Researchers at the Leibniz Institute for New Materials (INM), based in Saarbrücken, Germany have produced antimicrobial abrasion-resistant coatings containing silver and copper colloids that kill germs reliably, prevent them from becoming established, and are long-lasting.
The coatings are suitable for application on large and solid surfaces, on door handles and for textiles in hospitals, kitchens and sanitary facilities, air conditioning and ventilation systems, in food preparation and in the manufacture of packaging materials.
Carsten Becker-Willinger, Head of the Nanomers Program Division at INM, said: 'The new development combines two properties which means the presence of germs and fungi on these surfaces is zero.'
Silver or copper colloids, which gradually release germicidal metal ions into the environment are incorporated in the coating. These are only a few nanometres in size, but their particular ratio of size to surface area produces a distinctive long-term effect, he added.
'The “consumption” of metals to metal ions is then so low that the coating can be effective for several years.'
The long-term effect is increased by high abrasion resistance. The surface of the coating is also anti-adhesive, which means that neither dead nor fresh germs can adhere to the surface. As a result, the coating primarily counteracts the formation of an extensive biofilm.
The researchers were able to prove the double microbicidal and biofilm-inhibiting action using the standardised ASTM E2 180 test process.
The new material can be applied to a variety of substrates such as plastic, ceramic or metal using conventional techniques such as spraying or dipping, and cures thermally or photochemically. Selective variation of the individual components allows the developers to react to the particular and different needs of potential users.
The researchers will present this and further results at the International Nanotechnology Exhibition and Conference, nano tech 2015, in Tokyo, Japan, from 28–30 January.
