Hybridization-Induced Polarization of Graphene Sheets by Intercalation-Polymerized Polyaniline toward High Performance of Microwave Absorption

An intercalation polymerization is applied to regulate the hybridizing structures of polyaniline@graphene (PANI@GE). Polarization of GE sheets is realized, which is attributed to the hybridization by the in situ intercalation-polymerized PANI molecules. The polarizing effect on GE is confirmed by characterizations and density functional theory calculations, and the results indicate that distinct p-pi and pi-pi interactions exist between the PANI molecules and the GE sheets. As a result, this new structural hybrid leads to a high performance of microwave absorption. The minimum reflection loss (RL) of the optimized PANI@GE hybrid can be as low as -64.3 dB at 10.1 GHz with the RL bandwidth of -10 dB being 5.1 GHz (from 8.6 to 13.7 GHz). A further study reveals a special mechanism for the electromagnetic energy consumptions by the structural resonance of the polarized GE-based hybrids, a complex macromolecule. In addition, the fully separated GE provides a good impedance matching, together with the widely held multiscaled relaxations of the interfacial polarization.