Supramolecular Soft Material Enabled by Metal Coordination and Hydrogen Bonding: Stretchability,Self-Healing,Impact Resistance, 3D Printing,and Motion Monitoring

Metal coordination can significantly improve the macroscopic performance of many materials by enhancing their dynamic features. In this study, two supramolecular interactions, Fe³⁺–carboxylic acid coordination, and structural water-induced hydrogen bonding, into an artificial polymer were introduced. Various attractive features, including flexibility and stretchability, are achieved because of the bulk state and dynamic hydrogen bonds of poly(thioctic acid-water) (poly TA - H ]). These unique features are considerably enhanced after the incorporation of Fe³⁺ cations into poly TA - H ] because metal coordination increased the mobility of the poly TA - H ] chains. Thus, the poly(thioctic acid-water-metal) (poly TA - HM ]) copolymer exhibited better flexibility and stretchability. Moreover, notable underwater/low-temperature self-healing capacity is obtained via the synergistic effect of the metal and hydrogen bonding. Most of the impact energy is quickly absorbed by poly TA - H ] or poly TA - HM ] and effectively and rapidly dissipated via reversible debonding/bonding via the interactions between the metal and hydrogen. Macroscopic plastic deformation or structural failure is not observed during high-speed (50–70 m s^?1) impact experiments or high-altitude (90 m) falling tests. Furthermore, poly TA - HM ] displayed good thermal molding properties, which enabled its processing via 3D fused deposition modeling printing. Poly TA - HM ] also showed considerable effectiveness for monitoring complicated, dynamic, and irregular biological activities owing to its highly pressure-sensitive nature.