Development of Reusable Cloth Mask with Nanoparticle Filtration Efficiency Greater than 95%

Abstract

After the rapid spread of SARS-Cov-2 virus, the use of masks were suggested by the world health organization (WHO) to reduce the virus transmission, whose primary mode of transmission is suggested to be through respiratory droplets. The recommended face coverings were single use surgical and respirator masks made of non-woven materials. With the increased demand for masks worldwide, the environmental impacts of mask disposal and the pollution caused by microplastic fibers of the non-woven materials was presented. This challenge necessitates the need for the development of a novel reusable mask reducing the environmental effects, while providing the necessary personal protective properties. Based on the ASTM F2299 specifications, the performance, i.e., particle-size dependent filtration efficiency and pressure drop were studied for 20 samples with multilayer knit fabrics of natural and synthetic fibers (inner layer of pure cotton, cotton-nylon and cotton-polyester, middle layer of Lycra, and outer layer of superhydrophobic polyester). The results show that all the samples have an efficiency of >97.3% and 89.9-98.4% for large and fine particles, respectively. The best performing structure has a material composition of 41% superhydrophobic polyester, 26% natural cotton, 24% nylon and 9% Lycra. The filtration efficiency, pressure drop, and quality factor for this sample is 97.8% (for 100 nm particles), 4.04 mmmmHH2 OO/cccc2 and 4.77 kkkkkk-1 , respectively. It was also demonstrated that the developed mask maintained its performance after 50 wash/dry cycles, verifying its reusability.