The uptake of Gardenia yellow was most sensitive to the pH of dyebath. Gardenia yellow and curcumin had much higher building-up ability than R. emodi with anthraquinone structures.
Gardenia yellow possessed the highest fastness ratings, while curcuminand R. emodi showed poor wet rub fastness and wash fastness for staining.
Curcumin imparted the highestantioxidant activity to silk because of its high adsorption and two phenolic hydroxyl groups in its struc-ture and also gave the highest UV protection ability.
Curcumin and R. emodi provided higher antibacterialactivities than Gardenia yellow.
The post-mordanting with ferrous and ferric salts exerted great influenceon the color parameters, color fastness and UV protection ability of dyeings.
This study points out thatthe common dyeing process of three natural yellow dyes can impart the color and functional propertiesto silk.