other industries. The present review provides up-to-date systematic and organized information on the traditional usage, phytochemistry and pharmacology of annatto. It also highlights its non-food industrial applications in order to bring more interest on this dye plant, identifies the existing gaps and provides potential for future studies. Studies reported in this review have demonstrated that annatto holds a great potential for being exploited as source of drugs and a potential natural dye. However, further efforts are required to identify extract biomolecules and their action mechanisms in exhibiting certain biological activities in order to understand the full phytochemical profile and the complex pharmacological effects of this plant.

Mixed Metal Mordant Dyeing of Wool using Root Extract of Rheum emodi (Indian Rhubarb/Dolu)

In the present study, the root extract of Rheum emodi (Indian Rhubarb/Dolu/Revandchini) has been used as a natural dye to develop a variety of harmonizing natural shades on woolen yarn using combination of ecofriendly mixed metal mordants. Dyeings were carried out in neutral acidic, and alkaline medium using 0.5%–5% dye concentrations pre-treated with (4.5% iron + 0.1% tin), (2.5% iron + 0.5% tin), and (0.5% iron + 0.9% tin) mordant combinations. A total of 54 shades have been developed by varying the amount of dye and percentage combination of mordants. The hue of color ranged from reddish-brown, greenish-yellow to dark yellow. The color of dyed woolen yarns was investigated in terms of color strength (K/S), CIELab, CIELch values. Fastness properties (light, washing, and rub/crocking) of dyed woolen yarn samples were also assessed.

Enzymatic processing of natural fibres: white biotechnology for sustainable development

Industrial biotechnology has the potential to fulfil many key criteria of greener textile production. This review outlines the current research and future directions of the emerging applications of enzymatic technology in the sustainable production and processing of textiles. The state-of-the-art industrial enzymes in textile processing include amylases for desizing of cotton and cellulases for denim-washing and biopolishing. Aside from these established processes, emerging enzymatic processes such as cotton scouring and bleaching, bast fiber retting/degumming, wool scouring and shrink-proofing, silk degumming, bio-dye production and enzyme-assisted dyeing and finishing are at various stages of development. To illustrate the state-of-the-art, representative examples of enzymes in the processing of various types of textile substrates are discussed and evaluated in this article. The major limitations of the large scale implications of textile biotechnology are lack of sufficient research efforts to make it an economically viable option and issues related to technological glitches. The limitations of existing approaches will be highlighted and the requirements of continuous improvement to overcome current obstacles will be demonstrated by critical assessment.

Emerging Green Technologies and Environment Friendly Products for Sustainable Textiles

Textiles production processes such as sizing, scouring, bleaching, mercerizing, dyeing, printing, and finishing are characterized by a huge consumption of water, energy, and chemicals. The toxic effluent discharge generated in these processes mainly contains by-products, residual dyes, salts, acids and alkalis, auxiliary chemicals, and other solvents. Their discharge into neighboring water bodies is posing a serious threat to the flora and fauna. At present, however, development in the textile and clothing industry has focused on the use of some green technologies as alternatives to conventional wet processes to promote sustainable production and consumption of textiles and clothing. In recent years, emphasis has been put on developing cleaner, cost-effective, and value-added textile products for a variety of applications without compromising the issues related to health and the environment. This chapter is intended to provide a summary of recent developments in the coloration and finishing of textile fibers and to provide details of the ecofriendly strategies developed to reduce the waste generation in the textiles and clothing sector. Finally, their implications in the sustainability of clothing products are also outlined.

Developing a Shade Range on Wool by Madder (Rubia cordifolia) Root Extract with Gallnut (Quercus infectoria) as Biomordant

ABSTRACT Environmental issues inspire the revival of natural dyes that exhibit better biodegradability and more compatibility over synthetic ones. This research is aimed to investigate the effect of color and fastness properties on wool yarn substrate with natural anthraquinone colorants extracted from madder roots using gallnut (Quercus infectoria) extract as anchoring agent. Prior to the dyeing with Indian Madder (Rubia cordifolia), wool fibers were pre and post-treated with different concentrations of gallnut extract (viz 1–5% o.w.f) to get a broad range of beautiful and color fast shades. The feasibility of gallnut extract as an anchoring agent and its effect on color strength and color fastness to light, rubbing, and washing was investigated. Results of color characteristics showed that the color coordinates of the dyed samples were situated in the red-yellow quadrant of the CIELabcolor space. Bio-mordanting with gallnut extract produced shades of practically acceptable color depth, color fastness to light, washing and rubbing. Pre-treatment with gallnut extract is dominated over post-treatment in terms of better colorimetric and fastness results.

Bi and tri metal salt combinations plus colorants extracted from timber industry waste as effective dyeing materials to produce novel shades on wool

ABSTRACT This study was undertaken to propose alternative use for teak leaves, a timber industry byproduct, as potential dyeing source for wool fibers. The coloring potential of anthraquinone colorants from teak leaves were studied on wool with pre-mordanting method using double and triple mix metal salt combinations (ferrous sulphate, stannous chloride and potassium aluminum sulphate) as mordants. Thirty-six sober and elegant shades were developed on wool by varying the type of metal involved in combination as well as concentration of the dye. The hue of color developed ranged from light orange—brown to dark brown. The color strength (K/S) has been found to be very good in dyed woolen yarn samples and particularly was highest for iron + alum combination. Color fastness with respect to light exposure washing, rubbing for the developed shades ranged between good to very good, which confirmed the possibility of using waste leaves of Tectona grandis as a source of effective brown natural dye.