原位改性石墨烯EPD涂层的结构调控及海洋腐蚀防护研究

Metallic materials are the main structural materials for ship and ocean engineering, but they are easy to be corrosion damaged by the marine environmental mediums. These corrosion damages may cause material failure and threat security. Therefore it is very important to protect metal from corrosion damages. Research on modified graphene electrophoretic deposition(EPD) coating has proved its corrosion protection performance to metal substrate by our groups. However, for the poor structure and dispersion stability of non-covalent bond modified graphene, EPD efficiency and coating performances were both affected. Moreover, for the deficient mechanism study of corrosion protection performance effects by graphene modified structure, it’s hard to optimize modified graphene structure, and the graphene coating is also hard to give full play of corrosion protection performance. This project aims to improve anti-corrosion performances of metallic materials by graphene coating in a variety of marine environments. Firstly, EPD directional anchoring effects and coating physicochemical properties will be improved by construction of covalent bond interaction graphene that modified by in situ polyurethane grafting, which is suitable for cathode EPD coating formation. Secondly, modified structure of graphene will be optimized and designed again, which is according to the research on its physical chemistry and biochemistry corrosion protection mechanism. Therefore, surface activity of metal substrate will be reduced, antibacterial property will be increased, electrochemical and microbial corrosion barriers will be constructed, which means corrosion protection adaptability of coating in various marine environments has been enhanced. Finally, comprehensive performances of anti-corrosion graphene coating will be improved. This project has a broad application prospect in the field of marine corrosion protection for ocean engineering, ship and other industrial materials.

在复杂的海洋腐蚀环境下，海洋工程和舰船用金属材料易失效，威胁安全，因此腐蚀防护尤为重要。本课题组发现改性石墨烯电泳沉积（EPD）涂层可以提高对金属的腐蚀防护，但非共价键改性由于结构和分散稳定性差，影响EPD效率和涂层性能；此外，由于缺乏石墨烯改性结构对腐蚀防护影响的机制研究，缺少对其改性结构的合理优化设计，因此难以充分发挥涂层在多种海洋环境下的防腐功效。本项目以实现石墨烯涂层在多种海洋环境下对金属基材的腐蚀防护为目标，通过聚氨酯原位改性技术构建适宜阴极EPD成膜的共价键改性石墨烯，提高EPD定向锚固效率和涂层理化性能；并根据其物理化学和生物化学腐蚀防护机理进行改性结构的优化设计，降低金属基材表面活性，提高微生物抗菌性，构建电化学和微生物腐蚀屏障，增强涂层在多种海洋环境下的腐蚀防护适应性，提高石墨烯防腐涂层的综合性能。本项目在海洋工程、舰船等工业材料的海洋腐蚀防护领域具有广阔的应用前景。

随着我国对海洋资源开发和利用的深化，各类设施及装备逐步向海上部署，受到腐蚀的严峻考验，威胁到设施装备的使用安全和使用寿命。石墨烯由于稳定的sp2杂化结构，具有很好的化学稳定性和热稳定性，在金属材料防腐领域具有很大的潜力。片层取向堆积的石墨烯可以阻隔或延缓潮湿水分、氧气和腐蚀介质与金属基材的接触，达到物理阻隔防腐的效果，因此定向石墨烯涂层制备技术用于金属腐蚀防护是研究的重点。本项目主要开展以下方面的研究工作：.（1）通过聚氨酯化学反应在氧化石墨烯表面原位接枝阳离子型聚氨酯季铵盐，研究反应合成条件对产物结构的影响。通过原位聚氨酯接枝改性增强产物的结构稳定性，改变其表面电性能，形成微粒外层的空间位阻效应和电偶层效应，提高了改性GO在介质中的分散稳定性。.（2）研究外场条件和功能化改性石墨烯的物理化学结构对其定向锚固的影响作用，基于共价键作用原位接枝改性的氧化石墨烯，由于引入离子型亲水链段和吸附活性官能团，增进EPD定向锚固效率，形成定向紧密排列和稳定附着锚固的防护涂层，与金属表面活性点配位共价键合、电荷吸附锚固，降低了基材表面活性，增强了涂层与金属基材结合力，从而提高了涂层的硬度、耐蚀等综合理化性能，同时也赋予涂层一定的微生物腐蚀抗性。.（3）以环氧富锌底漆、改性石墨烯防腐涂层配套作为研究重点，探究配套涂层体系中改性石墨烯防腐涂层对存在孔隙的富锌底漆的封孔作用，以及在涂层体系中的过渡连接作用，石墨烯涂层可以使有机防腐涂层体系中涂层之间的结合更加紧密，有效增强涂层体系的抗腐蚀介质渗透性，提高涂层体系的耐蚀性能。