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| Research Progress on Trigger Mechanism and Preparation Strategy of Coatings of Defect Self-disclosure |
LI Gangqing1, LIU Xi2, SUN Xiaoguang1, PAN Jinglong2, CAO Xiangkang2, DONG Zehua2( ) |
1. CRRC Qingdao Sifang Co., Ltd., Qingdao 266111, China
2. Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China |
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Cite this article:
LI Gangqing, LIU Xi, SUN Xiaoguang, PAN Jinglong, CAO Xiangkang, DONG Zehua. Research Progress on Trigger Mechanism and Preparation Strategy of Coatings of Defect Self-disclosure. Journal of Chinese Society for Corrosion and protection, 2024, 44(3): 540-552.
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Abstract Organic coating is widely applied to hinder the corrosion of large-scale engineering facilities, such as offshore platforms, oceangoing freighters, oil and gas pipelines and rail equipment etc. However, coatings are often severely deteriorated in harsh service environments, thus leading to corrosion of metallic substrates, which may not only threaten the service safety of the engineering facilities but also cause significant economic losses. Moreover, the coating degradation is an unavoidable and spontaneous process, and it should be mentioned especially that some hidden coating defects are hard to be detected. Therefore, it has become a research hotspot to develop coatings with function of defect self-disclosure for early detection and maintenance of defects by applying color reaction or fluorescence probe technology. In this review, we summarize the latest advances in coatings of defect self-disclosure, as well as the relevant trigger mechanisms and preparation strategies. First, the coatings of defect self-disclosure can be classified as corrosion-triggered type and mechanical-triggered type based on their mechanisms. Then the corrosion-triggered coatings may be subdivided into pH response and metal ion response according to the fluorescence change or color reaction. Moreover, it sorts out the diverse characteristics of those coatings such as their sensing principles, influencing factors, advantages and drawbacks, and fluorescence/coloration performances. Second, two kinds of preparation strategies for coatings of defect self-disclosure are introduced, one is grafting indicator groups onto polymer chain segments to prepare coatings of intrinsic defect self-disclosure, and the other is to incorporate nano-containers loaded with indicator as the functional filler. The differences and limitations of these strategies are compared and analyzed, further focusing on the key role of nanocontainers and their compatibility with different types of coatings of defect self-disclosure. In addition, the corrosion inhibitors, healing agents, and polymer microcapsules in the coatings of defect self-disclosure can not only realize defect indication but also endow their corrosion self-healing performance for boosting their application in the industrial field. Finally, it is envisioned the development prospect of coatings of defect self-disclosure to provide theoretical guidance for the design and application of the coatings of defect self-disclosure.
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Received: 10 August 2023
32134.14.1005.4537.2023.246
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| Fund: National Key Research and Development Program(2020YFE0204900);CRRC Key Research and Development Project(2021CDB292) |
Corresponding Authors:
DONG Zehua, E-mail: zhdong@hust.edu.cn
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