▎ 摘　　要

We have demonstrated the concept of imprinting graphene on a polymer substrate via coextrusion of polypropylene/graphene (PP/G) composite and target polymers. First, we predicted by wetting coefficients that carbon nanotubes (CNTs) or graphene would prefer to localize in polyethylene (PE), polycarbonate (PC), or polystyrene (PS) over PP. On the basis of this hypothesis, we laminated target polymer substrates with PP/CNT or PP/G to verify the concept of imprinting prior to the coextrusion experiments. Fillers migrated from PP to target polymers exhibiting electrical conductivity at their surfaces. Migration was promoted by elevated temperature, long interfacial contact time, or applied pressure. We speculate that migration is driven by wetting of the fillers and their translational Brownian motion. The coextrusion process was mimicked by a dual-bore capillary rheometer with a miniature coextrusion die. Capillary coextrusion successfully transferred graphene from PP to the surface of PE, PC, or PS, in <10 s contact time, resulting in surface resistivity as low as similar to 10(5) ohm/sq. In the process, the graphene-loaded PP is stripped off and can be recycled. Lower resistance should be possible in an industrial process which can run at higher temperature. Imprinting via coextrusion could be a universal and recyclable process for fabricating functional substrates with surfaces coated with nanosized fillers of any kind.