06-08-2020, 01:00 PM
Quote:Zetta, a spinout from the Tokyo Institute of Technology, also known as Tokyo Tech, has developed a nonwoven nanofiber material that can be washed repeatedly without losing its ability to protect the wearer from viruses. The startup, based in the western Japanese city of Matsuyama, plans to get into the business of making masks from the high-tech fabric. Zetta will begin by making and marketing sheets designed to be attached to cloth masks. It will then work with a manufacturer to develop high-grade masks for health care workers...
The nanofiber has a diameter of 0.08 to 0.4 micrometers (millionths of a meter). That is less than one-tenth the size of an N95 respirator's fibers, which are designed to block at least 95% of airborne particles as small as 0.3 micrometers across. The materials used to make N95 masks have fiber diameters of 3 to 5 micrometers. The Z-Mask can block viruses smaller than 0.1 micrometer, such as the new coronavirus using the intermolecular forces that mediate interactions between molecules, including molecular attraction. In an experiment conducted by the government-run New Energy and Industrial Technology Development Organization, or NEDO, the Z-Mask was able to catch nearly 100% of particles roughly the same size as the coronavirus.
N95 masks generally use static electricity in the fibers to attract particles like a magnet. After several hours of continuous use, the performance of such masks starts to decline because of the effect of the wearer's moist breath. Health care workers typically must replace N95 respirators several times a day, one reason for the shortage of such masks in hospitals. Because the Z-Mask uses molecular attraction to catch viruses, its performance does not deteriorate unless the fiber is broken, according to the company. In an experiment carried out by Zetta, the mask retained its ability to filter out particles even after it was hand-washed 100 times with detergent. Tokyo university startup develops coronavirus-catching fabric - Nikkei Asian Review