Contained The Organic Modification Of The Silver Nano-titanium Dioxide And Antibacterial Plastic Paint

The performance of antibacterial plastic depends on the antibacterial agent. Ag supported antibacterial agent is the primary type of inorganic antibacterial agents which are used to manufacture antibacterial plastic. As the application of nanameter antibacterial agents in antibacterial plastic field, nanometer TiO₂ photocatalysis antibacterial agent gets considerable reseach. The main preparation method is master batch method in antibacterial plastic production, but the antibacterial agents do not have antibacterial activity which are enwrapped in the inner of plastic. In this study, silver doped nanometer TiO₂ was choosen as antibacterial agent, which was modified by stearic acid to get good dispersive property in plastic painting. The effects of antibacterial agent amount and film layers on antibacterial performance were investigated. The results are as follows:Organic surface modification of Ag doped TiO₂ with stearic acid is investigated. The effects of the reagent amount, concentration, the modification time, pH value and temperature were determined, the process conditions were optimized and the results were analysed by variance analysis. The prepared samples were characterized by FT-IR, SEM techniques, and the antibacterial property was determined. The results showed that the lipophilic degree reached up to 66.3% under optimum condition of stearic acid amount 1%, stearic acid concentration 0.0004 mol·L^-1, modification time 60 min, pH 6 and temperature 70℃and possessed improved hydrophobic property. The stearic acid was bonded on the surface of silver doped TiO₂ by chemical bond according to the FT-IR result. The dispersancy of silver-doped TiO₂ was improved after modification. Although antibacterial rate decreased slightly, it still achieved 99.77%. The powder after modification showed good dispersion in organic solvent without addition of dispersant, and the dispersive mechanism of antibacterial powder was steric hindrance theory.The surface of plastic was pretreated with chemical method and characterized by SEM. The effects of antibacterial agent amount and film layers on antibacterial properties and photocatalytic degradation rates of methyl orange of thin film on plastic were investigated in order to optimize the process conditions. The surface morphology of antibacterial film on plastic was characterized by SEM. The results showed that KMnO₄/concentrated HCl solution had better effect on treatment of plastic surface, the optimal treatment time is 60min, and temperature is 70℃, micro rough structure appeared on the plastic surface after treatment. The antibacterial powder distributed uniformly on plastic surface, but agglomeration phenomena could be observed. The optimal antibacterial amount was 2%, and the optimal film layer was 1 layer. The antibacterial plastic had antibacterial persistence, adhesion strength, and good water-resistance and chemical resistance.