Improved Electromagnetic Interference Shielding in Lightweight Polyvinylidene Fluoride-Carbon Nanotube Composite Films

Abstract

As electronic devices become smaller and more common, the problem of electromagnetic interference (EMI) becomes more serious, requiring better shielding solutions. In this study, lightweight polyvinylidene fluoride (PVDF) composite films mixed with multiwalled carbon nanotubes (MWCNT) were developed to improve EMI shielding. A solution casting method and a thin film applicator ensured uniform thickness and flexibility in PVDF-MWCNT films with varying MWCNT concentrations (0, 0.1, 1, and 2 wt%). Structural and surface properties were analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDS). Dielectric response, AC conductivity, and EMI shielding effectiveness (EMI-SE) in the Ku band (12–18 GHz) were measured. The PVDF film with 2 wt% MWCNT, at a thickness of 190 ± 10 μm, showed the highest complex permittivity and a record EMI-SE value of 53.08 dB. This high EMI-SE is attributed to increased multiple internal reflections within the thin film, enhancing attenuation and reducing reflection losses. These polymer nanocomposites offer a promising and lightweight option for advanced EMI shielding in the growing number of electronic devices.