Hydration of Hydrophilic Cloth Facial Coverings Greatly Increases the Filtration Properties for Nanometer and Micrometer-sized Particles

Published

March 8, 2021

Author(s)

Christopher Zangmeister, James Radney, Matthew Staymates, Edward P. Vicenzi, Jamie Weaver

Abstract

Filtration efficiencies (FE) of natural, synthetic, and blended fabrics were measured as a function of relative humidity (RH) for particles with mobility diameters between 50 nm and 825 nm. Fabrics were equilibrated at 99 % RH, mimicking conditions experienced when worn as a cloth facial covering. The FE increased after equilibration at 99 % RH by a relative percentage increase of 33 % ± 12 % for fabrics comprised of two layers of 100 % cotton when tested by 300 nm diameter NaCl aerosol. The FE for samples of synthetics and polyester/cotton blends were unchanged upon equilibration at 99 % RH. Increases in FE for 100 % cotton fabrics were a function of particle size and increased by a relative percentage increase of 61 % at the largest measured particle size (825 nm). Flow visualization data for 100 % cotton and polyester also showed that equilibration at 99 % RH increased capture of particles > 1 µm. The experimental results are consistent with increased particle capture due to H2O adsorption on the fiber surface.

Citation

ACS Applied Nano Materials

Pub Type

Journals

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Keywords

SARS-CoV-2, COVID-19, cloth masks, facial coverings, humidity, aerosols, respiratory protection

Citation

Zangmeister, C. , Radney, J. , Staymates, M. , Vicenzi, E. and Weaver, J. (2021), Hydration of Hydrophilic Cloth Facial Coverings Greatly Increases the Filtration Properties for Nanometer and Micrometer-sized Particles, ACS Applied Nano Materials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=931428 (Accessed November 25, 2025)