Researchers in the United States have devised a simple method for making N95 face masks that are not only efficient disease barriers but also on-contact germ killers.
Because antiviral and antibacterial masks do not need to be replaced as frequently, they can be worn for longer periods, resulting in less plastic waste.
“Hopefully, we are over the COVID pandemic,” said Helen Zha of Rensselaer Polytechnic Institute, “but this type of technology will become more vital.”
“The threat posed by airborne germs is not going away.” It’s past time to increase the performance and long-term viability of the materials we employ to defend ourselves.”
The ideal recipe
Zha, an assistant professor of chemical and biological engineering and a member of Rensselaer’s Center for Biotechnology and Interdisciplinary Studies (CBIS), worked on the study with Edmund Palermo, an associate professor of materials science and engineering and a member of Rensselaer’s Center for Materials, Devices, and Integrated Systems (cMDIS).
With the optimal recipe for improving face masks, researchers seek to combat contagious respiratory illnesses and environmental pollution.
“This was a comprehensive materials engineering problem with a fantastic, diversified team of partners,” stated Palermo.
“We believe the research is the first step toward longer-lasting, self-sterilizing personal protection equipment like the N95 respirator.” It may aid in the reduction of airborne pathogen transmission in general.”
Polymers with antimicrobial properties
The researchers successfully grafted broad-spectrum antibacterial polymers onto the polypropylene filters used in N95 face masks in a study recently published in Applied ACS Materials and Interfaces.
“The active filtering layers in N95 masks are quite vulnerable to chemical alteration,” Zha said.
“It can degrade their filtering performance to the point that they no longer operate like N95s.” They’re constructed of polypropylene, which is tough to change chemically.
“Another problem is that you don’t want to disturb the incredibly delicate network of fibers in these masks, which might make breathing through them more difficult.”
Zha and Palermo collaborated with researchers from Rensselaer Polytechnic Institute, Michigan Technological Institute, and Massachusetts Institute of Technology.
Using an ultraviolet (UV)-initiated grafting, the researchers covalently bonded antimicrobial quaternary ammonium polymers to the fiber surfaces of nonwoven polypropylene textiles.
Hills Inc. supplied the textiles, courtesy of Rensselaer graduate Tim Robson.
COVID-19
Zha and Palermo began their research in 2020, when N95 face masks were scarce, thanks to National Science Foundation Rapid Response Research (RAPID) funding.
Healthcare personnel was even reusing single-use masks. Face masks of various kinds are now readily accessible in 2022.
However, COVID-19 rates remain high, another pandemic is a probable possibility, and single-use, throwaway masks are stacking up in landfills.
“Attaching chemical groups that kill viruses or bacteria on contact with polypropylene is a good method,” said Shekhar Garde, dean of Rensselaer’s School of Engineering
“Given the quantity of polypropylene in daily life, this method may be effective in many situations.”
