A new filter can capture many times its weight in hazardous air pollution while letting air and light pass through easily. The material is made of a polymer called polyacrylonitrile, the same ingredient used to make acrylic yarns for clothing, some boat sails and surgical gloves. Using a fiber-pulling process called electrospinning, the liquid polymer is converted into nanofibers each a thousand times thinner than a human hair.
The Stanford University engineers who made the filter say its surface chemistry and the positioning of the fibers lets it absorb more than 95 percent of the smallest particulate matter (PM) in air pollution while remaining 90 percent transparent.
“The fiber just keeps accumulating particles, and can collect 10 times its own weight,” says Chong Liu, a materials science and engineering graduate student and lead author of a paper published this week in the journal Nature Communications. “The lifespan of its effectiveness depends on application, but in its current form, our tests suggest it collects particles for probably a week.”
For the entire story
Top two gifs created from video courtesy of Stanford University. Bottom gif created from video courtesy Liu et al./Nature Communications