Superelastic and multifunctional graphene-based aerogels by interfacial reinforcement with graphitized carbon at high temperatures

Although lightweight and three-dimensional graphene aerogels and foams combining ultrahigh electrical conductivity, superelasticity and fatigue resistance are highly desirable for widespread applications, it remains a large challenge to construct a multifunctional framework affording the rapid electron transport and efficient load transfer due to the weak interfaces between highly reduced graphene oxide sheets. Herein, we report an efficient approach for fabricating an integrated graphene aerogel by bridging its reduced graphene oxide sheets with polyimide macromolecules followed by graphitization at 2800 degrees C. During the graphitization process, the reduced graphene oxide sheets are thermally reduced to graphene efficiently by removing their residual oxygen-containing groups and healing their defects, while the polyimide component is graphitized to turbostratic carbon to bridge the graphene sheets, resulting in an integrated graphene aerogel with satisfactory mechanical and functional performances, including ultrahigh electrical conductivity (> 1000 Sm-1) at a low density, unprecedented high electromagnetic interference shielding effectiveness of similar to 83 dB in X-band, 90% reversible compressibility, and reliable resistance to fatigue for 1000 compressive cycles at 50% strain. The integrated graphene aerogels with such multifunctional performances hold a great promise for applications as electromagnetic interference shielding materials, oil adsorbents, and conductive scaffolds for polymer nanocomposites. (C) 2018 Elsevier Ltd. All rights reserved.