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Core Eudicots: Dicotyledons IV
Published in Donald H. Les, Aquatic Dicotyledons of North America, 2017
There are numerous economically important species in Fabaceae (Judd et al., 2016). The edible plants include many familiar “legumes” such as beans (Phaseolus), lentils (Lens), peanuts (Arachis), peas (Pisum), and soybeans (Glycine). Several genera (Medicago, Melilotus, Trifolium, Vicia) are important as animal forage crops. The familiar blue indigo dye is derived from Indigofera. Many species are cultivated as garden or ornamental plants. The most notable of these occur in the genera Acacia, Albizia, Anthyllis, Astragalus, Baptisia, Bauhinia, Caragana, Carmichaelia, Cassia, Cercis, Cytisus, Erythrina, Genista, Gleditsia, Glycine, Indigofera, Laburnum, Lathyrus, Lespedeza, Lotus, Lupinus, Medicago, Ononis, Oxytropis, Phaseolus, Pisum, Robinia, Senna, Sophora, Trifolium, Vicia, and Wisteria.
Dyeing and Recent Developments
Published in Asis Patnaik, Sweta Patnaik, Fibres to Smart Textiles, 2019
Prithwiraj Mal, Debojyoti Ganguly
Vat dyes are among the oldest natural colouring matter used for textile materials. Indigo is one of the natural vat dyes used in India since prehistoric time. Vat dyes (parent vat dye) are insoluble in water but become soluble after treatment with reducing agent and alkali. Further to the chemical reduction process, these dyes can also be reduced by fermentation process. Vat dyes in the soluble form are known as ‘leuco vat dye’, which have good affinity towards textile materials. After completion of dyeing of textile with leuco form of vat dye, it is re-oxidized in presence of aerial oxygen or other oxidizing agents into the insoluble parent vat dye. Dyeing with vat dyes involve the following four different steps (Trotman 1985; Roy Choudhury 2011). Vatting – Dissolution of vat dyes takes place under alkaline reducing condition with the help of sodium hydrosulphite and sodium hydroxide.Dyeing – Material is impregnated into dissolved vat dyes to absorb.Oxidation – The reduced absorbed dyes are oxidized in the presence of aerial oxygen or some oxidizing agents like hydrogen peroxide and convert it into its insoluble state.After treatment – The dyed fabric is washed thoroughly in the presence of detergent and soda ash to remove any unfixed dyes from the fabric surface.
Organic Rechargeable Batteries
Published in Toshio Naito, Functional Materials, 2019
Indigo has been widely used for dyeing and printing with dark blue. For example, it is utilized as a dye for blue jeans. On the other hand, indigo belongs to a two-electron redox system (Fig. 4.12). Therefore, indigo and its derivatives are candidates for positive-electrode materials that can be obtained at a reasonable manufacturing cost. Yao and coworkers reported on indigo carmine (5,5′-indigodisulfonic acid sodium salt) [16].
Efficient adsorption of cationic and anionic dyes on Algerian natural phosphate
Published in Journal of Dispersion Science and Technology, 2023
Bibba Ouissam, Samira Meski, Khireddine Hafit
Natural dyes for example, indigo have been being used for more than 5000 years.[4] Synthetic dyes have supplanted natural dyes due to their low cost and incomprehensible range of new colors. Based on research studies, it is estimated that 1.6 million tons of dyes are produced annually, and 10-15% of this volume is rejected as wastewater.[5] As a consequence, these dyes become a serious environmental concern because these compounds can pose particularly severe health risks for the human and aquatic ecosystem due to their toxicity, low degradation, their persistence in the environment and bioaccumulation in biological organisms.[6]
Photocatalytic activity of Cu@Ag BNCs synthesized by the green method: Photodegradation methyl orange and indigo carmine
Published in Inorganic and Nano-Metal Chemistry, 2023
Zahra Kheibarian, Esmaiel Soleimani, Hamid Reza Mardani
Most dyes are azo-based, which have one or more groups -N = N-. This group of dyes is very toxic and due to the low reactivity of azo bonds, they have high chemical and physical stability and are resistant to degradation.[3–5] Methyl orange (MO) is one of the azo group dyes which easily penetrate soil and living systems in small amounts and causes damage.[6] Another dye that pollutes sewage is Indigo Carmine, Acid Blue 74. Indigo Carmine (IC) is an indigo dye that is also used as a dye in the textile industry in addition to being used for medical diagnostic purposes. Although indigo carmine is harmless at small contents, the presence of large amounts of this pollutant in wastewater is harmful to the environment and humans due to its toxicity and carcinogenicity. Removal of these pollutants from wastewater has been considered by many research groups.[7–10] Researchers have proposed various methods for the effective treatment of colored effluents.[11] So far, physical, chemical, and biological methods such as adsorption, coagulation, membrane filtration, and ion exchange have been used to remove dyes. Some of these methods do not lead to dye degradation in one step but require more steps. Another way to remove dyes is the common oxidation process, which takes place in the presence of oxidizing agents such as oxygen, hydrogen peroxide, ozone, and permanganate. Nevertheless, these processes cannot completely oxidize stable chemical compounds. Also, by-products may be formed during the oxidation process which is even more toxic than the main pollutants.[12]
Small/Medium scale textile processing industries: case study, sustainable interventions and remediation
Published in Indian Chemical Engineer, 2022
Avanthi Althuri, Onkar Nath Tiwari, Vanitha T. K. Gowda, Miyon Moyong, S. Venkata Mohan
The prospering denim colouring business mainly includes dyeing, washing and softening processes [28]. Typically, for every colouring cycle, 200 g of dye and mild acids are used besides, chemicals like sodium hydrosulphite/sodium dithionite [25]. Mostly, the dyes used in these small scale commercial units are aniline derived dyes (synthetic dyes). Aniline (C6H5NH2), is an organic compound with a phenyl group linked to an amine group and belongs to the class of aromatic amines. The rationale for using aniline dyes is that these synthetic moieties are precursors to indigo colour which is the most commercially preferred shade for denims. Organically, indigo is a rare blue coloured pigment that is extracted from the leaves of certain plant species belonging to the genus Indigofera, and so historically, it has gained commercial significance and liking from the denim buyers. However, to cater to this upsurge in indigo demand that usually ranges in the tune of several thousand tons per annum, aniline based synthetic route was globally adopted. This chemical conversion method was developed in the late 1800s, where indoxyl is produced from the fusion of sodium phenylglycinate in a mixture of sodium hydroxide and sodamide. The use of aniline dyes in Shiv Vihar is high due to its extremely cheap market price that easily fits their budget. The most preferred aniline derived colour ‘Jamuni’ is generally used by the locals for denim dyeing [25]. The low investment and possibly attractive income from denim dyeing business has turned to be a threat to the residents of Shiv Vihar. Recently, the chemical routes and processes engaged in indigo dye synthesis are being scrutinised by the concerned authorities considering the negative impact of the harsh chemicals on human and animal health. Besides, global manufacturers are seeking for more eco-friendly and sustainable methods for indigo dye production.