Researchers make virus-fighting face masks
Researchers at Rensselaer Polytechnic Institute have developed an accessible way to make N95 face masks not only effective barriers to germs, but also non-contact germ killers. The antiviral, antibacterial masks can potentially be worn for longer, reducing plastic waste as the masks do not need to be replaced as often.
Helen Zha, assistant professor of chemical and biological engineering and member of the Center for Biotechnology and Interdisciplinary Studies in Rensselaer (CBIS), collaborated with Edmund Palermo, associate professor of materials science and engineering and member of the Center for Materials, Devices, and Integrated Systems (cMDIS) at Rensselaer, to fight infectious respiratory diseases and environmental pollution with the perfect recipe to improve face masks.
“This was a multifaceted materials engineering challenge with a great, diverse team of employees,” said Palermo. “We believe the work is a first step towards more durable, self-sterilizing personal protective equipment, such as the N95 respirator. It could help reduce the transmission of airborne pathogens in general.”
In recently published research in ACS applied materials and interfacesthe team successfully grafted broad-spectrum antimicrobial polymers onto the polypropylene filters used in N95 face masks.
“The active filtration layers in N95 masks are very sensitive to chemical modification,” Zha says. “It can make them perform worse in terms of filtration, so they essentially don’t perform like N95’s. They’re made of polypropylene, which is chemically difficult to modify. Another challenge is you get to see the very fine network of fibers in these masks, making it harder for them to breathe.”
Zha and Palermo, along with other researchers from Rensselaer, Michigan Technological Institute and Massachusetts Institute of Technology, covalently attached antimicrobial quaternary ammonium polymers to the fiber surfaces of nonwoven polypropylene fabrics using ultraviolet (UV) initiated grafting. The fabrics were donated by Hills Inc. thanks to Rensselaer alumnus Tim Robson.
“The process we developed uses a very simple chemistry to create this non-leaching polymer coating that can kill viruses and bacteria by essentially breaking open their outer layer,” Zha said. “It’s very simple and a potentially scalable method.”
The team only used UV light and acetone in their process, which are widely available, to make it easy to implement. In addition, the process can be applied to already manufactured polypropylene filters, rather than having to develop new ones.
The team did see a decrease in filtration efficiency when the process was applied directly to the filtration layer of N95 masks, but the solution is simple. The user could wear an unmodified N95 mask along with another polypropylene layer with the antimicrobial polymer on it. In the future, manufacturers could make a mask with the antimicrobial polymer incorporated into the top layer.
Thanks to a grant from the National Science Foundation Rapid Response Research (RAPID), Zha and Palermo started their research in 2020 when there was a shortage of N95 face masks.
Health professionals even reused masks intended for single use. Fast forward to 2022 and all types of face masks are now widely available. However, COVID rates are still high, the threat of another pandemic in the future is a clear possibility, and single-use disposable masks are piling up in landfills.
“Hopefully we are on the other side of the COVID pandemic,” Zha said. “But this kind of technology will become increasingly important. The threat of disease caused by airborne microbes is not going away. It is high time we improved the performance and durability of the materials we use to protect ourselves.”
“It is a smart strategy to attach chemical groups that kill viruses or bacteria on contact to polypropylene,” says Shekhar Garde, dean of the School of Engineering in Rensselaer. “Given the abundance of polypropylene in everyday life, this strategy may also be useful in many other contexts.”
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Mirco Sorci et al, Virucide N95 Respiratory Masks via Ultrathin Surface Grafted Quaternary Ammonium Polymer Coatings, ACS applied materials and interfaces (2022). DOI: 10.1021/acsami.2c04165
Quote: Researchers create virus-fighting face masks (2022, June 21) retrieved June 21, 2022 from https://phys.org/news/2022-06-virus-fighting-masks.html
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