Electrically-responsive graphene-based shape-memory composites
| Autor: | Ezra Feilden, Eduardo Saiz, Eleonora D'Elia, Hanaë Said Ahmed |
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| Přispěvatelé: | Office Of Naval Research Global |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Toughness
Materials science Bending (metalworking) Graphene Fracture mechanics 02 engineering and technology Shape-memory alloy 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention Shape-memory polymer law Catastrophic failure General Materials Science Composite material 0210 nano-technology Voltage |
| Popis: | Shape memory materials can open new design opportunities in fields as diverse as healthcare, transportation or energy generation. In this respect, shape memory polymers (SMPs) have attracted much attention due to their advantages over metals in terms of weight and reliability. However, they are still marred by slow reaction times and poor mechanical performance. In this work we show how, by integrating a graphene network in a SMP matrix, it is possible to create composites with very low carbon contents (below 1 wt%) able to change shapes in short times (10 s of seconds) in response to low electric voltages (0.95 ± 0.03) and shape recovery ratios (>0.98 ± 0.03). Due to the 2D nature of graphene, this network directs crack propagation during fracture resulting in materials that retain bending strengths close to 100 MPa and exhibit significant extrinsic toughening (with toughness that reach values up to 3 times the initiation value). Furthermore, changes in conductivity can be used to follow the formation and growth of damage in the material before catastrophic failure, allowing the use of this material as a damage sensor. These results provide practical guidelines for the design of reliable shape memory composites for structural and sensing applications. |
| Databáze: | OpenAIRE |
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