Weak Hydrogen Bonding Enables Hard, Strong, Tough, and Elastic Hydrogels

A new type of “rigid and tough” hydrogel with excellent elasticity is designed by dense clustering of hydrogen bonds within a loose chemical network. The resultant hydrogel exhibits a good combination of high modulus (28 MPa), toughness (9300 J m−3), extensibility (800%), and tensile stress (2 MPa). Furthermore, the gel displays good fatigue-resistance and complete and extremely fast recovery of shape and mechanical properties (3 min at 37 °C). As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from…