Environmental-friendly extraction of Peepal (Ficus Religiosa) bark-based reddish brown tannin natural dye for silk coloration

• Published in: Environmental science and pollution research international 2022-05, Vol.29 (23), p.35048-35060
• Main Authors: Habib, Noman, Akram, Waseem, Adeel, Shahid, Amin, Nimra, Hosseinnezhad, Mozhgan, Haq, Ehsan ul
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bark; Color; Coloration; Coloring agents; Dyeing; Dyes; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Iron; Microwave radiation; Microwaves; Mordant dyes; Research Article; Silk; Sustainability; Tannic acid; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-022-18507-5

The present study aims to extract a natural reddish brown colorant from Peepal ( Ficus religiosa ) for silk dyeing using the microwave radiation process (MW). The colorant was isolated in aqueous and acidic media, and MW treatment for 1, 2, 3, 4, and 5 min has been given to both fabric and extract to observe changes in color intensity. The dye variables have been optimized, and for sustainable shade making process with good fastness, 1.0–5.0 g/100 mL of sustainable chemical and bio-mordants has been employed. It has been found that after microwave treatment for 3 min, under selected conditions, the irradiated aqueous extract has given high color intensity onto silk fabric. The utilization of 3% of Al, 4% of Fe, and 2% of tannic acid (T.A.) as pre chemical mordant whereas 4% of Al, 4% of Fe, and 3% of tannic acid as post chemical mordant have given good color characteristics. In comparison, 4% of acacia and 3% of turmeric and pomegranate while 3% of acacia and turmeric and 4% of pomegranate extracts as post-bio-mordant have given excellent color characteristics. It is concluded that MW treatment has an excellent sustainable efficacy to isolate colorant from Peepal bark for silk dyeing, whereas the inclusion of bio-mordants has not only made the process more sustainable and environmental friendly but also best K/S, and L*a*b* values have been acquired.