Modification of graphene by polypyrrole and ionic liquids for dual-band electromagnetic interference shielding hydrogels

The most previous research aimed to electromagnetic interference shielding effectiveness (EMI SE) was focused on X-band, which were normally used in communications for satellites. Nowadays, the growth of terahertz technology for 6G communication transfigures mobile and information acquisition. However, few researches have broadcasted the fabrication of hydrogels with application in dual-band EMI SE in X-band and terahertz band (THz-band). Herein, polyvinyl alcohol (PVA) hydrogels applied to dual-band electromagnetic interference (EMI) shielding were prepared by a facile approach. Firstly, reduced graphene oxide (rGO) were modified by polypyrrole (PPy) and ionic liquids (IL) on its nano-sheets to increase the conductivity. Then, the modified rGO (I-P-rGO) was incorporated into PVA solution to in situ form the heterogeneous conducting network in the deformable PVA hydrogels. The obtained PVA/I-P-rGO composite hydrogels exhibited high EMI SE of 32.9 dB in X-band and 22.4 dB in THz-band with 10.0 wt% fillers content due to the heterogeneous conducting network architecture, which opens an avenue for hydrogels applied in shielding electromagnetic waves in X-band and THz-band band at the same time.