Study on antibacterial properties of copper-containing antibacterial stainless steels

The antibacterial properties and relevant mechanism of copper-containing ferritic and austenitic antibacterial stainless steels have been studied. Experimental results displayed that the copper-containing antibacterial stainless steels have the broad-spectrum antibacterial features, and the antibacterial rate against most of the Gram-negative bacteria and Gram-positive bacteria selected in the present work reached above 99.0%. Through studies on the different action times of E.coli in contact with ferritic antibacterial stainless steel, it was proved that the antibacterial rate of an antibacterial stainless steel should be related to the action time, and the antibacterial rate reached 99.9% only when the steel contacted with the bacteria for about 150 min. The AFM observation indicated that the antibacterial mechanism of the antibacterial stainless steels should be attributed to more leaking out of the materials and shriveling of the cells in the bacteria. The electrochemical experiments showed that after contacting with E.coli, the precipitation of Cu ions on the surface of antibacterial stainless steels became faster, resulting in a decrease of the pitting potential of the steel.