Researcher develops coating to inactivate Covid-19 virus

Ryan Young for Virginia Tech

A PROFESSOR at Virginia Polytechnic Institute and State University (Virginia Tech), US has developed a surface coating which inactivates the coronavirus that causes Covid-19.

SARS-CoV-2, the virus responsible for Covid-19 infection, remains viable on some solids for periods of up to one week, and a potential route for transmission is via exposure to an infectious dose from a solid surface. The ongoing coronavirus has therefore led to fears about touching common surfaces, such as doorknobs, light switches, and shopping carts.

Chemical engineering professor William Ducker began working on a surface coating which inactivates coronavirus in mid-March, and has now developed a copper oxide/polyurethane (Cu₂O/PU) coating which reduces viral titre by 99.9% in one hour, when applied to glass or stainless steel. Viral titre is a numerical expression of the quantity of virus in a given volume of fluid. Ducker believes he and his team could improve the current coating to work within minutes. 

It works by changing the structure of the virus. Once the virus makes contact with the coating it denatures the virus surface and collapses the viral envelope, and the virus is then no longer viable for further infection.

The coating consists of Cu₂O particles bound to PU. The advantage of a polyurethane coating is that PU is already used to coat a large number of everyday objects. In addition to glass and stainless steel, the coating adheres well to everyday objects such as doorknobs, pens, and keypad buttons.

The coating remained intact and active after 13 days immersed in water, and also retained its potency after five exposures to the virus followed by disinfection.

The coating is robust, and it performed well in a crosshatch durability test. Crosshatch tests are used to determine the resistance of coated materials to separation. The coating is cut to the surface in a lattice pattern, and then tape is used to try to remove the squares. In tests, an average of 2.4 out of 100 squares of the Cu₂O/PU coating were removed. Additionally, when tape was used to remove the top layer of particles from an unscratched sample there was a 0.25% loss of coverage and only a few particles were removed.

According to Ducker, the coating provides a medical benefit, but also offers the opportunity to address fears about touching objects. Ducker has a background in developing coating to work against bacteria to prevent other diseases and when he began this work he sought to do the same for Covid-19. “We have to use our chemical knowledge and experience of other viruses to guess what would kill it [SARS-CoV-2],” said Ducker.

He now hopes to attract funding to mass produce the coating.

ACS Applied Materials & Interfaces: http://doi.org/gg4z7j