Electromagnetic Interference Shielding and Dynamic Mechanical Analysis of Carbon Nanofiber Mat-Reinforced Polydimethylsiloxane Composites

The rapid development of flexible electronic devices, particularly for biomedical and structural applications, has led to concerns regarding electromagnetic interference (EMI). Polydimethylsiloxane (PDMS) and its composites are frequently employed as substrates for such devices. Therefore, evaluation of their dynamic mechanical, thermal, and EMI shielding properties is essential for practical applications. Here, we report the dynamic mechanical, thermal, and EMI shielding properties of PDMS composites reinforced with multiple layers of carbonized electrospun polyacrylonitrile fiber (CNF) mats. The addition of multiple layers of CNF mats into the PDMS matrix significantly affects the dynamic mechanical properties such as storage modulus, loss modulus, and damping factors. The degree of entanglement, C-factor, reinforcing efficiency factor, and adhesion factor of CNF mat-reinforced PDMS composites have been evaluated, and Cole–Cole analysis has been carried out. The thermogravimetric analysis showed that the composites were thermally stable up to 350 °C. The multilayer CNF mat-reinforced PDMS composite exhibited remarkable EMI shielding effectiveness of 50 dB (four-layer) in the frequency range 8.2–12.4 GHz. These studies indicate that the CNF mat-reinforced PDMS composites are suitable candidates to be used for flexible electronic devices and medical devices as well as for structural applications.