DESIGNING ANTI-MILDEW SMART MICROCAPSULES TO IMPROVE SELF-HEALING PERFORMANCE FOR WATER-BASED EPOXY COATINGS Ying Li1; 1INSTITUTE OF METAL RESEARCH, CHINESE ACADEMY OF SCIENCE, Shenyang, China; PAPER: 138/Corrosion/Regular (Oral) OS SCHEDULED: 17:50/Wed. 29 Nov. 2023/Boardroom ABSTRACT: The design and fabrication of stimuli-responsive smart anti-corrosive coatings with merits of eco-friendliness, multifunctionality and long-acting is a major demand in corrosion protective field, which can be fulfilled by adding smart microcapsules (MCs) into coatings [1,2] Nevertheless, owning to the unclear release controlling mechanism of MCs, the design of high-performance MCs on-demand fails to be achieved. In addition, the existing MCs are mostly fabricated by synthetic materials with undesirable eco-friendliness. On the other hands, although the addition of MCs can significantly improve the corrosion protective performance, this single function fails to fulfill multifunctional integration needs of protective coatings [3,4]. To tackle above issues, a MC is assembled by choosing 2-mercaptobenzimidazole (2-MBI) as inhibitor, HNTs as inhibitor carrier, and ε-PLL, SA as well as CTS as encapsulating polyelectrolytes. The release controlling mechanism was analyzed by UV-vis technique and the key factors regulating inhibitor release rate are also confirmed. In 3.5 wt.% NaCl solutions the inhibitor can be timely released in response to the invasion of water. In addition, the releasing speed was enhanced with the increments of pH values of release mediums. Furthermore, the whole release process can lasts for 216 hours. The release behavior fulfills the requirements of sensitivity, selectivity and sustainability raised by long-term smart anticorrosive coatings. Both the solubility of inhibitor and the porosity of SA layer regulate the release rate of inhibitor. The outermost CTS layer offers MCs superior antimicrobic performance, while the complex encapsulation with ε-PLL and SA significantly prolongs the release process. As comparing with the reference coating, the proposed water-based epoxy coating with 1 wt.% MCs embedded can provide an excellent corrosion protective. In addition, the tensile strength of proposed coating is increased by 20% and the wet adhesion (72 hours) is also increased by 20%. arine environment. References: [1] Q. Wang, W. Wang, X. Ji, X. Hao, C. Ma, W. Hao, X. Li, S. Chen, ACS Appl Mater Interfaces, 13 (2021) 3139-3152<br />[2] D. Li, B. Gong, Y. Liu, Z. Dang, Chemical Engineering Journal, 415 (2021)<br />[3] Z. Wu, D. Huang, W. Wei, W. Wang, X. Wang, Q. Wei, M. Niu, M. Lin, J. Rao, Y. Xie, Journal of Cleaner Production, 209 (2019) 273-282<br />[4] R. Zhang, Y. Li, Y. He, D. Qin, Journal of Materials Research and Technology, 9 (2020) 10148-10156 |