Composite Flexible Films Based on MWCNT and Modified Graphene for Electric Heating and EMI Shielding

The rapid advancement of advanced gadgets for electronic use has generated an urgent need for electromagnetic interference (EMI) shielding films possessing outstanding thermal conductivity. Nonetheless, achieving these dual characteristics through the establishment of a dense electrical network of connections within a framework of polymers remains challenging. In this study, flexible composite films (MPP) with enhanced performance were prepared using a solution-melting method with multiwalled carbon nanotubes (MWCNT-NH2), dopamine-modified graphene (P@GNs), and poly(vinylidene fluoride)-hexafluoropropylene copolymer (PVDF-HFP) to improve both EMI shielding and thermal conductivity. Dopamine hydrochloride (PDA) was employed to modify graphene during the fabrication process, and its synergistic interaction with MWCNT-NH2 established an effective conductive network that enhanced charge transfer efficiency in PVDF-HFP. The electrical resistivity and EMI shielding efficacy of the composite film are achieved through the judicious arrangement of conductive fillers and polymers. With the thickness of 0.2 mm, the film attained an electromagnetic shielding effectiveness (EMI SE) of 32.54 dB and an impressive in-plane conductivity of 1000 S/m. Additionally, the film demonstrated excellent thermal conductivity caused by its more prominent electrical conductivity, reaching a temperature of approximately 172 °C at 5 V. Considering these benefits, the flexible composite film produced throughout the current research holds significant promise for implementation in flexible electronics and electromagnetic shielding and may contribute innovative solutions for the forthcoming generation of advanced devices that utilize electronics.