Ultrasonic-assisted sustainable pollution free advanced method for isolation of colouring material from Amba Haldi (Curcuma aromatica) for wool dyeing.

The purpose of this research is to evaluate the colouring performance of Amba Haldi-based natural extracted yellowish colour for the dyeing of wool fabric using ultrasonic (US) treatments. Before and after the US treatment, the colourant was separated in aqueous and acidic solutions for up to 60 min. Scanning electron microscopy and Fourier-transform infrared spectroscopy were used to investigate the surface morphology and chemical changes in the cloth before and after radiation. On the wool fabric that was ultrasonically treated at 75°C for 45 min, an acidic extract of Amba Haldi powder after US treatment for 20 min showed good colour depth (K/S). Acacia extract (2%), pomegranate extract (1.5%) and pistachio extract (1%), when used as pre-biomordants, were shown to have excellent colour strength. Acacia (1.5%) extract, pomegranate (2%) extract and pistachio (1.5%) extract were also used as post-biomordants. As pre-chemical mordants, Al salts (1%), Fe salts (1.5%) and tannic acid salts (2%), whereas Al salts (2%), Fe salts (1%) and tannic acid salts (2%), have produced successful results as post-chemical mordants. Overall, it was discovered that pomegranate extract (2%), used as a post-bio-mordant, and salt of Fe (1.5%), used as a post-chemical mordant, both exhibit exceptional colour strength. Ultrasonic treatment, a procedure that is harmless for the environment, has only served to increase the colour strength of dye on wool fabric, and the addition of bio-mordants has made the process more sustainable.

Sustainable application of Cassia obovata-based chrysophanic acid as potential source of yellow natural colorant for textile dyeing.

In the current pandemic scenario, sustainable green products particularly antiviral, antioxidant, and antibacterial in nature are gaining worldwide fame in almost every walk of life. Cassia obovata (C. obovata) has been valorized as a source of yellow natural dye for nylon dyeing. For the isolation of dye extracts and for surface tuning, nylon fabrics were treated with microwave rays up to 10 min. For getting new shades with good to excellent fastness characteristics, sustainable bio-mordants in comparison with chemical mordants have been used at 60 °C, 70 °C, and 80°C. It has been found that for getting effective colorant yield, acidic extract should be exposed to MW ray treatment up to 6 min, and for getting improved fastness rating, bio-mordants have given excellent color characteristics. Statistical optimization of dyeing variable shows that application of 40 mL of C. obovata acidic extract of RE of 6 pH containing 3 g/100 mL of salt when employed at 55 °C for 45 min has given excellent results onto irradiated nylon fabric (RNF). It is inferred that Cassia obovata has an excellent potential for coloration of surface-modified fabrics, where the application of low amount of bio-mordants under statistical optimized conditions has made process more ecological, economical, and sustainable.

Environmental friendly sustainable application of plant-based mordants for cotton dyeing using Arjun bark-based natural colorant.

Ecofriendly exploration of Arjun bark (Terminalia arjuna) is a herbal natural colorant for cotton dyeing. This is because the demand for natural dyes has been increased worldwide due to their therapeutic usage and other food, textiles, agriculture, engineering, and medical applications. Therefore, this study has been carried out due to the isolation of colorant from Arjun bark in an acidified methanolic medium after exposure to ultrasonic rays up to 60 min. Additionally, using bio-mordants, it has been found that the application of 10% of Zeera (Cuminum cyminum) extract as meta-bio-mordant, 3% of Ilaichi (Elettaria cardamomum) extract as meta-bio-mordant, and10 % of Harmal (Peganum harmala) and Neem (Azadirachta indica) extract as meta-bio-mordants has given excellent color strength. These bio-mordants have not only made the coloration process more eco-friendly, viable, and greener, but also improved color strength with various tonal effects from red to reddish brown shades. Thus, it has been found that ultrasonic treatment as an environment-friendly tool has not only enhanced the color strength of natural colorant isolated from Arjun bark onto the cotton fabric under mild conditions.