Superb electromagnetic shielding polymer nanocomposites filled with 3-dimensional p-phenylenediamine/aniline copolymer nanofibers@copper foam hybrid nanofillers

The polymer nanocomposites with 3-dimensional (3D) nanofillers can form a 3D network and attain a uniform distribution of nanofillers, which benefits the transfer of charge carriers and phonons as well as the dispersion of stress at a very low loading of nanofillers. These polymer nanocomposites with high mechanical properties would have great potential for thermal and electrical conduction as well as electromagnetic interference (EMI) shielding. In this paper, the 3D epoxy nanocomposites are manufactured by stuffing epoxy resin into 3D p-phenylenediamine-aniline copolymer nanofibers@Cu foam (P-PANI@f-Cu) hybrid nanofillers that are constructed by electrophoretic deposition of phosphoric acid doped P-PANI copolymer nanofibers onto the surface of sodium hydroxide oxidized Cu foam. Benefiting from 3D continuous network of P-PANI@f-Cu hybrid nanofillers, the electrical conductivity and thermal conductivity of 3D P-PANI@f-Cu/epoxy nanocomposites with the P-PANI loading of 0.262 wt% could achieve 7.71 ± 0.04 S cm−1 and 5.4670 ± 0.0085 W m−1K−1, respectively, which are much better than that of pure epoxy (insulator and 0.2310 ± 0.0017 W m−1K−1, respectively) and epoxy composites filled with only Cu foam (4.46 ± 0.03 S cm−1 and 2.7907 ± 0.0057 W m−1K−1, respectively). Meanwhile, with a thickness of 1.8 mm, the average total EMI shielding effectiveness (SET) of 3D P-PANI@f-Cu/epoxy nanocomposites in the X-band range reaches a high value of 66.14 dB, which is capable of effectively shielding the electromagnetic signal between Bluetooth earphone and smartphone in the practical application. Furthermore, the 3D P-PANI@f-Cu hybrid nanofillers can efficiently prevent the crack growth in the epoxy nanocomposites and improve their mechanical properties including hardness and elastic modulus.