智能防腐涂层中氮化钛等离激元纳米结构的调控与作用机理

The photothermal triggered anti-corrosion coating can repair the coating defects and restore its anti-corrosion performance through locally melting and healing the damages under light-to-heat conversion. Photothermal triggered self-healing has many outstanding advantages, such as long operation distance, high precision and efficiency, and wide application fields, which shows great development potential. Meanwhile, the release of corrosion inhibitors in the coating helps to protect the metal against corrosion. However, currently there is no systematic understanding of the release kinetics and micro inhibition mechanism of corrosion inhibitors. In this project, based on the urgent requirements for the controllable preparation of high-performance photothermal self-healing coatings, as well as for the in-situ characterization of the inhibitor release process and inhibition behavior, the titanium nitride (TiN) plasmon nanostructures with photothermal and surface-enhanced Raman scattering (SERS) effects are fabricated. We design and fabricate a composite anti-corrosion coating of TiN layer-organic coating-inhibitors, and optimize the plasmon performances of TiN coatings to achieve photothermal self-healing function with high reparation efficiency. In addition, TiN can be utilized for in-situ SERS characterization of inhibitor molecules, aiming to establish the corresponding relationship between inhibitor release-interface adsorption-corrosion inhibition performance. This work demonstrates the key roles and synergistic effect of TiN, organic coatings and inhibitors in improving the overall anti-corrosion ability, and provides theoretical guidance and technical support for the development of new smart anti-corrosion coatings.

光热响应涂层通过光照产热效应促使涂层局域熔融而愈合损伤界面，达到修复涂层缺陷并恢复其防腐性能的目的。光热自修复具有操作距离远、修复精度和效率高、适用范围广等优点，具有巨大的开发潜力。同时，涂层中包覆的缓蚀剂释放后可及时抑制基体腐蚀，但是目前对于缓蚀剂的释放动力学及微观缓蚀机理缺乏系统的认识。本项目以高性能光热自修复涂层的可控制备、缓蚀剂释放和界面吸附的原位表征为需求牵引，以氮化钛等离激元纳米结构的光照产热与表面增强拉曼效应为实现途径，设计和制备氮化钛纳米镀层-有机涂层-缓蚀剂复合智能防腐涂层，系统开展氮化钛等离激元性能的调控与优化工作，实现涂层的快速、高效光热自修复，以及涂层中缓蚀剂分子的原位拉曼检测，揭示缓蚀剂释放-界面吸附-缓蚀性能之间的关联规律，阐明氮化钛镀层、有机涂层和缓蚀剂对提升材料整体耐蚀能力的关键作用和协同效应，为新型智能防腐涂层的开发提供理论依据和技术支撑。

有机防腐涂层可以阻隔腐蚀性介质与金属基底接触，然而在复杂的服役工况和多环境因素耦合的交互作用下，有机涂层会受到机械碰撞、冲刷磨损等综合因素影响，产生微观缺陷或宏观破损。自修复涂层可以利用分子间存在的可逆物理作用或化学反应完成对涂层损伤部位的修复，或者是将活性修复物质封装在载体中，通过活性物质释放抑制腐蚀进程。其中，光热自修复涂层具有可远距离触发、修复精度高、材料选择范围广等优点，在智能涂层研究领域具有巨大的应用发展潜力。本课题创新地应用等离激元氮化钛（TiN）作为光热转换材料，研究了纳米TiN的形貌结构、添加量等对其光热转换性能的影响，制备了基于TiN的载药纳米颗粒和低熔点微米胶囊，开发了一系列负载TiN基微纳米填料的光热自修复涂层；研究了长期浸泡、中性盐雾和户外暴晒等环境下涂层缺陷处的腐蚀萌生、抑制与发展规律，阐明了缓蚀剂释放与吸附、填料熔融与密封、涂层形状记忆恢复等不同机制对涂层长效防腐的关键作用与协同效应，达到了延长涂层防护寿命的目的。本项目的研究成果为进一步推动自修复防腐涂层的实际应用奠定了理论基础，提供了可行性方案，具有重要的科学意义。