Bioactive and multifunctional textile using plant-based madder dye: Characterization of UV protection ability and antibacterial activity

In the present work the natural madder dye (Rubia tinctorum L.) was applied to the simultaneous dyeing and functionalization of polyester (PET) fabric. In the first part of the study the color performance and the durability were revealed for exhaustion dyed fabric. The dyed fabric was then characterized with respect to ultraviolet (UV) protection ability and antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). CIELab color coordinates, namely the positive a* and b* values, confirmed a yellow/orange color of the dyed fabric. From durability tests, the color showed a moderate to good light fastness and good to excellent fastness to washing and rubbing. The madder dye improved both the UV protective performance and the antibacterial activity of the fabric. With 3 % on weight of fiber (owf) the UV protection factor increased up to 106, and the antibacterial activity up to 86 % against both types of bacteria tested.