For a long time we have used the copper for its bactericidal and virucidal properties. In fact, this metal is capable of destroying bacteria and viruses on contact, so it is mainly used to cover objects that are touched often such as door handles. Scientists have used this idea to create a spray solution which makes it possible to cover existing surfaces with copper nanowiresthus making them antimicrobials and antivirals.
This technology is currently being developed as part of a partnership between several entities. These entities are the Ames National Laboratory of the United States Department of Energy, the University of Iowa, as well as the University of Buffalo.
According to the information, this new study is based on the results of previous research carried out by the Ames. This research concerned the creation of a copper ink to print circuits on flexible electronic devices.
The use of the spray
The scientists behind this new study have developed two types of spray. The first contains segments of nano-wires made of pure copper and having a 60 nanometer diameter. The second type contains copper and zinc nano-wires with the same diameter. These two types each have their advantages and disadvantages.
In both cases, the nanowires are in a carrier solution like water or ethanol. When the liquid is sprayed on a surface made of plastic, glass, or stainless steel, it forms a thin antimicrobial film after drying.
Scientists have tested the solutions with the virus SARS-CoV-2 which is the virus causing the Covid-19. Laboratory tests showed that copper disks coated with the solutions were as effective as an uncoated copper disk. However, thanks to the greater surface area provided by the nanowires, the overlay was able to eliminate the virus in 20 minutes while the uncovered disc was able to do so in 40.
The researchers also observed differences between the two types of solution. In the first 10 minutes, the solution with pure copper nanowires was able to neutralize the virus twice as fast as the solution with copper and zinc nanowires. However, the latter solution remained active for a longer duration. This means it will need to be applied less frequently.
So, according to scientists, the solution with copper and zinc nanowires is better suited for real-world use.