基于微胶囊和介孔容器的自愈合型环氧涂层的构建及其腐蚀防护机理研究

The development of microcapsule or corrosion inhibitor capable of controllable release is important to develop self-healing coatings. Microcapsules are able to provide physical healing of coatings, while corrosion inhbitors are able to provide chemical healing of underfilm metals. The traditional research focuses either on physical healing or on chemical healing, ignoring the correlation between them. In this work, microcapsules with even diameter will be prepared, and then the performances of the microcapsules will be characterized. The physical healing provided by the microcapsules on epoxy coatings with artificial defect will be studied. At the same time, the surface modified mesoporous materials will be loaded with corrosion inhibitor based on their good loading ability. The mesoporous materials will be modified by polyelectrolytes to prepare the mesoporous containers capable of controllable releasing corrosion inhibitor, responding to the pH change in the environment. The chemical healing of underfilm substrate provided by the mesoporous containers will be studied. The epoxy coatings containing both the microcapsules and the mesoporous containers will be designed and prepared. The mutual effects of the release of core material from the microcapsules and the release of the corrosion inhibitor from the mesoporous containers will be studied. In addition, the chemical and electrochemical mechanisms of the self-healing process taking placed on underfilm and exposed substrates at the artificial defects are expected to be elucidated. The aim of the present work is to explore the protective mechanism of epoxy coatings with dual self-healing functions, thus to provide theoretical basis and foundation of application for developing new self-healing epoxy coatings.

微胶囊技术和腐蚀抑制剂的控释技术是发展自愈合涂层的两种重要手段。微胶囊可以提供涂层的物理愈合，腐蚀抑制剂释放可以提供涂层下金属基材的化学愈合。传统的研究往往忽略了两者的相关性。本项目拟制备尺寸均一化的微胶囊，表征微胶囊的特性，研究微胶囊对环氧涂层物理缺陷的愈合作用。同时，基于经过表面改性的介孔材料对腐蚀抑制剂具有良好的负载功能和聚电解质具有受pH刺激而触发软化的特征，构建可控释放腐蚀抑制剂的介孔“容器”体系，研究介孔“容器”体系对环氧涂层下基材腐蚀的化学愈合作用。设计和制备具有双重愈合功能的环氧涂层体系，明确微胶囊内部的芯材释放和介孔容器体系的腐蚀抑制剂可控释放对环氧涂层愈合功能的相互作用关系，阐明芯材和腐蚀抑制剂释放对环氧涂层缺陷处和界面处金属腐蚀自愈合的化学和电化学机制。本项研究将揭示具有双重愈合功能环氧涂层的腐蚀防护机制，为发展新型自愈合环氧涂层提供理论依据和应用基础。

近年来，能够动态响应环境改变调整性能的智能型涂层已经成为国内外的一个研究热点，也是最新一代的涂层技术之一。本项目基于涂层失效的两个基本原因：（1）涂层损伤；（2）基材腐蚀，发展能够修复涂层损伤和钝化基材腐蚀的智能型涂层。通过改变合成工艺参数，成功制备出适合普通环氧涂层划伤自修复的脲醛基微胶囊。微胶囊和环氧涂层具有良好的相容性，对涂层损伤具有优秀的修复能力，自修复涂层具有优秀的耐盐水浸泡和耐盐雾性能。通过合成新型介孔材料，采用不同的包覆工艺，发展了四种能够响应环境pH值可控释放腐蚀抑制剂的新型介孔容器，明确了硅烷表面改性能够显著增加介孔材料对腐蚀抑制剂的负载量和介孔容器的效率，明确了聚电解质组合对介孔容器释放腐蚀抑制剂的影响，阐明了介孔容器对完整涂层和有缺陷涂层基材腐蚀的钝化机制。研究结果证明基于微胶囊和介孔容器的双功能涂层能够同时修复缺陷和减轻基材腐蚀，增强涂层的耐腐蚀能力。除实验研究外，本项目对水/环氧/铝体系进行了分子动力学模拟，获得了微小间隙尺寸对水分子性质和能量的影响，为解释涂层剥离的微观机制提供了理论基础。