Supramolecular Interaction Mediated Affine Deformation for Energy-Dissipative Stiff Hydrogel.

Conventional energy-dissipative hydrogels usually suffer from low stiffness, precluding their application as structural materials. In this work, a distinctive supramolecular/polymer conjoined-network is proposed to overcome the long-standing stiffness-energy dissipation dilemma. By exchanging from a good solvent to a poor one, the intra- and intermolecular noncovalent interactions between supramolecular gelators and polymers are initially suppressed and then recovered, generating a supramolecular network and a polymer network, noncovalently conjoined with each other. This conjoined-network structure is found to deform affinely, preventing unexpected stress concentration, thus yielding favorable combined mechanical properties. When deformed, those supramolecular and polymer domains initially survive to arrest deformation, while later adaptively disassemble and fracture to dissipate substantial energy through diverse pathways and across multiple scales, enabling the desirable compatibility between stiffness and energy dissipation. Consequently, the supramolecular/polymer conjoined-network hydrogel achieves coordinatively enhanced stiffness (10-32 MPa) and energy dissipation (dissipated energy of 6-12 MJ/m3 and dissipation coefficient up to 99%), collectively providing superior impact resistance and shock attenuation to extend their application as structural materials.