Researchers have developed an environmentally-friendly air filter made from simple soy proteins. Better still, the research team claims that the design is more effective at catching particles than regular air filters, and is specifically able to capture gaseous particles such as carbon monoxide and formaldehyde. This makes the discovery not only timely, given the impact that air pollution is having on major cities throughout the world, but also ideal for the growing chemical industry or those who live near industrialized areas.
The online scientific journal, Phys.org, notes how the breakthrough was made by, “… researchers from the University of Science and Technology Beijing, and [a team from] the Washington State University, including Weihong (Katie) Zhong, professor in the School of Mechanical and Materials Engineering, and graduate student Hamid Souzandeh,” who, they explain, “used a pure soy protein along with bacterial cellulose for an all-natural, biodegradable, inexpensive air filter.”
While the use of such natural materials may seem obvious from an environmental perspective, the Washington State University website also outlines the economic advantages and logical thinking behind such a decision, stating that, “The soy protein and cellulose are cost effective and already used in numerous applications, such as adhesives, plastic products, tissue regeneration materials and wound dressings. [Furthermore] Soy contains a large number of functional chemical groups – it includes 18 types of amino groups, with each of the chemical groups having the potential to capture passing pollution at the molecular level.”
As Zhong notes, “We can take advantage of those chemical groups to grab the toxics in the air.”
She and her fellow researchers have now published their results in the journal, Composites Science and Technology, reporting that, “…conventional petroleum-based and chemically synthesized polymers [currently used in] commercial air filters are not eco-friendly materials and can cause secondary environmental pollution. To address this serious issue, the development of an environmentally friendly and multi-functional air filtering material is a critical need. In this study, soy protein isolate (SPI) and bacterial cellulose (BC) are employed to study the potential of biomaterials as high efficiency air filtering materials. Soy protein isolate contains many functional groups on its structure and these functional groups were exposed for interactions with pollutants via a denaturation process using acrylic acid treatment. The 3D nano-network of BC contributes to the preliminary physical capturing of PM particles, while the functional groups of SPI further attract the PM particles via electrostatic attraction and dipole interaction between the filter materials and the PM particles.”
The results from the study proved promising, claiming that, “The SPI/BC composite with an appropriately modified SPI possesses extremely high removal efficiencies for particulate pollutants with a broad range of sizes: 99.94% and 99.95% for PM2.5 removal efficiency and PM10, respectively, under extremely hazardous air conditions, while maintaining a very high air penetration rate of 92.63%.”
While naturally pleased with the added effectiveness of the soy-protein air filter, Zhong was keen to underline the advantages the filter had over those currently in use, saying, “Typical air filters, which are usually made of micron-sized fibers of synthetic plastics, physically filter the small particles but aren’t able to chemically capture gaseous molecules. Furthermore, they’re most often made of glass and petroleum products, which leads to secondary pollution.”
She also notes that there is a clear market for her product, saying, “Air pollution is a very serious health issue. If we can improve indoor air quality, it would help a lot of people.”
With this in mind, the team are continuing their work as they believe there are real practical advantages to their design of chemical filter, as the Phys.org explains, “In addition to the soy-based filters, the researchers have also developed gelatin- and cellulose-based air filters. They are also applying the filter material on top of low-cost and disposable paper towels to reinforce and improve its performance. They have filed patents on the technology and are interested in commercialization opportunities.”
Given that regular air filters are not especially efficient, and are generally aimed at removing larger pollutant particles, the fact that an improved device has arrived at a time when public awareness of the dangers of air pollution is higher than ever is significant. Even more important, is the fact that the filter is able to remove, “hazardous gaseous molecules, such as carbon monoxide, formaldehyde, sulfur dioxide and other volatile organic compounds.” Meanwhile its low cost and environmentally-friendly credentials are sure to have customers lining up for fresher air.