Of Fe <sub> 3 </ Sub> The O <sub> 4 </ Sub> / Sio <sub> 2 </ Sub> Magnetic Composite Nanomaterials And Bronze Surface Analysis Applications Research

In recent years, with the development of nanotechnology and nanomaterial,Fe3O4 magnetic nanoparticles (MNPs) were especially paid much attention because of their superparamagnetic, non-toxic and biocompatible paramagnetic properties. However, as using the Fe3O4 MNPs in different fields, there are still many drawbacks to be overcome, such as:(1) Fe3O4 MNPs are easily condensed, aggregated and presents the poor stability; (2) In addition, Fe3O4 MNPs are easily oxidized and their good magnetic property is destroyed; (3) Since it lacks the active chemical group on its surface, it difficulty to be labeled by other molecules. Therefore, it is very important to modify the surface of the MNPs to form the requirement of fabricating multifunctional, superparamagnetic Fe3O4-based magnetic nanocomposite.Two parts are included in this thesis:review and the experimental research.In the first part of this thesis, the synthesis development of magnetic nanoparticles and its application in recent years was introduced. This review was only focused on the progress of the synthetic methods of FeO4-based nanocomposite and its modification by different chemicals such as surfactant, organic molecule, polymers, silica and so on.In the second part, The research work including two sections are reported.1. The synthesis of the magnetic nanocomposite with fluorescent and its application for sensing oxygen on the surface of bronze wares.The nanocomposite of Fe3O4 MNPs with silica shell mixed fluorescent dye was synthesized via a modified water-in-oil reverse microemulsion method. Thereafter, transmission electron microscopy, fluorescence spectrum method and super-paramagnetic experimental etc., were used to characterize this nanocomposites. The related results showed that the introduction of PVP in the proposed synthesis system could greatly assistant the formation of well-dispersed Fe3O4 nanoparticles in the nanocomposites. Lastly, interaction between the nanocomposites and bronze wares was investigated.2. The synthesis of the multifunctional magnetic-silica nanocomposites and its application for sensing chloride ions on the surface of bronze waresThe nanocomposite of Fe3O4 MNPs with silica shell mixed lucigenin was synthesized via a modified water-in-oil reverse microemulsion method in this paper. Thereafter, transmission electron microscopy, fluorescence spectrum method etc., were used to characterize the nanocomposites. In addition, the interaction between the nanocomposites and bronze samples was investigated. The results showed that this multifunctional nanocomposite could be used to as a fluorescent nanosensor for chloride ion and presents the better analytical performances in real-time and in-situ sensing the chloride ion on the surface of the bronze wares. Based on the obtained results, a novel fluorescent method for nondestructive investigating the corroction mechanism of bronze wares with this chloride ions sensor was proposed in this work.