Eugenol-confined ZIF-8 modulates PLA nanofiber architecture for synergistic low-resistance and antibacterial PM filtration

Conventional air filtration media struggle to simultaneously address secondary biological pollution, the efficiency-permeability trade-off, and the environmental burden associated with disposable polymer filters. Direct blending of agglomerated or dense fillers can destabilize the electrospinning jet, disrupting the fiber network and increasing airflow resistance. In this study, biodegradable PLA nanofibers were combined with eugenol-loaded ZIF-8 nanoparticles to construct an antibacterial air filtration membrane. Prepared through an aqueous route, ZIF-8 served a dual function by regulating the architecture of the fibrous network and acting as a microporous reservoir for the natural antibacterial molecule eugenol. Comparison of pristine PLA, PLA/ZIF-8, and PLA/EUG@ZIF-8 membranes clarified each component's contribution. Pristine PLA provided a biodegradable fibrous matrix but showed inadequate filtration and negligible antibacterial activity. The incorporation of ZIF-8 optimized membrane morphology, enhanced particle capture, and imparted moderate bacterial inhibition. Notably, confinement of eugenol within ZIF-8 pores further enhanced antibacterial activity without disrupting the optimized membrane structure or air permeability. The PLA/EUG@ZIF-8 membrane delivered PM0.3, PM1.0, and PM2.5 filtration efficiencies of 99.62%, 99.99%, and 99.99%, respectively, with a low pressure drop of 69 Pa and a maximum quality factor of 0.1335 Pa⁻¹ . The composite also achieved near-complete inhibition of Escherichia coli (99.74%) and Staphylococcus aureus (99.48%). Numerical simulations showed a filtration trend consistent with the experimental results, indicating that the improved performance was mainly associatedwith the optimized fiber-pore structure rather than simple membrane densification. Thus, MOF-mediated natural antibacterials effectively fabricate biodegradable filters with excellent PM capture, low resistance, and strong antibacterial activity, promoting eco-friendly membranes.