Highly Perforated ZnO-Loaded Poly (Lactic Acid) Nanofibers Fabricated via Humidity-Controlled Self-Assembly Electrospinning for Inactivation of Airborne Pathogens
摘要
Self-disinfecting fibrous filters that combine high pathogen capture capability, intrinsic antimicrobial activity, durability, and energy-lean fabrication remain difficult to realize. This is mainly because antimicrobial functionality often requires post-treatment to expose active sites, which can compromise durability and reduce energy efficiency, and increase process complexity. Herein, a one-step, humidity-assisted electrospinning strategy that exploits the breath-figure effect to generate highly perforated ZnO/poly(lactic acid) nanofibers (HP-ZnO/PLA NFs) with ZnO preferentially exposed along pore walls is reported. Relative humidity (RH, 20%-60%) served as a direct process variable coupling textural porosity and Zn surface coverage: with increasing RH, the specific surface area increased from 0.64 to 10.92 m2 g−1, the Zn-covered surface atomic fraction increased from 24.2% to 44.9%, and the effective accessible ZnO area from 0.16 to 4.89 m2 g−1. The filters prepared at 60% RH achieved ≥ 96.8% filtration efficiency and ≥ 90.0% inactivation against Staphylococcus aureus, Escherichia coli, influenza A (H1N1), and human coronaviruses 229E and OC43. The filters also show negligible particle shedding (< 0.02 particles cm−3) and a low functionalization-specific energy consumption (approximately 0.17 kWh m−2), yielding an energy-normalized figure of merit of 23.5 logs per kWh m−2. These results indicate that the proposed strategy represents a scalable route for preparing durable, self-disinfecting air-filter media for indoor mitigation of airborne pathogens.
Graphical Abstract