BEIJING: Stanford Univ.’s Yi Cui and his students have turned a material commonly used in surgical gloves into a low-cost, highly efficient air filter. It could be used to improve facemasks and window screens, and maybe even scrub the exhaust from power plants.
In the past few years, Cui has made several business trips to China. Each time he has found himself choked by smog produced by automobiles and coal power plants.
After a few of these trips, Cui, an associate professor of materials science and engineering at Stanford, came up with an idea to clean the pollution. He and his graduate students set to work designing an inexpensive, efficient air filter that could ease the breathing for people in polluted cities.”My lab group really likes to solve problems, even if it’s something we’ve never worked on,” Cui said. “We think we could use this material for personal masks, window shades and maybe automobiles and industrial waste. It works really well, and it might be a game-changer.”
The work is published in the current issue of the journal Nature Communications.
This was the first time Cui’s group had designed an air filter – Cui’s work with nanomaterials focuses primarily on battery technology – so he and his students didn’t immediately look to materials that have traditionally been used in air filters.
Instead, they looked for polymers that would have a strong attraction to the main components of smog, particularly particle matters that are smaller than 2.5 microns, known as PM2.5. These pose the greatest risk to the human respiratory system and overall health; current filtration systems that can remove them from the air are very energy-intensive.
It turned out that polyacrylonitrile (PAN), a material commonly used to make surgical gloves, met these requirements.
