Preparation and Antibacterial Effect of Doped Tetra-Needle Like ZnO Whiskers

Tetra-needle like zinc oxide whiskers (T-ZnOw) were doped with Al3+, Fe3+ or Ag+. The morphological structures and the doped ions were characterized, and the results indicated that mostof the Aluminum existed in a second phase of ZnAl2O4, most of the Fe3+ solid-solutioned into the crystal lattice and the silver generated as nano-particles on the surface of the needles of the ZnO whiskers. Anti-bacterial experiments gave the result that Fe3+ doped T-ZnOw and the nano-silver adnascent ZnOw had obvious effect of killing and inhibiting the bacteria such as Staphylococcus Aureus (ATCC 6538), Escherichia Coli (ATCC 25922) and Candida Albicans (ATCC 10231). The minimum inhibitory concentrations (MIC) of the related doping T-ZnOw were 55~440 PPM. Further experiments indicated that there appeared high margin of safety and no stimulation on skins or eyes for the tested animals. Products such as plastics, coatings, fibbers and papers containing 2wt% of the doped T-ZnOw had more than 99% efficiency for anti the mentioned bacteria. Effect of degradation of organic compound for the doped T-ZnOw was also evaluated by degradation of formaldehyde. The mechanism was tentatively put forward to explain the phenomena and the effect of antibiosis.