Cellulose-Templated Graphene Monoliths with Anisotropic Mechanical, Thermal, and Electrical Properties

Assembling particular building blocks into composites with diverse targeted structures has attracted considerable interest for understanding its new properties and expanding the potential applications. Anisotropic organization is considered as a frequently used targeted architecture and possesses many peculiar properties because of its unusual shapes. Here, we show that anisotropic graphene monoliths (AGMs), three-dimensional architectures of well-aligned graphene sheets obtained by a dip-coating method using cellulose acetate fibers as templates show thermal-insulating, fire-retardant, and anisotropic properties. They exhibit a feature of higher mechanical strength and thermal/electrical conductivities in the axial direction than in the radial direction. Elastic polymer resins are then introduced into the pores of the AGMs to form conductive and flexible composites. The composites, as AGMs, retain the unique anisotropic properties, revealing opposite resistance change under compressions in different directions. The outstanding anisotropic properties of AGMs make them possible to be applied in the fields of thermal insulation, integrated circuits, and electromechanical devices.