INFLUENCE OF POWDER CHARACTERISTIC OF ZNO ON ANTIBACTERIAL ACTIVITY -EFFECT OF SPECIFIC SURFACE-AREA

The effects of shape, crystallinity and specific surface area of ZnO p owder on antibacterial activity were studied by measuring the change i n the electrical conductivity with bacterial growth. From the results, it was clarified that the antibacterial activity increased with the i ncrease of powder concentration in the physiological saline. The antib acterial activity against Escherichia coli strongly depended on the sp ecific surface area of the powder; the activity increased with the inc rease of the surface area, irrespective of the shape and the crystalli nity of their powders. In the case of Staphylococcus aureus, however, it was found that there was no difference in the activity according to the characteristic of the powders. The appearance of antibacterial ac tivity was found to be due to the generation of H2O2 from the surface of ZnO powder.