NOV 24, 2020 9:19 AM PST

How long does COVID-19 stay on surfaces?

New research published today in Physics of Fluids explores the drying times of COVID-19 on different think liquid film surfaces. In the study, authors Rajneesh Bhardwaj and Amit Agrawal, explain London-van der Waals forces interact to allow the virus to cling to surfaces and allow for hours, instead of seconds.

"To describe this thin film, we used tools that are otherwise seldom used by researchers within the engineering realm," said Bhardwaj. "Specifically, we developed a computational model for the evaporating mass rate of the film as a function of disjoining and Laplace pressures inside the film, using the Hertz-Knudsen law, a well-established kinetic theory of gases."

COVID-19 has been shown to be unlike typical respiratory droplets, which persist on surfaces for an average of seconds. "Our model for the thin film transport shows that survival or drying time of a thin liquid film on a surface is on the order of hours and days, similar to what has been observed in measurements of the virus titer [the lowest concentration of virus that still infects cells]," added Agrawal. "It captures the relatively longer survival time on plastic and glass compared to metals."

Improving our scientific comprehension of the virus’s ability to persist on different surfaces under ambient conditions can provide crucial information for developing policies that protect public health and safety.

"Our biggest surprise was that the drying time of this nanometric film is on the order of hours," said Bhardwaj. "It suggests the surface isn't completely dry, and the slowly evaporating nanometric film is providing the medium required for the survival of the coronavirus."

Photo: Pexels

As one might expect, this points again toward the need to be constantly disinfecting surfaces that are frequently touched, such as phones, keys, doorknobs, and light switches.

"We also recommend heating surfaces, because even short duration high temperatures, at which the surface is at a higher temperature than the ambient, can help evaporate the nanometric film and destroy the virus," advise the authors.

Sources: Physics of Fluids, Eureka Alert

About the Author
  • Kathryn is a curious world-traveller interested in the intersection between nature, culture, history, and people. She has worked for environmental education non-profits and is a Spanish/English interpreter.
You May Also Like
DEC 15, 2020
Chemistry & Physics
Over-the-air Charging - How Close Are We to Realize Tesla's Vision?
DEC 15, 2020
Over-the-air Charging - How Close Are We to Realize Tesla's Vision?
When inventor and visionary Nikola Tesla erected his Wardenclyffe Tower, a 186-feet tall and 68-feet wide monstrous towe ...
DEC 31, 2020
Chemistry & Physics
Improving the efficiency of desalination membranes
DEC 31, 2020
Improving the efficiency of desalination membranes
Researchers from The University of Texas at Austin and Penn State have taken a step toward developing a cost-effective d ...
FEB 09, 2021
Plants & Animals
Venus Flytraps Generate Magnetic Fields
FEB 09, 2021
Venus Flytraps Generate Magnetic Fields
The Venus flytrap (Dionaea muscipula) might be the most famous carnivorous plant; it can entice prey to land on its leaf ...
FEB 18, 2021
Chemistry & Physics
New insight on metal organic frameworks
FEB 18, 2021
New insight on metal organic frameworks
Researchers from KAUST have developed a metal organic framework (MOF) mimicking a class of inorganic porous materials ca ...
MAR 08, 2021
Chemistry & Physics
Newly observed quasar jet sheds light on early galaxy formation
MAR 08, 2021
Newly observed quasar jet sheds light on early galaxy formation
New observations from the National Science Foundation's Karl G. Jansky Very Large Array (VLA) and Very Long Baseline ...
MAR 11, 2021
Chemistry & Physics
More effective way of recycling carbon fibers
MAR 11, 2021
More effective way of recycling carbon fibers
A team from the University of Sydney's School of Civil Engineering has designed a method to improve the recycling of ...
Loading Comments...