长效流体—固体复合表面的制备及耐蚀性研究
发布时间：2018-10-24 22:25
【摘要】：腐蚀是材料在海洋环境应用中面临的重要问题。近年来,基于超疏水材料的防腐蚀引起了人们的关注。气-固复合结构的超疏水表面能够利用微纳米级粗糙结构驻留的空气垫隔绝基体金属与腐蚀性介质的直接接触,从而保护金属免遭腐蚀。然而,空气的溶解以及水蒸气的凝结作用使得超疏水表面在水下寿命短,难以实现对基体金属的长效保护,限制了此类材料在水下环境中的应用。本文针对超疏水材料水下环境寿命短的难题进行了两方面的探索:(1)在粗糙疏水结构中浸注不溶于水的全氟润滑油,构筑长效液-固复相疏水表面。(2)采用外加通气法规避传统超疏水层的有限量空气的溶解问题,实现超疏水层的长效化。两种疏水结构均用于低合金钢的防腐蚀,并在海水环境中表现出良好耐蚀性能,可作为特殊保护层用于海洋环境中材料的腐蚀防护。由于油不溶于水,在水压的作用下不会逸出,可与微纳米级粗糙结构形成水下稳定的液-固复合体系。本文采用溶解-沉积法在低合金钢表面构建了具有微米级粗糙结构的十四酸铁金属配合物,并在其表面浸润全氟聚醚油构成金属配合物-全氟聚醚油复合体系(SLIPS涂层)。利用扫描电子显微镜、能谱仪、接触角测试仪以及共聚焦显微镜分析了金属配合物的表面形貌、元素组成,湿润性以及表面粗糙度,并分析了复合体系的成膜机理和防腐机理。研究结果表明,制备的十四酸铁金属配合物与水滴的接触角高达152.45°。涂层表面形貌与电解时间以及电解质导电性有关,电解时间越长,高氯酸锂浓度越高,涂层表面越粗糙。基体金属表面不断溶解的铁离子与溶液中的十四酸反应构成金属配合物,该金属配合物主要为不连续的乳突和壳体。电化学实验表明经20μL全氟聚醚油覆盖的SLIPS涂层的腐蚀电流密度Icorr为低合金钢以及疏水性涂层的十分之一,且随着浸没时间延长而增大。由于油膜不能完全覆盖金属表面,表面发生腐蚀。当油膜含量为40μL,60μL和80μL时,其腐蚀电流密度Icorr相比20μL降低了6个数量级,且随着浸没时间的延长,试样表面不再发生腐蚀。完全覆盖基体表面的油膜的能够有效阻止腐蚀性介质与疏水涂层的接触,达到长效防腐蚀的目的。将传统立体网状结构的海绵采用一步浸泡法制备了整体具有疏水性的超疏水海绵,其与水滴接触角为163.6°,并可通过向其内部不断充入干燥空气得到长效超疏水效果。借助于湿敏电阻监测通入不同气体流量时海绵内部湿度变化,通气量越高,内部湿度越低,疏水性越好。电化学实验表明,当超疏水海绵浸没在水中46 h之后,海绵内部钢针的腐蚀电流密度Icorr提高了10倍,这是由于随着浸没时间延长,海绵内空气逸出,超疏水性能消失;但当有干燥空气不断充入时,钢针的腐蚀电流密度Icorr变化不大。不断通入的干燥气体能够有效的隔绝外界腐蚀介质与钢针的接触,保护钢针免于腐蚀。
[Abstract]:Corrosion is an important problem in marine environment application. In recent years, the anti-corrosion based on super-hydrophobic materials has attracted people's attention. the super-hydrophobic surface of the gas-solid composite structure can isolate the direct contact between the base metal and the corrosive medium by using the air cushion which resides on the micro-scale coarse structure so as to protect the metal from corrosion. However, the dissolution of air and the condensation of water vapor make the super-hydrophobic surface short in water and difficult to realize long-acting protection of matrix metal, which limits the application of such materials in underwater environment. In order to solve the problem of short life of super-hydrophobic material under water environment, this paper explores two aspects: (1) soaking water-insoluble perfluorolubricating oil in a rough hydrophobic structure, and constructing a long-acting liquid-solid complex-phase hydrophobic surface. and (2) adopting the external ventilation regulations to avoid the problem of limited air dissolution of the traditional super-hydrophobic layer and realizing the long-acting of the super-hydrophobic layer. Both hydrophobic structures are used for corrosion protection of low alloy steel and show good corrosion resistance in seawater environment, and can be used as special protection layer for corrosion protection of materials in the marine environment. As the oil is insoluble in water, the water does not escape under the action of water pressure, and the underwater stable liquid-solid composite system can be formed with the micro-scale coarse structure. In this paper, a tetradecanoic acid metal complex with micron-sized roughness structure was constructed on low alloy steel surface by dissolution-deposition method, and perfluoropolyether oil was soaked in the surface of low alloy steel to form a metal complex-perfluoropolyether oil composite system (SLIPS coating). Surface morphology, element composition, wettability and surface roughness of metal complex were analyzed by scanning electron microscope, energy spectrometer, contact angle tester and confocal microscope, and the film forming mechanism and anti-corrosion mechanism of the composite system were analyzed. The results showed that the contact angle of tetradecanoic acid metal complex with water drops reached 152. 45 掳. the surface morphology of the coating is related to the electrolysis time and the electrolyte conductivity, the longer the electrolysis time, the higher the lithium perchlorate concentration, and the more rough the coating surface. the continuously dissolving iron ions on the metal surface of the matrix form a metal complex with the tetradecanoic acid in the solution, and the metal complex is mainly discontinuous mastoid and shell. Electrochemical experiments show that the corrosion current density Icorr of the SLIPS coating covered with 20. m u.L of perfluoropolyether oil is one tenth of the low alloy steel and the hydrophobic coating, and increases as the immersion time is prolonged. Corrosion occurs on the surface because the oil film cannot completely cover the metal surface. When the oil film content is 40 & mu; L, 60 & mu; L, and 80 & mu; L, the corrosion current density Icorr is reduced by 6 orders of magnitude as compared to 20 & mu; L, and corrosion is no longer occurring on the surface of the sample as the immersion time is prolonged. the contact between the corrosive medium and the hydrophobic coating can be effectively prevented by completely covering the oil film on the surface of the substrate, so that the purpose of long-acting corrosion prevention is achieved. A super-hydrophobic sponge with hydrophobic property is prepared by one-step soaking method, and the contact angle of water drops is 163. 6 掳, and the long-acting super-hydrophobic effect can be obtained by continuously charging dry air into the sponge. By using the wet-sensitive resistor to monitor the change of humidity inside the sponge, the higher the volume of aeration, the lower the internal humidity and the better the hydrophobicity. The electrochemical experiments show that the corrosion current density Icorr of the steel needle inside the sponge is increased by 10 times when the super-hydrophobic sponge is immersed in water for 46 hours, which is due to the prolonged immersion time, the escape of air in the sponge, and the disappearance of the super-hydrophobic property; however, when the dry air is continuously filled, The corrosion current density Icorr of the steel needle is not large. the continuously communicated drying gas can effectively isolate the contact between the external corrosion medium and the steel needle and protect the steel needle from corrosion.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4
本文编号：2292742
[Abstract]:Corrosion is an important problem in marine environment application. In recent years, the anti-corrosion based on super-hydrophobic materials has attracted people's attention. the super-hydrophobic surface of the gas-solid composite structure can isolate the direct contact between the base metal and the corrosive medium by using the air cushion which resides on the micro-scale coarse structure so as to protect the metal from corrosion. However, the dissolution of air and the condensation of water vapor make the super-hydrophobic surface short in water and difficult to realize long-acting protection of matrix metal, which limits the application of such materials in underwater environment. In order to solve the problem of short life of super-hydrophobic material under water environment, this paper explores two aspects: (1) soaking water-insoluble perfluorolubricating oil in a rough hydrophobic structure, and constructing a long-acting liquid-solid complex-phase hydrophobic surface. and (2) adopting the external ventilation regulations to avoid the problem of limited air dissolution of the traditional super-hydrophobic layer and realizing the long-acting of the super-hydrophobic layer. Both hydrophobic structures are used for corrosion protection of low alloy steel and show good corrosion resistance in seawater environment, and can be used as special protection layer for corrosion protection of materials in the marine environment. As the oil is insoluble in water, the water does not escape under the action of water pressure, and the underwater stable liquid-solid composite system can be formed with the micro-scale coarse structure. In this paper, a tetradecanoic acid metal complex with micron-sized roughness structure was constructed on low alloy steel surface by dissolution-deposition method, and perfluoropolyether oil was soaked in the surface of low alloy steel to form a metal complex-perfluoropolyether oil composite system (SLIPS coating). Surface morphology, element composition, wettability and surface roughness of metal complex were analyzed by scanning electron microscope, energy spectrometer, contact angle tester and confocal microscope, and the film forming mechanism and anti-corrosion mechanism of the composite system were analyzed. The results showed that the contact angle of tetradecanoic acid metal complex with water drops reached 152. 45 掳. the surface morphology of the coating is related to the electrolysis time and the electrolyte conductivity, the longer the electrolysis time, the higher the lithium perchlorate concentration, and the more rough the coating surface. the continuously dissolving iron ions on the metal surface of the matrix form a metal complex with the tetradecanoic acid in the solution, and the metal complex is mainly discontinuous mastoid and shell. Electrochemical experiments show that the corrosion current density Icorr of the SLIPS coating covered with 20. m u.L of perfluoropolyether oil is one tenth of the low alloy steel and the hydrophobic coating, and increases as the immersion time is prolonged. Corrosion occurs on the surface because the oil film cannot completely cover the metal surface. When the oil film content is 40 & mu; L, 60 & mu; L, and 80 & mu; L, the corrosion current density Icorr is reduced by 6 orders of magnitude as compared to 20 & mu; L, and corrosion is no longer occurring on the surface of the sample as the immersion time is prolonged. the contact between the corrosive medium and the hydrophobic coating can be effectively prevented by completely covering the oil film on the surface of the substrate, so that the purpose of long-acting corrosion prevention is achieved. A super-hydrophobic sponge with hydrophobic property is prepared by one-step soaking method, and the contact angle of water drops is 163. 6 掳, and the long-acting super-hydrophobic effect can be obtained by continuously charging dry air into the sponge. By using the wet-sensitive resistor to monitor the change of humidity inside the sponge, the higher the volume of aeration, the lower the internal humidity and the better the hydrophobicity. The electrochemical experiments show that the corrosion current density Icorr of the steel needle inside the sponge is increased by 10 times when the super-hydrophobic sponge is immersed in water for 46 hours, which is due to the prolonged immersion time, the escape of air in the sponge, and the disappearance of the super-hydrophobic property; however, when the dry air is continuously filled, The corrosion current density Icorr of the steel needle is not large. the continuously communicated drying gas can effectively isolate the contact between the external corrosion medium and the steel needle and protect the steel needle from corrosion.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4
【参考文献】
相关期刊论文 前2条
1 李杨;王立达;刘贵昌;;铝基超疏水表面的制备及其耐蚀性[J];电镀与涂饰;2012年05期
2 刘通;刘涛;陈守刚;程莎;尹衍升;;超疏水表面改善铝基材料的抗海水腐蚀性能[J];无机化学学报;2008年11期
，本文编号：2292742
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