Superplastic Air‐Dryable Graphene Hydrogels for Wet‐Press Assembly of Ultrastrong Superelastic Aerogels with Infinite Macroscale

Abstract

AbstractHighly compressible graphene‐based monoliths with excellent mechanical, electrical, and thermal properties hold great potential as multifunctional structural materials to realize the targets of energy‐efficiency, comfort, and safety for buildings, vehicles, aircrafts, etc. Unfortunately, the ultralow mechanical strength and limited macroscale have hampered their practical applications. Herein, ultrastrong superelastic graphene aerogel with infinite macroscale is obtained by a facile wet‐press assembly strategy based on the novel superplastic air‐dryable graphene hydrogel (SAGH). The SAGH with isotropic, open‐cell, and highly porous microstructure is carefully designed by a dual‐template sol–gel method. Countless SAGH “bricks” can be assembled together orderly by press to form the strongly combined wet‐press assembled graphene aerogel (WAGA) “wall” after air‐drying. The WAGA with highly oriented, dense, multiple‐arch microstructure possesses arbitrary macroscale, outstanding compressive strength (47 MPa, over 10 times higher than the best ever reported), super elasticity (>97% strain), and high conductivity (378 S m−1). The strong adhesion is attributed to the tightly face‐to‐face contacted graphene interfaces caused by wet‐press and air‐drying. The WAGAs prove to be excellent multifunctional structural materials in the fields of high pressure/strain sensor, tunable mechanical energy absorber, high‐performance fire‐resistance, and thermal insulation. This facile strategy is easily extended to fabricate other similar metamaterials.