Flavonoid dyes from vine tea (Ampelopsis grossedentata) have excellent bioactive properties for dyeing and finishing of silk fabrics

Natural bioactive compounds are not only an ideal substitute for synthetic finishing agents, but have also attracted numerous interests in the textile industry. Here, we used vine tea (Ampelopsis grossedentata) as dyestuff, and selected the pad-steaming process in the presence of natural mordant to realize the dyeing and fixation of flavonoids colorant on silk fabrics. Results indicated that it endowed silk fabrics with unique flavonoid functions that allowed bioactive finishing of silk fabrics. The optimal extraction process of flavonoids dye from A. grossedentata was achieved at a temperature of 100°C, time 0.5 h and a bath ratio of 1:20. We adjusted the pH value of the dye liquor to 3, by adding mordant, and found that the K/S value of the silk fabric reached the maximum using dip-padding and steaming process. In addition, the fabric showed excellent color fastness to rubbing. FTIR, SEM and EDS results further confirmed that the silk fabric was successfully dyed with flavonoids colorant. Results from antioxidant and antibacterial tests revealed that the dyed fabric had excellent anti UV properties (UPF: 173.58), excellent antioxidant activity and antibacterial properties against both Escherichia coli and Staphylococcus aureus. Collectively, our results affirmed the simplicity, high efficiency and energy saving attributes of natural products in dyeing and functional finishing of textiles, thus provide a new direction for clean modification of textile materials.