Synthesis Of Nano-Metal Oxides And Metal Surface Corrosion Film By Hydrothermal Treatment

Hydrothermal process has the possibility to achieve some reactions which may not be carried out in conventional condition. In the preparation of nanomaterials, hydrothermal process has the advantages of small particles, uniform, non-agglomeration, high purity, well crystallized and morphology controllable. Recently, application of hydrothermal process in preparation of film has attracted much attention. In this paper, zirconia andγ-AlOOH were synthesized by hydrothermal process. Application of saturated CO₂ system in the preparation of zirconia hollow spheres and influence of pH on the morphology ofγ-AlOOH ware discussed. And the application ofγ-AlOOH sphere in electrochemistry was researched. Crystallization membrane on iron was synthesized by hydrothermal process and the protection mechanism was proposed. Electrochemistry and saline soak test were carried out. The anti-corrosive performance of samples was discussed on this basis. The main results are concluded as follows:(1) Sucrose transforms to carbon that has a seriously affect on the formation of zirconia hollow spheres when the reaction carried out. In order to eliminate the affect of sucrose, NH4HCO3 solution was used to provide the environment of saturated CO₂ system. Zirconia hollow structure was finally prepared in this reaction system. The effects of reaction solvent and surfactant on the morphology of samples were discussed. The results indicated that hollow structured zirconia was only obtained when water as reaction medium. In this process, CO₂ plays an important role in the formation of hollow structure, and the effect of surfactant is secondary.(2) Hollow structuredγ-AlOOH was synthesized with urea as precipiting agent. The electrochemistry application ofγ-AlOOH was discussed. The result indicates that SUDEI has a chemical adsorption withγ-AlOOH. And SUDEI provides a biological compatible contact surface which promotes the electron transfer process of Hb. The pH was adjusted by NaOH solution. The result indicates that the pH plays a key role in the formation of morphology ofγ-AlOOH. Three assembly ofγ-AlOOH was prepared in AMP-95 after reacted for12h.(3) Crystallization membrane on iron was synthesized by a hydrothermal process. On this base, a crystallization membrane protection mechanism was proposed. The influence of different reaction conditions on crystallization membrane was discussed. The results of the electrochemistry and saline soak test indicate that the optimal reaction condition is to react 12h under 300℃. The extension reaction time and the enhancement reaction temperature does not favor to production of the crystallization membrane. Electrochemistry application of the samples shows that the iron treated by the optimal reaction condition has a larger hindering effect on corrosive medium and O₂.