Study On The Preparation And Antibacterial Property Of Ag-TiO₂Nano Composite

With the continuous development of social economy and the improvement of lifelevel, there is an increasing concern about health problem. Recently, pharmaceuticalcompanies and researchers are searching for a new antibacterial agents because of thedevelopment of antibiotic resistance, and nanotechnology is expected to open a newavenues to fight and prevent disease using atomic scale tailoring of materialsWe introduced the research and development progress of antibacterial agent bothat home and abroad, from the development,preparation,application of nano-silverantibacterial materials, nano TiO2and doped TiO2antibacterial materials.we alsodiscussed the antibacterial properties and antibacterial mechanism of nano-silvercolloids and Ag-TiO2antibacterial materials.Firstly, we use tannic acid as a protective agent, NaBH4as a reducing agent toprepare a stable nano silver sol, SEM and DLS analysis shows that the nano-silvercolloids prepared whit this method are spherical, and the diameter of the nano silversare about50nm, then, we studied the effects of volume of NaBH4and concentrationof tannic acid on the prepare of nano silver sol, we also studied the antibacterialproperties of the nano silver sol, the experiments showed antibacterial propertiesgood, E.coli and S.au are the minimum inhibitory concentration5.31ppm.Secondly, we use TBOT as raw materials to prepare anatase TiO2at70℃,andwe obtained a good crystal properties anatase TiO2in this method, which effectivelyavoiding the deletion of TiO2surface groups and the reunion serious drawback afterburning. It is can be found by XRD that the sample containing anatase TiO2, and havea relatively high degree of crystallinity, the TEM revealed that the anatase TiO2areellipsoidal, about tens of nanometers, and then, we studied the relationship betweenaging time of the sample and the crystallinity of the TiO2, and found that with theincreasing of aging time, the crystal showes an increasing trend.Finally, we combine the nano silver and anatase TiO2colloidal, to make theAg-TiO2nanocomposites, through XRD and TEM characterization, we believe thatthe purpose of getting Ag-TiO2nanocomposite antibacterial materials is reaching.Then we testes the antibacterial properties of Ag-TiO2in darkness and light use MIC method, the results shows that Ag-TiO2in light have a higher antibacterial propertiesthan in darkness, and the MIC values of Ag and TiO2was0.025ppm and20ppmrespectively, which is much less than the concentration of the antibacterial inHG/T3794-2005, so we think they have high antibacterial activity.