Corona virus can infect surfaces for DAYS by transforming it into a microscopic pancake-like film, study results
- More than 99.9% of the liquid in corona virus droplets evaporates in minutes
- But the virus survives because the dry drop turns into a cake-like film
- It can stick to a surface for hours and become contagious
- Scientists recommend cleaning surfaces regularly to make sure the cov is not inhabited
Particles containing the corona virus that land on a surface are contagious for several days, evaporating the water in the droplet into a microscopic, pancake-like film.
This change causes more than 99.9 percent of the droplet fluid to disappear within minutes, but the virus survives on the protective film of the remaining fluid.
Small forces slow down the evaporation process by sticking a nanometer-thick film on a surface.
The film evaporates completely at different times depending on the material on which it lands, with a large drop on steel and copper lasting 24 and 16 hours, respectively.
But it can survive for more than 150 hours in polypropylene. A small drop, one tenth, on the glass will last more than 80 hours.
These figures are based on experiments conducted under laboratory conditions, and in the real world varying degrees of heat and air flow are low – factors that increase evaporation.
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The image (bottom) covers areas of the same size as the drop (top), with the same radius and vertical starting angle. The only measure of the dynamic is its vertical height
Rajneesh Bhardwaj and Amit Agarwal, professors at IIT Bombay, specialize in the use of computer modeling and physics to understand how corona virus droplets spread disease.
They have previously found that wearing a mask reduces the amount of clouds of corona virus particles produced by cough up to 23 times.
Particles containing the corona virus from sneezing and coughing are contagious for hours because the water in the droplet evaporates and turns from a sphere into a cake-like microscopic film (stock).
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Phone screens, cotton and wood are materials that can provide a safe haven for viruses and scientists are urging that they be thoroughly cleaned.
Scientists say these materials are more dangerous because droplets infected with the corona virus do not evaporate quickly from these surfaces.
Both glass and steel are hydrophilic, meaning they absorb water. Thus spreading water to the surface and promoting evaporation.
In film form, the corona virus can withstand many hours and even days, if left unchecked on hydrophobic surfaces.
The image covers the same size areas of the droplet, with the same aperture and vertical starting angle. The only measure of conversion is its vertical height.
Data from the study, published in Physics of fluids, The thickness of the film slowly decreases, and throughout this time the amount of corona virus in the droplet / film remains constant.
“Our biggest surprise is that the drying time of this nanometric film is in the order of hours,” Bhardwaj said.
‘This suggests that the surface is not completely dry, and that the slowly evaporating nanometric film provides the medium necessary for the survival of the corona virus.’
The researchers’ findings indicate that the virus could survive in a viable form for a long time and stressed the need for regular and thorough cleaning of surfaces.
“It is desirable to disinfect frequently touched surfaces such as door handles or hand-held devices, and within hospitals and other areas where explosions can occur,” Agarwal said.
‘We also recommend heating surfaces because even short-term high temperatures can cause the nanometric film to evaporate and destroy the virus as the surface is at a higher temperature than the ambient.’