• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.7
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• pp.736-747
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• 2011

This study investigates the current status and dyeing properties of various natural indigo powder dyes in the domestic market. Products from India, China, Europe are sold in the market and only a few manufacturers provide recommendation for the method of dyeing and information on the additives. Through the market research and the preliminary investigation on 21 products, 11 were selected for the dyeing experiment which include 3 Indian, 3 Chinese, 2 German, and 1 Pakistani origin indigo reduced powders, and 2 Indian origin dried indigo leaf powder. The two dyeing methods used were the precipitation method and the fresh juice method, both at $10^{\circ}C$, $25^{\circ}C$, and $60^{\circ}C$. Color difference, K/S value, and colorfastness of dyed cotton fabrics were examined. Indian reduced indigo powder showed the highest K/S value, deep dyeing, and the best color fastness. Chinese reduced indigo powder resulted in a more greenish and bluish color. Powders of dried indigo leaves were easy to use but resulted in a pale color due to low dye uptake.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.6
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• pp.929-941
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• 2014

Dyeability of Indian natural dyestuffs to fabrics was investigated. Indian dyestuffs are more inexpensive than domestic dyestuffs purchased at oriental medicine stores. We studied the dyeability of madder, marigold, and pomegranate imported from India on cotton, silk, and wool fabrics. Dyebaths of a combination ratio of 80:20, 60:40, 50:50, 40:60 and 20:80 of madder and marigold, fabrics with orange colors were dyed. To evaluate the dyeability of dyed fabrics, K/S values, Munsell color values and CIE L, a, b, ${\Delta}E$ were measured. The dyeability of fabrics dyed in dyebaths of pH 4 and pH 7 were higher than pH 10. The dyeability in pH 4 was better than pH 7. Silk fabrics dyed with madder and marigold showed good dyeability and wool fabrics showed good affinity in madder dyebath and fair affinity in marigold dyebath. Cotton fabrics showed fair affinity in a marigold dyebath of pH 4 and pH 7. Cotton fabrics dyed with a 60:40 ratio of madder and marigold showed 4.76YR of Munsell color value. Silk Fabrics dyed with a 40:60 ratio showed 4.76YR and wool fabrics dyed with 20:80 ratio showed 5.57RY. The ratios produced the closest colors to 5.0YR of orange. This result indicated that marigold had a more powerful effect on cotton fabrics while madder was stronger on wool fabrics. Fading grades of washing colorfastness of wool and silk fabrics dyed in mixed dyebaths were higher than 3.5-4.0 and higher than homogeneous dyebaths. Staining grades of washing colorfastness of all dyed fabrics were between grades 3.5-5.0. Colorfastness to dry-cleaning was high as grades 4.0-5.0 in all of dyed fabrics. Colorfastness to light of dyed fabrics showed a fair grade of 3.5-5.0; in addition, wool fabrics showed lower grades than silk and cotton fabrics.

• Journal of Microbiology and Biotechnology
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• v.21 no.3
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• pp.267-273
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• 2011

Methyl violet, used extensively in the commercial textile industry and as a biological stain, is a hazardous recalcitrant. Aspergillus sp. strain CB-TKL-1 isolated from a water sample from Tsumoriri Lake, Karzok, Ladakh, India, was found to completely decolorize methyl violet within 24 h when cultured under aerobic conditions at $25^{\circ}C$. The rate of decolorization was determined by monitoring the decrease in the absorbance maxima of the dye by UV-visible spectroscopy. The decolorization of methyl violet was optimal at pH 5.5 and $30^{\circ}C$ when agitated at 200 rpm. Addition of glucose or arabinose (2%) as a carbon source and sodium nitrate or soyapeptone (0.2%) as a nitrogen source enhanced the decolorization ability of the culture. Furthermore, the culture exhibited a maximum decolorization rate of methyl violet after 24 h when the C:N ratio was 10. Nine N-demethylated decolorized products of methyl violet were identified based on UV-visible spectroscopy, Fourier transform infrared (FTIR), and LC-MS analyses. The decolorization of methyl violet at the end of 24 h generated mono-, di-, tri-, tetra-, penta-, and hexa-N-demethylated intermediates of pararosaniline. The variation of the relative absorption peaks in the decolorized sample indicated a linear decrease of hexa-N-demethylated compounds to non-N-demethylated pararosaniline, indicating a stepwise N-demethylation in the decolorization process.