Aramid nanofiber-derived carbon aerogel film with skin-core structure for high electromagnetic interference shielding and solar-thermal conversion

Being as lightweight and thin as possible is highly desirable for electromagnetic interference (EMI) shielding materials in electronic devices as the high requirement in miniaturization and weight reduction. Constructing three-dimensional (3D) porous conductive architecture into two-dimensional (2D) film provides one of the feasible strategies. Herein, pyrolytic carbon aerogel films from aramid nanofiber (ANF) with novel skin-core structure containing compact film skin and 3D porous nanofiber network core were fabricated by a facile method. The abundant conjugate aromatic structure in backbone endows ANF-derived carbon aerogel film with a high conductivity of 1029.5 S/m. Remarkably, the high electrical conductivity, as well as the 3D porous skin-core structure, which not only constructs the interconnected electron transmission paths but also significantly extends the propagation path of EM waves, enables the carbon aerogel film a high EMI shielding effectiveness (SE) of 41.4 dB at low density (54.4 mg/cm3) and thin thickness (162 μm) with high specific shielding effectiveness (SSE/t) of up to 47122.6 dB cm2/g. Besides, ANF-derived carbon aerogel film exhibits an excellent photothermal conversion ability, which greatly broadens the application environment. More interestingly, the easy and flexible preparation method with adjustable film thickness, density and area makes large-scale production of carbon aerogel film possible.