Fabrication of Super Extensible and Highly Tough Graphene Composite Hydrogels by Thermal Treatment Strategy for the Mixture of Tannin and Graphene Oxide

Inspired by using the condensed tannins as coinitiator and crosslinker to prepare stretchable hydrogel (TIC‐gel) and by tannins' ability to prepare tannins‐reduced graphene oxide (TGO) at 80 °C, this paper designs a simple and effective method with a thermal treatment process for the mixture of tannin and graphene oxide (GO) to prepare super extensible TGO composite TIC‐gel (TGO‐gel). After the thermal treatment process, graphene oxide is reduced by tannin and its surface becomes orderly which leads to strong π–π stacking interaction between tannins and graphene sheets. By this way, the interaction between graphene sheets and polymer chains is improved. As a result, these composite hydrogels have high tensile strength (0.5–1.2 MPa) and extremely high elongations (3100–4800%) which are much higher than those of GO composites TIC‐gel (TA/GO‐gel) without thermal‐treated process and those of normal graphene composite hydrogel.