水熱法制備納米金屬氧化物和金屬表面防腐蝕晶化膜
發(fā)布時(shí)間：2018-08-05 09:55
【摘要】： 水熱法有可能實(shí)現(xiàn)在常規(guī)條件下不能進(jìn)行的反應(yīng),在合成納米材料方面具有顆粒小、均勻、無團(tuán)聚、純度高、晶型好、形狀可控等特點(diǎn)并且在制備薄膜方面有廣泛應(yīng)用。本文用水熱法合成了納米氧化鋯和氧化鋁,研究了飽和CO_2體系在制備納米氧化鋯空心球方面的應(yīng)用和pH值對γ-AlOOH形貌的影響。并對球形γ-AlOOH做了電化學(xué)方面的應(yīng)用;利用水熱法在鋼鐵表面上生成了一層水熱晶化膜,提出了高溫高壓下的水熱合成晶化膜保護(hù)機(jī)理,并對成膜后的鐵片進(jìn)行了電化學(xué)測試和鹽水完全浸泡實(shí)驗(yàn),討論了樣品的耐腐蝕性能。主要結(jié)果如下: (1)在雪碧中的飽和CO_2體系中制備納米氧化鋯時(shí),雪碧中的蔗糖在水熱環(huán)境中變?yōu)樘?嚴(yán)重影響了CO_2的氣模作用。為了消除雪碧中其他成分尤其是蔗糖對實(shí)驗(yàn)結(jié)果的影響,采用NH4HCO3的水溶液來提供飽和CO_2的反應(yīng)環(huán)境,最終在此反應(yīng)體系中得到了空心納米球結(jié)構(gòu),但團(tuán)聚嚴(yán)重。討論了不同反應(yīng)溶劑和表面活性劑對樣品形貌的影響,結(jié)果表明:在以NH4HCO3為產(chǎn)生CO_2源的條件下,只有在水介質(zhì)中才可以得到空心結(jié)構(gòu)的氧化鋯,在這個(gè)過程中,水溶的CO_2微氣泡的模板作用是主要的,而表面活性劑僅在水溶液中才起到一定的的模板作用。 (2)對加入SUDEI作表面活性劑合成的空心結(jié)構(gòu)γ-AlOOH進(jìn)行了電化學(xué)測試。結(jié)果表明,SUDEI在水熱過程中與γ-AlOOH產(chǎn)生了化學(xué)吸附的表面修飾,為Hb提供一個(gè)具有生物相容性的界面,促進(jìn)了Hb在電極表面的直接電化學(xué)行為,加快了Hb的電子轉(zhuǎn)移速率。用氫氧化鈉調(diào)節(jié)反應(yīng)介質(zhì)的pH值,結(jié)果表明,pH值是影響γ-AlOOH形貌的重要因素。用AMP-95做反應(yīng)溶劑,反應(yīng)12h后得到了比較罕見的γ-AlOOH三次組裝體。 (3)通過水熱結(jié)晶的方法在鋼鐵表面水熱合成了一層黑色晶化膜,提出了在高溫高壓下的水熱合成晶化膜保護(hù)機(jī)理,探討了不同反應(yīng)條件對成膜的影響,并對處理后的樣品進(jìn)行了電化學(xué)測試和耐腐蝕實(shí)驗(yàn),結(jié)果表明,在300℃下水熱反應(yīng)12h是最佳的水熱條件,延長反應(yīng)時(shí)間和提高反應(yīng)溫度不利于晶化膜的生成,樣品的電化學(xué)極化曲線測試表明經(jīng)鹽酸處理的鐵片在300℃下水熱反應(yīng)12h后樣品對腐蝕介質(zhì)和O_2向金屬表面擴(kuò)散的阻礙作用更大。
[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 緯 -AlOOH were studied. The electrochemical application of spherical 緯 -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 緯 -AlOOH synthesized by adding SUDEI as surfactant has been electrochemical tested. The results show that SUDEI has chemisorption surface modification with 緯 -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 緯 -AlOOH. A rare 緯 -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，
本文編號：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 緯 -AlOOH were studied. The electrochemical application of spherical 緯 -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 緯 -AlOOH synthesized by adding SUDEI as surfactant has been electrochemical tested. The results show that SUDEI has chemisorption surface modification with 緯 -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 緯 -AlOOH. A rare 緯 -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，
本文編號：2165429
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