Tunable swelling and deswelling of temperature- and light-responsive graphene oxide-poly(N-isopropylacrylamide) composite hydrogels

Tunable swelling and deswelling behaviors of graphene oxide-poly(N-isopropylacrylamide) (GO-PNIPAM) composite hydrogels are demonstrated by controlling the internal microstructures and the rate of the external temperature change. The different internal microstructures of GO-PNIPAM composite hydrogels as a function of concentrations of GO and chemical crosslinkers explain their different swelling and deswelling ratios. Furthermore, the light-driven shape deformation of GO-PNIPAM is demonstrated by utilizing the photothermal properties of GO. This approach offers promise for light and temperature-responsive actuators and sensors, and biomedical applications.