Graphene/carbon nanotube/polypyrrole composite films for electromagnetic interference shielding

Polypyrrole (PPy), an ideal organic electroactive material, shows limited application in the field of electromagnetic interference (EMI) shielding for its relatively low shielding effectiveness (SE), significant stiffness, difficult solubility, and poor processing performance. A strategy is proposed to construct three-dimensional network structures of graphene/CNT/polypyrrole by electrochemical deposition to improve the EMI SE of polypyrrole composite films. In the graphene/CNT/polypyrrole films, the graphene/CNT substrates form the skeletons, and polypyrrole acts as bridges between graphene sheets and CNTs to form percolation networks in the multiphase and multihierarchical nanocomposites. When the deposition time increases to 80 min, the content of polypyrrole increases to 30 wt%, the conductivity improves by 27.7%, and the EMI SE improves by 11.4% at X-band. The final film thickness is 249 mu m, the conductivity is 3.06 S/mm, and the average EMI SE is 59.6 dB.