反渗透-阳极氧化复合膜的制备及离子通道阻断作用研究

The anodization is one of the most commonly used techniques for surface protection of aluminum and its alloys. But porous-type oxide layer of the anodic aluminum oxide (AAO) film is vulnerable to corrosive medium, localized corrosion will be caused and then shorten the life of related devices apparently. In this study, a reverse osmosis-anodic aluminum oxide (RO-AAO) composite film was fabricated on aluminum substrate and the barrier function of RO membrane to salt ions was employed to improve corrosion resistance of the composite film evidently. Through the experiments including polymer monomer test, nanoparticle doping test and graft modification test, blocking of ion channels was achieved in molecular level and the surface was also prepared with well abrasive resistance or super-hydrophobicity. The order of influences of polymer monomer, film thickness, crosslinking density and surface hydrophobicity to both the blocking efficiency and the corrosion resistance were individually explored by parallel controlled trials including ion permeation rate measurement, electrochemical impedance spectroscopy and immersion test. Then, the relationship between ion channel blocking rate and corrosion resistance was discussed in detail. In summary, this study will effectively improve the corrosion protection performance of aluminum and its alloys in marine environment, and further provides new ways for development of multifunctional composite film materials.

阳极氧化作为铝及其合金最常用表面防护处理方式之一，所得阳极氧化膜的表面多孔层易受腐蚀介质侵蚀并导致局部腐蚀，显著降低器件使用寿命。本研究利用反渗透膜的盐离子高效分隔功能，在铝基体表面的多孔阳极氧化膜上通过界面聚合法制备反渗透-阳极氧化复合膜，实现二者有机结合及耐蚀性显著提高。对复合膜进行聚合单体筛选、纳米粒子掺杂和表面枝接修饰，建立分子水平的离子渗透通道阻断方法，并制备耐磨或超疏水的功能性表面。通过平行对照实验，测定复合膜的离子渗透速率、交流阻抗谱和浸泡腐蚀实验，比较单体种类、膜厚、交联密度、表面疏水性等因素分别对离子通道阻断效率和耐蚀性的影响力次序，明确离子通道阻断效率与复合膜耐蚀性的关联机制。本课题的顺利实施，可深入提高海洋环境中铝合金材料的耐蚀防护性能，并为开发新型多功能复合薄膜材料提供新途径。

阳极氧化作为一种广泛采用的铝合金高效防护技术，如何深入提高其在海洋等极端环境下的防护性能，已成为限制未来铝合金产业深入发展的重要问题。本项目提出以阳极氧化铝（AAO）的自身多孔结构作为支撑体，通过界面聚合反应制备阳极氧化铝-反渗透膜（RO-AAO） 复合结构，利用高交联密度有机物的分子水平阻隔能力，实现对氯离子等腐蚀性介质的高效阻隔，开发相关封孔技术和表面修饰技术，探讨离子阻隔水平对腐蚀防护水平的内在关联和客观作用机制。基于项目制定的研究方案和研究目标，项目研究团队开展了RO-AAO复合膜的制备及其形貌调控研究，通过有机物沉积封孔实现自修复功能，利用表面修饰LDHs超疏水薄膜进一步提高基体与腐蚀介质的阻隔水平，并通过石墨烯掺杂深入提高LDHs薄膜自身的阻隔性能，建立结合直接封孔和表面修饰方式的腐蚀性离子高水平阻隔方案，分析并阐述其对基体耐腐蚀性能的提高作用机制，为铝合金材料的高效耐蚀保护提供重要技术支撑。项目负责人按照研究计划，合理安排研究内容和实施方案，组织研究团队系统开展相关研究工作，顺利完成相关研究内容并达到预期目标。项目负责人及时总结相关科研成果，积极参与学术交流活动，依照预期研究目标，发表SCI论文6篇，协助培养研究生4名。