Synthesis And Antibacterial Activities Of Inorganic Antimicrobial Nanomaterials

With population growth and industrialization,water pollution is becoming more and more serious,especially the increase of pathogenic microorganisms which greatly threaten the human health.Although conventional chemical disinfectants are effective for killing various bacteria,some disinfection byproducts and drug-resistance bacteria are emerging.Therefore,it is necessary to develop new antibacterial methods to solve these problems.The research contains three parts.First,carbonate ions released by gradual hydrolysis of urea under hydrothermal conditions.The reaction of carbonate with magnesium acetate produces porous MgCO₃.Finally,MgCO₃ was calcined at high temperature to obtain high purity mesoporous MgO NPs.From the result of antibacterial test,the material has strong antibacterial activity against both gram-positive and negative bacteria.MgO NPs at a concentration of 500 mg/L killed 99% of the bacteria within 24 hours.Next,ZnS quantum dots doped with different metal ions were prepared by microemulsion method.The antibacterial properties of ZnS quantum dots doped with different metals and different proportions were investigated by flask inactivation test in the light.It is determined that Cu doping can improve the antibacterial performance of ZnS quantum dots more effectively than other ions and the ZnS QDs with Cu doping of 3% has the hightest antibacterial activity.Cu doped ZnS quantum dots at a concentration of 62.5 mg/L can kill 99% of Escherichia coli within 2 hours under light.Finally,sol-gel reaction of TEOS was used to coat mesoporous Si O2 on to the surface of yeast cells with CTAB as porogen and Ag-Si O2/Fe3O4@C-Ag magnetic hollow microspheres were obtained through calcining,hydrothermal oxidation decomposition of ferrocene and Ag+ reduction reaction successively.The prepared material has excellent antibacterial activity due to the high surface area and large amount of Ag NPs on the inner and outer surface and 99% of the tested bacteria were killed within 4 hours with 200 mg/L of the disinfectant.The superparamagnetism of the material also facilitates the recovery.Figure 25;Table 7;Reference 98...