不锈钢双极板表面聚多巴胺-Ti3C2Tx(MXene)-导电聚合物复合涂层构建及协同防腐机制

开发新型高效导电耐蚀涂层是突破质子交换膜燃料电池（PEMFC）金属双极板腐蚀瓶颈问题的关键。本项目首先利用多巴胺自聚合特性在不锈钢表面构建聚多巴胺（PDA）底层，然后采用电聚合在PDA表面沉积Ti3C2Tx(MXene)改性的导电聚合物（CPs）面层，获得PDA-Ti3C2Tx(MXene)-CPs导电耐蚀复合涂层。利用Ti3C2Tx(MXene)二维材料高导电导热特性及其物理屏障、阴极保护作用提高双极板的导电耐蚀性能；通过引入植酸和樟脑磺酸，巧妙实现涂层在微小缺陷处自修复。通过研究复合涂层组成与制备工艺对导电耐蚀性能的影响，获得附着力高、电导率高、防腐性能优异的PDA-Ti3C2Tx(MXene)-CPs复合涂层及制备技术，揭示界面结合机理，阐明协同防腐机制，为高性能不锈钢双极板在PEMFC中的应用提供技术积累。

The development of new and high-efficiency conductive and anticorrosive coatings is the key to resolve the corrosion bottleneck problem of metallic bipolar plates for proton exchange fuel cell (PEMFC).In the present project, we design a novel composite coating system which contains a polydopamine (PDA) layer and a conductive polymer (CP) layer modified by Ti3C2Tx(MXene) for corrosion protection of stainless steel bipolar plates in PEMFC. In this PDA-Ti3C2Tx(MXene)-CPs composite coating system, the utilized dopamine which exhibits self-polymerization property can construct a flat and dense PDA underlayer on the surface of stainless steel bipolar plates, while the conductivity and the corrosion resistance of the coating can be improved by the outer CPs layer modified by the Ti3C2Tx(MXene), which is a new 2d material with many advantages such as high electric and thermal conductivity, physical barrier and cathodic protection anticorrosive mechanism. Meanwhile, the self-healing property of the composite coating can be obtained by the introduction of special dopants, e.g., phytic acid and camphorsulfonic acid, further achieve the long-term intelligent corrosion protection for stainless steel bipolar plates. This project will systematically investigate the effects of the preparation on the key performance of PDA-Ti3C2Tx(MXene)-CPs composite coating, such as corrosion resistance and conductivity, and ultimately fabricate a composite coating system with strong adhesion, superior electrical conductivity and excellent corrosion protection ability. This project will reveal the interface bonding mechanism between PDA and stainless steel bipolar plates, and will clarify the cooperative anticorrosion mechanisms of PDA-Ti3C2Tx(MXene)-CPs composite coating, further provide a theoretical foundation and technical accumulation for the practical application of the high-performance stainless steel bipolar plates in PEMFC.