An air filter comprised of maize protein rather than petroleum products may collect both microscopic particles and hazardous compounds like formaldehyde, which existing air filters cannot. The discovery might lead to improved air purifiers, especially in areas of the globe where air quality is extremely low. In the journal Separation and Purification Technology, researchers from Washington State University report on the design and testing of materials for this bio-based filter.
“Particulate debris isn’t that difficult to filter, but concurrently capturing different types of chemical gas molecules is more important,” said Katie Zhong, a professor in WSU’s Department of Mechanical and Materials Engineering and a corresponding author on the work. “These protein-based air filtration materials seem to be highly promising for capturing a wide range of air contaminants.”
Asthma, heart disease, and lung cancer are all linked to poor air quality. Commercial air purifiers remove microscopic particles like soot, smoke, or automobile exhaust that may be taken directly into the lungs, but air pollution also often includes harmful gaseous molecules like carbon monoxide, formaldehyde, and other volatile organic compounds.
Typical high efficiency particulate air filters, often known as HEPA filters, have micron-sized holes and can catch tiny particles but not gaseous molecules. They are often composed of petroleum compounds and glass, which causes secondary pollution when old filters are discarded, according to Zhong. The WSU researchers created a more ecologically friendly air filter consisting of maize protein fibres that captured 99.5% of tiny particulate matter, equivalent to commercial HEPA filters, and 87% of formaldehyde, which is greater than specifically designed air filters for both sorts of toxins.
The researchers picked maize to analyse since it is a common agricultural crop in the United States. Corn protein is also hydrophobic, which means it repels water and might be useful in a damp environment, such as a mask.
Functional groups are amino acids found in maize protein. When these functional groups are exposed at the protein’s surface, they behave as numerous hands, gripping the harmful chemical molecules. The researchers proved this by exposing a functional group on the protein surface, which binds formaldehyde. They hypothesise that additional protein rearrangement might result in a tentacle-like collection of functional groups capable of grabbing a variety of substances from the air.
“Based on the technique, it’s extremely logical to predict that this protein-based air filter would be able to catch more species of hazardous chemical compounds,” Zhong added.
The three-dimensional structure they discovered also holds greater promise for a straightforward production approach than the previous research team’s thin films of proteins. They glued the nanofibers together using a little quantity of a chemical called polyvinyl alcohol to create a lightweight foam-like substance.
“Our discovery paves the way for the development of ecologically friendly, multi-functional air filters constructed from plentiful natural biomass,” Zhong added. “I feel that this technology is critical to people’s health and the environment, and that it should be marketed.”
Further testing, including the use of other functional group structures and other harmful chemical compounds, is desired by the researchers. The research was carried out by graduate student Shengnan Lin, Ming Luo, Flaherty assistant professor at the WSU Department of Mechanical and Materials Engineering, and post-doctoral scholar Xuewei Fu, in addition to Zhong.
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