Stainless Steel Surface Antibacterial Films

The stainless steel is one of the most useful metal materials in human life, and to be endowed with antibacterial performance is the new hot research in antibacterial materials. This thesis is researching the surface antibacterial application in stainless steel. Preparing two antibacterial films that have different properties in the surface of stainless steel, silver doped TiO2 or SiO2 films and silver doped SCA (Silane Coupling Agents) film.For enhancing the soakage capability and the combine intension between inorganic films and stainless steel plate, and improving the reactivity of stainless steel, to enhance the combine intension between SCA film and stainless steel plate, the stainless steel plates are oxidized. The experiment prepared two oxidized stainless steels in different oxidation degree, AA and AB, respectively used as experiment plates in silver doped TiO2 or SiO2 antibacterial stainless steel and silver doped SCA antibacterial stainless steel. At the same time, use non-oxidized stainless steel as experiment plates to prepare antibacterial stainless steel.The silver doped TiO2 or SiO2 sols are prepared through Sol-Gel method, Ti(OC4H9)4 and Si(OC2Hs)4 are chosen as precursors respectively, and HNOs is catalyzer, AgNO3 is the second component for inducting silver ion. The inorganic film is formed on stainless steel plate through dipping-draught method, and under the dropping rate 10cm/min. The temperature of heat treatment is 550 C. Finally, silver doped TiO2 or SiO2 antibacterial stainless steel is prepared.The silver doped SCA hydrolyzed solution is prepared through hydrolysis method, Vinyltrimethylsilane(VTMS) is chosen as precursor, and ethanol is impregnant, and acetic acid is catalyzer, AgNO3 is the second component for inducting silver ion. The SCA film is formed on stainless steel plate through dipping-draught method, and drying in 80 C in an hour. After these processes, silver doped SCA antibacterial stainless steel is prepared.The samples are investigated with SEM(Scanning Electron MicroscopeXRD(X-ray Diffraction), XPS(X-ray Photoelectron Spectroscopy), contact angle test, erosion test, mechanism performance test and antibacterial test, and the relation between structure and property is discussed.According to the data of XPS, XRD and SEM, discovered the TiO2 film exist as titania in a great measure, and have a little rutile after 550癈 heat treatment. Pure TiO2 film exist a mass of ferric oxide. In silver doped TiO2 film, the TiO2 react with ferric oxide, and fabricate FeTiO3 as the exist of silver. With the silver content increased, the content of FeTiO3 also increased. After 550癈 heat treatment, the SiO2 film still keep amorphism. Silver exist as Ag+, Ag2+ or Ag in TiO2 film, and mostly in Ag+. In SCA film, silver exist as form of Ag+ in one compound.According to the experiment of antibacterial test using escherichia coli, the antibacterial mode of silver is by contact, and two or three percent silver doped film can get good antibacterial property. The SCA film can release Ag+ slowly. TiO2 film is antibacterial through photocatalysis. The silver doped TiO2 film baffle the separate of electron and cavity, change the energy gap's framework of TiO2, and improve its activity performance of photocatalysis.