Ultrahigh Strength and Modulus Graphene-Based Hybrid Carbons with AB-Stacked and Turbostratic Structures

Graphene-based hybrid carbons composed of a mix of AB-stacked and turbostratic regions are reported. Macroscopic graphene films consisting of stacked graphenes are prepared using a liquid crystal graphene oxide dispersion. The graphene films are then infiltrated with bioinspired adhesives, catecholamines, and polymerized to obtain graphene/poly(catecholamine) composites. After heat treatment up to 3000 oC, the composite films are transformed to have both AB-stacked (mainly from graphene oxide) and turbostratic (mainly from poly(catecholamines)) structures, and exhibit significantly improved mechanical properties compared to the films having a predominant AB-stacked structure made from only graphene oxide. They have almost twice the fracture strength (1012 +/- 146 MPa) and approximate to 1.5x increase of both Young's modulus (21.87 +/- 2.24 GPa) and strain-to-failure (8.91 +/- 0.50%). In addition, the films have an in-plane electrical conductivity as high as 1320 +/- 159 S cm(-1). Such hybrid-carbon films with the indicated mechanical and electrical properties have many promising uses, such as for light-weight structural materials, and in flexible electronics such as for wearable heaters or in sensing electrodes.