Cyclodextrin Nano-Assemblies Enabled Robust, Highly Stretchable, and Healable Elastomers with Dynamic Physical Network

Artificial materials with biomimic self-healing ability are fascinating, however, the balance between mechanical properties and self-healing performance is always a challenge. Here, a robust, highly stretchable self-healing elastomer with dynamic reversible multi-networks based on polyurethane matrix and cyclodextrin-assembled nanosheets is proposed. The introduction of cyclodextrin nano-assemblies with abundant surface hydroxyl groups not only forms multiple interfacial hydrogen bonding but also enables a strain-induced reversible crystalline physical network owing to the special nanoconfined effect. The formation and dissociation of a dynamic crystalline physical network under stretching-releasing cycles skillfully balance the contradiction between mechanical robustness and self-healing ability. The resulting nanocomposites exhibit ultra-robust tensile strength (40.5 MPa), super toughness (274.7 MJ m(-3)), high stretchability (1696%), and desired healing efficiency (95.5%), which can lift a weight approximate to 100 000 times their own weight. This study provides a new approach to the development of mechanically robust self-healing materials for engineering applications such as artificial muscles and healable robots.