Three-dimensional (3D) graphene-based porous materials with a combination of low density, superelasticity , excellent mechanical resilience and tunable functionalities can be used in diverse applications. Here we report an approach of fabricating the stable and flexible 3D graphene aerogel materials with tunable functionality via a general silane-assisted processing that maintains an effective control of the chemistry, architecture and functionality of these porous structures. Simultaneous reduction and functionalization were achieved under both a low temperature and a low graphene oxide concentration in aqueous solution via using a facile one-step co-assembly method. The introduction of silane bonding tailors both the porous microstructure and the surface property of the lightweight aerogel effectively, subsequently providing improved mechanical properties and versatile functionalities including super compressive elasticity, outstanding cyclic resilient property, good electrical conductivity , stable viscoelastic properties, high level energy absorption capacity, excellent hydrophobicity , remarkable thermal stability and extremely high sensitivity of elasticity-dependent electrical conductivity. This opens up scalable and low-cost ways to the integration of microscopic two-dimensional graphene sheets into macroscopic 3D graphene aerogel materials, thus providing the possibility of fabricating novel lightweight porous aerogel materials with controllable functionalities and reversible compressibility for applications in numerous fields.
Carbon nanofibers are widely used for electromagnetic wave (EMW) absorption. However, it is still worthy attention for rationally optimizing their permittivity. Herein, a satisfactory EMW absorber of few-layer BN nanosheets decorated N-doped carbon nanofibers (BNNS-CNFs) was successfully prepared by electrospinning-assisted synthetic technology. The permittivity of CNFs can be adjusted by introducing of BNNS and N-doped in carbon matrix. As a EMW absorber, BNNS-CNFs/paraffin hybrid with a low filling ratio of 10 wt% shows excellent absorption performances. The minimum reflection loss (RL) is about −58.41 dB at a thickness of 1.6 mm and the widest absorption bandwidth (RL<−10 dB) of 5.76 GHz can be obtained at 1.75 mm. The significant enhancement of EMW absorption performance is mainly attributed to the improvement of impedance match and multiple polarizations after introduction of BNNS and more defects by N-doped. Thus, BNNS-CNFs with lightweight and wide-band at low load content would be utilized as a high-efficiency EMW absorber.
危险品化学品经营许可证（带存储）