Effectiveness of Common Fabrics to Block Aqueous Aerosols of COVID Virus-like Nanoparticles

TL;DR

This study evaluates common fabric materials for face masks, demonstrating that layered fabrics with absorbent and hydrophobic components can effectively block virus-like aerosols, offering protection comparable to N95 respirators.

Contribution

It provides a systematic assessment of over 70 fabric combinations, identifying effective layered designs for virus aerosol filtration using realistic aerosol simulation.

Findings

Layered fabrics with absorbent and hydrophobic layers are effective.

Materials like terry cloth, quilting cotton, and non-woven polypropylene perform well.

Fabric masks can match or surpass N95 filtration efficiency.

Abstract

Layered systems of commonly available fabric materials can be used by the public and healthcare providers in face masks to reduce the risk of inhaling viruses with protection about equivalent or better than the filtration and adsorption offered by 5-layer N95 respirators. Over 70 different common fabric combinations and masks were evaluated under steady state, forced convection air flux with pulsed aerosols that simulate forceful respiration. The aerosols contain fluorescent virus-like nanoparticles to track transmission through materials that greatly assist the accuracy of detection, thus avoiding artifacts including pore flooding and the loss of aerosol due to evaporation and droplet break-up. Effective materials comprise both absorbent, hydrophilic layers and barrier, hydrophobic layers. Although the hydrophobic layers can adhere virus-like nanoparticles, they may also repel droplets from adjacent absorbent layers and prevent wicking transport across the fabric system. Effective designs are noted with absorbent layers comprising terry cloth towel, quilting cotton and flannel. Effective designs are noted with barrier layers comprising non-woven polypropylene, polyester and polyaramid.