Sustainable Dyeing of Wool and Silk with Conocarpus erectus L. Leaf Extract for the Development of Functional Textiles

Abstract

Natural dyes derived from plants offer a sustainable alternative to synthetic dyes for textile coloration. This study examined the extraction of natural dyes from Conocarpus erectus L. leaves and their application on wool and silk fabrics. Aqueous extraction in an alkaline medium was used to obtain dyes from raw leaves, which were then applied to pre-mordanted silk and wool fabrics by applying the ultrasonic-assisted exhaust dyeing method. The dyed fabrics were evaluated for color strength (K/S) and CIELAB color coordinates. The color fastness (washing, rubbing, and light), ultraviolet protection factor, mosquito repellency, and antibacterial activity were established using standard testing protocols. The surface morphologies of silk and wool were examined using scanning electron microscopy. Interestingly, the dyed fabrics displayed good color strength and color fastness properties. Moreover, the dyed wool samples revealed satisfactory antibacterial activity against Gram-negative (E. coli) and Gram-positive (S. aureus) in both qualitative and quantitative assessment methods, good ultraviolet protection in terms of UPF, and good mosquito repellency against Aedes aegypti. This study for the first time presented the application of a medicinal plant (Conocarpus erectus L.) in the field of textile dyeing and finishing. Hence, the use of Conocarpus erectus L. leaf dyes offers significant results on wool and silk fabrics and contributes to sustainable functional textile production.