New Coating Deactivates COVID-19 Virus on Surfaces

Jul 16, 2020

Scientists at Virginia Tech have found a way to deactivate the virus that causes COVID-19 on surfaces and objects.

They created a compund that can be easily painted onto things like doorknobs and desktops, bus seats, and more. The protection lasts for at least a year and likely longer according to the team. Their findings have just been published in the American Chemical Society Journal of Applied Materials and Interfaces.


William Ducker is a professor of Chemical Engineering at Virginia Tech. As he watched the coronavirus re-arrange life on this planet as we know it, he hatched an idea for creating some kind of substance that could knock out coronavirus on surfaces.

“Everybody is worried about touching communal items nowadays, like door knobs and things that you come across, then you look at it and you wonder whether when you touch it, you're going to get sick by getting coronavirus. So, we wanted to invent a coating for things like door knobs and credit card readers at the checkout and the coating itself would kill coronavirus.”

With virtually no budget to speak of, Ducker and his team had to buy materials off the shelf.  They began creating samples in his makeshift lab – most labs were closed at Tech when they began their work.

At first it wasn’t easy to find a lab capable of testing the samples, no one was returning his calls with a yes, until he found University of Hong Kong School of Public Health’s Leo Poon and Alex Chin, to do the testing.

“We send them across and they send us back the results. So that's always pretty exciting for me because they're exactly 12 hours apart from us in time. And I always get the results first thing in the morning.”

That’s when the project started to pick up speed. They quickly found a magic mixture that would kill 99.9% of the virus on surfaces. The one that worked is cuprous oxide, a form of copper, mixed with everyday household polyurethane.

“Cuprous oxide is cheap. It's a mineral that they dig out of the earth. And I thought that would be better and cheaper and easier to make a film [to coat an object] because instead of making a whole object, it's really only necessary to make the coating.”

 You just paint it on. It takes two coats actually, to obliterate the virus on the painted surface.  And when we say ‘you paint,’ we do mean you.

“It's not complicated. Any individual could do it.”

The paint is made from cuprous oxide particles, a form of copper, mixed with one of the most well-studied polymers on the planet, polyurethane. 

After the team confirmed that combination works, they tested it against coronavirus using polyurethane alone.

“After we showed the film works, we did a controlled experiment and we coated surfaces with polyurethane only. And then we tested that with coronavirus, and we found that polyurethane [by itself] does absolutely nothing. So please don't rush out and put polyurethane on items and expect that to inactivate coronavirus. According to our studies, it does not work.”

Ducker would also like to see industry try the new paint he calls “Safety Coat.” Think: public transit, air travel, day care centers, offices and classrooms. 

“The coating that we came up with,” he explains, “you can just take [something] like a wooden doorknob or a metal doorknob, then you can coat [or paint] it over the surface of it. It inactivates 99.9% of the coronavirus in just one hour."

And testing is underway to see if they can bring that down to just a few minutes.

“We'd like to get it down to the period between users, or the checkouts facility, or people who touched the same door knob a couple of minutes apart.”

“My main thing is to get it out there, so it's useful. We’ve published it in the open literature so that people can see what we've done."

But how it works?

 “It might be surprising, but I don't really know exactly how it works. I've got a few theories. I'm a scientist.  Another thing I wanted to do is just make it work faster."

Early testing showed the virus busted after one hour.  But that’s the shortest test they did, initially. 

Ducker says, “An hour is not good enough. I want it to work in minutes." Professor Poon is testing it now in a shorter time period. “And I want to redesign the film, so it works really, really quickly. And there might be other materials that work better. So, where we have a very active program at the moment, trying to beat our own threshold, cuprous oxide is the best in the world now. Can we do something that's better?"

Ducker is quick to caution that Safe Coat does not replace any of the well-known strategies for preventing the spread of COVID-19 droplets through the air. The masks and the handwashing are more imperative than ever, but he thinks Safety Coat could be part of the solution.

“This solution is about more than safety. It's also about removing the fear. People really are afraid of touching doorknobs and pens and things.”  He’d like his team to be part of removing that fear.

Ducker would like to get this new Safety Coat to prevent c0ronavirus, out to the public in a matter of weeks.  He’d like to hear from people who are interested in working with it.

 “So, if you have a need for a product that will inactivate coronavirus, when a droplet gets on it, then please contact me and I will do my best to get you a sample that you can test.”

The sample and will have a kind of dark orange color.  The small amount of copper in cuprous oxide is why. Ducker hopes that orange will signify a beacon of safety when you spot it in your travels.

Here's how to get in touch with William Ducker: wducker@vt.edu

**Editor's Note: RADIO IQ is a service of Virginia Tech.