[论文解读] Carbon nanotube/metal corrosion issues for nanotube coatings and inclusions in a matrix

Farhad Daneshvar|arXiv (Cornell University)|Nov 3, 2018

Carbon Nanotubes in Composites参考文献 36被引用 4

一句话总结

本综述研究了碳纳米管（CNTs）在提升金属基复合材料和涂层耐腐蚀性方面的作用。CNTs通过形成钝化层、增强涂层-基体界面结合力以及在富锌聚合物涂层中实现牺牲保护，从而提高耐腐蚀性能；其中，镍基-CNT电沉积材料表现出显著的性能提升，而镁基复合材料的结果则存在矛盾。

ABSTRACT

Corrosion is an inevitable phenomenon that is inherent in metals and even though there has been significant research on this subject, no ideal protection has been discovered to fully prevent corrosion. However, methods such as using protective coatings, and modifying the structure or composition of the material have been used to slow down gradual corrosion and fortunately they proved to be quite beneficial. The research focus has shifted to integrating novel materials and structures to improve the corrosion resistance of composites. Carbon nanotubes (CNTs) are an attractive and promising filler due to their chemical inertness and high mechanical, electrical, and thermal properties. CNTs can fill the gaps of metals and polymer-based composites by forming a passive layer on metals and promoting sacrificial protection in zinc rich polymer (ZRP) coatings, and can therefore function as an anti-corrosion filler. This paper reviews the research that has been performed to better understand the influence of CNTs on corrosion resistance in composites. Accordingly, in metal matrix composites (MMCs), most of the work has been carried out on electrodeposited coatings, namely Ni-based-CNT composites, which show improved corrosion resistance by CNT addition. On the other hand, there are a few papers that have studied the corrosion resistance of Mg-based-CNT composites and their corrosion results contradict those obtained from other metal-CNT composites. For ZRPs or polymer-based coatings there are a few papers that studied the effect of CNTs on the corrosion of said composites. It is believed that CNTs can strengthen the adhesion between the coating and the substrate and facilitate sacrificial protection by Zn particles by forming a conductive network, hence the improved corrosion resistance.

研究动机与目标

• 评估碳纳米管（CNTs）作为金属基复合材料（MMCs）和聚合物涂层中抗腐蚀填料的有效性。
• 识别CNTs增强耐腐蚀性的机理，包括钝化层形成和导电网络效应。
• 分析腐蚀性能差异，特别是镁基-CNT复合材料与其他金属-CNT体系之间的对比。
• 总结当前将CNTs整合到保护性涂层和结构复合材料中的研究趋势与挑战。

提出的方法

• 系统性回顾关于CNTs在金属和聚合物基复合材料中应用的同行评审文献。
• 分析镍基-CNT电沉积、镁基-CNT复合材料以及富锌聚合物（ZRP）涂层相关研究的实验数据。
• 评估CNTs在促进界面结合、形成钝化层以及构建导电网络以实现牺牲保护方面的作用。
• 比较不同CNT-复合材料体系中腐蚀电位、电流密度和极化电阻等腐蚀抵抗性能指标。
• 采用动电位极化和电化学阻抗谱（EIS）等电化学技术作为主要评估工具。
• 重点关注CNT集成过程中结构与成分的改性，以优化耐腐蚀性能。

实验结果

研究问题

• RQ1 碳纳米管如何影响镍基金属基复合材料的耐腐蚀性？
• RQ2 在富锌聚合物涂层中添加CNTs后，其增强耐腐蚀保护的机理是什么？
• RQ3 为何镁基-CNT复合材料的腐蚀性能表现与其它金属-CNT体系相比存在矛盾？
• RQ4 CNTs在复合材料体系中在多大程度上增强了涂层与金属基体之间的结合力？
• RQ5 导电CNT网络的形成如何在富锌聚合物涂层中促进牺牲保护作用？

主要发现

• 镍基-CNT电沉积材料因CNT诱导的钝化层形成和涂层完整性提升，表现出更优的耐腐蚀性能。
• 在富锌聚合物（ZRP）涂层中，CNTs可形成导电网络，增强锌颗粒的牺牲保护作用，从而提高整体耐腐蚀性。
• CNTs可增强涂层与金属基体之间的界面结合力，减少分层和腐蚀起始。
• 镁基-CNT复合材料表现出不一致的腐蚀性能，部分研究报道其性能反而下降，表明界面相互作用复杂。
• CNTs的化学惰性有助于其在复合基体中的长期稳定性，但其分散性和界面结合仍是关键挑战。
• 电化学测量结果显示，CNT改性体系的腐蚀电流密度降低，极化电阻提高，证实了耐腐蚀性能的增强。