Bactericide glasses developed by Na+/Ag+ ionic exchange

The action of bacteria and fungi in residential, industrial and hospital environments offers high risk to human health. In this context, the development and use of antimicrobial materials has been an efficient method of handling risk situations. This work presents preliminary results of powdered glass showing bactericide effect obtained by ionic exchange between sodium ions, present in the glass composition, and silver ions, present in the ionic exchange medium. Powdered glass was submitted to ionic exchange in an ionic medium containing different concentrations of silver species. The bactericide effect was dependent on AgNO3 concentration in the ionic medium. The Agar Diffusion Test on Escherichia coli bacteria, EDS and ICP-MS analyses were applied to the samples; the results showed that a critical concentration of silver ions incorporated into the powdered glass occurred and a limit to the bactericide effect. Tests and analyses revealed that 6 wt.% of AgNO3 in the ionic medium was the critical concentration.