Scientists have developed a special type of cotton facemask that kills up to 99.9999% of bacteria and viruses within 60 minutes of daylight exposur
Scientists have developed a special type of cotton facemask that kills up to 99.9999% of bacteria and viruses within 60 minutes of daylight exposure.
Facemasks made of various cloth materials can filter nanoscale aerosol particles, potentially helping to reduce the spread of diseases, including COVID-19. But live bacteria and viruses on the surface of the mask can still be contagious.
Now a team has developed a new cotton fabric that releases reactive oxygen species (ROS) when exposed to daylight, killing microbes attached to the fabric’s surfaces while being washable, reusable and safe for the wearer.
The researchers made their antimicrobial fabrics by attaching positively charged chains of 2-diethylaminoethyl chloride (DEAE-Cl) to ordinary cotton. Then, they dyed the modified cotton in a solution of a negatively charged photosensitizer (a compound that releases ROS upon exposure to light), which attached to the DEAE chains by strong electrostatic interactions.
The cloth masks can be disinfected by spending an hour outside in sunshine, or a longer period of time under office or building lights, which are much less intense than sunlight.
