Scientists at the Queensland Institute of Technology, Australia, conducted a series of experiments on aluminum alloy 6063 with aggressive sodium hydroxide (NaOH), better known as alkali. Their goal was to process the metal for three hours.
As a result, its smooth surface has changed at a microscopic level, a series of ridges have formed on it. At the same time, the surface became hydrophilic, that is, it attracts water.
When some viruses and bacteria hit such a surface (for example, Pseudomonas aeruginosa and Staphylococcus aureus), their outer membranes sagged between the microscopic ridges and ruptured, and the microorganisms themselves died.
Most of the bacteria died within three hours of exposure. At the same time, after two hours, the number of respiratory viruses on the metal surface has significantly decreased. These performances were much better than in a similar situation on plastic and smooth aluminum surfaces. Moreover, over time, the alkali-treated aluminum plates retained their bactericidal properties.
Scientists believe that such technology will be useful for the treatment of frequently used surfaces in public places - for example, on cruise ships and at airports.