Masks are effective for preventing the spread of COVID-19 and other respiratory infections. If antimicrobial properties can be applied to the non-woven fabric filters in masks, they can become a more effective countermeasure against human-to-human and environmental infections. We investigated the possibilities of carrying antimicrobial agents on the fiber surfaces of non-woven fabric filters by applying silica-resin coating technology, which can form silica-resin layers on such fabrics at normal temperature and pressure. Scanning electron microscopy and electron probe microanalysis showed that a silica-resin layer was formed on the fiber surface of non-woven fabric filters. Bioassays for coronavirus and quantitative reverse transcription-polymerase chain reactions (RT-PCR) revealed that all antimicrobial agents tested loaded successfully onto non-woven fabric filters without losing their inactivation effects against the human coronavirus (inhibition efficacy: >99.999%). These results indicate that this technology could be used to load a functional substance onto a non-woven fabric filter by vitrifying its surface. Silica-resin coating technology also has the potential of becoming an important breakthrough not only in the prevention of infection but also in various fields, such as prevention of building aging, protection of various cultural properties, the realization of a plastic-free society, and prevention of environmental pollution.
Keywords: COVID-19; SARS-CoV-2; antiviral activity; mask; non-woven fabric; silica-resin coating technology.