贻贝仿生自愈合防腐涂层的构建及其作用机制

The coatings can be susceptible to form the bubble, pinhole, and filiform corrosion during the paint process and the long term use, causing the localized corrosion of metal and the failure of coating. Preparation the anti-corrosive coating with the self-healing function has become research hotspots. The foot cells of mussels can secrete adhesion protein, which can firmly adhere to the surface of various materials in the wet environment. This project will combine the super adhesion properties of mussel with anti-corrosive self-healing coatings. We will use layer-by-layer method to prepare intelligent nanocontainers encapsulating dopamine and inhibitors. By studying the molecular self-assembly process of multiple intermolecular interactions for regulation, we want to reveal the relationship between structure of nanocontainers and dynamics laws. On this basis, the project will systematically study the dosage of the nanocontainers from the experimental and theoretical aspects, which guided the design of anti-corrosive self-healing coatings. The failure process of self-healing coating / mild steel system was identified by multi-factor coupling accelerated test and micro-zone electrochemical scanning. Moreover, we want to explore the inner relationship between the coating properties and the oxidation, self-polymerization and crosslinking reaction of dopamine in situ area of corrosion under weak basic conditions. This project can provide a theoretical and experimental guidance for the development of self-healing coating with high anticorrosive performances.

涂层在长期使用过程中容易发生鼓泡、针孔、丝状腐蚀等现象，引发金属的局部腐蚀并导致涂层提前失效，开发具有自愈合功能的防腐涂层成为研究热点。贻贝的足腺细胞能够分泌黏附蛋白，可在潮湿环境中牢固黏附于各种材料的表面。本项目拟将贻贝的超强黏附特性与自愈合防腐涂层相结合，采用层层自组装技术分别制备封装多巴胺和缓蚀剂的仿生智能纳米容器，通过研究分子自组装过程对分子间的多重弱相互作用进行调控，揭示纳米容器的微观结构与动力学释放的关系与规律。在此基础上，从实验和理论两个方面系统优化纳米容器用量并构建自愈合防腐涂层，运用多因素耦合等效加速试验技术和微区电化学扫描表征自愈合防腐涂层/碳钢体系的腐蚀失效过程，探索多巴胺在腐蚀微区弱碱性条件下的氧化、自聚合和交联反应与涂层防腐性能的内在联系，本项目的开展将为新型自愈合防腐涂层的设计提供新理论依据和技术指导。

涂层在使用过程中会鼓泡、出现针孔和发生丝状腐蚀，这会引发金属的局部腐蚀并导致涂层折寿，开发具有自主修复功能的涂层可以解决上述问题。在过去的15年里，针对自愈合涂层的研究吸引了化学、材料、物理等多领域研究人员的广泛关注。项目负责人属于国内最早对这一领域进行研究的人员之一。本项目的主要研究工作可以分为如下三个部分：本首先，我们利用聚多巴胺膜将缓蚀剂封装于介孔二氧化硅纳米颗粒中，制备了智能纳米容器，并将其掺杂于醇酸树脂水性涂料，成功构筑贻贝仿生自愈合防腐涂层，电化学、盐水浸泡和盐雾试验都证明涂层具有较好的防腐性能；第二，针对聚多巴胺的成膜缓慢问题，我们采用单宁酸络合物取代聚多巴胺膜制备新一代智能防腐纳米容器，既提升纳米容器的制备效率，又避免因聚多巴胺成膜缓慢带来的缓蚀剂泄露问题；最后，针对海洋环境中的微生物污损问题，我们通过表面修饰和乳液聚合等方法制备了防腐抗污功能一体化微胶囊，并成功构筑了具有防污功能的自愈合防腐涂层，局部交流阻抗证实该涂层具有自愈合防腐性能，抗菌实验显示其具有的防污性能，上述研究工作初步探索了多功能自愈合防腐涂层的设计理念与制备过程，针对该方向深入研究亟需经费支持。本项目的开展为新型自愈合防腐涂层的设计提供新理论依据和技术指导。