Co-modification of engineered cellulose surfaces using antibacterial copper-thiosemicarbazone complexes and flame retardants

Lyocell fibers, the most successful regenerated cellulose fibers, have already attracted much attention. However, the use of traditional Lyocell fibers in the field of personal protective equipment (PPE) is limited, due to the lack of antibacterial properties. Additionally, the flame-retardant properties of Lyocell fibers are also required for the specific applications. Here, we co-conjugated phosphorus flame retardants and copper-thiosemicarbazone complexes with antibacterial performance on Lyocell fibers through chemical crosslinkers. The chemical composition and morphology of our engineered Lyocell fibers were fully characterized, and their mechanical properties were also maintained. Flame retardants can import flame-retardant properties (LOI: 25.0 % - 25.7 %) to Lyocell fibers, which also show promising antibacterial activity , suppressing Escherichia coli (GIR: 20.51 % - 66.67 %) and Staphylococcus aureus (GIR: 74.19 % - 93.54 %). Such an improved sustainable formulation can be used to produce the next-generation of Lyocell-based PPE, to meet the demand for the antibacterial and flame-retardant properties of fibers in special applications.