Dyeing performance of wool fabric with natural pigment from Cordyceps militaris

As a sustainable and ecological dye resource, the biomass materials are receiving more and more attention. In this work, the pigments in Cordyceps militaris were extracted and applied for dyeing wool fabrics, and the various properties were investigated. The extracted pigments and dyed wool fibers were analyzed and characterized by ultraviolet-visible (UV-Vis) spectroscopy, Liquid Chromatography-Mass Spectrometry (LC-MS) and Fourier Transform Infrared (FTIR) spectroscopy. The single-factor experiments were used to screen and optimize the dyeing process. Six metal mordants with different use order were compared with each other, and their possible mordanting mechanisms were proposed. The color fastnesses, UV resistance and antioxidant properties were evaluated after dyeing. The results showed that UV-Vis, LC-MS and FTIR analysis confirmed that the main components of C. militaris extract was lutein. The optimal dyeing process for the extract was as follows: dyestuff mass 200% (o.m.f.), dyeing temperature 90 ?, dyeing time 45 min, bath pH 5.0, Na2SO4 mass 0 g/L. Metal ions are added to form chelate bonds between the dyes and the fibers, further improving the color fastness. The dyed fabric exhibits excellent UV resistance and its UPF (Ultraviolet Protection Factor) value increases with the color yield. Meanwhile, the dyed wool fabric could exhibit up to 94.77% antioxidant activity. These results provide new insight for the application of C. militaris pigments on wool fabric.