Research On The Preparation And Properties Of Silver Peroxide Ultrafine

Since they can lead to the infection of virus, controlling the growth and propagation of harmful bacteria is of great practical significance for protecing people's lives and safety. More recently, inorganic antibacterial agents have gradually become the hotspot of antibacterial research, because of they possessing such merits as safety, stability and no secondary pollution, and silver bactericides are the typical representative. At present, study on silver bactericides has mainly focused on nano-silver and monovalence silver compounds, while the bactericidal research on high valence silver compounds is only at starting stage. Aiming at high valence silver compounds having characteristics of quick bactericidal speed, high oxidation activity and ability of decomposing organic matters, this paper has investigated the preparation technology of high valence silver oxide by chemical precipitation, using silver nitrate, potassium persulfate, ozone and alkali as reaction materials. The products were characterized by XRD, XPS, TEM, SEM and laser particle sizer; The stability of prepared AgO was studied by differential thermal analysis method, thermogravimetry and thermostatic heating method; And the antimicrobial activity and effective using conditions were researched by shake-flask method.The results show that the oxidation of silver nitrate by potassium persulfate and ozone has optimum temperature, which is 60℃and 45℃respectively. The optimum preparation process parameters for potassium persulfate oxidating silver nitrate are n(K2S2O8):n(AgNO3) 3, n(KOH):n(AgNO3) 7.5 and reaction time 20min; the AgO content of prepared powder was 91.02%. The optimum preparation process parameters for ozone oxidating silver nitrate are n(NaOH) 0.28 mol and reaction time 7.4h. The AgO content of prepared powder could be about 100%. The prepared AgO has a lamelliform or cosh like shape, the relatively narrow surface width of most powders is about 200nm and the particle size is between 100-300nm. The AgO powders prepared by potassium persulfate and ozone oxidants both belong to simple monoclinic crystal system. AgO is unstable at high temperature and can be long preserved under 70℃without decomposition. The decomposition of AgO carries out in two steps, firstly decomposing to Ag2O, then to Ag. The AgO prepared by different oxidants both possessed extremely strong antimicrobial activity. The antibacterial rate for 1ppm AgO against Staphlococcus aureus and Escherichia coil both exceeded 99.9%in 30min. For the same antibacterial effect, the higher concentration the AgO has, the shorter time antibacterial action needs; And in turn the lower concentration, the longer time. The antibacterial effect of AgO is better than Ag2O. For the same concentration, the antibacterial rate of AgO was 7 times of Ag2O.