Several Properties of Ultrafine Ferrite Particles with Bacterial Removing Effect

摘要

A bacterial removing effect of ultrafine ferrite particles prepared by chemical coprecipitation has been investigated. The ten kinds of ferrite nanoparticles were tested, and CdFe_2O_4, CuFe_2O_4, ZnFe_2O_4, Ca_(0.5)Zn_(0.5)Fe_2O_4 and Ni_(0.5)Zn_(0.5)Fe_2O_4 showed the effects to reduce bacterial titers of L. pneumophila, S. aureus, P. aeruginosa, B. subtilis and E. coli. in the liquid culture. The crystal structure of ZnFe_2O_4, Ca_(0.5)Zn_(0.5)Fe_2O_4 and Ni_(0.5)Zn_(0.5)Fe_2O_4 analized by XRD method was the spinet structure, while CdFe_2O_4 and CuFe_2O_4 are composed of the spinet structure and small amounts of byproduct's. These ferrite particles shared common physical properties, ie, average size of ferrite particles with bacterial removing effect's was uniformly less than 15 nm, specific surface area was more than 140 m~2/g, saturation magnetization was less than 0.35 T and coercivity was less than 6.4 kA/m.