Biodegradable, Efficient, and Breathable Multi‐Use Face Mask Filter

Abstract

The demand for face masks is increasing exponentially due to the coronavirus pandemic and issues associated with airborne particulate matter (PM). However, both conventional electrostatic‐ and nanosieve‐based mask filters are single‐use and are not degradable or recyclable, which creates serious waste problems. In addition, the former loses function under humid conditions, while the latter operates with a significant air‐pressure drop and suffers from relatively fast pore blockage. Herein, a biodegradable, moisture‐resistant, highly breathable, and high‐performance fibrous mask filter is developed. Briefly, two biodegradable microfiber and nanofiber mats are integrated into a Janus membrane filter and then coated by cationically charged chitosan nanowhiskers. This filter is as efficient as the commercial N95 filter and removes 98.3% of 2.5 µm PM. The nanofiber physically sieves fine PM and the microfiber provides a low pressure differential of 59 Pa, which is comfortable for human breathing. In contrast to the dramatic performance decline of the commercial N95 filter when exposed to moisture, this filter exhibits negligible performance loss and is therefore multi‐usable because the permanent dipoles of the chitosan adsorb ultrafine PM (e.g., nitrogen and sulfur oxides). Importantly, this filter completely decomposes within 4 weeks in composting soil.

Microstructure analysis and image-based modelling of face masks for COVID-19 virus protection

“…This knowledge might in turn provide a source of inspiration for the design of functional materials in the face covering fields. For instance, Choi et al 35 developed a biodegradable, efficient and breathable multi-use face mask filter. Many administrations (i.e., WTO) proposed that wearing a mask can reduce the risk of virus infections, and we strength this argument with 3D microstructure analysis.…”

Facemasks: A Looming Microplastic Crisis

“…Many researchers have investigated the possibility of reusing facemasks after their disinfection with UV radiation. Choi et al [ 29 ] have recently developed a biodegradable facemask from chitosan. However, these technologies remain unpopular and unknown.…”

Eco-Friendly Poly(Vinyl Alcohol) Nanofiber-Based Air Filter for Effectively Capturing Particulate Matter

“…As shown in the figure, the pore size was effectively reduced by the formation of PVA NFs with an average diameter of~150 nm on a nonwoven substrate with an average diameter of~20 µm. This means that the pore size of the PVA NF-based filter could be adjusted by controlling the electrospinning time; thus, the limit of the PM size collected by the filter can be reduced (see Figure S3) [1,13].…”

“…and respiratory viral infections (coronavirus, Spanish flu, etc.) [1][2][3][4]. PP is an extremely useful plastic because of its physical and thermal properties, such as light weight and heat resistance.…”