Structural, Thermal, and Electrical Characteristics of Various Graphene/PMMA Nanocomposites Aimed for EMI Shielding

The increasing prevalence of electronic devices and the development of “smart buildings” have intensified the problem of electromagnetic interference (EMI) pollution. Consequently, there is a pressing need for advanced EMI shielding materials. Graphene‐based polymer nanocomposites are exceptionally promising for this role, owing to graphene’s outstanding electrical and structural characteristics. However, the effectiveness of these composites is highly dependent on the quality of the graphene and its dispersion within the polymer matrix. The synthesis method of graphene, therefore, plays a crucial role in determining the final properties of the nanocomposite. In this study, we report the design and characterization of polymer‐based nanocomposite films based on poly(methyl methacrylate) (PMMA) and incorporating different types of graphene, prepared by a solution casting method. Various graphene samples (NG5–NG10) were obtained by molten salt electrolysis performed at different temperatures (330°C–390°C) and voltages (10–15 V), using the nonstationary current regimes. The obtained nanocomposite films were studied with SEM and TEM microscopy, Raman and XRD spectroscopy, and conductivity measurements. PMMA/nanostructured graphene (NG) exhibited structural parameters depending on the used graphene type and synthesis voltage. Also, PMMA/NG nanocomposites demonstrated changes in electrical resistivity response. The incorporation of just 1 wt% of graphene into the PMMA matrix resulted in a dramatic improvement in electrical properties. Specifically, the electrical resistivity was reduced by seven orders of magnitude for neat PMMA versus the PMMA/NG5 nanocomposite. These findings demonstrate that tuning the electrochemical synthesis parameters is a critical strategy for optimizing the properties of graphene and developing effective PMMA‐based nanocomposites for EMI shielding applications.