Evaluating the potential of natural dyes from nutshell wastes: Sustainable colouration and functional finishing of wool fabric

Currently, synthetic dyes are widely used to colour textile materials. However, safer and more sustainable bio-based alternatives currently being explored. In this context, by-products wastes from agricultural value chains have been investigated as potential sources of natural dyes. Nutshell promising because they abundant, contain interesting dye molecules such quinones easier handle their low moisture content. Hence, the present study aims at exploring extracts shells peanut ( Arachis hypogaea L . ), cashew nut Anacardium occidentale L.), coconut Cocos nucifera ) macadamia Macadamia integrifolia substrates. For purpose, nutshell colourants were extracted then applied wool fabrics. Then, analysed for total phenolic content using Folin–Ciocalteu method; qualitatively screened presence quinone-based molecules. Next, effect main dyeing parameters, pH mordant concentrations, on K/S was assessed. After this, kinetics, colourimetric properties, UV protection environmental impact The phytochemical screening indicated compounds (within a range 71.3 ± 1.7–1664.4 7.7 mg GAE/100 g), confirming colouring quinones. process, 3 shell 5 other extracts, gave best (0.6 0.1–14.9 1.0), while mixed 1,2 order model describing adsorption. Also, good resistance washing (4–5), light (3–8) staining (4–5) achieved, even without use mordants. mordants increased fastness properties. improved by up 79%, with FeSO 4 providing protection. Furthermore, extract about 60% environmentally friendlier compared dyeing. Thus, nutshell-based can provide clean source that be substitute analogues. • Agro-nut waste wool. Nut biocolourants give Mix describe extract-wool adsorption kinetics. 40% sustainable.