A review on conductive polymeric nanocomposites for advanced electromagnetic interference shielding: materials, mechanisms, and applications

The increasing complexity and density of electronic systems have amplified the need for effective electromagnetic interference (EMI) shielding materials to ensure functionality, signal integrity, and compliance with electromagnetic compatibility regulations. Conventional shielding materials such as metals suffer from inherent drawbacks including high density, rigidity, corrosion susceptibility, and processing difficulties. In this review, conductive polymeric nanocomposites have been evaluated as a highly promising group of materials for use as EMI shielding due to their distinctive blending of lightweight nature, flexibility, processability, and tuneful electrical characteristics. These nanocomposites are typically composed of insulating matrix of polymer embedded with electrical-conductive nano-fillers like carbon nanotubes (CNTs), carbon black, graphene or metallic nanoparticles. The incorporation of these fillers enables the formation of percolative conductive networks inside the polymer matrix, which significantly enhances the electrical-conductivity and EMI shielding effectiveness (SE) of the obtained material. Shielding in these materials arises from reflection and absorption of incident electromagnetic waves, with multiple internal reflections contributing under conditions of relatively low absorption. The scalability and environmental resistance of conductive polymeric nanocomposites make them attractive for use in industries such as aerospace, automotive, consumer electronics, and healthcare, where multifunctional, lightweight, and durable materials are essential. In conclusion, conductive polymeric nanocomposites show a versatile and future-ready solution for EMI shielding, bridging the gap between performance, functionality, and manufacturability. Their adaptability and technological advancement make them central to next-generation electromagnetic shielding materials. Surface functionalization of fillers enhances compatibility with the polymer matrix, promoting uniform dispersion and improved interfacial polarization, contributing to absorption-dominant shielding.