The two-dimensional lamellar MXene nanosheets have exhibited remarkable potential in enhancing the corrosion resistance of waterborne epoxy (WEP) coating because of their excellent mechanical strength and physical barrier effect. However, the inherent instability of MXene in aqueous environments posed a significant challenge due to its susceptibility to oxidation and decomposition. Moreover, the excellent electrical conductivity of MXene can trigger galvanic corrosion, accelerating the rate of corrosion in coatings. To overcome these limitations, a facial surface functionalization of MXene nanosheets via one-step dopamine-triggered crosslinking with polyethyleneimine was developed, which was applied to reinforce the waterborne epoxy coating by a simple spraying technique. The efficient dispersion of functional filler, enhanced physical barrier, and interface compatibility contributed to the exceptional anticorrosion ability of WEP coating. Uniquely, the impedance of the 0.5 wt% modified MXene/WEP composite coating remained at 2.72 × 10 Ω·cm (at 0.01 Hz) after immersion in 3.5 wt% NaCl for 30 days, even with the coating thickness of around 55 ± 5 µm. This value was two orders of magnitude higher than neat WEP coating. Therefore, this work expanded the use of two-dimensional lamellar MXene nanosheets as functional fillers for realizing the long-term anti-corrosion ability of the waterborne epoxy coating.

中文翻译：

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二维层状MXene纳米片/水性环氧复合涂层：多巴胺引发的表面改性和长期防腐性能


二维层状MXene纳米片由于其优异的机械强度和物理阻隔效果，在增强水性环氧（WEP）涂层的耐腐蚀性方面表现出显着的潜力。然而，MXene 在水环境中固有的不稳定性由于其易氧化和分解而带来了重大挑战。此外，MXene优异​​的导电性会引发电偶腐蚀，加速涂层的腐蚀速度。为了克服这些限制，开发了一种通过一步多巴胺触发与聚乙烯亚胺交联的 MXene 纳米片的面部表面功能化，并通过简单的喷涂技术用于增强水性环氧涂层。功能性填料的有效分散、增强的物理阻隔性和界面相容性使得WEP涂层具有优异的防腐能力。独特的是，0.5 wt% 改性 MXene/WEP 复合涂层的阻抗在 3.5 wt% NaCl 中浸泡 30 天后仍保持在 2.72 × 10 Ω·cm（0.01 Hz），即使涂层厚度约为 55 ± 5 µm 。该值比纯 WEP 涂层高两个数量级。因此，本工作扩大了二维层状MXene纳米片作为功能填料的用途，以实现水性环氧涂料的长期防腐能力。