Synergistic Modification of Polylactic Acid Fibrous Membranes with Improved Light-Induced Antibacterial, Mechanical, and Biodegradable Performances

Reusable and biodegradable facemasks with enhanced antibacterial and mechanical functions are considered sustainable personal protective equipment (PPE) to protect the public from future outbreaks or pandemics of infectious diseases. This study successfully employed biobased plasticizers to inherently work with an edible photosensitizer vitamin K3 (VK3) to provide a combination of desired mechanical, biodegradable, and antibacterial functions onto polylactide (PLA) fibers. These additives demonstrated good compatibility with VK3 and PLA, resulting in improved softness and toughness and accelerated enzymatic degradation of the modified PLA membranes. Among the plasticizers, glycerol tributyrate (GT) revealed a superior synergistic effect with VK3 in PLA membranes by promoting a type I photoreaction of the excited VK3, which generated more than three times hydroxyl radicals compared to other plasticizers under both daylight (D65) and UVA irradiation, in addition to the consistent production of singlet oxygen. The dramatically increased reactive oxygen species (ROS) production on the PLA membranes leads to rapid antibacterial function (6-log reduction of Escherichia coli within 30 min), a critical performance metric for biocidal materials. These findings offer new insights into the development of eco-friendly, multifunctional, and degradable facemask materials, providing a promising approach for future sustainable and biocidal PPE.