Professor Ko's team in Seoul National University announced that they have developed a new type of transparent air filtering device that can not only self-sterilize its surface by chemical and thermal disinfection mechanisms, but also capture airborne particles.
During the outbreak of pandemic, air filters have been considered as important hygiene supply for preventing virus transmission. However, most air filters have little antimicrobial ability , which can potentially cause proliferation and secondary transmission of microbes. Therefore, disinfection of air filter is highly required for the safe use of it.
Poor transparency of air filters is another important issue in the current situation. Nowadays, wearing mask is mandatory or encouraged to inhibit spread of contagious virus. However, face mask disturbs precise communication between people by blocking sound and screening facial expressions. Especially, people with hearing loss, who largely depend on such visual information (movements of lips and tongue), consider face masks as an huge obstacle.
Prof. Ko's research team developed an transparent air filter that can self-sterilize its surface by introducing highly thin, antimicrobial, and electrically conductive copper nanowire network as a filtering layer. Due to its thinness, this air filter can pass through proper amount of light, showing moderate visible light transmittance. Due to the chemical composition of this air filter, Cu, pathogen such as a species of bacteria (E. coli) were successfully disinfected by oligodynamic effect. Also, by active Joule-heating, a species of bacteria (G. anodireducens), which can even survive on metal surface, were thermally sterilized with excellent disinfection efficiency. Besides, very narrow pores of copper nanowire network could effectively capture airborne particles by mechanical and electrostatic mechanisms. The team finally demonstrated a face mask integrated with this air filter that can actively sterilize its surface and effectively capture airborne particles, while preserving moderate optical transparency which is helpful for precise communication.
This research is expected to present powerful tool for a worldwide peril provoked by a series of pandemic and air pollution, while maintaining social-connectedness.
Transparent Air Filters with Active Thermal Sterilization