▎ 摘　　要

In the age of mobile electronics and increased aerospace interest, multifunctional materials such as the polymer composites reported here are interesting alternatives to conventional materials, offering reduced cost and size of an electrical device packaging. We report a detailed study of an ecological and dual-functional polymer composite for electromagnetic interference (EMI) shielding and heat management applications. We studied a series of polylactic acid/graphene nanoplatelet composites with six graphene nanoplatelet loadings, up to 15 wt%, and three different flake lateral sizes (0.2, 5 and 25 mu m). The multifunctionality of the composites is realized via high EMI shielding efficiency exceeding 40 dB per 1 mm thick sample and thermal conductivity of 1.72 W/mK at 15 wt% nanofiller loading. The EMI shielding efficiency measurements were conducted in the microwave range between 0.2 to 12 GHz, consisting of the highly relevant X-band (8-12 GHz). Additionally, we investigate the influence of the nanofiller lateral size on the studied physical properties to optimize the studied functionalities per given nanofiller loading.