The new transparent material can effectively capture the respiratory droplets from the air

While plexiglass barriers are seemingly everywhere these days – between grocery store aisles, around restaurant tables, and above office cubicles – they are a flawed solution to blocking the transmission of the virus.

Instead of capturing respiratory droplets and virus-laden aerosols, plexiglass separators only deflect the droplets, causing them to bounce but stay in the air. To improve the function of these protective barriers, researchers at Northwestern University have developed a new transparent material that can capture droplets and aerosols, effectively removing them from the air.

The material is a clear, viscous liquid that can be painted onto any surface, including plastic, glass, wood, metal, stainless steel, concrete, and textiles. When the droplets collide with the coated surface, they stick to it, are absorbed and dry. The coating is also compatible with antiviral and antimicrobial materials, so disinfecting agents, such as copper, could be added to the formula.

Droplets collide with interior surfaces all the time. At present, plexiglass dividers are deviant devices; they deflect the droplets. If a surface could effectively trap droplets, then each droplet effectively removed from indoor air would be a successful removal of a potential source of transmission. “

Jiaxing Huang, lead author of the study, Northwestern University

The research will be published Wednesday (June 16) in the journal Chemistry. In the study, the researchers found that even when bombarded surfaces with aerosol droplets – at concentrations several orders of magnitude higher than typical of an indoor environment – the coated surfaces still captured three times more aerosol droplets than uncoated surfaces.

Huang is a professor of materials science and engineering at the McCormick School of Engineering at Northwestern. Zhilong Yu, Murak Kadir and Yihan Liu – all members of Huang’s lab – co-authored the article. The team embarked on this project during the stay-at-home order at the start of the pandemic.

The main ingredient in the Northwestern team material is a polyelectrolyte polymer which is commonly used in a wide variety of cosmetic products. When applied with a blade or brush, the resulting formula produces consistent, conformal coatings on a wide range of interior surfaces without damaging or discoloring the original material.

Huang’s team found that the surfaces also remained transparent and haze-free even when sprayed with droplets. In other words, the surfaces did not appear dirty or soiled after being sprayed with droplets. If used on plexiglass barriers, these coated barriers would not need to be cleaned more frequently than uncoated barriers.

Most infectious diseases are spread by respiratory droplets and aerosols, which humans constantly release when they talk, laugh, sing, and breathe out. Because the coating is so versatile, Huang imagines that it could be used on plexiglass barriers and face shields as well as non-contact or low-contact surfaces, such as walls or even curtains, to remove these droplets. air.

“There are massive areas of interior surfaces that are barely touched by people or pets. If we reused these surfaces ‘in slow motion’ to capture respiratory droplets, then they could become functional ‘devices’ to help. reduce airborne transmission of infectious diseases “. he said. “Pathogens trapped on the surface can then be easily inactivated over time, which can be accelerated by pre-applied disinfecting ingredients. They can also be removed during routine cleaning.”

While Huang says face masks are an irreplaceable public health tool to help prevent the spread of infectious droplets, he believes that trapping droplets on surfaces could be another effective tool.

“In a video game, for example, you don’t want to enter a battlefield with just one piece of armor,” he said. “It makes sense to take advantage of multiple layers of defense. “