Fabriation And Antibacterial Study Of Layer-by-layer Strippable Silver Thin Films

Micro/nano thin film has been a popular subject in the field of materials science. Although several methods have been developed to prepare micro/nano thin film, there are still some drawbacks in the existing methods. For example, some methods have special requirements for the substrate, which limited the practical application of micro/nano thin film. However, the insufficiency can be make up via transfer technology. In this disertation, layer-by-layer strippable silver micro/nano thin films were prepared by chemical deposition, followed by polylactic-acid-film-based transfer technology. The morphologies and structures of the silver thin film were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results show that the surface morphology and micro/nano structure of the film could be maintained perfectly during the transfer process. It suggests that the superposition and stripping of membrane has no significant effect on the surface structure.Due to its excellent antibacterial property and high safety, silver is widely used as antibacterial material. While the silver thin film with micro-nano structure have been applied more effectively and widely in the fields of biology, medicine, optics than silver because it has the unique surface and volume effect, quantum size effect of the micro/nano materials. However, the antibacterial ability of the silver would decline with time. Therefore, it is significant to prepare a novel silver film with a lasting antibacterial property. The antibacterial property of the silver film was tested qualitatively and quantitatively by bacteriostasis circle method and soak culture method. The results indicated that the silver film exhibited excellent and lasting antibacterial properties via membrane transfer technology. When the silver thin film was stripped, the sublayer still has a strong antimicrobial property. It can be seen from the result that the upper-layer played a very good protection to the sub-layer in the multilayer film, which prolonged the antibacterial time. Therefore, the novel silver film will have a broad application prospect in the field of antibacterial.