水热法制备纳米金属氧化物和金属表面防腐蚀晶化膜
发布时间：2018-08-05 09:55
【摘要】： 水热法有可能实现在常规条件下不能进行的反应,在合成纳米材料方面具有颗粒小、均匀、无团聚、纯度高、晶型好、形状可控等特点并且在制备薄膜方面有广泛应用。本文用水热法合成了纳米氧化锆和氧化铝,研究了饱和CO_2体系在制备纳米氧化锆空心球方面的应用和pH值对γ-AlOOH形貌的影响。并对球形γ-AlOOH做了电化学方面的应用;利用水热法在钢铁表面上生成了一层水热晶化膜,提出了高温高压下的水热合成晶化膜保护机理,并对成膜后的铁片进行了电化学测试和盐水完全浸泡实验,讨论了样品的耐腐蚀性能。主要结果如下: (1)在雪碧中的饱和CO_2体系中制备纳米氧化锆时,雪碧中的蔗糖在水热环境中变为炭,严重影响了CO_2的气模作用。为了消除雪碧中其他成分尤其是蔗糖对实验结果的影响,采用NH4HCO3的水溶液来提供饱和CO_2的反应环境,最终在此反应体系中得到了空心纳米球结构,但团聚严重。讨论了不同反应溶剂和表面活性剂对样品形貌的影响,结果表明:在以NH4HCO3为产生CO_2源的条件下,只有在水介质中才可以得到空心结构的氧化锆,在这个过程中,水溶的CO_2微气泡的模板作用是主要的,而表面活性剂仅在水溶液中才起到一定的的模板作用。 (2)对加入SUDEI作表面活性剂合成的空心结构γ-AlOOH进行了电化学测试。结果表明,SUDEI在水热过程中与γ-AlOOH产生了化学吸附的表面修饰,为Hb提供一个具有生物相容性的界面,促进了Hb在电极表面的直接电化学行为,加快了Hb的电子转移速率。用氢氧化钠调节反应介质的pH值,结果表明,pH值是影响γ-AlOOH形貌的重要因素。用AMP-95做反应溶剂,反应12h后得到了比较罕见的γ-AlOOH三次组装体。 (3)通过水热结晶的方法在钢铁表面水热合成了一层黑色晶化膜,提出了在高温高压下的水热合成晶化膜保护机理,探讨了不同反应条件对成膜的影响,并对处理后的样品进行了电化学测试和耐腐蚀实验,结果表明,在300℃下水热反应12h是最佳的水热条件,延长反应时间和提高反应温度不利于晶化膜的生成,样品的电化学极化曲线测试表明经盐酸处理的铁片在300℃下水热反应12h后样品对腐蚀介质和O_2向金属表面扩散的阻碍作用更大。
[Abstract]:Hydrothermal method is possible to realize the reaction which can not be carried out under the conventional conditions. It has the characteristics of small particle size, homogeneity, no agglomeration, high purity, good crystal shape and controllable shape in the synthesis of nanomaterials, and it has been widely used in the preparation of thin films. In this paper, nanocrystalline zirconia and alumina were synthesized by hydrothermal method. The application of saturated CO_2 system in the preparation of nano-zirconia hollow spheres and the effect of pH value on the morphology of 纬 -AlOOH were studied. The electrochemical application of spherical 纬 -AlOOH, the formation of a hydrothermal crystallization film on the surface of iron and steel by hydrothermal method, and the protection mechanism of hydrothermal composite crystallization film at high temperature and high pressure were proposed. The corrosion resistance of the samples was discussed by electrochemical test and salt water immersion test. The main results are as follows: (1) when nano-zirconia was prepared in the saturated CO_2 system in Sprite, the sucrose in Sprite was converted into carbon in hydrothermal environment, which seriously affected the gas-mode effect of CO_2. In order to eliminate the influence of other components of Sprite, especially sucrose, on the experimental results, the solution of NH4HCO3 was used to provide the reaction environment of saturated CO_2. Finally, the hollow nanospheres were obtained in this reaction system, but the agglomeration was serious. The effects of different reaction solvents and surfactants on the morphology of the samples were discussed. The results showed that zirconia with hollow structure could be obtained only in aqueous medium under the condition of NH4HCO3 as the source of CO_2. The template effect of water-soluble CO_2 microbubble is the main, while the surfactant only plays a role as template in aqueous solution. (2) the hollow structure 纬 -AlOOH synthesized by adding SUDEI as surfactant has been electrochemical tested. The results show that SUDEI has chemisorption surface modification with 纬 -AlOOH during hydrothermal process, which provides a biocompatible interface for HB, promotes the direct electrochemical behavior of HB on the electrode surface and accelerates the electron transfer rate of HB. The pH value of the reaction medium was adjusted by sodium hydroxide. The results show that pH value is an important factor affecting the morphology of 纬 -AlOOH. A rare 纬 -AlOOH triple assembly was obtained by using AMP-95 as the reaction solvent for 12 h. (3) A black crystalline film was synthesized on the surface of steel by hydrothermal crystallization. The protective mechanism of hydrothermal synthesis crystallization film at high temperature and high pressure was put forward. The effect of different reaction conditions on the film formation was discussed. The electrochemical test and corrosion resistance test of the treated samples were carried out. The optimum hydrothermal condition is water thermal reaction at 300 鈩，
本文编号：2165429
[Abstract]:Hydrothermal method is possible to realize the reaction which can not be carried out under the conventional conditions. It has the characteristics of small particle size, homogeneity, no agglomeration, high purity, good crystal shape and controllable shape in the synthesis of nanomaterials, and it has been widely used in the preparation of thin films. In this paper, nanocrystalline zirconia and alumina were synthesized by hydrothermal method. The application of saturated CO_2 system in the preparation of nano-zirconia hollow spheres and the effect of pH value on the morphology of 纬 -AlOOH were studied. The electrochemical application of spherical 纬 -AlOOH, the formation of a hydrothermal crystallization film on the surface of iron and steel by hydrothermal method, and the protection mechanism of hydrothermal composite crystallization film at high temperature and high pressure were proposed. The corrosion resistance of the samples was discussed by electrochemical test and salt water immersion test. The main results are as follows: (1) when nano-zirconia was prepared in the saturated CO_2 system in Sprite, the sucrose in Sprite was converted into carbon in hydrothermal environment, which seriously affected the gas-mode effect of CO_2. In order to eliminate the influence of other components of Sprite, especially sucrose, on the experimental results, the solution of NH4HCO3 was used to provide the reaction environment of saturated CO_2. Finally, the hollow nanospheres were obtained in this reaction system, but the agglomeration was serious. The effects of different reaction solvents and surfactants on the morphology of the samples were discussed. The results showed that zirconia with hollow structure could be obtained only in aqueous medium under the condition of NH4HCO3 as the source of CO_2. The template effect of water-soluble CO_2 microbubble is the main, while the surfactant only plays a role as template in aqueous solution. (2) the hollow structure 纬 -AlOOH synthesized by adding SUDEI as surfactant has been electrochemical tested. The results show that SUDEI has chemisorption surface modification with 纬 -AlOOH during hydrothermal process, which provides a biocompatible interface for HB, promotes the direct electrochemical behavior of HB on the electrode surface and accelerates the electron transfer rate of HB. The pH value of the reaction medium was adjusted by sodium hydroxide. The results show that pH value is an important factor affecting the morphology of 纬 -AlOOH. A rare 纬 -AlOOH triple assembly was obtained by using AMP-95 as the reaction solvent for 12 h. (3) A black crystalline film was synthesized on the surface of steel by hydrothermal crystallization. The protective mechanism of hydrothermal synthesis crystallization film at high temperature and high pressure was put forward. The effect of different reaction conditions on the film formation was discussed. The electrochemical test and corrosion resistance test of the treated samples were carried out. The optimum hydrothermal condition is water thermal reaction at 300 鈩，
本文编号：2165429
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