In situ polymerization of graphene-polyaniline@polyimide composite films with high EMI shielding and electrical properties

With the increasing demands of the electronics industry, electromagnetic interference (EMI) shielding has become a critical issue that severely restricts the application of devices. In this work, we have proposed a “non-covalent welding” method to fabricate graphene-polyaniline (Gr-PANI) composite fillers. The Gr sheets are welded with PANI via π–π non-covalent interactions. Furthermore, a flexible polyimide (PI) composite film with superior EMI shielding effectiveness is prepared by in situ polymerization. The 40% content of Gr-PANI(10:1) (the mass ratio of Gr to PANI is 10 : 1) shows a superior electrical conductivity (σ) as high as 2.1 ± 0.1 S cm(−1), 1.45 times higher than that of Gr@PI film at the same loading. Moreover, the total shielding effectiveness (SE(T)) of EMI of the Gr-PANI(10:1)@PI reaches ∼21.3 dB and an extremely high specific shielding effectiveness value (SSE) of 4096.2 dB cm(2) g(−1) is achieved. Such a “non-covalent welding” approach provides a facile strategy to prepare high-performance PI-based materials for efficient EMI shielding.