Electrospun Multiscale Poly(lactic acid) Nanofiber Membranes with a Synergistic Antibacterial Effect for Air-Filtration Applications

Pollution of particulate matter (PM) threatens human health and the environment. Owing to its tiny particle size, large specific surface area, and porous structure, PM readily adsorbs and retains airborne bacteria. Therefore, it is essential to develop nanofiber air-filtration materials with excellent antibacterial properties. This work reports a strategy to prepare multiscale poly(lactic acid) nanofiber membranes with antibacterial properties induced by the synergistic effects of quaternary ammonium salts and N -halamine via electrospinning. The membrane exhibited a long-lasting and excellent bactericidal effect (>99%) against Staphylococcus aureus and Escherichia coli; after 10 chlorination cycles, the membrane displayed a high bacteriostatic rate (>90%). Additionally, compared to unmodified PLA nanofiber membranes, the modified multiscale PLA nanofiber membranes prepared by mild modification possessed good antibacterial properties and had no impact on mechanical properties and filtration performance; the membrane's tensile strength also increased from 10.52 to 14.19 MPa. A filter prepared using the as-prepared membrane exhibited efficient interception of the PM 0.3 performance (99.992%) and low air resistance (107 Pa). Notably, the as-prepared air filter exhibited a higher filtration performance than commercial filters. The materials developed in this work will have broad applications in air filtration, medical hygiene, and environmental protection.