Enhanced electromagnetic interference shielding effectiveness of polycarbonate/graphene nanocomposites foamed via 1-step supercritical carbon dioxide process

Abstract

The dielectric and electromagnetic interference (EMI) shielding properties of polycarbonate/graphene nanocomposites foamed using supercritical carbon dioxide were studied as a function of their cellular and compositemorphology. Foamed polycarbonate filled with 0.5% (by weight) graphene exhibited enhanced EMI shielding effectiveness, which was found to depend on cellular and composite morphology in a complex manner. Foamed composites presented a maximum specific EMI shielding effectiveness of ~39 dB cm3/g, which is approximately 35 times greater than that of unfoamed composite (1.1 dB cm3/g). In addition, the relative permittivity was found to increase up to 3.25 times. The results suggest that graphene filled polymer foams can enhance the performance of electronic devices, opening up the possibility of using these materials in electronic applications.