Sustainable isolation of licorice (Glycyrrhiza glabra L.)-based yellow natural colorant for dyeing of bio-mordanted cotton.

Sustainability in the utilization of products in all fields particularly food textiles, solar cells, etc. is of prime concern to the global community. In this study, licorice (Glycyrrhiza glabra L.) as a source of herbal-based coloring agent for cotton dyeing has been explored under the influence of ultrasonic (US) waves. Methanolic extract of licorice bark after US treatment for 20 min has shown excellent color depth (K/S) onto ultrasonically treated cotton fabric at 65°Cfor 45 min. Applying bio-mordants, it has been found that acacia extract (1%), henna (5%), and pomegranate and turmeric extracts (7%) as pre-bio-mordant, whereas acacia, turmeric, and henna extracts (7%) and pomegranate extract (5%) as post-bio-mordants, exhibited superb color strength. Salts of Al (7%) and salts of Fe (3%) as pre chemical mordants, while salts of Al (3%) and salts of Fe (5%) as post chemical mordants, have given good results. Overall, it has been found that salt of Fe (3%) as pre-chemical mordant and extract of turmeric (7%) as post bio-mordant have shown superb color strength. It can be concluded that US treatment being an environmentally safe means has only improved the color strength of colorant onto cotton fabric and the adding of bio-mordants has contrived the method more sustainable.