Shape memory/change effect in a double network nanocomposite tough hydrogel

[Display omitted] •Mechano-responsive shape change effect after water wetting.•Water-induced shape memory effect.•Heating induced shape memory effect based on absorbed water. In this paper, we present a systematic investigation on the shape memory/change effect in a double network nanocomposite tough hydrogel. Water-content dependency of the response of this hydrogel to heating and wetting by water is confirmed. Since this hydrogel is tough (even after being fully wetted in water) and has a relatively lower swelling ratio, apart from conventional shape memory/change effect as in ordinary hydrogels, additional features have been realized. These features include heating induced shape memory effect utilizing the absorbed water as the transition component, mechano-responsive shape change effect after water wetting and water-induced shape memory effect.