Shape memory polymers (SMPs) are polymeric materials that are capable of fixing temporary shape and recovering the permanent shape in response to external stimuli. In particular, supramolecular interactions and dynamic covalent bond have recently been introduced as temporary switches to construct supramolecular shape memory hydrogels (SSMHs), arising as promising materials since they can exhibit excellent cycled shape memory behavior at room temperature. On the other hand, hydrogels, conventionally, are flexible but sometimes extremely soft, and they can be easily damaged under external force, which could limit their long-time application. Therefore, self-healing hydrogels that can be rapidly auto-repaired when the damage occurs have been recently developed to solve this problem. These materials present more than one triggering stimulus that can be used to induce the shape memory and self-healing effect. These driven forces can be originated from hydrogen bonds, hydrophobic interactions, and reversible covalent bonds, among others. Beyond all these, hybrid organic-inorganic interactions represent an interesting possibility due to their versatility and favorable properties that allow the fabrication of multiresponsive hydrogels. In this chapter, shape memory hydrogels based on noncovalent interactions are described.
Part of the book: Shape-Memory Materials