| The main methods of the metal corrosion are to add corrosion inhibitor in corrosive environment and to form a protective layer on the metal. But the two methods both have insufficiencies. The former can't guarantee the anti-corrosion in the mobile environment and the latter can't play the role of anti-corrosion when the cover is broken. Halloysite, as a natural clay mineral, has been widely applied in slow-release preparation, adsorption and composite materials because of its special structure and abundant reserves.Firstly, the clay halloysite were tested under different conditions of acid and alkali in order to explore the influence of acid or alkali modification to the crystalline structure and morphology of halloysite and to investigate the acid and alkali resistance of the halloysite, which has provided a certain theoretical basis for halloysite as a carrier.(1) Halloysite mainly has two structures, that is the block one and the tubular one.(2) Acid and alkali etching can remove the alumina layer in the inner surface of tubular halloysite, increase the aperture and the entrance. And with the increase of concentration, the degree of etching will become greater.Taking 2-Mercaptobenzothiazole(MBT) and 2-Mercaptobenzimidazole(MBI) as inhibitor and modified halloysite nanotubes, the carrier material were prepared by vacuum, ultrasonic, mixing process in order to seek a simple and efficient way.(1) The loading capacity of the same material from high to low were ultrasonic circulation 1h, vacuum 3h, agitating continuously 24 h. And ultimately loading balance needs ultrasonic 2h.(2) The loading capacity of the different preprocessed halloysite obey the following order: J-HNTs > S-HNTs > O-HNTs.(3) When ultimately loading capacity is not affected by solvent, such as corrosion inhibitor MBI, ethanol was chosen as solvent. When solvent affects the loading capacity, such as corrosion inhibitor MBT, acetone was chosen as solvent.(4) The loading can be divided into three periods. The loading capacities are the same in different situations in the beginning. And then the situations change and they quickly load separately. In the end, the different situations separate clearly, and tend to keep stable.(5) The dynamics of loading were in pseudo-second order model, and the correlation coefficients were all higher than 0.99.The four loading material of each inhibitor, Y-J-HNTs, Y-S-HNTs, B-J-HNTs, B-S-HNTs, were prepared via the best method to explore the release regularity of the corrosion medium.(1) The release quantity of the block halloysite is far less than the tubular halloysite.(2) The release process can be mainly divided into two stages: the early stage is the quick release and the later one is smooth release back into balance.(3) The release rule of the corrosion inhibitor MBT is: acid etching > alkaline etching, ethanol type > acetone. The release rule of the corrosion inhibitor MBI is alkali etching > acid etching, ethanol > acetone.(4) Based on the analysis of the loading and releasing percentage, MBT-B-J-HNTs were chosen as the best material for corrosion inhibitor MBT, and MBI-B-J-HNTs were the one for MBI.According to the above study, in this paper, the loading of corrosion inhibitor and halloysite and nanotubes is divided into three categories. One is chemical adsorption on the inside and outside surface, one is physical adsorption on the inside and outside surface, another one is the physical filling in the nanometer tube. As for the release, the first period is release of physical adsorption inhibitor, and the second period is the releasing of chemical adsorption.As a slow-release anti-corrosion material, the anti-corrosion effect of the loading materials were tested using potentiodynamic polarization curve with aluminum alloy, galvanized iron and pure copper for the metal base. Results show that the loading materials have certain anti-corrosion effect. |
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