Development of an engineered face mask with optimized nanoparticle layering for filtration of air pollutants and viral pathogens

Abstract

Face masks became a critical part of the personal protective equipment for front-line workers and the public during the COVID-19 pandemic. Studies conducted during the pandemic have shown a strong positive correlation between COVID-19 mortality and air pollution. This project’s goals are to develop an engineered face mask with an optimized layering of nanoparticles to filter PM<sub>2.5</sub> and viral pathogens, that is cost-effective, reusable, and clinically safe. The nanoparticles were selected based on their filtration, virucidal, and non-toxic properties. The experiment was designed with a wind-tunnel using vacuum pumps to simulate human breathing. The results indicate that particle filtration efficiency (PFE), tested with PM<sub>2.5</sub> from incense sticks measured by laser particle detectors improved by ≈100% as compared to uncoated masks. Virus Filtration Efficiency (VFE), tested using nebulized NaCl particles as a virus surrogate, improved by ≈140% with nanoparticle coatings. The filtration efficiency was independent of the source of PM<sub>2.5</sub>. The nanoparticle retention efficacy was well within the permissible exposure limits per OSHA standards. An accelerated durability test demonstrated ≈95% effectiveness maintained over 4 equivalent days of wear. This multi-purpose, reusable mask can be effective in polluted cities, in fire-prone areas and can protect people against the deadly effects of viruses.