Supramolecular Self-Healing Gels

Abstract

Supramolecular hydrogels have a unique crosslinked structure because of utilizing supramolecular binding motifs including dynamic covalent bonds (Schiff-base linkage, Diels–Alder reaction, disulfide exchange reaction, and boronic ester formation) and noncovalent bonds (hydrogen bonding, electrostatic interactions, hydrophobic interactions, and host–guest interactions). When the supramolecular binding motifs can act as dynamic crosslinks, the supramolecular hydrogels can have a function of self-healing that is defined as healing damages, restoring itself to normality intrinsically. By a combination of double network structure or slide-ring structure such as polyrotaxanes with the supramolecular binding motifs, the supramolecular self-healing hydrogels become tough, which is capable of long-term use for various applications. These supramolecular self-healing hydrogels have been developed for biomedical and industrial applications, including tissue engineering, corrosion, and biofouling.