Pickering emulsion strategy for high compressive carbon aerogel as lightweight electromagnetic interference shielding material and flexible pressure sensor

Lightweight and elastic carbon aerogels (CAs) are promising candidates for use in the development of pressure sensors and electromagnetic interference (EMI) shielding materials. However, the development of a simple strategy for the fabrication of CAs with the properties of high compression and excellent fatigue resistance is still significantly challenging. In this study, Pickering emulsion gel technology, which depends on the aqueous dispersion of cellulose nanofibrils (CNF), graphene oxide (GO), and 1, 2-dichloroethane solution of polymethyl methacrylate (PMMA) that occurs in mixture, emulsification, gelation, and freeze-drying process, was used to form a CNF-GO/PMMA composite aerogel. Subsequently, the final carbon aerogel (C-RGO/P) was obtained through annealing treatment. The resultant C-RGO/P exhibits super compressibility and excellent elasticity, and can resist an extreme compressive strain of 99.3% while maintaining 92.6% of the height retention after 5000 cycles at the strain of 80%. Additionally, it exhibits high sensitivity at the working pressure range of 0–1000 Pa, and can thus act as a wearable pressure sensor for the accurate monitoring of human physiological signals. Moreover, it can be used as an EMI shielding material with satisfactory EMI shielding effectiveness (SE) of 36.75 dB and specific shielding effectiveness (SSE) of 29400 dB cm3 g−1.