凯发

A family of materials with an ability to change few of its original properties by the application of any external stimuli, such as stress, temperature, moisture, pH, electric and magnetic fields are called Smart Materials. Generally speaking, smart materials has four functions, including sensory function, response function, self-repairing ability and controllablity. Graphene is an exciting material, which has a large theoretical specific surface area (2630 m2g−1), high intrinsic mobility (200000 cm2 v−1s−1), high Young’s modulus (∼1.0 TPa) and thermal conductivity (∼5000 Wm−1K−1), and its optical transmittance (∼97.7%) and good electrical conductivity has been applied such as for transparent conductive electrodes, among many other potential applications. Based on these, we developed a series of graphene-based smart materials, including (1) Laser-triggered self-healing hydrogels based on graphene networks. The hydrogels we developed exhibit good neural compatibility, high conductivity, low impedance and efficient near-infrared-triggered photothermal self-healing behavior, which obtain by building a graphene–poly(N,N-dimethylacrylamide) (PDMAA) cross-linking structure. (2) Magnetically-functionalized graphene/Fe3O4 hybrids. The hybrids showed a good response to the external magnet. More important, it was obtained through a one-step solvothermal method using GO and FeCl3/6H2O as the precursors. And we found the hybrids were expected to be used as a light-driven and magnetic controlled switch for applications in microreactors. (3) Stimulus-sensitive volume changes graphene microgel. The microgels were prepared by a hydrothermal method, and exhibit reversible volume changes in response to an electric current, which had good electrical conductivity, high mechanical strength and a tunable electrical conductivity. (4) Graphene self-power sensor. Unlike many other sensors, the all-graphene thin-film sensor can sense heat and cold, measure the dimensions of the heated/cooled area, discern human touch from other pressures, and enable human touch locating and pressure level. More important, the graphene sensors could work under zero working voltage. (5) Graphene based actuator. Using the strong water absorption/desorption capability of GO and good photothermal heating effects of rGO, a kind of graphene monolayer (GM) paper was prepared, which exhibited fast and powerful actuation performance in response to moisture, heat, and light. And it has potential in artificial muscles, robotic hands, and electromagnetic-free generators. In view of these graphene-based smart materials showed more excellent properties than the traditional smart materials. We believe these graphene-based smart materials could find a wide range of application areas including solving engineering problems with high efficiency, producing new generation wearable electronics and so on.