Integrating Thermal Self-Healing and Reversible Iodine Capture in a Zn(II)-Coordinated Bis( triazolyl)pyridine Appended Metallopolymer

Abstract

Metallopolymers featuring dynamic metal–ligand interactions have emerged as promising self-healing materials owing to their ability to autonomously repair mechanical damage. Herein, we report the design and synthesis of a hexyl-substituted 2,6-bis(1,2,3-triazol-4-yl)pyridine (HBTP)-based monomer, which has been copolymerized with methyl methacrylate (MMA) or butyl methacrylate (BMA) or lauryl methacrylate (LMA) via ivvivv reversible addition–fragmentation chain-transfer (RAFT) polymerization. Subsequent coordination-driven cross-linking of the pendant HBTP units with Zn(II) ions affords metallopolymer films exhibiting thermally activated self-healing behavior. Systematic investigation reveals that both the counteranion and Zn(II)-metallopolymer backbone significantly influence the healing performance. The Zn(II)-coordinated LMA-based metallopolymer with chloride counteranions shows the best performance, achieving complete scratch recovery within 6 h and complete cut-healing within 12 h at 70 °C. In addition, the metallopolymer films are capable of efficient and reversible iodine vapor capture through charge-transfer interactions within the polymer matrix, making them promising candidates for radioactive iodine sequestration and environmental remediation. Importantly, the self-healing and iodine-capture functions operate independently without mutual interference. The integration of mechanical durability and reversible iodine sequestration within a single material platform highlights the potential of these metallopolymers for applications in protective coatings, functional films, and advanced smart materials.