Design and characterization of UV-driven rechargeable antibacterial nanofibrous membranes for food packaging applications.

This study utilized electrospinning to create in situ composite layers of polyvinyl alcohol (PVA) and polylactic acid (PLA) films. Through molecular grafting, the antimicrobial photoinitiator 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BD) was anchored to the PVA surface, followed by chlorogenic acid (CA) attachment, forming a composite film with rechargeable photodynamic properties. Scanning electron microscopy showed that the nanofiber structure remained intact post-grafting, while nuclear magnetic resonance confirmed successful bonding of BD and CA with PVA. The composite films exhibited enhanced hydrophobicity, with the PLA/PVA-BDCA film achieving a 44 % increase in contact angle. Antibacterial tests showed significant efficacy in both light and dark conditions, with light exposure doubling the antibacterial rate. The PLA/PVA-BDCA film reduced colony counts by about 3 log units and generated the highest free radical levels (approx. 400 μg/g), over twice that of other films. Ultraviolet irradiation enabled regeneration of its antibacterial function up to five cycles, supporting its sustainable use.