Aramid nanofiber-induced assembly of graphene nanosheets toward highly thermostable and freestanding films for electromagnetic interference shielding

Abstract

Graphene nanosheets (GNSs) hold tremendous potential for electromagnetic interference (EMI) shielding applications. However, fabricating highly conductive freestanding GNS shielding films remains challenging due to their poor dispersion and weak film-forming ability. Herein, aramid nanofibers (ANFs) were used as both a dispersant and binder to address the dispersion and film-forming problem of GNSs. Only 20 wt% ANF yielded a homogeneous GNS dispersion without precipitation after standing for 100 days. The resultant GNS/ANF films exhibited ultraflexibility and high electrical conductivity (12141.5 S/m). A superior EMI shielding effectiveness of 35.6 dB was achieved for the GNS/ANF films (20 μm thick). The GNS/ANF films also exhibited excellent thermostability and nonflammability. This study opens an avenue for the assembly of GNSs into highly conductive freestanding films, showing strong potential applications in EMI shielding for modern high-power electronic devices.