Highly Ordered 3D Graphene-Based Polymer Composite Materials Fabricated by "Particle-Constructing" Method and Their Outstanding Conductivity

The fabrication of graphene-based polymer composite materials is of interest and significance from an academic and an application viewpoint. The widely used method to obtain such composites was liquid-phase blend of graphene nanosheets (GNSs) and polymer solutions followed by casting or heat pressing. Until now, the challenge of dispersing the GNSs uniformly in the polymer matrix to form controllable and regular structure still remains. Here, we developed a unique "particle-constructing" method for fabricating highly ordered 3D graphene-based polymer composite materials, throughout which the GNSs formed intact, uniform and well-defined network structure. The strategy contains two steps: wrapping polymer microspheres with GNSs and mold-compressing them at room temperature, followed by an appropriate heat treatment. The composite materials exhibited outstanding electrical properties involving extremely low percolation threshold and much higher conductivity. The method can be easily extended to fabricate highly ordered GNS aerogels and more GNS-based composite materials. The results represent an important step toward developing GNS-based composite materials with high performance.