Biodegradable and high-performance multiscale structured nanofiber membrane as mask filter media via poly(lactic acid) electrospinning

The usage of single-use face masks (SFMs) has increased since the outbreak of the coronavirus pandemic. However, non-degradability and mismanagement of SFMs have raised serious environmental concerns. Moreover, both melt-blown and nanofiber-based mask filters inevitably suffer from poor filtration performance, like a continuous decrease in the removal efficiency for particulate matter (PM) and weak breathability. Herein, we report a new method to create biodegradable and reusable fibrous mask filters. The filter consists of a true nanoscale bio-based poly(lactic acid) (PLA) fiber (an average size of 37 +/- 4 nm) that is fabricated via electrospinning of an extremely dilute solution. Furthermore, we designed a multi scale structure with integrated features, such as low basis weight (0.91 g m(-2)), small pore size (0.73 mu m), and high porosity (91.72%), formed by electrospinning deposition of true nanoscale fibers on large pore of 3D scaffold nanofiber membranes. The resultant mask filter exhibited a high filtration efficiency (PM0.3- 99.996%) and low pressure drop (104 Pa) superior to the commercial N95 filter. Importantly, this filter has a durable filtering efficiency for PM and natural biodegradability based on PLA. Therefore, this study offers an innovative strategy for the preparation of PLA nanofibers and provides a new design for highperformance nanofiber filters. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This study introduces a new method for creating biodegradable and reusable fibrous mask filters using true nanoscale bio-based poly(lactic acid) (PLA) fibers. The designed filter exhibits high filtration efficiency and low pressure drop, making it suitable for mask preparation.