Sudy On Applications Of ZNO/AG Nano-Composite Antibacterial In Medical Plastic And Ship Antifouling Paints

In this paper, ZnO/Ag nano-composite antibacterial was synthesized by the two-step precipitation method and afterwards its applications in medical plastic and ship antifouling paints were studied.The mechanical properties of the medical antibacterial PVC prepared by conventional methods didn't perform well, which limited its widespread use. ZnO/Ag was modified by three titanate coupling agents before added into PVC. Then the antibacterial PVC was prepared by the method of twin-roll mixing and changes of their mechanical properties and antimicrobial properties were discussed. The research contents are as follows:(1) Kinds of coupling agents were applied to modify ZnO/Ag nanocomposite antibacterial in order to change its surface polarity from hydrophilic to hydrophobic. By the method of activation index, the optimum mass fraction of coupling agent and the modification technology were determined.(2)Antibacterial PVC was made by two-roll mixing. In this procedure modified and unmodified ZnO/Ag were added respectively with different mass fractions. Afterwards the tensile strength and elongation at break of antibacterial PVC were measured according to GB/T1040-92《Plastic tensile test method》;the inhibition rates of antibacterial PVC on Staphylococcus aureus and Escherichia coli were tested.The results are as follows: All the three kinds of coupling agents could improve the hydrophobicity of antimicrobial agent. The activation index of modified ZnO/Ag exceeded 95% and the mechanical properties of antibacterial PVC were improved when the mass fraction of coupling agent was 5%.In the process of exploring the application of ZnO/Ag in antifouling paints, the antifouling properties of the functional resin were analyzed firstly in which ZnO/Ag played as the exclusive active ingredient. On this basis, the performances of antifouling paints with ZnO/Ag were studied. The research contents are as follows:(1)Kinds of surfactant were used to modify ZnO/Ag. And then the modification effect was characterized by the method of sedimentation rate and TEM in order to determine the optimum surfactant and its modification tecnology.(2)Acrylic containing ZnO/Ag was prepared according to an established formula. Afterwards its antibacterial and algal-suppression performance was tested in laboratory and its antifouling properties were investigated in Tangdao Bay of Qingdao. In the same way the corresponding properties of the antifouling paints prepared by another formula in which ZnO/Ag and Cu O were both used. Finally the mechanism was preliminarily studied.The results are as follows: With ZnO/Ag added in, the functional resin showed a good antibacterial and algal-suppression performance. When the mass fraction of ZnO/Ag was 7%, the inhibition rate of Staphylococcus aureus was 96.3% and E.coli 99.7%. The Platymonas subcordiformis and Skeletonema costatuma in the erlenmeyer flask could be considered restrained. ZnO/Ag was modified by 5wt% dispersant Dispers 655 prior to applying to antifouling paints. The sedimentation of the modified ZnO/Ag could still be maintained below 10% in xylene even after 7 days. The viscosities and proportions of antifouling paints would be enhanced with the amount of ZnO/Ag increasing, whereas other physical properties were affected little. The addition of dispersant had little influence on kinds of physical properties.