Activated carbon sphere with antibacterial characteristics : Special issue on smart materials-fundamentals and applications

The activated carbon sphere containing zinc oxide was prepared by carbonizing a zinc ion-exchange resin at different temperatures in nitrogen gas. Zinc oxide of hexagonal type was detected in all carbon samples, the amount of which decreased with an increase in the carbonization temperature. However, the specific surface areas of carbon samples increased with increasing temperature of the resin. The antibacterial activity on their carbon samples was studied without the presence of light. The antibacterial activity on carbon samples containing zinc oxide increased with the amount of zinc oxide in the carbon samples. The antibacterial activity for Staphylococcus aureus was stronger than that for Escherichia coli. By an oxygen electrode analysis, it is shown that hydrogen peroxide was generated on the carbon samples. The concentration of hydrogen peroxide increased with increasing carbonization temperature of the resin. The antibacterial activity is found to be caused by the generation of hydrogen peroxide from zinc oxide dispersed in activated carbon sphere.