Eco-friendly utilization of microwaves for extraction of dye from logwood and its application onto silk

• Natural dyes were extracted from logwood. • The dyed silk fabric shows good color strength and fastness properties. • The use of bio-mordant makes the process more environmentally. • Natural dyes can be the replacement of synthetic dyestuff. For minimizing the pollution associated with synthetic colorants, the world again is going to realize the benefits of natural colorants in applied fields such as textiles, food flavors, etc. As part of the ongoing research project, hematein is being investigated as a potential natural colorant derived from logwood chips, and its implementation on silk fabric is being investigated under the effect of microwave radiations. A number of dyeing variables, including pH, dyeing duration, temperature of the dye bath, volume of extraction, and salt concentration, have been investigated, and the effect of isolation medium has also been evaluated. For new shades with improved fastness ratings, extracts of various sustainable bio-mordants and chemical mordant such as salts of aluminum and copper, and tannic acid were also used. An experiment revealed that treating un-irradiated silk with 40 mL of methanolic extract with a pH of 2, irradiated for 6 min, produced outstanding outcomes when dyed at 90°C for 60 min. The dyeing process included the addition of 9 g of salt per 100 mL of solution as an exhausting agent. In these circumstances, the utilization of sustainable mordants has not only enhanced the ratings of color fastness but has also rendered the procedure more environmentally friendly and less polluting. Therefore, microwave radiation has great potential for extracting colorants from plants and effectively applying them to natural materials under decreased conditions.