Nano-dry-salt deposition on electret nonwoven confers anticoronaviral effect while retaining aerosol filtration performance

Safe-by-design concepts for anticoronaviral functions are important in the production of air filters, face masks, and touch substrates because these interventions may be effective in allowing continued socioeconomic activity and alleviation of the global recession. Recent attempts to provide anticoronaviral functions have involved alternative compositions and architectures aimed at producing nanoscale compounds for highly effective anticoronaviral activities. However, translating the nanocompounds to the field requires considerable investment and time as well as actual trials; thus, they may not be a viable option for timely deployment during the COVID-19 pandemic. With these considerations in mind, we have used sodium chloride, which is generally recognized as safe (GRAS), to functionalize nonwoven sheets as frequently touched surfaces. Specifically, we produced nano-dry-salt (NDS) particles through Collison-type atomization and subsequent diffusion drying, and these NDS particles were finally deposited on electret meltblown nonwovens in a single-pass air flow. The resulting GRAS NDS deposited electret nonwovens were examined for effectiveness in anticoronaviral function and aerosol filtration with pressure drop. The treated nonwovens exhibited significant inactivation of airborne human coronaviruses (surrogates of SARS-CoV-2) while retaining the original filtration performance, even under saliva droplet and dust exposures. Several realizable platforms can thus be presented to quickly incorporate NDS deposition in conventional nonwoven production.