Modified nonwoven with graphene for electromagnetic shielding and infrared stealth

Abstract

This work presents the development and characterisation of porous nonwoven composites based on aluminosilicate ceramic fibers functionalized with reduced graphene oxide (RGO) for electromagnetic shielding and infrared stealth applications. Graphene oxide (GO) was synthesised via a modified Hummers’ method and subsequently adsorbed onto commercial ceramic fiber substrates, followed by reduction via hydrothermal synthesis and thermal treatments at 500 and 1000 °C. The impact of graphene content and reduction temperature on the electrical and shielding performance was systematically studied. Structural and morphological analyses (SEM, FT-IR, XRD) confirmed the successful integration of RGO within the porous matrix. Electromagnetic characterisation in the 8–18 GHz range revealed that shielding performance is predominantly governed by absorption rather than reflection, with the best-performing composites achieving up to 18 dB of total shielding effectiveness (∼98.4% attenuation) after four GO adsorption cycles and thermal reduction at 1000 °C. The synergistic combination of high conductivity, hierarchical porosity, and thermal stability enabled efficient energy dissipation via Joule heating, dipolar polarisation, and dielectric loss mechanisms. Additional tests demonstrated excellent thermal insulation capacity and reproducible Joule-heating behaviour, supporting the composite's multifunctional potential in advanced shielding and thermal management applications.