Development of Electrospun Nanofibrous Filters for Controlling Coronavirus Aerosols

Abstract

Airborne transmission of SARS-CoV-2 plays a critical role in spreading COVID-19. To protect public health, we designed and fabricated electrospun nanofibrous air filters that hold promise for applications in personal protective equipment and indoor environment. Due to ultrafine nanofibers (~300 nm), the electrospun air filters had a much smaller pore size compared to the surgical mask and cloth masks (a couple of microns versus tens to hundreds of microns). A coronavirus strain was used to generate aerosols for filtration efficiency tests, which can better represent SARS-CoV-2 than other agents used for aerosol generation in previous studies. The electrospun air filters showed excellent performance by capturing up to 99.9% of coronavirus aerosols, which outperformed many commercial face masks. In addition, since NaCl aerosols have been widely used in filtration tests, we compared the filtration efficiency obtained from the coronavirus aerosols and the NaCl aerosols. The NaCl aerosols were demonstrated as an eligible surrogate for the coronavirus aerosols in the filtration tests, when air filters and face masks with diverse pore sizes, morphologies, and efficiencies were used. Our work paves a new avenue for advancing air filtration by developing electrospun nanofibrous air filters for controlling SARS-CoV-2 airborne transmission. Moreover, the removal efficiency of the NaCl aerosols can be reasonably translated into understanding how air filters capture the coronavirus aerosols.