Electromagnetic interference shielding and thermal properties of non-covalently functionalized reduced graphene oxide/epoxy composites

Graphene oxide (GO) was non-covalently functionalized using sulfanilic acid azocromotrop (SAC) followed by hydrazine reduction to achieve SAC functionalized reduced GO (SAC-rGO). Fourier transform infrared spectra analysis and electrical conductivity measurements confirmed the successful functionlization and reduction of GO. The electrical conductivity of similar to 515 S.m(-1) for SAC-rGO was recorded. The non-covalently functionalized reduced GO was subsequently dispersed in epoxy matrix at the loading level of 0.3 to 0.5 wt% to investigate its electromagnetic interference (EMI) shielding properties. The morphological and structural characterization of the SAC-rGO/epoxy composites was carried out using X-ray diffraction and Transmission electron microscopy analysis, which revealed the good dispersion of SAC-rGO in the epoxy. The SAC-rGO/epoxy composites showed the EMI shielding of -22.6 dB at the loading of 0.5 wt% SAC-rGO. Dynamical mechanical properties of the composites were studied to establish the reinforcing competency of the SAC-rGO. The storage modulus of the composites was found to increase within the studied temperature. Thermal stability of pure epoxy and its composites were compared by selecting the temperatures at 10 and 50% weight loss, respectively.