Filter Made of Nanofiber Captures Nearly All Coronavirus Aerosols
The nanofiber filter was able to remove 99.9% of the coronavirus aerosols, while cotton masks only removed 45%-73%.
A recent study conducted by investigators from the University of California at Riverside, in collaboration with the George Washington University, discovered that a filter made from polymer nanothreads can capture up to 99.9% of Coronavirus aerosols.
Results from the study were published in the journal Environmental Science & Technology Letters.
"Our work is the first study to use coronavirus aerosols for evaluating filtration efficiency of face masks and air filters," Yun Shen, a corresponding author on the study said. "Previous studies have used surrogates of saline solution, polystyrene beads, and bacteriophages -- a group of viruses that infect bacteria."
For the study, the team of investigators sent high electrical voltage through a drop of liquid polyvinylidene fluoride to spin threads about 300 nanometers in diameter and created a nanofiber filter. The technique is known as electrospinning and can be a cheap way to mass produce the filters for personal protective equipment and air filtration systems.
The then compared the nanofiber filters against surgical masks, cotton masks and neck gaiters to see how well each of them prevented airborne aerosols.
Most studies up until now have used other materials to mimic both the size and behavior of coronaviruses, but the investigators in this study uses an aerosolized saline solution and an aerosol that contained a coronavirus from the same family as COVID-19.
Findings from the study showed that the cotton mask and neck gaiter removers around 45% to 73% of the aerosols, while the surgical mask removed around 98%. However, the nanofiber filter removed almost all of the coronavirus aerosols, just about 99.9%.
"Electrospinning can advance the design and fabrication of face masks and air filters," Shen said. "Developing new masks and air filters by electrospinning is promising because of its high performance in filtration, economic feasibility, and scalability, and it can meet on-site needs of the masks and air filters."