Flame retardant and multifunctional BC/MXene/MSiCnw/FRTPU aerogel composites with superior electromagnetic interference shielding via “Consolidating” method

The demand for high-strength, flexible, and multifunctional electromagnetic interference (EMI) shielding materials has significantly increased in many fields. Herein, inspired by reinforced concrete pouring in construction, we propose a “consolidating” method to successfully fabricate flame-retardant thermoplastic polyurethane (TPU) reinforced bacterial cellulose (BC)/MXene/modified silicon carbide nanowires (MSiCnw) aerogel composites. The obtained aerogel composites have a disordered pore structure, in which BC/MXene/MSiCnw is used as the internal skeleton, and the tightly attached flame retardant TPU sheet is used as the protective layer. The as-synthesized aerogel composites possess excellent mechanical properties, withstanding repeated compression and exhibiting a compressive strength of 8.86 kPa which is 735.8% higher than that of BC aerogel. At a low MXene content (6.17 wt%), the aerogel composite exhibits an EMI utilization efficiency of 1209.08 dB/g g−1 and an average EMI shielding effectiveness of up to 81.6 dB (K-band). Furthermore, the aerogel composites show excellent flame retardant property (69.8% reduction in peak of heat release rate). More interestingly, the aerogel composite displays satisfactory thermal insulation performances and reaches a low thermal conductivity of 34.4 mW/m K−1. Overall, the as-prepared highly fire safe BC/MXene/MSiCnw/FRTPU aerogel composites show multifunctional properties, making them suitable for applications in electromagnetic shielding and thermal insulation.