One of the biggest problems the world has been suffered is air pollution. In this crucial time, the Washington State University researchers developed an affordable soy-based air filter that can capture almost all toxic fine polluting particles like carbon monoxide and formaldehyde which the current air filters unable to do.
According to a study, the eco-friendly air filter out of soybean protein can remove more than 99.94 percent of PM 2.5 pollutants, the fine particles in smog that are smaller than 2.5 microns in diameter and most harmful to health.
The WSU team is working with researchers from the University of Science and Technology Beijing including professor in the School of Mechanical and Materials Engineering, Weihong (Katie) Zhong and graduate student Hamid Souzandeh. The whole team used a pure soy protein with bacterial cellulose for biodegradable, 100% natural, inexpensive air filter.
PM 2.5 pollutants are produced by all types of ignition. It can pass through human lungs and enter a person’s blood supply.
Zhong said the available air filters are generally produced using micro-sized fibres of synthetic plastics and filter only the small particles. These are unable to filter chemically trap gaseous molecules. Usually, they are made of petroleum and glass products which cause secondary pollution.
How soy used as air filter
The researchers developed the air filtering material with soy protein and bacterial cellulose (an organic compound formed by bacteria). The two components are very cheap and already used in many applications like adhesives, plastic products, tissue regeneration and wound dressing materials.
Soy has several functional chemical groups which include 18 types of amino groups. Each chemical group has the capability to capture passing pollution at the molecular level. The researchers used an acrylic acid treatment to disentangle the highly rigid soy protein, in order to expose the chemical groups to the pollutants.
In a much polluted environment, people might be breathing an unknown mix of pollutants that could prove challenging to purify. But the soy protein with its large number of functional groups is able to attract a wide variety of polluting molecules.
Zhong said, “We can take advantage from those chemical groups to grab the toxics in the air.” She averred the filter could remove most toxic chemical pollutants in the air including carbon monoxide and sulphur dioxide which the available filters unable to do.
She told the filter material could also be used in existing air filter machines.
Besides that, the research team has also created gelatine and cellulose-based air filters. They are also applying the filter material on top of the cheap and disposable paper towel to strengthen it and to improve its performance. The researchers have filed patents on this technology and they are interested in commercialisation opportunities.