Corrosion resistance of superhydrophobic layered double hydroxide films on aluminum
Corrosion resistance of superhydrophobic layered double hydroxide films on aluminum
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铝表面超疏水层状双氢氧化物薄膜的耐腐蚀性能
DOI：
10.1002/anie.200704694
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发表时间：
2008-01-01
影响因子：
16.6
通讯作者：
Duan, Xue
中科院分区：
文献类型：
--
作者：
Zhang, Fazhi;Zhao, Lili;Duan, Xue
金属腐蚀的成本相当于工业化国家GDP的几个百分点。[1]在铝的情况下，铬酸盐涂层[2]提供了高效的腐蚀保护，但环境法规越来越限制其使用。阳极氧化[3]增加了氧化层的厚度，但保留了其多孔性。[4]层状材料如阴离子粘土（如层状双氢氧化物）[5，6]和阳离子粘土（如蒙脱石）[7]已被广泛研究作为有机防腐涂料或聚合物-粘土纳米复合耐腐蚀涂料中的添加剂。沸石[8，9]也被用作耐腐蚀涂层材料。表面活性剂分子在表面上的疏水自组装单分子层（SAMs）[10]最近已被提出作为腐蚀抑制剂，但具有以下缺点：该层具有有限的稳定性和允许水到达下面表面的分子大小的缺陷。如果表面活性剂可以被引入到无机基质中，那么这些问题将会得到缓解，其中的薄膜已经被预先牢固地结合到铝表面上。它们可以用通式[M2+ 1-xM 3 + x（OH）2] Anoxy x/n·mH 2 O表示，其中阳离子M2+和M3+占据水镁石层中的八面体空穴，阴离子Anoxy位于水化层间廊道中。[11]在宽范围内改变组合物的能力允许制备具有各种性质的材料。我们最近表明[12]，NiAl-LDH-CO 3 2 H2O薄膜可以直接在多孔阳极氧化铝/铝（PAO/Al）基底上形成;由于PAO/Al是Al 3+的唯一来源，因此薄膜直接在基底上生长，因此表现出良好的粘附力和机械稳定性。[13]用月桂酸钠（正十二烷酸酯）处理导致表面结合的月桂酸酯膜显示出超疏水性，水接触角（CA）大于1608。在这里，我们表明，插层月桂酸阴离子的离子交换与
The costs of metal corrosion amount to several percent of the GDP of an industrialized country.[1] In the case of aluminum, chromate-based coatings [2] provide highly effective corrosion protection, but environmental regulations are increasingly restricting their use. Anodization [3] increases the thickness of the oxide layer, but it retains its porous nature.[4] Layered materials such as anionic clays (eg, layered double hydroxides)[5, 6] and cationic clays (eg, montmorillonite)[7] have been widely investigated as additives in organic anticorrosion coatings or as polymer–clay nanocomposite corrosion-resistant coatings. Zeolites [8, 9] have also been explored as corrosion-resistant coating materials. Hydrophobic self-assembled monolayers (SAMs)[10] of surfactant molecules on the surface have recently been proposed as corrosion inhibitors but suffer from the drawbacks that the layers have limited stability and molecule-sized defects which allow water to reach the underlying surface. These problems should be mitigated if the surfactant could be incorporated in an inorganic host matrix, a thin film of which has been previously strongly bonded to the aluminum surface.Layered double hydroxides (LDHs) are one such potential inorganic host. They can be expressed by the general formula [M2+ 1ÀxM3+ x (OH) 2] AnÀ x/n· mH2O, where the cations M2+ and M3+ occupy the octahedral holes in a brucite-like layer and the anion AnÀ is located in the hydrated interlayer galleries.[11] The ability to vary the composition over a wide range allows materials with a wide variety of properties to be prepared. We recently showed [12] that an NiAl-LDH–CO3 2À film can be formed directly on porous anodic alumina/aluminum (PAO/Al) substrates; since PAO/Al is the only source of Al3+, the thin film grows directly on the substrate and thus exhibits good adhesion and mechanical stability.[13] Treatment with sodium laurate (n-dodecanoate) results in surface-bonded laurate films showing superhydrophobicity with water contact angles (CA) greater than 1608. Here we show that intercalation of laurate anions by ion exchange with