Construction, mechanism and prospective of conductive polymer composites with multiple interfaces for electromagnetic interference shielding: A review

Electromagnetic interference (EMI) shielding materials have become very important materials in modern society due to the increasing electromagnetic pollution. Although metal-based materials exhibited high shielding performance, they had lots of drawbacks, such as high density, less flexibility, low corrosion resistance, costly processing, and high surface reflection. Conductive polymer composites (CPC) gradually have come to the fore in recent years because the shortages of metal-based materials could overcome by CPC. However, the high-performance EMI shielding usually required high content of conductive fillers in CPC, which leaded to new drawbacks, such as mechanical deterioration, cost increase, and processing difficulties. Therefore, the main challenge for EMI shielding CPC was to achieve high EMI shielding effectiveness (SE) at low content of conductive fillers. In this paper, the CPC with multiple interfaces which has demonstrated to improve EMI SE was reviewed. First of all, the theory of EMI shielding in CPC was introduced in detail. Second, the CPC with various multiple structures, including foamed/porous, segregated, multi-component, multilayered/sandwiched, and prefabricated conductive networks, was discussed. Third, the reported mechanism of CPC with multiple interfaces was given in this paper.