Graphene-Polymer Composite Materials

We present two novel techniques for generating graphene - polymer composite materials that serve to minimize the loading of graphene while retaining its electrical conductivity.  In the first we add silica microspheres to the polymer (polystyrene) along with the graphene.  The dispersed silica spheres reduce the volume available to the graphene, thereby reducing the graphene concentration required for getting the target electrical conductivity.  Our experimental results and simple models corroborate this results from this technique.   In the second technique we use electrostatics to coat polystyrene pellets with graphene, and use compression molding to create composites.  We show electrical percolation at near theoretical limits.  We optimize loading and processing conditions for both techniques, to provide an optimal balance between electrical and mechanical properties.