Industrial-grade carbon black in microcapacitive architectures: A novel approach to X-band EMI shielding

Interference from electromagnetic waves poses significant challenges, leading to potential malfunctions in communication devices and possible health issues for the general public. This concern is particularly critical in the microwave frequency range, especially the X-band (8–12 GHz), due to the rapid growth in telecommunications. Although many articles have been published on electromagnetic coatings, few have addressed the synthesis of an EMI shielding coating using an easy, cost-effective method. This article discusses a coating with a low thickness but over 99% EMI shielding, made from cost-effective materials and using a straightforward process. We investigated the electromagnetic shielding performance of a carbon-based coating composed of graphite and industrial carbon black. This high shielding effectiveness, despite the use of industrial carbon black, may be attributed to carbon black filling the gaps between graphite particles, forming a conductive network and, subsequently, microcapacitors, as evidenced by field-emission scanning electron microscopy images and electromagnetic test results. This non-metallic coating offers a cost-effective solution for general applications, with minimal thickness and easy synthesis, for electromagnetic interference mitigation.