▎ 摘　　要

Highly ordered polycarbonate films containing parallel graphite nanoplatelets have been produced by squeezing the corresponding random nanocomposites in the melt. Orientation of the conductive fillers is observed in the plane of the film, i.e., perpendicular to the squeezing direction. It only appears above a critical concentration of 15 wt. % and results from a confinement effect. Oriented samples show a resonance-like sharp increase of the conductivity at a given frequency in the microwave region, with the possibility to control the value of this frequency and the resulting absorption by changing the nanoplatelets concentration. Above this frequency, the oriented polymer nanocomposites show a high level of electromagnetic absorption, which opens the possibility to tailor materials with effective electromagnetic interference shielding by absorption in selected frequency ranges. The in-plane stacking of conductive nanoplatelets separated by insulating polymer induces their strong capacitive coupling to the signal propagating in the plane of the polymer film. As a result, the equivalent circuit of this propagation becomes a resonant system composed of capacitors, inductors, and resistors, which agrees well with the experimental results. (C) 2014 AIP Publishing LLC.