which is rapidly
exchanged for other cations present in the contact medium
and released. A high bactericidal efficiency of these materials
has been demonstrated, even at low silver loadings [14]. The
second group includes products containing metallic silver,
which is progressively oxidized and dissolved, releasing
ionic silver after being in contact with the medium.
As a nanoparticulated material, metallic silver shows a
high surface area to volume ratio that accelerates the
oxidation kinetics, increasing the release of silver ions and
enhancing bactericidal action compared to the same bulk
material. Hence, nanoparticulate silver has been applied
as a bactericidal agent for more than 100 years [15] and
currently is being used in a variety of products, including
textiles, cosmetics, utensils, wound dressings, ointments, food
preservation devices and air purifiers [16].