Coating Deactivates Covid-19 Viruses on Surfaces

William Ducker (Ryan Young, Virginia Tech)

16 July 2020. A chemical engineering lab developed a coating that when applied to surfaces quickly inactivates viruses responsible for Covid-19 infections. A team from Virginia Tech in Blacksburg and University of Hong Kong describe the coating in an article appearing 13 July in the journal ACS Applied Materials & Interfaces (paid subscription required).

Seven months into the pandemic, most evidence indicates the SARS-CoV-2 virus responsible for Covid-19 infections is transmitted person-to-person through the air, in droplets or as aerosol clouds. Yet the viruses can still accumulate on surfaces, requiring public establishments, such as businesses and schools, to frequently clean areas where members of the public can be exposed. Also, frequent hand washing is recommended as a technique to reduce the chance of infection from contact with surfaces where SARS-CoV-2 viruses may accumulate.

Virginia Tech chemical engineering professor William Ducker studies interactions between pathogens and solid surfaces, particularly materials that prevent the build-up of biofilms, stubborn bacterial communities that can form on medical devices and present a serious public health problem. In dealing with biofilms, Ducker’s lab designs materials that stop individual bacterium cells from attaching and accumulating on surfaces to prevent these communities from forming.

Beginning in March, Ducker and colleagues took the same approach for dealing with SARS-CoV-2 viruses. The researchers — including doctoral students Saeed Behzadinasab and Mohsen Hosseini from Ducker’s lab, and chemistry research manager Xu Feng — designed a material made with cuprous oxide, a copper-based material. Cuprous oxide is highly reactive and unstable, which damages cell structures including bacteria and viruses. While cuprous oxide is toxic to pathogens, their small molecule size prevents them from harming humans and animals.

The team still needed a way to easily apply cuprous oxide to surfaces. Their solution is polyurethane, a common, familiar polymer film applied as a liquid and used in furniture coatings. As polyurethane dries, its resins bind tightly together, making a tough finish that resists water, solvents, and abrasions. Initial tests at Virginia Tech show the coating could be readily applied to glass and stainless steel surfaces.

To test their cuprous oxide/polyurethane coating with SARS-CoV-2, the researchers enlisted the help of public health virologist Leo Poon at University of Hong Kong who studies coronaviruses. The tests in Hong Kong show in as little as one hour, cuprous oxide/polyurethane deactivates virtually all, 99.9 percent, of SARS-CoV-2 viruses that land on surfaces with the coating. “One hour is the shortest period that we have tested so far,” says Ducker in a Virginia Tech statement, “and tests at shorter periods are ongoing.”

Further tests display the coating’s toughness and resilience. Results show the coating remains intact, even when roughed up with a razor blade, and continues to deactivate SARS-CoV-2 viruses after being immersed in water for 13 days. The coating also inactivates multiple waves of coronaviruses, and continues to work even after washing with disinfectants.

The university says Ducker is seeking funds to scale up the coating for mass production. Even when the coating is used on a mass scale, hand-washing will still be encouraged, but as Ducker notes, “people won’t have to worry as much about touching objects. It will be both practical and fear reducing.”

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