New Steel Alloy Can Kill The COVID-19 Virus in Under Six Hours
Researchers at the University of Hong Kong have developed a novel type of stainless steel alloy that kills the COVID-19 virus within six hours. More specifically, the steel can deactivate 99.75% of the virus in three hours and reach a final 99.99% in six.
This anti-pathogen steel would be ideal for surfaces that come into contact with many people’s hands, such as doorknobs, handrails, lift buttons, and more. Public areas, venues, train stations, airports, and a wide range of places could use this material, not just for COVID-19 but for any virus.
As the study that looked into the performance of the alloy details, it’s also excellent in deactivating the H1N1 virus and the Escherichia Coli bacterium. Most likely, it would do well against many more pathogens if tested.
The secret lies in adding small amounts (20 wt%) of copper in the alloy, distributing it equally so that the physical and mechanical properties of the stainless steel aren’t affected, but the anti-microbial properties are retained.
The team explained that simply using a copper coating on top of regular stainless steel wouldn’t work because the thickness of coatings is limited due to its softness, and it tends to deplete quickly.
“Cu-rich precipitates are homogeneously distributed in the entire bulk sample for the anti-pathogen stainless steel, not only on their surfaces. Therefore, there will always be Cu-rich precipitates exposed on the surfaces of the anti-pathogen SS, even if the samples are continuously damaged during service, leading to a long-term anti-microbial property.”
The only issue remains the resistance to corrosion, which prohibits using more copper in the alloy, something that would make it even more potent against pathogens. In the small concentrations explored, however, the demise of the corrosion performance remains well within acceptable levels.
Interestingly, the researchers tested silver and other metals with known antibacterial properties but found that they don’t possess copper’s antiviral strength. The exact mechanism that helps copper deactivate viruses remains debatable, but it could be thanks to the formation of reactive oxygen species by free copper ions suppressing viral proliferation.