Textile dyeing using natural mordants and dyes: a review

Chromaticity of Gromwell, Cape jasmine Dyeing, and Effects of Zinc Oxide/Polyphenol Treatment with Copper Mordanting for UV Protection

“…Therefore, the FTIR spectrum in Figure 3 contained oxygen; consequently, it was found that the CJS-Yellow dye was xanthophyll. This fact was also proven in reference [38,44]. Medium peaks of C-O functional groups can be seen at 1045 cm −1 in the yellow dyes and at 1022 cm −1 in the violet dyes.…”

“…These values were mathematically modified for the ΔE*cmc of the color tolerance CMC system with quasimetric parameters. This was because theoretically calculated chromatic values are inconsistent with human perception; hence, it is necessary to minimize the inconsistence of ΔE via various formulae, as suggested in several papers [37,38,51]. First, the color of violet-dyed samples changed much more substantially (mean ΔE: 20.42) than that of the yellow-dyed ones (mean ΔE: 5.57) after UV exposure, as already found in Figure 7.…”

“…Using ATR-FTIR spectra, structural investigations were carried out to investigate the auxochromic and chromophoric groups of two dyes derived from natural plants. The yellow-to-orange color hue of Cape jasmine seeds is derived from long conjugated double bonds of carotenoids that are categorized into carotenes and xanthophylls, with carbon and hydrogen in common and oxygen existing only in the xanthophylls [38]. As a medicinal herb due to its antioxidants, antiinflammation, and detoxification, shikonin (C16H16O5), one of the naphthoquinone compounds, imparts its violet and purple hues via its naphthalene group (with an absorption peak at approximately 490, 520, and 560 nm) [39][40][41].…”

Chromaticity of Gromwell, Cape Jasmine Dyeing, and Effects of Zinc Oxide/Polyphenol Treatment with Copper Mordanting for UV Protection

“…Using ATR-FTIR spectra, structural investigations were carried out to investigate the auxochromic and chromophoric groups of two dyes derived from natural plants. The yellow to orange color hue of Cape Jasmine seeds is derived from long conjugated double bonds of carotenoids that are categorized into carotenes and xanthophylls, with carbon, hydrogen in common, and oxygen existing in the only xanthophylls [33]. As a medicinal herb due to its antioxidants, antiinflammation, and detoxification, shikonin (C16H16O5), one of the naphthoquinone compounds, is imparted its violet and purple hues by its naphthalene group (absorption peak at approximately 490, 520, and 560 nm) [34][35][36].…”

“…On the contrary, the reflectance rates sharply decreased from 11.14% to 3.84% in the violet-dyed cotton (11C-31C) after the ZnO/polyphenol treatment. This can be attributed to the hydroxyl groups of polyphenolic tannin, which can cross-link other molecules with their (-OH) bonds to improve dye affinity [33]. When the tannin from gallnut reacted with the shikonin chromophores, the double bond (C=C) aromatic rings from a phenolic compound could impart π-electron bonds to its carboxylic group, resulting in the improvement of UV absorption [47].…”