A phase change supramolecular assembly with a rapid self-healing behavior via thermally actuated reversible associations

• Phase change supramolecular assembly with a rapid self-healing behavior was designed and synthesized. • The switching between rigidity and flexibility of this material was highly reversible. • This material can be used in orthopedic immobilization and thermal therapy of damaged tissues. Phase change materials (PCMs) have demonstrated great potential and vast development prospects in many cutting-edge fields. However, the design and development of smart PCMs with rapid self-healing abilities, and with a reversible switching between rigidity and flexibility, remain challenge. We have here described a strategy that utilizes dynamic carboxylate/zinc ions interactions to achieve this objective. The phase change supramolecular (EAA-Zn-SA) was developed from a commercial, inexpensive and nontoxic ethylene acrylic acid copolymer (EAA) and stearic acid (SA) via crosslinking by zinc ions. It had an excellent leakage-proof, comparable energy storage capacity (130.8 J/g) and could be directly charged by using solar irradiation. As the dynamic carboxylate/zinc ions interactions are temperature sensitive, the designed supramolecular also possessed reversible switching between rigidity and flexibility upon heating or cooling. As a result, the EAA-Zn-SA did not only offer a rapid self-healing behavior, but was also available for orthopedic immobilization and thermal therapy of the human body. This strategy may open a brand-new door for the preparation of a healable phase change supramolecular and enlarge the practical application of PCMs.