Enhanced microwave absorption properties of conducting polymer@graphene composite to counteract electromagnetic radiation pollution: green EMI shielding

Abstract

Conducting polymers have been thoroughly investigated and found to have extensive applications in the fields of microwave absorption and electromagnetic (EM) shielding owing to their distinctive characteristics and adaptability. In the present work, conducting polymer (PEDOT and polyaniline) and graphene composites were prepared via an in situ chemical polymerization technique. Further, these composite materials were characterized to determine their potential to address the issue of EM radiation pollution in the microwave frequency (12.4 GHz to 18 GHz). The PEDOT/graphene composites exhibited significant shielding effectiveness of up to 46.53 dB, achieving a green index (g_s) of 1.17. Also, absorption was observed to be the dominant shielding mechanism in all the samples owing to significant dielectric losses (ε′′/ε′ ≈ 1.9–3.1) and microwave conductivity (σ_s = 19.9–73.6 S m⁻¹) in the samples at 18 GHz. Both dielectric loss and conduction loss occurred because of the strong interactions involving polarization, charge propagation, and the creation of conductive routes through the incorporation of graphene in the polymer matrix. These properties/shielding results indicate the potential of the composites to be used as lightweight EM shielding materials. These materials are suitable shield materials for electronic devices to protect them from harmful electromagnetic radiation, making them vital in various applications.