Researchers at the Korea Research Institute of Chemical Technology in Daejeon, 164 kilometers south of Seoul, showcase a filter for N95 respirators, which is reusable and 100 percent biodegradable in soil in a month, in this photo provided by the institute.
DAEJEON, March 23 (Korea Bizwire) — A team of South Korean scientists have developed eco-friendly filters for protective masks that are 100 percent biodegradable.
The Korea Research Institute of Chemical Technology announced Monday that it had developed a fully biodegradable mask filter that uses polybutylene succinate (PBS), an aliphatic polyester.
The institute said that the filter can fully decompose in just 30 days.
The PBS filters are easier to breathe with, and can withstand humidity, allowing them to be used multiple times, the research team explained.
The research team first extracted fabrics of the biodegradable plastic, one that is only a nanometer wide and another that is as thin as a single micrometer. Then, they criss-crossed them on top of each other to produce a non-woven fabric.
These fabrics were then coated with chitosan nanowhiskers to successfully intercept fine dust.
Other mask filters normally employ an electrostatic mechanism to capture foreign particles. Since static electricity is vulnerable to humidity, these filters lose effectiveness over time.
Chitosan, on the other hand, takes on the qualities of an anode, and is capable of pulling in fine dust, viruses, and other foreign particles that are cathodic.
Since it relies on permanent positively charged materials instead of static electricity, it can withstand humidity and can be used multiple times.
This newly developed filter can intercept 98.3 percent of all viruses and fine dust for each 2.5 micrometers of air, which is as effective as commercial N95 protective mask filters.
In a test for biodegradability, the filter fully decomposed in 28 days in composting soil.
H. M. Kang (hmkang@koreabizwire.com)
