Actuation of shape memory poly(vinyl alcohol) and graphene oxide film in water

The PVA/GO film prepared by vacuum-assisted self-assembly exhibits quick thermo-/water-responsive shape memory effect. The anisotropic lamellar structure of GO sheets and plenty of chemical groups containing oxygen in the PVA/GO film facilitate rapid recovery in water. The lamellar structure of GO sheets improves the recovery stress of composite and results in a 16-fold increase in Young's modulus. PVA molecular chain slides along the direction of the laminated GO sheets, consistent with the extension direction, ensuring that the composite film maintains a large fracture strain. The straight film is programmed into a spiral shape by the plasticization of water on PVA instead of ordinary heating and the spiral film can drive a weight 160 times its own weight to rotate in water at room temperature (about 25 degrees C).