海洋环境腐蚀与生物污损重点实验室知识库

海洋环境腐蚀与生物污损是海洋工程设施领域所面临的棘手问题。仿生超疏水材料因其具有独特的表面结构及成分而具有优异的拒水性，其有望应用于解决海洋环境腐蚀与生物污损的问题。本论文分别采用阳极氧化法、水热法、刻蚀法对海洋环境中常用的5083铝合金表面进行了仿生超疏水处理。首先，通过一系列的表征手段测试了所制备超疏水样品表面的微纳米形貌及组成成分。其次，对所制备超疏水样品表面的润湿性及自清洁能力进行了测试。最重要的是，通过电化学阻抗谱测试来评价所制备样品的耐海水腐蚀性能和通过舟形藻和细菌的粘附测试来表征其海洋防生物污损性能。

（1）首先，本文通过采用传统两步阳极氧化法和自组装法制备了超疏水5083铝合金。通过形貌和成分测试表明5083铝合金经阳极氧化处理后，其表面形成了海绵状的微纳米结构，其表面粗糙度也得到了提升。表面主要生成了Al₂O₃，低表面能的1H,1H,2H,2H-全氟辛基三乙氧基硅烷（POTS）分子也成功的接枝在阳极氧化铝表面。经接触角测试测得所制备超疏水5083铝合金表面的静态接触角为159°±1°。所制备的超疏水样品对细砂粒也具有良好的自清洁能力。值得关注的是所制备的超疏水5083铝合金具有良好的耐海水腐蚀性能，超疏水5083铝合金比空白5083铝合金的电荷转移电阻高出了5个数量级，计算得到其缓蚀效率高达99.99%。更值得注意的是，对比布满舟形藻的空白铝合金表面，超疏水5083铝合金表面几乎没有发现舟形藻的存在，这表明超疏水5083铝合金可以大大降低舟形藻在铝合金表面的粘附和增殖。

（2）另外，由于之前文献所报道的仿生超疏水材料的制备方法比较复杂且耗时，本实验又开发了一种新颖且方便的一步水热法制备仿生超疏水表面的方法。此方法是将5083铝合金在全氟辛酸水溶液中经水热处理后烘干即可制备得到超疏水表面。经过形貌和成分表征发现，5083铝合金经水热处理后其表面刻蚀形成了花瓣状的微纳米结构，全氟辛酸（PFOA）分子也成功接枝到样品的表面来降低表面能。所制备的超疏水表面具有优异的拒水性，其静态接触角高达167°±1°。另外，所制备的超疏水表面具有优异的自清洁性能。一步水热法所制备的超疏水表面的缓蚀效率达到了94.45%，具有很好的耐海水腐蚀性能，且其能够很好的抵御盐雾试验。通过细菌粘附实验，对比空白样品表面布满了绿色的活菌和红色的死菌，而对于所制备的超疏水5083铝合金，其表面仅观察极少量红色的死菌，表明所制备的超疏水表面具有优异的耐海洋生物污损性能。

（3）经上述实验测得超疏水样品具有优异的自清洁性能、耐海水腐蚀和耐生物污损性能。为了探究这些性能与润湿性之间的规律，本实验通过简单的氨水刻蚀法和低表面能的POTS修饰制备了具有不同润湿性的疏水表面和超疏水表面。5083铝合金经过氨水刻蚀处理不同时间后，其表面形成了不同的微纳米结构，从而具有不同的表面粗糙度。POTS分子也成功接枝到样品的表面来降低表面能。所制备的疏水表面因其滚动角较大，其自清洁性能较为逊色。超疏水样品具有优异的自清洁性能。所制备的疏水样品和超疏水样品因本身的微纳米结构不同而导致粗糙度的差异，影响了样品本身的耐腐蚀性能和抗生物污损性能。疏水样品的缓蚀率为97.56%，超疏水样品的缓蚀率则高达99.99%。疏水样品表面有少量死菌粘附，超疏水样品表面几乎无细菌附着。因此，只有当样品的润湿性达到超疏水的情况，样品才能具有优异的自清洁性能、耐海水腐蚀和耐生物污损性能。

Marine environmental corrosion and biofouling are thorny issues in the field of marine engineering facilities. Biomimetic superhydrophobic materials have excellent water repellency due to their unique structure and composition, and biomimetic superhydrophobic materials are expected to be applied to solve the problems of marine environmental corrosion and biofouling. In this study, the superhydrophobic surface were prepared on the surface of 5083 aluminum alloy samples by anodic oxidation treatment, hydrothermal method and etching method. Firstly, the micro-nano morphology and composition of the superhydrophobic samples were tested by some characterization methods. Secondly, the wettability and self-cleaning ability of the prepared superhydrophobic samples were tested. The most important was that the seawater corrosion resistance of the prepared samples were evaluated by electrochemical impedance spectroscopy, the marine biofouling resistance were characterized by adhesion test using the navicular algae and bacteria.

(1) Firstly, the superhydrophobic 5083 aluminum alloy was prepared by traditional two-step anodic oxidation and self-assembly method. The morphology and composition tests showed that sponge-like micro-nano structure was formed on the surface of 5083 aluminum alloy after anodization process, and its surface roughness was also improved. Al₂O₃ was mainly formed on the surface. The 1H, 1H, 2H, 2H-perfl- uorooctyltriethoxysilane (POTS) molecules with low surface energy were successfully grafted on the surface of anodized aluminum. The static contact angle of the superhydrophobic 5083 aluminum alloy surface was 159°±1°. The superhydrophobic samples also had good self-cleaning ability for fine sand particles. It was worth noting that the superhydrophobic 5083 aluminum alloy has good seawater corrosion resistance. The charge transfer resistance of superhydrophobic 5083 aluminum alloy was five orders of magnitude higher than that of bare 5083 aluminum alloy, and the corrosion inhibition efficiency was as high as 99.99%. More notably, compared with the bare aluminum alloy surface covered with navicular algae, there was almost no navicular algae on the superhydrophobic 5083 aluminum alloy surface, which indicated that the superhydrophobic 5083 aluminum alloy could greatly reduce the adhesion and proliferation of navicular algae.

(2) In addition, because the preparation methods of superhydrophobic materials reported in previous literatures were complex and time-consuming, a novel and convenient one-step hydrothermal method for preparing bionic superhydrophobic surfaces had been developed in this experiment. In this method, 5083 aluminum alloy was hydrothermally treated in perfluorooctanoic acid (PFOA) aqueous solution, and then dried to obtain superhydrophobic surface. Through morphology and composition characterization, it was found that petal-shaped micro-nano structures were formed on the surface of 5083 aluminum alloy after hydrothermal treatment, and PFOA molecules were successfully grafted onto the surface of the sample to reduce the surface energy. The prepared superhydrophobic surface had good water repellency, and its static contact angle reached 167°±1°. In addition, the prepared superhydrophobic surface had excellent self-cleaning performance. The superhydrophobic surface prepared by one-step hydrothermal method had good corrosion resistance, its corrosion inhibition efficiency reached 94.45%, and it could well resist salt spray test. Through the bacterial adhesion experiment, compared with the bare sample whose surface was covered with green living bacteria and red dead bacteria, but only a small amount of red dead bacteria were observed on the surface of the prepared superhydrophobic 5083 aluminum alloy, which indicated that the prepared superhydrophobic surface had excellent resistance to marine biofouling.

(3) According to the above experiments, the superhydrophobic samples have excellent self-cleaning performance, seawater corrosion resistance and biofouling resistance. In order to explore the law between these properties and wettability, hydrophobic surfaces and superhydrophobic surfaces with different wettability were prepared by simple ammonia etching and low surface energy POTS modification. Different micro-nano structures were formed on the surface of 5083 aluminum alloy after being etched by ammonia water for different times, which resulted in different surface roughness. POTS molecules were successfully grafted onto the surface of samples to reduce the surface energy. The self-cleaning performance of the prepared hydrophobic surface was inferior because of its large rolling angle. Superhydrophobic samples had excellent self-cleaning performance. The roughness of hydrophobic samples and super-hydrophobic samples were different due to their micro-nano structures, which affected the corrosion resistance and biofouling resistance of samples. The corrosion inhibition rate of hydrophobic samples was 97.56%, while that of super-hydrophobic samples was as high as 99.99%. A small amount of dead bacteria adhered to the surface of hydrophobic samples, and almost no bacteria adhered to the surface of superhydrophobic samples. Therefore, only when the wettability of the sample was superhydrophobic can the sample had excellent self-cleaning performance, seawater corrosion resistance and biofouling resistance.