70% alcohol is one of the main products used in disinfection, as well as a lesser known class of substances, quaternary ammonium, which is common in household disinfectants. In the Covid-19 pandemic, 70% alcohol and disinfectants with quaternary ammonium, along with other disinfection methods, are among the most important recommendations for cleaning surfaces.
A project developed by researchers at the Federal University of Grande Dourados (UFGD) combined the two materials in order to achieve a more lasting effect on the hygiene and disinfection of hands, surfaces and masks.
The UFGD has already received alcohol donations from plants in the region to prepare 70% alcohol for hospitals, health posts and other facilities in Mato Grosso do Sul. As part of the institutional efforts to combat the pandemic, a group coordinated researcher Eduardo José Arruda proposed an additional solution to improve the use of this alcohol and extend the disinfection effects.
“Alcohol works as long as it is liquid, but it evaporates quickly with the heat of the surfaces and loses its biological activity. We wanted a simple solution based on the materials available on the market to extend the disinfection effect, ”says Arruda. The work had a partnership with the Functional Materials Development Center (CDMF) at the Federal University of São Carlos (UFSCar).
Quaternary ammonium cells have a known effect on microorganisms such as bacteria, fungi and viruses and cause, among other things, the rupture of the cell membrane or the protective layers of viruses for these organisms. Its molecules can organize themselves in various forms, such as: B. micelles, for example in household detergents. In combination with 70% alcohol from the UFGD group, they form a bioactive film that remains on the skin of our hands and other surfaces after the alcohol has evaporated.
An added benefit is the ability to transfer the film between surfaces, such as from the hand, to support poles in public transport vehicles.
The challenge of the research group was to find the most suitable concentration of additives that is safe for human health and effective against microorganisms. After an initial formulation for cleaning hands and surfaces, researchers identified other possible uses in disinfecting cloth masks and other materials. This disinfection can be done by immersing the masks in the product, with rapid drying due to the evaporation of 70% alcohol. For this purpose, humectants and other cosmetic substances were added to protect the skin from prolonged contact with the material.
The group continues to carry out complementary tests to analyze the effectiveness not only against Sars-CoV-2, but also against other microorganisms.