Molecularly Engineered Dual‐Crosslinked Hydrogel with Ultrahigh Mechanical Strength, Toughness, and Good Self‐Recovery

A molecularly engineered dual‐crosslinked hydrogel with extraordinary mechanical properties is reported. The hydrogel network is formed with both chemical crosslinking and acrylic–Fe(III) coordination; these, respectively, impart the elasticity and enhance the mechanical properties by effectively dissipating energy. The optimal hydrogel achieves a tensile stress of ca. 6 MPa at a large elongation ratio (>7 times), a toughness of 27 MJ m −3 , and a stiffness of ca. 2 MPa, and has good self‐recovery properties.