(200b) Constructing Ternary Conductive Polymer Composites with Cocontinuous Polymer Blends and Interfacial Graphene Nanoplatelets

Conductive polymer composites have a wide range of industrial applications such as electrostatic discharge (ESD) protection and electromagnetic interference (EMI) shielding. Current technology requires high loadings of conductive fillers to achieve a percolated structure inside the polymer matrix, thereby sacrificing material processability. In this study, we construct a class of conductive polymer composites using polymer blends with lower critical solution temperatures and interfacial graphene nanoplatelets. When a polymer blend is raised above its critical temperature, it spontaneously phase separates into a cocontinuous structure via spinodal decomposition. By controlling the wetting property of graphene nanoplatelets, we selectively localize the graphene nanoplatelets at the interface of cocontinuous polymer blends, which gives rise to a percolated graphene structure with ultra-low percolation thresholds for electrical conductivity. Strong electric fields have also been applied during sample annealing, allowing us to test the influence of electric fields on the graphene localization and the alignment of graphene nanoplatelets in cocontinuous polymer composites.