Coronovirus microscopes can remain contagious on surfaces for DAES by turning into a pancake-like film, the study found
- More than 99.9% of the liquid in coronavirus droplets evaporates within minutes
- But the virus survives because the drying drop turns into a pancake-like film
- It sticks to the surface for hours and can remain contagious upon touching.
- Scientists recommend regularly cleaning surfaces to ensure that the Kovid does not reside.
Coronovirus particles that land on a surface remain in a microscopic, pancake-like film for several days, when the droplet evaporates into the water.
This conversion disappears in place of more than 99.9 percent of the droplet liquid, but the virus survives in a protective film of the remaining fluid.
Small forces keep the film, which is only nanometers thick, stick to a surface and slow down the evaporation process.
The film evaporates completely at different times, depending on the material on which it has landed with a large drop on stainless steel and copper for 24 and 16 hours, respectively.
But it can survive for more than 150 hours on polypropylene. A small droplet, just one-tenth the size, remains on the glass for more than 80 hours.
These data, based on experiments conducted in laboratory conditions, and are likely to be lower in the real world, are variable amounts of heat and airflow – factors that promote evaporation.
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The film (below) covers the same areas as the droplet (above) with the same radius and initial angle. The only measurement that changes is its vertical height
Rajneesh Bhardwaj and Amit Agarwal, IIT Bombay professors, are experts in using computer modeling and physics to understand how coronavirus disease can spread.
He has previously found by wearing a face mask that the size of a cloud of infectious coronovirus particles decreases by up to 23 times due to cough.
Sneezing and coughing coronovirus particles that remain contagious on the ground for several hours as water evaporates in a droplet and transforms from a sphere into a pancake-like, microscopic film (stock)
The phone screen must be cleaned regularly to prevent coronavirus
Smartphone users should make concerted efforts to clean their screens regularly to prevent COVID-19, warns the new study.
Also, phone screens, cotton and wood are materials that can provide a safe haven for viruses and should be cleaned thoroughly, scientists urge.
These materials are high-risk, scientists say, because coronovirus-containing infectious droplets do not rapidly evaporate from these surfaces.
Both glass and stainless steel are hydrophilic, meaning they attract water. This causes the water to circulate on the surface, which promotes evaporation.
In film form, coronovirus can remain for several hours, and even days, on hydrophobic surfaces, if left incomplete.
The film covers areas similar to drops, with the same radius and starting angle. The only measurement that changes is its vertical height.
Data from studies published in Physics of Fluids found that the film thickness gradually decreases and throughout this time, the amount of coronavirus in the droplets / film is constant.
Bhardwaj said, “Our biggest surprise was that the drying time of this nanometric film is on the order of hours.”
‘This suggests that the surface is not completely dry, and the nanometric film slowly evaporating is providing the necessary medium for the existence of coronoviruses.’
The researchers say that their findings indicate that the virus can survive in a viable form for a long time and emphasizes the need for regular and intensive cleaning of surfaces.
“It is desirable to disinfect door handles or hand held devices and surfaces that often spread to hospitals and other areas,” Aggarwal said.
‘We also recommend heating surfaces, because even high temperatures of short duration, at which the surface is at temperatures higher than ambient, can help evaporate the nanometer film and destroy the virus.’