Sonochemical mordanting as a green and effective approach in enhancing cotton bio natural dye affinity through soy surface modification.

As a clean technology, ultrasonics has been widely explored in textile dyeing. Mordanting is commonly used for the achievement of efficient textile dyeing, however little attention has been paid on application of ultrasonics in mordanting. This study investigated sonochemical mordanting and its efficiency in subsequent dyeing. Ultrasonic bath, together with traditional water bath and magnetic stirring bath were investigated. Soy protein and F. Artemisiae argyi (FAA) were used as a mordant and natural dye, due to the their natural compatibility with cotton as well as biological properties. All the materials used in this work were natural with very little chemicals (present no harm to the environment) applied. Results showed that while soy mordanting in water bath can significantly increase fiber natural dye uptake, the dye affinity can be enhanced further when ultrasonic irradiation was applied. Ultrasonic mordanting was found to be able to produce higher fabric color strength (K/S) while consuming less soy protein when compared with other mordanting baths. Less weight increase as a result of ultrasonic irradiation can also provide cotton fabric with softer handle than those processed in traditional water bath. UV protection of dyed fabrics was found to be significantly improved from the control sample, with samples processed with ultrasonics showing the greatest improvement. In addition to the increased dye affinity as a result of soy mordanting, fabric bio function of antibacterial property was found to be simultaneously and successfully achieved. • Applying ultrasonics in mordanting process prior to dyeing, which is rarely reported. • Natural dye uptake can be increased with less mordant required through sonochemical mordanting. • Fabric handle can be improved along with the increased color strength of fabric through sonochemical mordanting. • UV protection and antibacterial properties of fabric can be improved significantly through the process. • A successful development of a green and efficient process in cotton dyeing and bio finishing. [ABSTRACT FROM AUTHOR]